text: /******************************************************************************
   * The MIT License (MIT)
   *
   * Copyright (c) 2019-2021 Baldur Karlsson
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   ******************************************************************************/
  
  #include <float.h>
  #include <math.h>
  #include <algorithm>
  #include "core/settings.h"
  #include "driver/shaders/spirv/spirv_editor.h"
  #include "driver/shaders/spirv/spirv_op_helpers.h"
  #include "vk_core.h"
  #include "vk_debug.h"
  #include "vk_replay.h"
  #include "vk_shader_cache.h"
  
  RDOC_CONFIG(rdcstr, Vulkan_Debug_PostVSDumpDirPath, "",
              "Path to dump gnerated SPIR-V compute shaders for fetching post-vs.");
  RDOC_EXTERN_CONFIG(bool, Vulkan_Debug_DisableBufferDeviceAddress);
  
  #undef None
  
  struct VkXfbQueryResult
  {
    uint64_t numPrimitivesWritten;
    uint64_t numPrimitivesGenerated;
  };
  
  static const char *PatchedMeshOutputEntryPoint = "rdc";
  static const uint32_t MeshOutputDispatchWidth = 128;
  static uint32_t MeshOutputBufferArraySize = 64;
  
  // 0 = output
  // 1 = indices
  // 2 = vbuffers
  static const uint32_t MeshOutputReservedBindings = 3;
  
  enum StorageMode
  {
    Binding,
    EXT_bda,
    KHR_bda,
  };
  
  static void ConvertToMeshOutputCompute(const ShaderReflection &refl,
                                         const SPIRVPatchData &patchData, const char *entryName,
                                         StorageMode storageMode, rdcarray<uint32_t> instDivisor,
                                         const ActionDescription *action, uint32_t numVerts,
                                         uint32_t numViews, uint32_t baseSpecConstant,
                                         rdcarray<uint32_t> &modSpirv, uint32_t &bufStride)
  {
    rdcspv::Editor editor(modSpirv);
  
    editor.Prepare();
  
    uint32_t numInputs = (uint32_t)refl.inputSignature.size();
  
    uint32_t numOutputs = (uint32_t)refl.outputSignature.size();
    RDCASSERT(numOutputs > 0);
  
    if(storageMode == Binding)
    {
      for(rdcspv::Iter it = editor.Begin(rdcspv::Section::Annotations),
                       end = editor.End(rdcspv::Section::Annotations);
          it < end; ++it)
      {
        // we will use descriptor set 0 bindings 0..N for our own purposes when not using buffer
        // device address.
        //
        // Since bindings are arbitrary, we just increase all user bindings to make room, and we'll
        // redeclare the descriptor set layouts and pipeline layout. This is inevitable in the case
        // where all descriptor sets are already used. In theory we only have to do this with set 0,
        // but that requires knowing which variables are in set 0 and it's simpler to increase all
        // bindings.
        if(it.opcode() == rdcspv::Op::Decorate)
        {
          rdcspv::OpDecorate dec(it);
          if(dec.decoration == rdcspv::Decoration::Binding)
          {
            RDCASSERT(dec.decoration.binding < (0xffffffff - MeshOutputReservedBindings));
            dec.decoration.binding += MeshOutputReservedBindings;
            it = dec;
          }
        }
      }
    }
  
    struct inputOutputIDs
    {
      // if this is a builtin value, what builtin value is expected
      ShaderBuiltin builtin = ShaderBuiltin::Undefined;
      // ID of the variable itself. This is the original Input/Output pointer variable that we convert
      // to a private pointer
      rdcspv::Id variable;
      // constant ID for the index of this attribute
      rdcspv::Id indexConst;
      // base gvec4 type for this input. We always fetch uvec4 from the buffer but then bitcast to
      // vec4 or ivec4 if needed
      rdcspv::Id fetchVec4Type;
      // the actual gvec4 type for the input, possibly needed to convert to from the above if it's
      // declared as a 16-bit type since we always fetch 32-bit.
      rdcspv::Id vec4Type;
      // the base type for this attribute. Must be present already by definition! This is the same
      // scalar type as vec4Type but with the correct number of components.
      rdcspv::Id baseType;
      // Uniform Pointer type ID for this output. Used only for output data, to write to output SSBO
      rdcspv::Id ssboPtrType;
      // Output Pointer type ID for this attribute.
      // For inputs, used to 'write' to the global at the start.
      // For outputs, used to 'read' from the global at the end.
      rdcspv::Id privatePtrType;
    };
  
    rdcarray<inputOutputIDs> ins;
    ins.resize(numInputs);
    rdcarray<inputOutputIDs> outs;
    outs.resize(numOutputs);
  
    std::set<rdcspv::Id> inputs;
    std::set<rdcspv::Id> outputs;
  
    std::map<rdcspv::Id, rdcspv::Id> typeReplacements;
  
    // keep track of any builtins we're preserving
    std::set<rdcspv::Id> builtinKeeps;
  
    // detect builtin inputs or outputs, and remove builtin decorations
    for(rdcspv::Iter it = editor.Begin(rdcspv::Section::Annotations),
                     end = editor.End(rdcspv::Section::Annotations);
        it < end; ++it)
    {
      if(it.opcode() == rdcspv::Op::Decorate)
      {
        rdcspv::OpDecorate decorate(it);
        // remove any builtin decorations
        if(decorate.decoration == rdcspv::Decoration::BuiltIn)
        {
          // subgroup builtins can be allowed to stay
          if(decorate.decoration.builtIn == rdcspv::BuiltIn::SubgroupEqMask ||
             decorate.decoration.builtIn == rdcspv::BuiltIn::SubgroupGtMask ||
             decorate.decoration.builtIn == rdcspv::BuiltIn::SubgroupGeMask ||
             decorate.decoration.builtIn == rdcspv::BuiltIn::SubgroupLtMask ||
             decorate.decoration.builtIn == rdcspv::BuiltIn::SubgroupLeMask ||
             decorate.decoration.builtIn == rdcspv::BuiltIn::SubgroupLocalInvocationId ||
             decorate.decoration.builtIn == rdcspv::BuiltIn::SubgroupSize)
          {
            builtinKeeps.insert(decorate.target);
            continue;
          }
  
          // we don't have to do anything, the ID mapping is in the rdcspv::PatchData, so just discard
          // the location information
          editor.Remove(it);
        }
        // remove all invariant decorations
        else if(decorate.decoration == rdcspv::Decoration::Invariant)
        {
          editor.Remove(it);
        }
        // same with flat/noperspective
        else if(decorate.decoration == rdcspv::Decoration::Flat ||
                decorate.decoration == rdcspv::Decoration::NoPerspective)
        {
          editor.Remove(it);
        }
        else if(decorate.decoration == rdcspv::Decoration::Location ||
                decorate.decoration == rdcspv::Decoration::Component)
        {
          // we don't have to do anything, the ID mapping is in the rdcspv::PatchData, so just discard
          // the location information
          editor.Remove(it);
        }
        // remove block decoration from input or output structs
        else if(decorate.decoration == rdcspv::Decoration::Block)
        {
          if(outputs.find(decorate.target) != outputs.end() ||
             inputs.find(decorate.target) != inputs.end())
            editor.Remove(it);
        }
      }
  
      if(it.opcode() == rdcspv::Op::MemberDecorate)
      {
        rdcspv::OpMemberDecorate memberDecorate(it);
        if(memberDecorate.decoration == rdcspv::Decoration::BuiltIn)
          editor.Remove(it);
      }
    }
  
    // rewrite any inputs and outputs to be private storage class
    for(rdcspv::Iter it = editor.Begin(rdcspv::Section::TypesVariablesConstants),
                     end = editor.End(rdcspv::Section::TypesVariablesConstants);
        it < end; ++it)
    {
      // rewrite any input/output variables to private, and build up inputs/outputs list
      if(it.opcode() == rdcspv::Op::TypePointer)
      {
        rdcspv::OpTypePointer ptr(it);
  
        rdcspv::Id id;
  
        if(ptr.storageClass == rdcspv::StorageClass::Input)
        {
          id = ptr.result;
          inputs.insert(id);
        }
        else if(ptr.storageClass == rdcspv::StorageClass::Output)
        {
          id = ptr.result;
          outputs.insert(id);
  
          rdcspv::Iter baseIt = editor.GetID(ptr.type);
          if(baseIt && baseIt.opcode() == rdcspv::Op::TypeStruct)
            outputs.insert(ptr.type);
        }
        else if(ptr.storageClass == rdcspv::StorageClass::Private ||
                ptr.storageClass == rdcspv::StorageClass::Function)
        {
          // with variable pointers, we could have a private/function pointer into one of the pointer
          // types we've replaced (e.g. Input and Output where one is patched to be private and the
          // other is replaced since we deduplicate pointer types)
          //
          // we don't have to re-order the declaration, since we're iterating the types in order so
          // the replacement is always earlier than the type it was replacing
  
          if(typeReplacements.find(ptr.type) != typeReplacements.end())
          {
            editor.PreModify(it);
  
            ptr.type = typeReplacements[ptr.type];
            it = ptr;
  
            // if we didn't already have this pointer, process the modified type declaration
            editor.PostModify(it);
          }
        }
  
        if(id)
        {
          rdcspv::Pointer privPtr(ptr.type, rdcspv::StorageClass::Private);
  
          rdcspv::Id origId = editor.GetType(privPtr);
  
          if(origId)
          {
            // if we already had a private pointer for this type, we have to use that type - we can't
            // create a new type by aliasing. Thus we need to replace any uses of 'id' with 'origId'.
            typeReplacements[id] = origId;
  
            // and remove this type declaration
            editor.Remove(it);
          }
          else
          {
            editor.PreModify(it);
  
            ptr.storageClass = rdcspv::StorageClass::Private;
            it = ptr;
  
            // if we didn't already have this pointer, process the modified type declaration
            editor.PostModify(it);
          }
        }
      }
      else if(it.opcode() == rdcspv::Op::Variable)
      {
        rdcspv::OpVariable var(it);
  
        bool mod = false;
  
        if(builtinKeeps.find(var.result) != builtinKeeps.end())
        {
          // if this variable is one we're keeping as a builtin, we need to do something different.
          // We don't change its storage class, but we might need to redeclare the pointer as the
          // right matching storage class (because it's been patched to private). This might be
          editor.PreModify(it);
  
          rdcspv::Id ptrId = var.resultType;
          // if this is in typeReplacements the id is no longer valid and was removed
          auto replIt = typeReplacements.find(ptrId);
          if(replIt != typeReplacements.end())
            ptrId = replIt->second;
  
          rdcspv::OpTypePointer ptr(editor.GetID(ptrId));
  
          // declare if necessary the right pointer again, and use that as our type
          var.resultType = editor.DeclareType(rdcspv::Pointer(ptr.type, var.storageClass));
  
          it = var;
          editor.PostModify(it);
  
          // copy this variable declaration to the end of the section, after our potentially 'new'
          // recreated pointer type
  
          rdcspv::Operation op = rdcspv::Operation::copy(it);
          editor.Remove(it);
          editor.AddVariable(op);
          // don't need to add this to the globals because if it needed to be in there it already was
  
          // don't do any of the rest of the processing
          continue;
        }
        else if(var.storageClass == rdcspv::StorageClass::Input)
        {
          mod = true;
          editor.PreModify(it);
  
          var.storageClass = rdcspv::StorageClass::Private;
  
          inputs.insert(var.result);
        }
        else if(var.storageClass == rdcspv::StorageClass::Output)
        {
          mod = true;
          editor.PreModify(it);
  
          var.storageClass = rdcspv::StorageClass::Private;
  
          outputs.insert(var.result);
        }
  
        auto replIt = typeReplacements.find(var.resultType);
        if(replIt != typeReplacements.end())
        {
          if(!mod)
            editor.PreModify(it);
          mod = true;
          var.resultType = replIt->second;
        }
  
        if(mod)
        {
          it = var;
          editor.PostModify(it);
        }
  
        // if we repointed this variable to an existing private declaration, we must also move it to
        // the end of the section. The reason being that the private pointer type declared may be
        // declared *after* this variable. There can't be any dependencies on this later in the
        // section because it's a variable not a type, so it's safe to move to the end.
        if(replIt != typeReplacements.end())
        {
          // make a copy of the opcode
          rdcspv::Operation op = rdcspv::Operation::copy(it);
          // remove the old one
          editor.Remove(it);
          // add it anew
          editor.AddVariable(op);
          // don't need to add this to the globals because if it needed to be in there it already was
        }
      }
      else if(it.opcode() == rdcspv::Op::TypeFunction)
      {
        rdcspv::OpTypeFunction func(it);
  
        bool mod = false;
  
        auto replIt = typeReplacements.find(func.result);
        if(replIt != typeReplacements.end())
        {
          editor.PreModify(it);
          mod = true;
          func.result = replIt->second;
        }
  
        for(size_t i = 0; i < func.parameters.size(); i++)
        {
          replIt = typeReplacements.find(func.parameters[i]);
          if(replIt != typeReplacements.end())
          {
            if(!mod)
              editor.PreModify(it);
            mod = true;
            func.parameters[i] = replIt->second;
          }
        }
  
        if(mod)
        {
          it = func;
          editor.PostModify(it);
        }
      }
      else if(it.opcode() == rdcspv::Op::ConstantNull)
      {
        rdcspv::OpConstantNull nullconst(it);
  
        auto replIt = typeReplacements.find(nullconst.resultType);
        if(replIt != typeReplacements.end())
        {
          editor.PreModify(it);
          nullconst.resultType = replIt->second;
          it = nullconst;
          editor.PostModify(it);
        }
      }
      else if(it.opcode() == rdcspv::Op::Undef)
      {
        rdcspv::OpUndef undef(it);
  
        auto replIt = typeReplacements.find(undef.resultType);
        if(replIt != typeReplacements.end())
        {
          editor.PreModify(it);
          undef.resultType = replIt->second;
          it = undef;
          editor.PostModify(it);
        }
      }
    }
  
    for(rdcspv::Iter it = editor.Begin(rdcspv::Section::Functions); it; ++it)
    {
      // identify functions with result types we might want to replace
      if(it.opcode() == rdcspv::Op::Function || it.opcode() == rdcspv::Op::FunctionParameter ||
         it.opcode() == rdcspv::Op::Variable || it.opcode() == rdcspv::Op::AccessChain ||
         it.opcode() == rdcspv::Op::InBoundsAccessChain || it.opcode() == rdcspv::Op::Bitcast ||
         it.opcode() == rdcspv::Op::Undef || it.opcode() == rdcspv::Op::ExtInst ||
         it.opcode() == rdcspv::Op::FunctionCall || it.opcode() == rdcspv::Op::Phi ||
         it.opcode() == rdcspv::Op::Select)
      {
        editor.PreModify(it);
  
        rdcspv::Id id = rdcspv::Id::fromWord(it.word(1));
        auto replIt = typeReplacements.find(id);
        if(replIt != typeReplacements.end())
          id = replIt->second;
        it.word(1) = id.value();
  
        editor.PostModify(it);
      }
    }
  
    rdcspv::Id entryID;
  
    std::set<rdcspv::Id> entries;
  
    for(const rdcspv::EntryPoint &entry : editor.GetEntries())
    {
      if(entry.name == entryName && entry.executionModel == rdcspv::ExecutionModel::Vertex)
        entryID = entry.id;
  
      entries.insert(entry.id);
    }
  
    RDCASSERT(entryID);
  
    // tracks all the global variables we use, for compliance with SPIR-V 1.4.
    rdcarray<rdcspv::Id> globals;
  
    // we remove all entry points, we'll create one of our own.
    for(rdcspv::Iter it = editor.Begin(rdcspv::Section::EntryPoints),
                     end = editor.End(rdcspv::Section::EntryPoints);
        it < end; ++it)
    {
      rdcspv::OpEntryPoint entry(it);
  
      // when we find the entry point we're patching, grab it's interface for the set of globals. We
      // will be patching and Input/Output variables to private, but from SPIR-V 1.4 the interface
      // needs to include privates as well.
      if(entry.entryPoint == entryID)
        globals = entry.iface;
  
      editor.Remove(it);
    }
  
    for(rdcspv::Iter it = editor.Begin(rdcspv::Section::DebugNames),
                     end2 = editor.End(rdcspv::Section::DebugNames);
        it < end2; ++it)
    {
      if(it.opcode() == rdcspv::Op::Name)
      {
        rdcspv::OpName name(it);
  
        if(inputs.find(name.target) != inputs.end() || outputs.find(name.target) != outputs.end())
        {
          editor.Remove(it);
          if(typeReplacements.find(name.target) == typeReplacements.end())
            editor.SetName(name.target, "emulated_" + name.name);
        }
  
        // remove any OpName for the old entry points
        if(entries.find(name.target) != entries.end())
          editor.Remove(it);
  
        // remove any OpName for deleted types
        if(typeReplacements.find(name.target) != typeReplacements.end())
          editor.Remove(it);
      }
    }
  
    rdcspv::StorageClass bufferClass;
    if(storageMode == Binding)
      bufferClass = editor.StorageBufferClass();
    else
      bufferClass = rdcspv::StorageClass::PhysicalStorageBuffer;
  
    // declare necessary variables per-output, types and constants. We do this last so that we don't
    // add a private pointer that we later try and deduplicate when collapsing output/input pointers
    // to private
    for(uint32_t i = 0; i < numOutputs; i++)
    {
      inputOutputIDs &io = outs[i];
  
      io.builtin = refl.outputSignature[i].systemValue;
  
      // constant for this index
      io.indexConst = editor.AddConstantImmediate(i);
  
      io.variable = patchData.outputs[i].ID;
  
      // base type - either a scalar or a vector, since matrix outputs are decayed to vectors
      {
        rdcspv::Scalar scalarType = rdcspv::scalar(refl.outputSignature[i].varType);
  
        io.vec4Type = editor.DeclareType(rdcspv::Vector(scalarType, 4));
  
        if(refl.outputSignature[i].compCount > 1)
          io.baseType =
              editor.DeclareType(rdcspv::Vector(scalarType, refl.outputSignature[i].compCount));
        else
          io.baseType = editor.DeclareType(scalarType);
      }
  
      io.ssboPtrType = editor.DeclareType(rdcspv::Pointer(io.baseType, bufferClass));
      io.privatePtrType =
          editor.DeclareType(rdcspv::Pointer(io.baseType, rdcspv::StorageClass::Private));
  
      RDCASSERT(io.baseType && io.vec4Type && io.indexConst && io.privatePtrType && io.ssboPtrType,
                io.baseType, io.vec4Type, io.indexConst, io.privatePtrType, io.ssboPtrType);
    }
  
    // repeat for inputs
    for(uint32_t i = 0; i < numInputs; i++)
    {
      inputOutputIDs &io = ins[i];
  
      io.builtin = refl.inputSignature[i].systemValue;
  
      // constant for this index
      io.indexConst = editor.AddConstantImmediate(i);
  
      io.variable = patchData.inputs[i].ID;
  
      rdcspv::Scalar scalarType = rdcspv::scalar(refl.inputSignature[i].varType);
  
      // doubles are loaded as uvec4 and then packed in pairs, so we need to declare vec4ID as uvec4
      if(refl.inputSignature[i].varType == VarType::Double)
      {
        io.fetchVec4Type = io.vec4Type =
            editor.DeclareType(rdcspv::Vector(rdcspv::scalar<uint32_t>(), 4));
      }
      else
      {
        io.vec4Type = editor.DeclareType(rdcspv::Vector(scalarType, 4));
  
        // if the underlying scalar is actually
        switch(refl.inputSignature[i].varType)
        {
          case VarType::Half:
            io.fetchVec4Type = editor.DeclareType(rdcspv::Vector(rdcspv::scalar<float>(), 4));
            break;
          case VarType::SShort:
          case VarType::SByte:
            io.fetchVec4Type = editor.DeclareType(rdcspv::Vector(rdcspv::scalar<int32_t>(), 4));
            break;
          case VarType::UShort:
          case VarType::UByte:
            io.fetchVec4Type = editor.DeclareType(rdcspv::Vector(rdcspv::scalar<uint32_t>(), 4));
            break;
          default: io.fetchVec4Type = io.vec4Type; break;
        }
      }
  
      if(refl.inputSignature[i].compCount > 1)
        io.baseType = editor.DeclareType(rdcspv::Vector(scalarType, refl.inputSignature[i].compCount));
      else
        io.baseType = editor.DeclareType(scalarType);
  
      io.privatePtrType =
          editor.DeclareType(rdcspv::Pointer(io.baseType, rdcspv::StorageClass::Private));
  
      RDCASSERT(io.baseType && io.vec4Type && io.indexConst && io.privatePtrType, io.baseType,
                io.vec4Type, io.indexConst, io.privatePtrType);
    }
  
    rdcspv::Id u32Type = editor.DeclareType(rdcspv::scalar<uint32_t>());
    rdcspv::Id uvec4Type = editor.DeclareType(rdcspv::Vector(rdcspv::scalar<uint32_t>(), 4));
  
    rdcspv::Id uvec4StructPtrType;
    rdcspv::Id uintStructPtrType;
  
    rdcspv::Id arraySize = editor.AddConstantImmediate<uint32_t>(MeshOutputBufferArraySize);
  
    rdcspv::Id vbuffersVariable, ibufferVariable;
  
    rdcarray<rdcspv::Id> vbufferSpecConsts(MeshOutputBufferArraySize);
    rdcarray<rdcspv::Id> vbufferVariables(MeshOutputBufferArraySize);
    rdcspv::Id ibufferSpecConst;
    rdcspv::Id outputSpecConst;
  
    {
      rdcspv::Id runtimeArrayID =
          editor.AddType(rdcspv::OpTypeRuntimeArray(editor.MakeId(), uvec4Type));
      editor.AddDecoration(rdcspv::OpDecorate(
          runtimeArrayID,
          rdcspv::DecorationParam<rdcspv::Decoration::ArrayStride>(sizeof(uint32_t) * 4)));
  
      rdcspv::Id uvec4StructType =
          editor.AddType(rdcspv::OpTypeStruct(editor.MakeId(), {runtimeArrayID}));
      editor.SetName(uvec4StructType, "__rd_uvec4Struct");
  
      editor.AddDecoration(rdcspv::OpMemberDecorate(
          uvec4StructType, 0, rdcspv::DecorationParam<rdcspv::Decoration::Offset>(0)));
  
      uvec4StructPtrType = editor.DeclareType(rdcspv::Pointer(uvec4StructType, bufferClass));
      editor.SetName(uvec4StructPtrType, "__rd_uvec4Struct_ptr");
  
      runtimeArrayID = editor.AddType(rdcspv::OpTypeRuntimeArray(editor.MakeId(), u32Type));
      editor.AddDecoration(rdcspv::OpDecorate(
          runtimeArrayID, rdcspv::DecorationParam<rdcspv::Decoration::ArrayStride>(sizeof(uint32_t))));
  
      rdcspv::Id uintStructType =
          editor.AddType(rdcspv::OpTypeStruct(editor.MakeId(), {runtimeArrayID}));
  
      editor.SetName(uintStructType, "__rd_uintStruct");
  
      editor.AddDecoration(rdcspv::OpMemberDecorate(
          uintStructType, 0, rdcspv::DecorationParam<rdcspv::Decoration::Offset>(0)));
  
      uintStructPtrType = editor.DeclareType(rdcspv::Pointer(uintStructType, bufferClass));
      editor.SetName(uintStructPtrType, "__rd_uintStruct_ptr");
  
      if(storageMode == Binding)
      {
        editor.DecorateStorageBufferStruct(uvec4StructType);
        editor.DecorateStorageBufferStruct(uintStructType);
  
        rdcspv::Id structArrayType = editor.AddType(
            rdcspv::OpTypeArray(editor.MakeId(), uvec4StructType,
                                editor.AddConstantImmediate<uint32_t>(MeshOutputBufferArraySize)));
        rdcspv::Id vbuffersType = editor.DeclareType(rdcspv::Pointer(structArrayType, bufferClass));
  
        vbuffersVariable = editor.MakeId();
        editor.AddVariable(rdcspv::OpVariable(vbuffersType, vbuffersVariable, bufferClass));
        editor.AddDecoration(rdcspv::OpDecorate(
            vbuffersVariable, rdcspv::DecorationParam<rdcspv::Decoration::DescriptorSet>(0)));
        editor.AddDecoration(rdcspv::OpDecorate(
            vbuffersVariable, rdcspv::DecorationParam<rdcspv::Decoration::Binding>(2)));
  
        globals.push_back(vbuffersVariable);
  
        editor.SetName(vbuffersVariable, "__rd_vbuffers");
  
        if(action->flags & ActionFlags::Indexed)
        {
          rdcspv::Id ibufferType = editor.DeclareType(rdcspv::Pointer(uintStructType, bufferClass));
  
          ibufferVariable = editor.MakeId();
          editor.AddVariable(rdcspv::OpVariable(ibufferType, ibufferVariable, bufferClass));
          editor.AddDecoration(rdcspv::OpDecorate(
              ibufferVariable, rdcspv::DecorationParam<rdcspv::Decoration::DescriptorSet>(0)));
          editor.AddDecoration(rdcspv::OpDecorate(
              ibufferVariable, rdcspv::DecorationParam<rdcspv::Decoration::Binding>(1)));
  
          globals.push_back(ibufferVariable);
  
          editor.SetName(ibufferVariable, "__rd_ibuffer");
        }
      }
      else
      {
        editor.AddDecoration(rdcspv::OpDecorate(uvec4StructType, rdcspv::Decoration::Block));
        editor.AddDecoration(rdcspv::OpDecorate(uintStructType, rdcspv::Decoration::Block));
  
        // add the extension
        editor.AddExtension(storageMode == KHR_bda ? "SPV_KHR_physical_storage_buffer"
                                                   : "SPV_EXT_physical_storage_buffer");
  
        // change the memory model to physical storage buffer 64
        rdcspv::Iter it = editor.Begin(rdcspv::Section::MemoryModel);
        rdcspv::OpMemoryModel model(it);
        model.addressingModel = rdcspv::AddressingModel::PhysicalStorageBuffer64;
        it = model;
  
        // add capabilities
        editor.AddCapability(rdcspv::Capability::PhysicalStorageBufferAddresses);
  
        if(storageMode == EXT_bda)
          editor.AddCapability(rdcspv::Capability::Int64);
  
        for(uint32_t i = 0; i <= MeshOutputBufferArraySize + 1; i++)
        {
          rdcspv::Id *dstId = NULL;
          if(i < MeshOutputBufferArraySize)
            dstId = &vbufferSpecConsts[i];
          else if(i == MeshOutputBufferArraySize)
            dstId = &ibufferSpecConst;
          else if(i == MeshOutputBufferArraySize + 1)
            dstId = &outputSpecConst;
  
          if(!dstId)
            break;
  
          if(storageMode == KHR_bda)
          {
            rdcspv::Id addressConstantLSB =
                editor.AddSpecConstantImmediate<uint32_t>(0U, baseSpecConstant + i * 2 + 0);
            rdcspv::Id addressConstantMSB =
                editor.AddSpecConstantImmediate<uint32_t>(0U, baseSpecConstant + i * 2 + 1);
  
            rdcspv::Id uint2 = editor.DeclareType(rdcspv::Vector(rdcspv::scalar<uint32_t>(), 2));
  
            *dstId = editor.AddConstant(rdcspv::OpSpecConstantComposite(
                uint2, editor.MakeId(), {addressConstantLSB, addressConstantMSB}));
          }
          else
          {
            *dstId = editor.AddSpecConstantImmediate<uint64_t>(0ULL, baseSpecConstant + i * 2);
          }
  
          if(i == MeshOutputBufferArraySize)
            editor.SetName(*dstId, "__rd_ibufferConst");
          else
            editor.SetName(*dstId, StringFormat::Fmt("__rd_vbufferConst%u", i));
        }
      }
    }
  
    rdcspv::Id uvec4PtrType = editor.DeclareType(rdcspv::Pointer(uvec4Type, bufferClass));
    rdcspv::Id uintPtrType = editor.DeclareType(rdcspv::Pointer(u32Type, bufferClass));
  
    if(numInputs > 0)
    {
      editor.AddCapability(rdcspv::Capability::SampledBuffer);
    }
  
    rdcspv::Id outBufferVarID;
    rdcspv::Id outputStructPtrType;
    rdcspv::Id numVertsConstID = editor.AddConstantImmediate<uint32_t>(numVerts);
    rdcspv::Id numInstConstID = editor.AddConstantImmediate<uint32_t>(action->numInstances);
    rdcspv::Id numViewsConstID = editor.AddConstantImmediate<uint32_t>(numViews);
  
    editor.SetName(numVertsConstID, "numVerts");
    editor.SetName(numInstConstID, "numInsts");
    editor.SetName(numViewsConstID, "numViews");
  
    // declare the output buffer and its type
    {
      rdcarray<rdcspv::Id> members;
      for(uint32_t o = 0; o < numOutputs; o++)
        members.push_back(outs[o].baseType);
  
      // struct vertex { ... outputs };
      rdcspv::Id vertStructID = editor.DeclareStructType(members);
      editor.SetName(vertStructID, "vertex_struct");
  
      // vertex vertArray[];
      rdcspv::Id runtimeArrayID =
          editor.AddType(rdcspv::OpTypeRuntimeArray(editor.MakeId(), vertStructID));
      editor.SetName(runtimeArrayID, "vertex_array");
  
      uint32_t memberOffset = 0;
      for(uint32_t o = 0; o < numOutputs; o++)
      {
        uint32_t elemSize = RDCMAX(4U, VarTypeByteSize(refl.outputSignature[o].varType));
  
        uint32_t numComps = refl.outputSignature[o].compCount;
  
        // ensure member is std430 packed (vec4 alignment for vec3/vec4)
        if(numComps == 2)
          memberOffset = AlignUp(memberOffset, 2U * elemSize);
        else if(numComps > 2)
          memberOffset = AlignUp(memberOffset, 4U * elemSize);
  
        // apply decoration to each member in the struct with its offset in the struct
        editor.AddDecoration(rdcspv::OpMemberDecorate(
            vertStructID, o, rdcspv::DecorationParam<rdcspv::Decoration::Offset>(memberOffset)));
  
        memberOffset += elemSize * refl.outputSignature[o].compCount;
      }
  
      // align to 16 bytes (vec4) since we will almost certainly have
      // a vec4 in the struct somewhere, and even in std430 alignment,
      // the base struct alignment is still the largest base alignment
      // of any member
      bufStride = AlignUp16(memberOffset);
  
      // struct meshOutput { vertex vertArray[]; };
      rdcspv::Id outputStructID = editor.DeclareStructType({runtimeArrayID});
      editor.SetName(outputStructID, "meshOutput");
  
      // meshOutput *
      outputStructPtrType = editor.DeclareType(rdcspv::Pointer(outputStructID, bufferClass));
      editor.SetName(outputStructPtrType, "meshOutput_ptr");
  
      // the array is the only element in the output struct, so
      // it's at offset 0
      editor.AddDecoration(rdcspv::OpMemberDecorate(
          outputStructID, 0, rdcspv::DecorationParam<rdcspv::Decoration::Offset>(0)));
  
      // set array stride
      editor.AddDecoration(rdcspv::OpDecorate(
          runtimeArrayID, rdcspv::DecorationParam<rdcspv::Decoration::ArrayStride>(bufStride)));
  
      if(storageMode == Binding)
      {
        // meshOutput *outputData;
        outBufferVarID =
            editor.AddVariable(rdcspv::OpVariable(outputStructPtrType, editor.MakeId(), bufferClass));
        editor.SetName(outBufferVarID, "outputData");
  
        globals.push_back(outBufferVarID);
  
        editor.DecorateStorageBufferStruct(outputStructID);
  
        // set binding
        editor.AddDecoration(rdcspv::OpDecorate(
            outBufferVarID, rdcspv::DecorationParam<rdcspv::Decoration::DescriptorSet>(0)));
        editor.AddDecoration(rdcspv::OpDecorate(
            outBufferVarID, rdcspv::DecorationParam<rdcspv::Decoration::Binding>(0)));
      }
      else
      {
        editor.AddDecoration(rdcspv::OpDecorate(outputStructID, rdcspv::Decoration::Block));
      }
    }
  
    rdcspv::Id uint32Vec3ID = editor.DeclareType(rdcspv::Vector(rdcspv::scalar<uint32_t>(), 3));
    rdcspv::Id invocationPtr =
        editor.DeclareType(rdcspv::Pointer(uint32Vec3ID, rdcspv::StorageClass::Input));
    rdcspv::Id invocationId = editor.AddVariable(
        rdcspv::OpVariable(invocationPtr, editor.MakeId(), rdcspv::StorageClass::Input));
    editor.AddDecoration(rdcspv::OpDecorate(
        invocationId,
        rdcspv::DecorationParam<rdcspv::Decoration::BuiltIn>(rdcspv::BuiltIn::GlobalInvocationId)));
  
    globals.push_back(invocationId);
  
    editor.SetName(invocationId, "rdoc_invocation");
  
    // make a new entry point that will call the old function, then when it returns extract & write
    // the outputs.
    rdcspv::Id wrapperEntry = editor.MakeId();
    // don't set a debug name, as some drivers get confused when this doesn't match the entry point
    // name :(.
    // editor.SetName(wrapperEntry, "RenderDoc_MeshFetch_Wrapper_Entrypoint");
  
    // if we're not using all globals, this is only Input variables so only our invocation Id
    if(!editor.EntryPointAllGlobals())
      globals = {invocationId};
  
    // insert the new patched entry point with the globals
    editor.AddOperation(editor.Begin(rdcspv::Section::EntryPoints),
                        rdcspv::OpEntryPoint(rdcspv::ExecutionModel::GLCompute, wrapperEntry,
                                             PatchedMeshOutputEntryPoint, globals));
  
    // Strip away any execution modes from the original shaders
    for(rdcspv::Iter it = editor.Begin(rdcspv::Section::ExecutionMode);
        it < editor.End(rdcspv::Section::ExecutionMode); ++it)
    {
      if(it.opcode() == rdcspv::Op::ExecutionMode)
      {
        rdcspv::OpExecutionMode execMode(it);
  
        // We only need to be cautious about what we are stripping for the entry
        // that we are actually translating, the rest aren't used anyways.
        if(execMode.entryPoint == entryID)
        {
          // Lets check to make sure we don't blindly strip away execution modes that
          // might actually have an impact on the behaviour of the shader.
          switch(execMode.mode)
          {
            case rdcspv::ExecutionMode::Xfb: break;
            default: RDCERR("Unexpected execution mode");
          }
        }
  
        editor.Remove(it);
      }
    }
  
    // Add our compute shader execution mode
    editor.AddExecutionMode(rdcspv::OpExecutionMode(
        wrapperEntry,
        rdcspv::ExecutionModeParam<rdcspv::ExecutionMode::LocalSize>(MeshOutputDispatchWidth, 1, 1)));
  
    rdcspv::Id zero = editor.AddConstantImmediate<uint32_t>(0);
  
    rdcspv::MemoryAccessAndParamDatas memoryAccess;
  
    // add the wrapper function
    {
      rdcspv::OperationList ops;
  
      rdcspv::Id voidType = editor.DeclareType(rdcspv::scalar<void>());
      rdcspv::Id funcType = editor.DeclareType(rdcspv::FunctionType(voidType, {}));
  
      ops.add(rdcspv::OpFunction(voidType, wrapperEntry, rdcspv::FunctionControl::None, funcType));
  
      ops.add(rdcspv::OpLabel(editor.MakeId()));
      {
        // convert the pointers here
        if(storageMode != Binding)
        {
          memoryAccess.setAligned(sizeof(uint32_t));
  
          if(ibufferSpecConst != rdcspv::Id())
          {
            // if we don't have the struct as a bind, we need to cast it from the pointer. In
            // KHR_buffer_device_address we bitcast since we store it as a uint2
            if(storageMode == KHR_bda)
              ibufferVariable =
                  ops.add(rdcspv::OpBitcast(uintStructPtrType, editor.MakeId(), ibufferSpecConst));
            else
              ibufferVariable = ops.add(
                  rdcspv::OpConvertUToPtr(uintStructPtrType, editor.MakeId(), ibufferSpecConst));
  
            editor.SetName(ibufferVariable, "__rd_ibuffer");
          }
  
          for(size_t s = 0; s < refl.inputSignature.size(); s++)
          {
            uint32_t idx = refl.inputSignature[s].regIndex;
  
            if(vbufferSpecConsts[idx] != rdcspv::Id() && vbufferVariables[idx] == rdcspv::Id())
            {
              if(storageMode == KHR_bda)
                vbufferVariables[idx] = ops.add(
                    rdcspv::OpBitcast(uvec4StructPtrType, editor.MakeId(), vbufferSpecConsts[idx]));
              else
                vbufferVariables[idx] = ops.add(rdcspv::OpConvertUToPtr(
                    uvec4StructPtrType, editor.MakeId(), vbufferSpecConsts[idx]));
  
              editor.SetName(vbufferVariables[idx], StringFormat::Fmt("__rd_vbuffers[%u]", idx));
            }
          }
  
          {
            if(storageMode == KHR_bda)
              outBufferVarID =
                  ops.add(rdcspv::OpBitcast(outputStructPtrType, editor.MakeId(), outputSpecConst));
            else
              outBufferVarID = ops.add(
                  rdcspv::OpConvertUToPtr(outputStructPtrType, editor.MakeId(), outputSpecConst));
  
            editor.SetName(outBufferVarID, "__rd_outbuf");
          }
        }
  
        // uint3 invocationVec = gl_GlobalInvocationID;
        rdcspv::Id invocationVector =
            ops.add(rdcspv::OpLoad(uint32Vec3ID, editor.MakeId(), invocationId));
  
        // uint invocation = invocationVec.x
        rdcspv::Id uintInvocationID =
            ops.add(rdcspv::OpCompositeExtract(u32Type, editor.MakeId(), invocationVector, {0U}));
  
        // arraySlotID = uintInvocationID;
        rdcspv::Id arraySlotID = uintInvocationID;
  
        editor.SetName(uintInvocationID, "arraySlot");
  
        // uint viewinst = uintInvocationID / numVerts
        rdcspv::Id viewinstID =
            ops.add(rdcspv::OpUDiv(u32Type, editor.MakeId(), uintInvocationID, numVertsConstID));
  
        editor.SetName(viewinstID, "viewInstance");
  
        rdcspv::Id instID =
            ops.add(rdcspv::OpUMod(u32Type, editor.MakeId(), viewinstID, numInstConstID));
  
        editor.SetName(instID, "instanceID");
  
        rdcspv::Id viewID =
            ops.add(rdcspv::OpUDiv(u32Type, editor.MakeId(), viewinstID, numInstConstID));
  
        editor.SetName(viewID, "viewID");
  
        // bool inBounds = viewID < numViews;
        rdcspv::Id inBounds = ops.add(rdcspv::OpULessThan(editor.DeclareType(rdcspv::scalar<bool>()),
                                                          editor.MakeId(), viewID, numViewsConstID));
  
        // if(inBounds) goto continueLabel; else goto killLabel;
        rdcspv::Id killLabel = editor.MakeId();
        rdcspv::Id continueLabel = editor.MakeId();
        ops.add(rdcspv::OpSelectionMerge(killLabel, rdcspv::SelectionControl::None));
        ops.add(rdcspv::OpBranchConditional(inBounds, continueLabel, killLabel));
  
        // continueLabel:
        ops.add(rdcspv::OpLabel(continueLabel));
  
        // uint vtx = uintInvocationID % numVerts
        rdcspv::Id vtxID =
            ops.add(rdcspv::OpUMod(u32Type, editor.MakeId(), uintInvocationID, numVertsConstID));
        editor.SetName(vtxID, "vertexID");
  
        rdcspv::Id vertexIndexID = vtxID;
  
        // if we're indexing, look up the index buffer. We don't have to apply vertexOffset - it was
        // already applied when we read back and uniq-ified the index buffer.
        if(action->flags & ActionFlags::Indexed)
        {
          rdcspv::Id idxPtr;
  
          // idxptr = &ibuffer.member0[vertexIndex]
          idxPtr = ops.add(rdcspv::OpAccessChain(uintPtrType, editor.MakeId(), ibufferVariable,
                                                 {zero, vertexIndexID}));
  
          // vertexIndex = *idxptr
          vertexIndexID = ops.add(rdcspv::OpLoad(u32Type, editor.MakeId(), idxPtr, memoryAccess));
        }
  
        // we use the current value of vertexIndex and use instID, to lookup per-vertex and
        // per-instance attributes. This is because when we fetched the vertex data, we advanced by
        // (in non-indexed draws) vertexOffset, and by instanceOffset. Rather than fetching data
        // that's only used as padding skipped over by these offsets.
        rdcspv::Id vertexLookupID = vertexIndexID;
        rdcspv::Id instanceLookupID = instID;
  
        if(!(action->flags & ActionFlags::Indexed))
        {
          // for non-indexed draws, we manually apply the vertex offset, but here after we used the
          // 0-based one to calculate the array slot
          vertexIndexID =
              ops.add(rdcspv::OpIAdd(u32Type, editor.MakeId(), vtxID,
                                     editor.AddConstantImmediate<uint32_t>(action->vertexOffset)));
        }
        editor.SetName(vertexIndexID, "vertexIndex");
  
        // instIndex = inst + instOffset
        rdcspv::Id instIndexID =
            ops.add(rdcspv::OpIAdd(u32Type, editor.MakeId(), instID,
                                   editor.AddConstantImmediate<uint32_t>(action->instanceOffset)));
        editor.SetName(instIndexID, "instanceIndex");
  
        rdcspv::Id idxs[64] = {};
  
        for(size_t i = 0; i < refl.inputSignature.size(); i++)
        {
          ShaderBuiltin builtin = refl.inputSignature[i].systemValue;
          if(builtin != ShaderBuiltin::Undefined)
          {
            rdcspv::Id valueID;
            CompType compType = CompType::UInt;
  
            if(builtin == ShaderBuiltin::VertexIndex)
            {
              valueID = vertexIndexID;
              // although for indexed draws we accounted for vertexOffset when looking up fixed
              // function vertex inputs, we still need to apply it to the VertexIndex builtin here.
              if(action->flags & ActionFlags::Indexed)
              {
                valueID = ops.add(
                    rdcspv::OpIAdd(u32Type, editor.MakeId(), valueID,
                                   editor.AddConstantImmediate<uint32_t>(action->vertexOffset)));
              }
            }
            else if(builtin == ShaderBuiltin::InstanceIndex)
            {
              valueID = instIndexID;
            }
            else if(builtin == ShaderBuiltin::ViewportIndex)
            {
              valueID = viewID;
            }
            else if(builtin == ShaderBuiltin::BaseVertex)
            {
              if(action->flags & ActionFlags::Indexed)
              {
                valueID = editor.AddConstantImmediate<uint32_t>(action->vertexOffset);
              }
              else
              {
                valueID = editor.AddConstantImmediate<int32_t>(action->baseVertex);
                compType = CompType::SInt;
              }
            }
            else if(builtin == ShaderBuiltin::BaseInstance)
            {
              valueID = editor.AddConstantImmediate<uint32_t>(action->instanceOffset);
            }
            else if(builtin == ShaderBuiltin::DrawIndex)
            {
              valueID = editor.AddConstantImmediate<uint32_t>(action->drawIndex);
            }
            else if(builtin == ShaderBuiltin::SubgroupEqualMask ||
                    builtin == ShaderBuiltin::SubgroupGreaterMask ||
                    builtin == ShaderBuiltin::SubgroupGreaterEqualMask ||
                    builtin == ShaderBuiltin::SubgroupLessMask ||
                    builtin == ShaderBuiltin::SubgroupLessEqualMask ||
                    builtin == ShaderBuiltin::IndexInSubgroup || builtin == ShaderBuiltin::SubgroupSize)
            {
              // subgroup builtins we left alone, these are still builtins
              continue;
            }
  
            if(valueID)
            {
              if(VarTypeCompType(refl.inputSignature[i].varType) == compType)
              {
                ops.add(rdcspv::OpStore(ins[i].variable, valueID));
              }
              else
              {
                // assume we can just bitcast
                rdcspv::Id castedValue =
                    ops.add(rdcspv::OpBitcast(ins[i].baseType, editor.MakeId(), valueID));
                ops.add(rdcspv::OpStore(ins[i].variable, castedValue));
              }
            }
            else
            {
              RDCERR("Unsupported/unsupported built-in input %s", ToStr(builtin).c_str());
            }
          }
          else
          {
            if(idxs[i] == 0)
              idxs[i] = editor.AddConstantImmediate<uint32_t>((uint32_t)i);
  
            if(idxs[refl.inputSignature[i].regIndex] == 0)
              idxs[refl.inputSignature[i].regIndex] =
                  editor.AddConstantImmediate<uint32_t>(refl.inputSignature[i].regIndex);
  
            uint32_t location = refl.inputSignature[i].regIndex;
  
            // idx = vertexIndex
            rdcspv::Id idx = vertexLookupID;
  
            // maybe idx = instanceIndex / someDivisor
            if(location < instDivisor.size())
            {
              uint32_t divisor = instDivisor[location];
  
              if(divisor == ~0U)
              {
                // this magic value indicates vertex-rate data
                idx = vertexLookupID;
              }
              else if(divisor == 0)
              {
                // if the divisor is 0, all instances read the first value.
                idx = editor.AddConstantImmediate<uint32_t>(0);
              }
              else if(divisor == 1)
              {
                // if the divisor is 1, it's just regular instancing
                idx = instanceLookupID;
              }
              else
              {
                // otherwise we divide by the divisor
                rdcspv::Id divisorId = editor.AddConstantImmediate<uint32_t>(divisor);
                idx = ops.add(rdcspv::OpUDiv(u32Type, editor.MakeId(), instanceLookupID, divisorId));
              }
            }
  
            if(refl.inputSignature[i].varType == VarType::Double)
            {
              // since doubles are packed into two uints, we need to multiply the index by two
              idx = ops.add(rdcspv::OpIMul(u32Type, editor.MakeId(), idx,
                                           editor.AddConstantImmediate<uint32_t>(2)));
            }
  
            rdcspv::Id ptrId;
  
            // when we're loading from bindings, the vbuffers variable is an array of N structs each
            // containing uvec4[],
            // when we're using buffer device address we have one variable per vbuffer and it's a
            // plain uvec4*
  
            // uvec4 *vertex = &vbuffers[reg].member0[idx]
            if(storageMode == Binding)
              ptrId =
                  ops.add(rdcspv::OpAccessChain(uvec4PtrType, editor.MakeId(), vbuffersVariable,
                                                {idxs[refl.inputSignature[i].regIndex], zero, idx}));
            else
              // uvec4 *vertex = &vbufferN.member0[idx]
              ptrId = ops.add(rdcspv::OpAccessChain(uvec4PtrType, editor.MakeId(),
                                                    vbufferVariables[refl.inputSignature[i].regIndex],
                                                    {zero, idx}));
  
            // uvec4 result = *vertex
            rdcspv::Id result =
                ops.add(rdcspv::OpLoad(uvec4Type, editor.MakeId(), ptrId, memoryAccess));
  
            // if we want this as ivec4 or vec4, bitcast now
            if(ins[i].fetchVec4Type != uvec4Type)
              result = ops.add(rdcspv::OpBitcast(ins[i].fetchVec4Type, editor.MakeId(), result));
  
            // we always fetch as full 32-bit values, but if the input was declared as a different
            // size (typically ushort or half) then convert here
            if(ins[i].fetchVec4Type != ins[i].vec4Type)
            {
              if(VarTypeCompType(refl.inputSignature[i].varType) == CompType::Float)
                result = ops.add(rdcspv::OpFConvert(ins[i].vec4Type, editor.MakeId(), result));
              else if(VarTypeCompType(refl.inputSignature[i].varType) == CompType::UInt)
                result = ops.add(rdcspv::OpUConvert(ins[i].vec4Type, editor.MakeId(), result));
              else
                result = ops.add(rdcspv::OpSConvert(ins[i].vec4Type, editor.MakeId(), result));
            }
  
            uint32_t comp = Bits::CountTrailingZeroes(uint32_t(refl.inputSignature[i].regChannelMask));
  
            if(refl.inputSignature[i].varType == VarType::Double)
            {
              // since doubles are packed into two uints, we now need to fetch more data and do
              // packing. We can fetch the data unconditionally since it's harmless to read out of the
              // bounds of the buffer
  
              rdcspv::Id nextidx = ops.add(rdcspv::OpIAdd(u32Type, editor.MakeId(), idx,
                                                          editor.AddConstantImmediate<uint32_t>(1)));
  
              // uvec4 *vertex = &vbuffers[reg].member0[nextidx]
              if(storageMode == Binding)
                ptrId = ops.add(
                    rdcspv::OpAccessChain(uvec4PtrType, editor.MakeId(), vbuffersVariable,
                                          {idxs[refl.inputSignature[i].regIndex], zero, nextidx}));
              else
                // uvec4 *vertex = &vbufferN.member0[nextidx]
                ptrId = ops.add(rdcspv::OpAccessChain(
                    uvec4PtrType, editor.MakeId(), vbufferVariables[refl.inputSignature[i].regIndex],
                    {zero, nextidx}));
              rdcspv::Id result2 =
                  ops.add(rdcspv::OpLoad(uvec4Type, editor.MakeId(), ptrId, memoryAccess));
  
              rdcspv::Id glsl450 = editor.ImportExtInst("GLSL.std.450");
  
              rdcspv::Id uvec2Type = editor.DeclareType(rdcspv::Vector(rdcspv::scalar<uint32_t>(), 2));
              rdcspv::Id comps[4] = {};
  
              for(uint32_t c = 0; c < refl.inputSignature[i].compCount; c++)
              {
                // first extract the uvec2 we want
  
                // uvec2 packed = result.[xy/zw] / result2.[xy/zw];
                rdcspv::Id packed = ops.add(rdcspv::OpVectorShuffle(
                    uvec2Type, editor.MakeId(), result, result2, {c * 2 + 0, c * 2 + 1}));
  
                char swizzle[] = "xyzw";
  
                editor.SetName(packed, StringFormat::Fmt("packed_%c", swizzle[c]));
  
                // double comp = PackDouble2x32(packed);
                comps[c] = ops.add(rdcspv::OpGLSL450(editor.DeclareType(rdcspv::scalar<double>()),
                                                     editor.MakeId(), glsl450,
                                                     rdcspv::GLSLstd450::PackDouble2x32, {packed}));
              }
  
              // if there's only one component it's ready, otherwise construct a vector
              if(refl.inputSignature[i].compCount == 1)
              {
                result = comps[0];
              }
              else
              {
                rdcarray<rdcspv::Id> ids;
  
                for(uint32_t c = 0; c < refl.inputSignature[i].compCount; c++)
                  ids.push_back(comps[c]);
  
                // baseTypeN value = result.xyz;
                result = ops.add(rdcspv::OpCompositeConstruct(ins[i].baseType, editor.MakeId(), ids));
              }
            }
            else if(refl.inputSignature[i].compCount == 1)
            {
              // for one component, extract x
  
              // baseType value = result.x;
              result =
                  ops.add(rdcspv::OpCompositeExtract(ins[i].baseType, editor.MakeId(), result, {comp}));
            }
            else if(refl.inputSignature[i].compCount != 4)
            {
              // for less than 4 components, extract the sub-vector
  
              rdcarray<uint32_t> swizzle;
  
              for(uint32_t c = 0; c < refl.inputSignature[i].compCount; c++)
                swizzle.push_back(c + comp);
  
              // baseTypeN value = result.xyz;
              result = ops.add(
                  rdcspv::OpVectorShuffle(ins[i].baseType, editor.MakeId(), result, result, swizzle));
            }
  
            // copy the 4 component result directly
  
            // not a composite type, we can store directly
            if(patchData.inputs[i].accessChain.empty())
            {
              // *global = value
              ops.add(rdcspv::OpStore(ins[i].variable, result));
            }
            else
            {
              // for composite types we need to access chain first
              rdcarray<rdcspv::Id> chain;
  
              for(uint32_t accessIdx : patchData.inputs[i].accessChain)
              {
                if(idxs[accessIdx] == 0)
                  idxs[accessIdx] = editor.AddConstantImmediate<uint32_t>(accessIdx);
  
                chain.push_back(idxs[accessIdx]);
              }
  
              rdcspv::Id subElement = ops.add(rdcspv::OpAccessChain(
                  ins[i].privatePtrType, editor.MakeId(), patchData.inputs[i].ID, chain));
  
              ops.add(rdcspv::OpStore(subElement, result));
            }
          }
        }
  
        // real_main();
        ops.add(rdcspv::OpFunctionCall(voidType, editor.MakeId(), entryID));
  
        for(uint32_t o = 0; o < numOutputs; o++)
        {
          rdcspv::Id loaded;
  
          // not a structure member or array child, can load directly
          if(patchData.outputs[o].accessChain.empty())
          {
            // type loaded = *globalvar;
            loaded =
                ops.add(rdcspv::OpLoad(outs[o].baseType, editor.MakeId(), patchData.outputs[o].ID));
          }
          else
          {
            // structure member, need to access chain first
            rdcarray<rdcspv::Id> chain;
  
            for(uint32_t idx : patchData.outputs[o].accessChain)
            {
              if(idxs[idx] == 0)
                idxs[idx] = editor.AddConstantImmediate<uint32_t>(idx);
  
              chain.push_back(idxs[idx]);
            }
  
            // type *readPtr = globalvar.globalsub...;
            rdcspv::Id readPtr = ops.add(rdcspv::OpAccessChain(
                outs[o].privatePtrType, editor.MakeId(), patchData.outputs[o].ID, chain));
            // type loaded = *readPtr;
            loaded = ops.add(rdcspv::OpLoad(outs[o].baseType, editor.MakeId(), readPtr));
          }
  
          // access chain the destination
          rdcspv::Id writePtr;
  
          // type *writePtr = &outBuffer.verts[arraySlot].outputN
          writePtr = ops.add(rdcspv::OpAccessChain(outs[o].ssboPtrType, editor.MakeId(), outBufferVarID,
                                                   {zero, arraySlotID, outs[o].indexConst}));
  
          // *writePtr = loaded;
          ops.add(rdcspv::OpStore(writePtr, loaded, memoryAccess));
        }
  
        // goto killLabel;
        ops.add(rdcspv::OpBranch(killLabel));
  
        // killLabel:
        ops.add(rdcspv::OpLabel(killLabel));
      }
      ops.add(rdcspv::OpReturn());
  
      ops.add(rdcspv::OpFunctionEnd());
  
      editor.AddFunction(ops);
    }
  }
  
  void VulkanReplay::ClearPostVSCache()
  {
    VkDevice dev = m_Device;
  
    for(auto it = m_PostVS.Data.begin(); it != m_PostVS.Data.end(); ++it)
    {
      if(it->second.vsout.idxbuf != VK_NULL_HANDLE)
      {
        m_pDriver->vkDestroyBuffer(dev, it->second.vsout.idxbuf, NULL);
        m_pDriver->vkFreeMemory(dev, it->second.vsout.idxbufmem, NULL);
      }
      m_pDriver->vkDestroyBuffer(dev, it->second.vsout.buf, NULL);
      m_pDriver->vkFreeMemory(dev, it->second.vsout.bufmem, NULL);
  
      if(it->second.gsout.buf != VK_NULL_HANDLE)
      {
        m_pDriver->vkDestroyBuffer(dev, it->second.gsout.buf, NULL);
        m_pDriver->vkFreeMemory(dev, it->second.gsout.bufmem, NULL);
      }
    }
  
    m_PostVS.Data.clear();
  }
  
  void VulkanReplay::FetchVSOut(uint32_t eventId, VulkanRenderState &state)
  {
    VulkanCreationInfo &creationInfo = m_pDriver->m_CreationInfo;
  
    const VulkanCreationInfo::Pipeline &pipeInfo = creationInfo.m_Pipeline[state.graphics.pipeline];
  
    const ActionDescription *action = m_pDriver->GetAction(eventId);
  
    const VulkanCreationInfo::ShaderModule &moduleInfo =
        creationInfo.m_ShaderModule[pipeInfo.shaders[0].module];
  
    ShaderReflection *refl = pipeInfo.shaders[0].refl;
  
    // set defaults so that we don't try to fetch this output again if something goes wrong and the
    // same event is selected again
    {
      m_PostVS.Data[eventId].vsin.topo = state.primitiveTopology;
      m_PostVS.Data[eventId].vsout.buf = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].vsout.bufmem = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].vsout.instStride = 0;
      m_PostVS.Data[eventId].vsout.vertStride = 0;
      m_PostVS.Data[eventId].vsout.numViews = 1;
      m_PostVS.Data[eventId].vsout.nearPlane = 0.0f;
      m_PostVS.Data[eventId].vsout.farPlane = 0.0f;
      m_PostVS.Data[eventId].vsout.useIndices = false;
      m_PostVS.Data[eventId].vsout.hasPosOut = false;
      m_PostVS.Data[eventId].vsout.flipY = false;
      m_PostVS.Data[eventId].vsout.idxbuf = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].vsout.idxbufmem = VK_NULL_HANDLE;
  
      m_PostVS.Data[eventId].vsout.topo = state.primitiveTopology;
    }
  
    // no outputs from this shader? unexpected but theoretically possible (dummy VS before
    // tessellation maybe). Just fill out an empty data set
    if(refl->outputSignature.empty())
      return;
  
    // we go through the driver for all these creations since they need to be properly
    // registered in order to be put in the partial replay state
    VkResult vkr = VK_SUCCESS;
    VkDevice dev = m_Device;
  
    VkDescriptorPool descpool = VK_NULL_HANDLE;
    rdcarray<VkDescriptorSetLayout> setLayouts;
    rdcarray<VkDescriptorSet> descSets;
  
    VkPipelineLayout pipeLayout = VK_NULL_HANDLE;
  
    StorageMode storageMode = Binding;
  
    if(m_pDriver->GetExtensions(NULL).ext_KHR_buffer_device_address)
    {
      storageMode = KHR_bda;
    }
    else if(m_pDriver->GetExtensions(NULL).ext_EXT_buffer_device_address)
    {
      storageMode = EXT_bda;
  
      if(!m_pDriver->GetDeviceEnabledFeatures().shaderInt64)
      {
        static bool warned = false;
        if(!warned)
        {
          warned = true;
          RDCLOG(
              "EXT_buffer_device_address is available but shaderInt64 isn't, falling back to binding "
              "storage mode");
        }
      }
    }
  
    if(Vulkan_Debug_DisableBufferDeviceAddress() ||
       m_pDriver->GetDriverInfo().BufferDeviceAddressBrokenDriver())
      storageMode = Binding;
  
    if(m_pDriver->GetDeviceProps().limits.maxPerStageDescriptorStorageBuffers - 2 <
       MeshOutputBufferArraySize)
    {
      RDCWARN("Default buffer descriptor array size %u is over device limit, clamping to %u",
              MeshOutputBufferArraySize,
              m_pDriver->GetDeviceProps().limits.maxPerStageDescriptorStorageBuffers - 2);
  
      MeshOutputBufferArraySize =
          m_pDriver->GetDeviceProps().limits.maxPerStageDescriptorStorageBuffers - 2;
    }
  
    for(size_t i = 0; i < refl->inputSignature.size(); i++)
    {
      if(refl->inputSignature[i].regIndex >= MeshOutputBufferArraySize)
      {
        RDCERR("Input %s refers to attribute %u which is out of our array size %u",
               refl->inputSignature[i].varName.c_str(), refl->inputSignature[i].regIndex,
               MeshOutputBufferArraySize);
        return;
      }
    }
  
    VkGraphicsPipelineCreateInfo pipeCreateInfo;
  
    // get pipeline create info
    m_pDriver->GetShaderCache()->MakeGraphicsPipelineInfo(pipeCreateInfo, state.graphics.pipeline);
  
    VkDescriptorSetLayoutBinding newBindings[] = {
        // output buffer
        {
            0, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1, VK_SHADER_STAGE_COMPUTE_BIT, NULL,
        },
        // index buffer (if needed)
        {
            1, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1, VK_SHADER_STAGE_COMPUTE_BIT, NULL,
        },
        // vertex buffers
        {
            2, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, MeshOutputBufferArraySize,
            VK_SHADER_STAGE_COMPUTE_BIT, NULL,
        },
    };
    RDCCOMPILE_ASSERT(ARRAY_COUNT(newBindings) == MeshOutputReservedBindings,
                      "MeshOutputReservedBindings is wrong");
  
    // the spec says only one push constant range may be used per stage, so at most one has
    // VERTEX_BIT. Find it, and make it COMPUTE_BIT
    VkPushConstantRange push;
    uint32_t numPush = 0;
    rdcarray<VkPushConstantRange> oldPush = creationInfo.m_PipelineLayout[pipeInfo.layout].pushRanges;
  
    // ensure the push range is visible to the compute shader
    for(const VkPushConstantRange &range : oldPush)
    {
      if(range.stageFlags & VK_SHADER_STAGE_VERTEX_BIT)
      {
        push = range;
        push.stageFlags = VK_SHADER_STAGE_COMPUTE_BIT;
        numPush = 1;
        break;
      }
    }
  
    if(storageMode == Binding)
    {
      // create a duplicate set of descriptor sets, all visible to compute, with bindings shifted to
      // account for new ones we need. This also copies the existing bindings into the new sets
      PatchReservedDescriptors(state.graphics, descpool, setLayouts, descSets,
                               VK_SHADER_STAGE_COMPUTE_BIT, newBindings, ARRAY_COUNT(newBindings));
  
      // if the pool failed due to limits, it will be NULL so bail now
      if(descpool == VK_NULL_HANDLE)
        return;
  
      VkPipelineLayoutCreateInfo pipeLayoutInfo = {
          VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO,
          NULL,
          0,
          (uint32_t)setLayouts.size(),
          setLayouts.data(),
          numPush,
          &push,
      };
  
      vkr = m_pDriver->vkCreatePipelineLayout(dev, &pipeLayoutInfo, NULL, &pipeLayout);
      CheckVkResult(vkr);
    }
    else
    {
      // using BDA we don't need to add any new bindings but we *do* need to patch the descriptor set
      // layouts to be compute visible. However with update-after-bind descriptors in the mix we can't
      // always reliably do this, as making a copy of the descriptor sets can't be done (in general).
      //
      // To get around this we patch descriptor set layouts at create time so that COMPUTE_BIT is
      // present wherever VERTEX_BIT was, so we can use the application's descriptor sets and layouts
  
      const rdcarray<ResourceId> &sets = creationInfo.m_PipelineLayout[pipeInfo.layout].descSetLayouts;
  
      setLayouts.reserve(sets.size());
  
      for(size_t i = 0; i < sets.size(); i++)
        setLayouts.push_back(GetResourceManager()->GetCurrentHandle<VkDescriptorSetLayout>(sets[i]));
  
      VkPipelineLayoutCreateInfo pipeLayoutInfo = {
          VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO,
          NULL,
          0,
          (uint32_t)setLayouts.size(),
          setLayouts.data(),
          numPush,
          &push,
      };
  
      vkr = m_pDriver->vkCreatePipelineLayout(dev, &pipeLayoutInfo, NULL, &pipeLayout);
      CheckVkResult(vkr);
  
      // clear the array because it's not needed after and we want to avoid releasing real resources
      setLayouts.clear();
    }
  
    VkBuffer meshBuffer = VK_NULL_HANDLE, readbackBuffer = VK_NULL_HANDLE;
    VkDeviceMemory meshMem = VK_NULL_HANDLE, readbackMem = VK_NULL_HANDLE;
  
    VkBuffer uniqIdxBuf = VK_NULL_HANDLE;
    VkDeviceMemory uniqIdxBufMem = VK_NULL_HANDLE;
    VkDescriptorBufferInfo uniqIdxBufDescriptor = {};
  
    VkBuffer rebasedIdxBuf = VK_NULL_HANDLE;
    VkDeviceMemory rebasedIdxBufMem = VK_NULL_HANDLE;
  
    uint32_t numVerts = action->numIndices;
    VkDeviceSize bufSize = 0;
  
    uint32_t numViews = 1;
  
    {
      const VulkanCreationInfo::RenderPass &rp = creationInfo.m_RenderPass[state.renderPass];
  
      if(state.subpass < rp.subpasses.size())
      {
        numViews = RDCMAX(numViews, (uint32_t)rp.subpasses[state.subpass].multiviews.size());
      }
      else
      {
        RDCERR("Subpass is out of bounds to renderpass creation info");
      }
    }
  
    uint32_t idxsize = state.ibuffer.bytewidth;
  
    uint32_t maxIndex = RDCMAX(action->baseVertex, 0) + numVerts - 1;
  
    uint32_t maxInstance = action->instanceOffset + action->numInstances - 1;
  
    const VkMemoryAllocateFlagsInfo memFlags = {
        VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_FLAGS_INFO, NULL, VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT,
    };
  
    if(action->flags & ActionFlags::Indexed)
    {
      const bool restart = pipeCreateInfo.pInputAssemblyState->primitiveRestartEnable &&
                           SupportsRestart(MakePrimitiveTopology(state.primitiveTopology, 3));
      bytebuf idxdata;
      rdcarray<uint32_t> indices;
      uint8_t *idx8 = NULL;
      uint16_t *idx16 = NULL;
      uint32_t *idx32 = NULL;
  
      // fetch ibuffer
      if(state.ibuffer.buf != ResourceId())
        GetBufferData(state.ibuffer.buf, state.ibuffer.offs + action->indexOffset * idxsize,
                      uint64_t(action->numIndices) * idxsize, idxdata);
  
      // figure out what the maximum index could be, so we can clamp our index buffer to something
      // sane
      uint32_t maxIdx = 0;
  
      // if there are no active bindings assume the vertex shader is generating its own data
      // and don't clamp the indices
      if(pipeCreateInfo.pVertexInputState->vertexBindingDescriptionCount == 0)
        maxIdx = ~0U;
  
      for(uint32_t b = 0; b < pipeCreateInfo.pVertexInputState->vertexBindingDescriptionCount; b++)
      {
        const VkVertexInputBindingDescription &input =
            pipeCreateInfo.pVertexInputState->pVertexBindingDescriptions[b];
        // only vertex inputs (not instance inputs) count
        if(input.inputRate == VK_VERTEX_INPUT_RATE_VERTEX)
        {
          if(b >= state.vbuffers.size())
            continue;
  
          ResourceId buf = state.vbuffers[b].buf;
          VkDeviceSize offs = state.vbuffers[b].offs;
  
          VkDeviceSize bufsize = creationInfo.m_Buffer[buf].size;
  
          // the maximum valid index on this particular input is the one that reaches
          // the end of the buffer. The maximum valid index at all is the one that reads
          // off the end of ALL buffers (so we max it with any other maxindex value
          // calculated).
          if(input.stride > 0)
            maxIdx = RDCMAX(maxIdx, uint32_t((bufsize - offs) / input.stride));
        }
      }
  
      // in case the vertex buffers were set but had invalid stride (0), max with the number
      // of vertices too. This is fine since the max here is just a conservative limit
      maxIdx = RDCMAX(maxIdx, action->numIndices);
  
      // do ibuffer rebasing/remapping
  
      if(idxsize == 4)
        idx32 = (uint32_t *)&idxdata[0];
      else if(idxsize == 1)
        idx8 = (uint8_t *)&idxdata[0];
      else
        idx16 = (uint16_t *)&idxdata[0];
  
      // only read as many indices as were available in the buffer
      uint32_t numIndices = RDCMIN(uint32_t(idxdata.size() / idxsize), action->numIndices);
  
      uint32_t idxclamp = 0;
      if(action->baseVertex < 0)
        idxclamp = uint32_t(-action->baseVertex);
  
      // grab all unique vertex indices referenced
      for(uint32_t i = 0; i < numIndices; i++)
      {
        uint32_t i32 = 0;
        if(idx32)
          i32 = idx32[i];
        else if(idx16)
          i32 = uint32_t(idx16[i]);
        else if(idx8)
          i32 = uint32_t(idx8[i]);
  
        // apply baseVertex but clamp to 0 (don't allow index to become negative)
        if(i32 < idxclamp)
          i32 = 0;
        else if(action->baseVertex < 0)
          i32 -= idxclamp;
        else if(action->baseVertex > 0)
          i32 += action->baseVertex;
  
        // we clamp to maxIdx here, to avoid any invalid indices like 0xffffffff
        // from filtering through. Worst case we index to the end of the vertex
        // buffers which is generally much more reasonable
        i32 = RDCMIN(maxIdx, i32);
  
        auto it = std::lower_bound(indices.begin(), indices.end(), i32);
  
        if(it != indices.end() && *it == i32)
          continue;
  
        indices.insert(it - indices.begin(), i32);
      }
  
      // if we read out of bounds, we'll also have a 0 index being referenced
      // (as 0 is read). Don't insert 0 if we already have 0 though
      if(numIndices < action->numIndices && (indices.empty() || indices[0] != 0))
        indices.insert(0, 0);
  
      maxIndex = indices.back();
  
      // set numVerts
      numVerts = (uint32_t)indices.size();
  
      // An index buffer could be something like: 500, 501, 502, 501, 503, 502
      // in which case we can't use the existing index buffer without filling 499 slots of vertex
      // data with padding. Instead we rebase the indices based on the smallest vertex so it becomes
      // 0, 1, 2, 1, 3, 2 and then that matches our stream-out'd buffer.
      //
      // Note that there could also be gaps, like: 500, 501, 502, 510, 511, 512
      // which would become 0, 1, 2, 3, 4, 5 and so the old index buffer would no longer be valid.
      // We just stream-out a tightly packed list of unique indices, and then remap the index buffer
      // so that what did point to 500 points to 0 (accounting for rebasing), and what did point
      // to 510 now points to 3 (accounting for the unique sort).
  
      // we use a map here since the indices may be sparse. Especially considering if an index
      // is 'invalid' like 0xcccccccc then we don't want an array of 3.4 billion entries.
      std::map<uint32_t, size_t> indexRemap;
      for(size_t i = 0; i < indices.size(); i++)
      {
        // by definition, this index will only appear once in indices[]
        indexRemap[indices[i]] = i;
      }
  
      // create buffer with unique 0-based indices
      VkBufferCreateInfo bufInfo = {
          VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
          NULL,
          0,
          indices.size() * sizeof(uint32_t),
          VK_BUFFER_USAGE_STORAGE_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_SRC_BIT,
      };
  
      // the flag is the same for KHR and EXT
      if(storageMode != Binding)
        bufInfo.usage |= VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT;
  
      vkr = m_pDriver->vkCreateBuffer(dev, &bufInfo, NULL, &uniqIdxBuf);
      CheckVkResult(vkr);
  
      uniqIdxBufDescriptor.buffer = uniqIdxBuf;
      uniqIdxBufDescriptor.offset = 0;
      uniqIdxBufDescriptor.range = VK_WHOLE_SIZE;
  
      VkMemoryRequirements mrq = {0};
      m_pDriver->vkGetBufferMemoryRequirements(dev, uniqIdxBuf, &mrq);
  
      VkMemoryAllocateInfo allocInfo = {
          VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO, NULL, mrq.size,
          m_pDriver->GetUploadMemoryIndex(mrq.memoryTypeBits),
      };
  
      if(storageMode == KHR_bda)
        allocInfo.pNext = &memFlags;
  
      vkr = m_pDriver->vkAllocateMemory(dev, &allocInfo, NULL, &uniqIdxBufMem);
  
      if(vkr == VK_ERROR_OUT_OF_DEVICE_MEMORY || vkr == VK_ERROR_OUT_OF_HOST_MEMORY)
      {
        RDCWARN("Failed to allocate %llu bytes for unique index buffer", mrq.size);
        return;
      }
  
      CheckVkResult(vkr);
  
      vkr = m_pDriver->vkBindBufferMemory(dev, uniqIdxBuf, uniqIdxBufMem, 0);
      CheckVkResult(vkr);
  
      byte *idxData = NULL;
      vkr = m_pDriver->vkMapMemory(m_Device, uniqIdxBufMem, 0, VK_WHOLE_SIZE, 0, (void **)&idxData);
      CheckVkResult(vkr);
      if(vkr != VK_SUCCESS)
        return;
  
      memcpy(idxData, &indices[0], indices.size() * sizeof(uint32_t));
  
      VkMappedMemoryRange range = {
          VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE, NULL, uniqIdxBufMem, 0, VK_WHOLE_SIZE,
      };
  
      vkr = m_pDriver->vkFlushMappedMemoryRanges(m_Device, 1, &range);
      CheckVkResult(vkr);
  
      m_pDriver->vkUnmapMemory(m_Device, uniqIdxBufMem);
  
      // rebase existing index buffer to point to the right elements in our stream-out'd
      // vertex buffer
      for(uint32_t i = 0; i < numIndices; i++)
      {
        uint32_t i32 = 0;
        if(idx32)
          i32 = idx32[i];
        else if(idx16)
          i32 = uint32_t(idx16[i]);
        else if(idx8)
          i32 = uint32_t(idx8[i]);
  
        // preserve primitive restart indices
        if(restart && i32 == (0xffffffff >> ((4 - idxsize) * 8)))
          continue;
  
        // apply baseVertex but clamp to 0 (don't allow index to become negative)
        if(i32 < idxclamp)
          i32 = 0;
        else if(action->baseVertex < 0)
          i32 -= idxclamp;
        else if(action->baseVertex > 0)
          i32 += action->baseVertex;
  
        if(idx32)
          idx32[i] = uint32_t(indexRemap[i32]);
        else if(idx16)
          idx16[i] = uint16_t(indexRemap[i32]);
        else if(idx8)
          idx8[i] = uint8_t(indexRemap[i32]);
      }
  
      bufInfo.size = RDCMAX((VkDeviceSize)64, (VkDeviceSize)idxdata.size());
      bufInfo.usage = VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
  
      vkr = m_pDriver->vkCreateBuffer(dev, &bufInfo, NULL, &rebasedIdxBuf);
      CheckVkResult(vkr);
  
      m_pDriver->vkGetBufferMemoryRequirements(dev, rebasedIdxBuf, &mrq);
  
      allocInfo.allocationSize = mrq.size;
      allocInfo.memoryTypeIndex = m_pDriver->GetUploadMemoryIndex(mrq.memoryTypeBits);
  
      vkr = m_pDriver->vkAllocateMemory(dev, &allocInfo, NULL, &rebasedIdxBufMem);
  
      if(vkr == VK_ERROR_OUT_OF_DEVICE_MEMORY || vkr == VK_ERROR_OUT_OF_HOST_MEMORY)
      {
        RDCWARN("Failed to allocate %llu bytes for rebased index buffer", mrq.size);
        return;
      }
  
      CheckVkResult(vkr);
  
      vkr = m_pDriver->vkBindBufferMemory(dev, rebasedIdxBuf, rebasedIdxBufMem, 0);
      CheckVkResult(vkr);
  
      vkr = m_pDriver->vkMapMemory(m_Device, rebasedIdxBufMem, 0, VK_WHOLE_SIZE, 0, (void **)&idxData);
      CheckVkResult(vkr);
      if(vkr != VK_SUCCESS)
        return;
  
      memcpy(idxData, idxdata.data(), idxdata.size());
  
      VkMappedMemoryRange rebasedRange = {
          VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE, NULL, rebasedIdxBufMem, 0, VK_WHOLE_SIZE,
      };
  
      vkr = m_pDriver->vkFlushMappedMemoryRanges(m_Device, 1, &rebasedRange);
      CheckVkResult(vkr);
  
      m_pDriver->vkUnmapMemory(m_Device, rebasedIdxBufMem);
    }
  
    uint32_t baseSpecConstant = 0;
  
    bytebuf specData;
    rdcarray<VkSpecializationMapEntry> specEntries;
  
    // copy over specialization info
    for(uint32_t s = 0; s < pipeCreateInfo.stageCount; s++)
    {
      if(pipeCreateInfo.pStages[s].stage == VK_SHADER_STAGE_VERTEX_BIT)
      {
        if(pipeCreateInfo.pStages[s].pSpecializationInfo)
        {
          specData.assign((const byte *)pipeCreateInfo.pStages[s].pSpecializationInfo->pData,
                          pipeCreateInfo.pStages[s].pSpecializationInfo->dataSize);
          specEntries.assign(pipeCreateInfo.pStages[s].pSpecializationInfo->pMapEntries,
                             pipeCreateInfo.pStages[s].pSpecializationInfo->mapEntryCount);
        }
        break;
      }
    }
  
    // don't overlap with existing pipeline constants
    for(const VkSpecializationMapEntry &specConst : specEntries)
      baseSpecConstant = RDCMAX(baseSpecConstant, specConst.constantID + 1);
  
    uint32_t bufStride = 0;
    rdcarray<uint32_t> modSpirv = moduleInfo.spirv.GetSPIRV();
  
    struct CompactedAttrBuffer
    {
      VkDeviceMemory mem;
      VkBuffer buf;
      VkDescriptorBufferInfo descriptor;
    };
  
    rdcarray<uint32_t> attrInstDivisor;
    rdcarray<CompactedAttrBuffer> vbuffers(MeshOutputBufferArraySize);
  
    {
      rdcarray<VkWriteDescriptorSet> descWrites(MeshOutputBufferArraySize);
      uint32_t numWrites = 0;
  
      const VkPipelineVertexInputStateCreateInfo *vi = pipeCreateInfo.pVertexInputState;
  
      RDCASSERT(vi->vertexAttributeDescriptionCount <= MeshOutputBufferArraySize);
  
      // we fetch the vertex buffer data up front here since there's a very high chance of either
      // overlap due to interleaved attributes, or no overlap and no wastage due to separate compact
      // attributes.
      rdcarray<bytebuf> origVBs;
      origVBs.reserve(16);
  
      for(uint32_t vb = 0; vb < vi->vertexBindingDescriptionCount; vb++)
      {
        uint32_t binding = vi->pVertexBindingDescriptions[vb].binding;
        if(binding >= state.vbuffers.size())
        {
          origVBs.push_back(bytebuf());
          continue;
        }
  
        VkDeviceSize offs = state.vbuffers[binding].offs;
        VkDeviceSize stride = state.vbuffers[binding].stride;
        uint64_t len = 0;
  
        if(vi->pVertexBindingDescriptions[vb].inputRate == VK_VERTEX_INPUT_RATE_INSTANCE)
        {
          len = (uint64_t(maxInstance) + 1) * stride;
  
          offs += action->instanceOffset * stride;
        }
        else
        {
          len = (uint64_t(maxIndex) + 1) * stride;
  
          offs += action->vertexOffset * stride;
        }
  
        len = RDCMIN(len, state.vbuffers[binding].size);
  
        origVBs.push_back(bytebuf());
        if(state.vbuffers[binding].buf != ResourceId())
          GetBufferData(state.vbuffers[binding].buf, offs, len, origVBs.back());
      }
  
      for(uint32_t i = 0; i < vi->vertexAttributeDescriptionCount; i++)
      {
        const VkVertexInputAttributeDescription &attrDesc = vi->pVertexAttributeDescriptions[i];
        uint32_t attr = attrDesc.location;
  
        RDCASSERT(attr < 64);
        if(attr >= vbuffers.size())
        {
          RDCERR("Attribute index too high! Resize array.");
          continue;
        }
  
        uint32_t instDivisor = ~0U;
        size_t stride = 1;
  
        const byte *origVBBegin = NULL;
        const byte *origVBEnd = NULL;
  
        for(uint32_t vb = 0; vb < vi->vertexBindingDescriptionCount; vb++)
        {
          const VkVertexInputBindingDescription &vbDesc = vi->pVertexBindingDescriptions[vb];
          if(vbDesc.binding == attrDesc.binding)
          {
            origVBBegin = origVBs[vb].data() + attrDesc.offset;
            origVBEnd = origVBs[vb].data() + origVBs[vb].size();
  
            if(origVBs[vb].empty())
              origVBBegin = origVBEnd = NULL;
  
            stride = vbDesc.stride;
            if(vbDesc.inputRate == VK_VERTEX_INPUT_RATE_INSTANCE)
              instDivisor = pipeInfo.vertexBindings[vbDesc.binding].instanceDivisor;
            else
              instDivisor = ~0U;
            break;
          }
        }
  
        if(attrDesc.binding < state.vbuffers.size())
          stride = (size_t)state.vbuffers[attrDesc.binding].stride;
  
        // in some limited cases, provided we added the UNIFORM_TEXEL_BUFFER usage bit, we could use
        // the original buffers here as-is and read out of them. However it is likely that the offset
        // is not a multiple of the minimum texel buffer offset for at least some of the buffers if
        // not all of them, so we simplify the code here by *always* reading back the vertex buffer
        // data and uploading a compacted version.
  
        // we also need to handle the case where the format is not natively supported as a texel
        // buffer.
  
        // we used to use expanded texel buffers (i.e. expand to uint4, float4, int4 etc from any
        // smaller format) but since we want to support buffer_device_address to avoid descriptor
        // patching entirely it's easier to have an SSBO-based path. For that reason we only upload
        // this data as 16-byte strided data and read it out of a uint4[] then bitcast to int4 or
        // float4. That way the uint4[] SSBO can be easily substituted for a buffer device address
        VkFormat origFormat = attrDesc.format;
        VkFormat expandedFormat = VK_FORMAT_R32G32B32A32_SFLOAT;
  
        if(IsDoubleFormat(origFormat))
          expandedFormat = VK_FORMAT_R32G32B32A32_UINT;
        else if(IsUIntFormat(origFormat))
          expandedFormat = VK_FORMAT_R32G32B32A32_UINT;
        else if(IsSIntFormat(origFormat))
          expandedFormat = VK_FORMAT_R32G32B32A32_SINT;
  
        uint32_t origElemSize = GetByteSize(1, 1, 1, origFormat, 0);
        uint32_t elemSize = GetByteSize(1, 1, 1, expandedFormat, 0);
  
        // doubles are packed as uvec2
        if(IsDoubleFormat(origFormat))
          elemSize *= 2;
  
        // used for interpreting the original data, if we're upcasting
        ResourceFormat fmt = MakeResourceFormat(origFormat);
  
        {
          VkBufferCreateInfo bufInfo = {
              VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
              NULL,
              0,
              elemSize * (maxIndex + 1),
              VK_BUFFER_USAGE_STORAGE_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_SRC_BIT,
          };
  
          if(instDivisor != ~0U)
            bufInfo.size = elemSize * (maxInstance + 1);
  
          // the flag is the same for KHR and EXT
          if(storageMode != Binding)
            bufInfo.usage |= VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT;
  
          vkr = m_pDriver->vkCreateBuffer(dev, &bufInfo, NULL, &vbuffers[attr].buf);
          CheckVkResult(vkr);
  
          VkMemoryRequirements mrq = {0};
          m_pDriver->vkGetBufferMemoryRequirements(dev, vbuffers[attr].buf, &mrq);
  
          VkMemoryAllocateInfo allocInfo = {
              VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO, NULL, mrq.size,
              m_pDriver->GetUploadMemoryIndex(mrq.memoryTypeBits),
          };
  
          if(storageMode == KHR_bda)
            allocInfo.pNext = &memFlags;
  
          vkr = m_pDriver->vkAllocateMemory(dev, &allocInfo, NULL, &vbuffers[attr].mem);
  
          if(vkr == VK_ERROR_OUT_OF_DEVICE_MEMORY || vkr == VK_ERROR_OUT_OF_HOST_MEMORY)
          {
            RDCWARN("Failed to allocate %llu bytes for patched vertex buffer", mrq.size);
            return;
          }
  
          CheckVkResult(vkr);
  
          vkr = m_pDriver->vkBindBufferMemory(dev, vbuffers[attr].buf, vbuffers[attr].mem, 0);
          CheckVkResult(vkr);
  
          byte *dst = NULL;
          vkr =
              m_pDriver->vkMapMemory(m_Device, vbuffers[attr].mem, 0, VK_WHOLE_SIZE, 0, (void **)&dst);
          CheckVkResult(vkr);
          if(vkr != VK_SUCCESS)
            return;
  
          const byte *dstBase = dst;
          (void)dstBase;
  
          const byte *dstEnd = dst + bufInfo.size;
  
          if(dst)
          {
            FloatVector defaultValue(0.0f, 0.0f, 0.0f, 1.0f);
            if(fmt.compType == CompType::UInt || fmt.compType == CompType::SInt || fmt.compCount == 4)
              defaultValue.w = 0.0f;
  
            const byte *src = origVBBegin;
  
            // fast memcpy compaction case for regular 32-bit types. Any type like R32G32B32 or so on
            // can be memcpy'd into place and read, since we discard any unused components and there's
            // no re-interpretation needed.
            if(fmt.type == ResourceFormatType::Regular && fmt.compByteWidth == 4)
            {
              size_t expandedComponentBytes = sizeof(FloatVector) - origElemSize;
  
              while(src < origVBEnd && dst < dstEnd)
              {
                if(expandedComponentBytes > 0)
                  memcpy(dst + origElemSize, ((byte *)&defaultValue) + origElemSize,
                         expandedComponentBytes);
                memcpy(dst, src, origElemSize);
  
                // advance by the *destination* element size of 16 bytes
                dst += elemSize;
                src += stride;
              }
  
              // fill the rest with default values
              while(dst < dstEnd)
              {
                memcpy(dst, &defaultValue, sizeof(FloatVector));
                dst += elemSize;
              }
            }
            else
            {
              uint32_t zero = 0;
  
              // upcasting path
              if(IsDoubleFormat(origFormat))
              {
                while(src < origVBEnd && dst < dstEnd)
                {
                  // the double is already in "packed uvec2" order, with least significant 32-bits
                  // first, so we can copy directly
                  memcpy(dst, src, sizeof(double) * fmt.compCount);
                  dst += sizeof(double) * fmt.compCount;
  
                  // fill up to *8* zeros not 4, since we're filling two for every component
                  for(uint8_t c = fmt.compCount * 2; c < 8; c++)
                  {
                    memcpy(dst, &zero, sizeof(uint32_t));
                    dst += sizeof(uint32_t);
                  }
  
                  src += stride;
                }
              }
              else if(IsUIntFormat(expandedFormat))
              {
                while(src < origVBEnd && dst < dstEnd)
                {
                  uint32_t val = 0;
  
                  const byte *s = src;
  
                  uint8_t c = 0;
                  for(; c < fmt.compCount; c++)
                  {
                    if(fmt.compByteWidth == 1)
                      val = *s;
                    else if(fmt.compByteWidth == 2)
                      val = *(uint16_t *)s;
                    else if(fmt.compByteWidth == 4)
                      val = *(uint32_t *)s;
  
                    memcpy(dst, &val, sizeof(uint32_t));
                    dst += sizeof(uint32_t);
                    s += fmt.compByteWidth;
                  }
  
                  for(; c < 4; c++)
                  {
                    memcpy(dst, &zero, sizeof(uint32_t));
                    dst += sizeof(uint32_t);
                  }
  
                  src += stride;
                }
              }
              else if(IsSIntFormat(expandedFormat))
              {
                while(src < origVBEnd && dst < dstEnd)
                {
                  int32_t val = 0;
  
                  const byte *s = src;
  
                  uint8_t c = 0;
                  for(; c < fmt.compCount; c++)
                  {
                    if(fmt.compByteWidth == 1)
                      val = *(int8_t *)s;
                    else if(fmt.compByteWidth == 2)
                      val = *(int16_t *)s;
                    else if(fmt.compByteWidth == 4)
                      val = *(int32_t *)s;
  
                    memcpy(dst, &val, sizeof(int32_t));
                    dst += sizeof(int32_t);
                    s += fmt.compByteWidth;
                  }
  
                  for(; c < 4; c++)
                  {
                    memcpy(dst, &zero, sizeof(uint32_t));
                    dst += sizeof(uint32_t);
                  }
  
                  src += stride;
                }
              }
              else
              {
                while(src < origVBEnd && dst < dstEnd)
                {
                  bool valid = false;
                  FloatVector vec = HighlightCache::InterpretVertex(src, 0, 0, fmt, origVBEnd, valid);
  
                  memcpy(dst, &vec, sizeof(FloatVector));
                  dst += sizeof(FloatVector);
                  src += stride;
                }
  
                // fill the rest with default values
                while(dst < dstEnd)
                {
                  memcpy(dst, &defaultValue, sizeof(FloatVector));
                  dst += elemSize;
                }
              }
            }
          }
  
          VkMappedMemoryRange range = {
              VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE, NULL, vbuffers[attr].mem, 0, VK_WHOLE_SIZE,
          };
  
          vkr = m_pDriver->vkFlushMappedMemoryRanges(m_Device, 1, &range);
          CheckVkResult(vkr);
  
          m_pDriver->vkUnmapMemory(m_Device, vbuffers[attr].mem);
        }
  
        attrInstDivisor.resize(RDCMAX(attrInstDivisor.size(), size_t(attr + 1)));
        attrInstDivisor[attr] = instDivisor;
  
        vbuffers[attr].descriptor.buffer = vbuffers[attr].buf;
        vbuffers[attr].descriptor.offset = 0;
        vbuffers[attr].descriptor.range = VK_WHOLE_SIZE;
  
        if(!descSets.empty())
        {
          descWrites[numWrites].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
          descWrites[numWrites].dstSet = descSets[0];
          descWrites[numWrites].dstBinding = 2;
          descWrites[numWrites].dstArrayElement = attr;
          descWrites[numWrites].descriptorCount = 1;
          descWrites[numWrites].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
          descWrites[numWrites].pBufferInfo = &vbuffers[attr].descriptor;
          numWrites++;
        }
      }
  
      // add a write of the index buffer
      if(uniqIdxBuf != VK_NULL_HANDLE && !descSets.empty())
      {
        descWrites[numWrites].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
        descWrites[numWrites].dstSet = descSets[0];
        descWrites[numWrites].dstBinding = 1;
        descWrites[numWrites].dstArrayElement = 0;
        descWrites[numWrites].descriptorCount = 1;
        descWrites[numWrites].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;
        descWrites[numWrites].pBufferInfo = &uniqIdxBufDescriptor;
        numWrites++;
      }
  
      if(numWrites > 0)
        m_pDriver->vkUpdateDescriptorSets(dev, numWrites, descWrites.data(), 0, NULL);
    }
  
    if(!Vulkan_Debug_PostVSDumpDirPath().empty())
      FileIO::WriteAll(Vulkan_Debug_PostVSDumpDirPath() + "/debug_postvs_vert.spv", modSpirv);
  
    ConvertToMeshOutputCompute(*refl, *pipeInfo.shaders[0].patchData,
                               pipeInfo.shaders[0].entryPoint.c_str(), storageMode, attrInstDivisor,
                               action, numVerts, numViews, baseSpecConstant, modSpirv, bufStride);
  
    if(!Vulkan_Debug_PostVSDumpDirPath().empty())
      FileIO::WriteAll(Vulkan_Debug_PostVSDumpDirPath() + "/debug_postvs_comp.spv", modSpirv);
  
    {
      // now that we know the stride, create buffer of sufficient size
      // this can't just be bufStride * num unique indices per instance, as we don't
      // have a compact 0-based index to index into the buffer. We must use
      // index-minIndex which is 0-based but potentially sparse, so this buffer may
      // be more or less wasteful
      VkBufferCreateInfo bufInfo = {VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO};
  
      // set bufSize
      bufSize = bufInfo.size = uint64_t(numVerts) * uint64_t(action->numInstances) *
                               uint64_t(bufStride) * uint64_t(numViews);
  
      bufInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
      bufInfo.usage |= VK_BUFFER_USAGE_TRANSFER_DST_BIT;
      bufInfo.usage |= VK_BUFFER_USAGE_STORAGE_BUFFER_BIT;
      bufInfo.usage |= VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
  
      // the flag is the same for KHR and EXT
      if(storageMode != Binding)
        bufInfo.usage |= VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT;
  
      vkr = m_pDriver->vkCreateBuffer(dev, &bufInfo, NULL, &meshBuffer);
      CheckVkResult(vkr);
  
      bufInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
  
      vkr = m_pDriver->vkCreateBuffer(dev, &bufInfo, NULL, &readbackBuffer);
      CheckVkResult(vkr);
  
      VkMemoryRequirements mrq = {0};
      m_pDriver->vkGetBufferMemoryRequirements(dev, meshBuffer, &mrq);
  
      VkMemoryAllocateInfo allocInfo = {
          VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO, NULL, mrq.size,
          m_pDriver->GetGPULocalMemoryIndex(mrq.memoryTypeBits),
      };
  
      if(storageMode == KHR_bda)
        allocInfo.pNext = &memFlags;
  
      vkr = m_pDriver->vkAllocateMemory(dev, &allocInfo, NULL, &meshMem);
  
      if(vkr == VK_ERROR_OUT_OF_DEVICE_MEMORY || vkr == VK_ERROR_OUT_OF_HOST_MEMORY)
      {
        RDCWARN("Failed to allocate %llu bytes for output vertex SSBO", mrq.size);
        return;
      }
  
      CheckVkResult(vkr);
  
      vkr = m_pDriver->vkBindBufferMemory(dev, meshBuffer, meshMem, 0);
      CheckVkResult(vkr);
  
      m_pDriver->vkGetBufferMemoryRequirements(dev, readbackBuffer, &mrq);
  
      allocInfo.pNext = NULL;
      allocInfo.memoryTypeIndex = m_pDriver->GetReadbackMemoryIndex(mrq.memoryTypeBits);
  
      vkr = m_pDriver->vkAllocateMemory(dev, &allocInfo, NULL, &readbackMem);
  
      if(vkr == VK_ERROR_OUT_OF_DEVICE_MEMORY || vkr == VK_ERROR_OUT_OF_HOST_MEMORY)
      {
        RDCWARN("Failed to allocate %llu bytes for readback memory", mrq.size);
        return;
      }
  
      CheckVkResult(vkr);
  
      vkr = m_pDriver->vkBindBufferMemory(dev, readbackBuffer, readbackMem, 0);
      CheckVkResult(vkr);
    }
  
    VkComputePipelineCreateInfo compPipeInfo = {VK_STRUCTURE_TYPE_COMPUTE_PIPELINE_CREATE_INFO};
  
    // repoint pipeline layout
    compPipeInfo.layout = pipeLayout;
  
    // create vertex shader with modified code
    VkShaderModuleCreateInfo moduleCreateInfo = {
        VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO, NULL,         0,
        modSpirv.size() * sizeof(uint32_t),          &modSpirv[0],
    };
  
    VkShaderModule module;
    vkr = m_pDriver->vkCreateShaderModule(dev, &moduleCreateInfo, NULL, &module);
    CheckVkResult(vkr);
  
    compPipeInfo.stage.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
    compPipeInfo.stage.module = module;
    compPipeInfo.stage.pName = PatchedMeshOutputEntryPoint;
    compPipeInfo.stage.stage = VK_SHADER_STAGE_COMPUTE_BIT;
  
    // append our own if we're using BDA
    if(storageMode != Binding)
    {
      // ensure we're 64-bit aligned first
      specData.resize(AlignUp(specData.size(), (size_t)8));
  
      uint32_t baseOffset = (uint32_t)specData.size();
  
      rdcarray<uint64_t> addresses(MeshOutputBufferArraySize + 2);
  
      for(uint32_t i = 0; i <= MeshOutputBufferArraySize + 1; i++)
      {
        RDCCOMPILE_ASSERT(VK_STRUCTURE_TYPE_BUFFER_DEVICE_ADDRESS_INFO ==
                              VK_STRUCTURE_TYPE_BUFFER_DEVICE_ADDRESS_INFO_EXT,
                          "KHR and EXT buffer_device_address should be interchangeable here.");
        VkBufferDeviceAddressInfo getAddressInfo = {VK_STRUCTURE_TYPE_BUFFER_DEVICE_ADDRESS_INFO};
  
        if(i < MeshOutputBufferArraySize)
          getAddressInfo.buffer = vbuffers[i].buf;
        else if(i == MeshOutputBufferArraySize)
          getAddressInfo.buffer = uniqIdxBuf;
        else if(i == MeshOutputBufferArraySize + 1)
          getAddressInfo.buffer = meshBuffer;
  
        // skip
        if(getAddressInfo.buffer == VK_NULL_HANDLE)
          continue;
  
        if(storageMode == KHR_bda)
          addresses[i] = m_pDriver->vkGetBufferDeviceAddress(dev, &getAddressInfo);
        else
          addresses[i] = m_pDriver->vkGetBufferDeviceAddressEXT(dev, &getAddressInfo);
  
        VkSpecializationMapEntry entry;
        entry.offset = baseOffset + i * sizeof(uint64_t);
        entry.constantID = baseSpecConstant + i * 2 + 0;
  
        // for EXT we have one 64-bit spec constant per address, for KHR we have a uvec2 - two
        // constants
        if(storageMode == EXT_bda)
        {
          entry.size = sizeof(uint64_t);
          specEntries.push_back(entry);
        }
        else
        {
          entry.size = sizeof(uint32_t);
          specEntries.push_back(entry);
  
          entry.offset += sizeof(uint32_t);
          entry.constantID++;
  
          entry.size = sizeof(uint32_t);
          specEntries.push_back(entry);
        }
      }
  
      specData.append((const byte *)addresses.data(), addresses.byteSize());
    }
  
    VkSpecializationInfo specInfo = {};
    specInfo.dataSize = specData.size();
    specInfo.pData = specData.data();
    specInfo.mapEntryCount = (uint32_t)specEntries.size();
    specInfo.pMapEntries = specEntries.data();
  
    compPipeInfo.stage.pSpecializationInfo = &specInfo;
  
    // create new pipeline
    VkPipeline pipe;
    vkr = m_pDriver->vkCreateComputePipelines(m_Device, VK_NULL_HANDLE, 1, &compPipeInfo, NULL, &pipe);
  
    if(vkr != VK_SUCCESS)
    {
      RDCERR("Failed to create patched compute pipeline: %s", ToStr(vkr).c_str());
      return;
    }
  
    // make copy of state to draw from
    VulkanRenderState modifiedstate = state;
  
    // bind created pipeline to partial replay state
    modifiedstate.compute.pipeline = GetResID(pipe);
  
    // move graphics descriptor sets onto the compute pipe.
    modifiedstate.compute.descSets = modifiedstate.graphics.descSets;
  
    if(!descSets.empty())
    {
      // replace descriptor set IDs with our temporary sets. The offsets we keep the same. If the
      // original draw had no sets, we ensure there's room (with no offsets needed)
      if(modifiedstate.compute.descSets.empty())
        modifiedstate.compute.descSets.resize(1);
  
      for(size_t i = 0; i < descSets.size(); i++)
      {
        modifiedstate.compute.descSets[i].pipeLayout = GetResID(pipeLayout);
        modifiedstate.compute.descSets[i].descSet = GetResID(descSets[i]);
      }
    }
    else
    {
      for(size_t i = 0; i < modifiedstate.compute.descSets.size(); i++)
        modifiedstate.compute.descSets[i].pipeLayout = GetResID(pipeLayout);
    }
  
    {
      VkCommandBuffer cmd = m_pDriver->GetNextCmd();
  
      if(cmd == VK_NULL_HANDLE)
        return;
  
      VkCommandBufferBeginInfo beginInfo = {VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO, NULL,
                                            VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT};
  
      vkr = ObjDisp(dev)->BeginCommandBuffer(Unwrap(cmd), &beginInfo);
      CheckVkResult(vkr);
  
      // fill destination buffer with 0s to ensure unwritten vertices have sane data
      ObjDisp(dev)->CmdFillBuffer(Unwrap(cmd), Unwrap(meshBuffer), 0, bufSize, 0);
  
      VkBufferMemoryBarrier meshbufbarrier = {
          VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER,
          NULL,
          VK_ACCESS_TRANSFER_WRITE_BIT | VK_ACCESS_HOST_WRITE_BIT,
          VK_ACCESS_SHADER_READ_BIT | VK_ACCESS_SHADER_WRITE_BIT,
          VK_QUEUE_FAMILY_IGNORED,
          VK_QUEUE_FAMILY_IGNORED,
      };
  
      meshbufbarrier.size = VK_WHOLE_SIZE;
  
      VkMemoryBarrier globalbarrier = {
          VK_STRUCTURE_TYPE_MEMORY_BARRIER, NULL,
          VK_ACCESS_TRANSFER_WRITE_BIT | VK_ACCESS_HOST_WRITE_BIT,
          VK_ACCESS_SHADER_READ_BIT | VK_ACCESS_SHADER_WRITE_BIT,
      };
  
      // wait for uploads of index buffer (if used), compacted vertex buffers, and the above fill to
      // finish.
      DoPipelineBarrier(cmd, 1, &globalbarrier);
  
      // vkUpdateDescriptorSet desc set to point to buffer
      VkDescriptorBufferInfo fetchdesc = {0};
      fetchdesc.buffer = meshBuffer;
      fetchdesc.offset = 0;
      fetchdesc.range = bufSize;
  
      if(!descSets.empty())
      {
        VkWriteDescriptorSet write = {
            VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET, NULL, descSets[0], 0,   0, 1,
            VK_DESCRIPTOR_TYPE_STORAGE_BUFFER,      NULL, &fetchdesc,  NULL};
        m_pDriver->vkUpdateDescriptorSets(dev, 1, &write, 0, NULL);
      }
  
      // do single draw
      modifiedstate.BindPipeline(m_pDriver, cmd, VulkanRenderState::BindCompute, true);
      uint64_t totalVerts = numVerts * uint64_t(action->numInstances) * uint64_t(numViews);
  
      // the validation layers will probably complain about this dispatch saying some arrays aren't
      // fully updated. That's because they don't statically analyse that only fixed indices are
      // referred to. It's safe to leave unused array indices as invalid descriptors.
      ObjDisp(cmd)->CmdDispatch(Unwrap(cmd), uint32_t(totalVerts / MeshOutputDispatchWidth) + 1, 1, 1);
  
      // wait for mesh output writing to finish
      meshbufbarrier.buffer = Unwrap(meshBuffer);
      meshbufbarrier.size = bufSize;
      meshbufbarrier.srcAccessMask = VK_ACCESS_SHADER_WRITE_BIT;
      meshbufbarrier.dstAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
  
      DoPipelineBarrier(cmd, 1, &meshbufbarrier);
  
      VkBufferCopy bufcopy = {
          0, 0, bufSize,
      };
  
      // copy to readback buffer
      ObjDisp(dev)->CmdCopyBuffer(Unwrap(cmd), Unwrap(meshBuffer), Unwrap(readbackBuffer), 1, &bufcopy);
  
      meshbufbarrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
      meshbufbarrier.dstAccessMask = VK_ACCESS_HOST_READ_BIT;
      meshbufbarrier.buffer = Unwrap(readbackBuffer);
  
      // wait for copy to finish
      DoPipelineBarrier(cmd, 1, &meshbufbarrier);
  
      vkr = ObjDisp(dev)->EndCommandBuffer(Unwrap(cmd));
      CheckVkResult(vkr);
  
      // submit & flush so that we don't have to keep pipeline around for a while
      m_pDriver->SubmitCmds();
      m_pDriver->FlushQ();
    }
  
    for(CompactedAttrBuffer attrBuf : vbuffers)
    {
      m_pDriver->vkDestroyBuffer(dev, attrBuf.buf, NULL);
      m_pDriver->vkFreeMemory(dev, attrBuf.mem, NULL);
    }
  
    // readback mesh data
    byte *byteData = NULL;
    vkr = m_pDriver->vkMapMemory(m_Device, readbackMem, 0, VK_WHOLE_SIZE, 0, (void **)&byteData);
    CheckVkResult(vkr);
    if(vkr != VK_SUCCESS)
      return;
  
    VkMappedMemoryRange range = {
        VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE, NULL, readbackMem, 0, VK_WHOLE_SIZE,
    };
  
    vkr = m_pDriver->vkInvalidateMappedMemoryRanges(m_Device, 1, &range);
    CheckVkResult(vkr);
  
    // do near/far calculations
  
    float nearp = 0.1f;
    float farp = 100.0f;
  
    Vec4f *pos0 = (Vec4f *)byteData;
  
    bool found = false;
  
    // expect position at the start of the buffer, as system values are sorted first
    // and position is the first value
  
    for(uint32_t i = 1;
        refl->outputSignature[0].systemValue == ShaderBuiltin::Position && i < numVerts; i++)
    {
      //////////////////////////////////////////////////////////////////////////////////
      // derive near/far, assuming a standard perspective matrix
      //
      // the transformation from from pre-projection {Z,W} to post-projection {Z,W}
      // is linear. So we can say Zpost = Zpre*m + c . Here we assume Wpre = 1
      // and we know Wpost = Zpre from the perspective matrix.
      // we can then see from the perspective matrix that
      // m = F/(F-N)
      // c = -(F*N)/(F-N)
      //
      // with re-arranging and substitution, we then get:
      // N = -c/m
      // F = c/(1-m)
      //
      // so if we can derive m and c then we can determine N and F. We can do this with
      // two points, and we pick them reasonably distinct on z to reduce floating-point
      // error
  
      Vec4f *pos = (Vec4f *)(byteData + i * bufStride);
  
      // skip invalid vertices (w=0)
      if(pos->w != 0.0f && fabs(pos->w - pos0->w) > 0.01f && fabs(pos->z - pos0->z) > 0.01f)
      {
        Vec2f A(pos0->w, pos0->z);
        Vec2f B(pos->w, pos->z);
  
        float m = (B.y - A.y) / (B.x - A.x);
        float c = B.y - B.x * m;
  
        if(m == 1.0f)
          continue;
  
        if(-c / m <= 0.000001f)
          continue;
  
        nearp = -c / m;
        farp = c / (1 - m);
  
        found = true;
  
        break;
      }
    }
  
    // if we didn't find anything, all z's and w's were identical.
    // If the z is positive and w greater for the first element then
    // we detect this projection as reversed z with infinite far plane
    if(!found && pos0->z > 0.0f && pos0->w > pos0->z)
    {
      nearp = pos0->z;
      farp = FLT_MAX;
    }
  
    m_pDriver->vkUnmapMemory(m_Device, readbackMem);
  
    // clean up temporary memories
    m_pDriver->vkDestroyBuffer(m_Device, readbackBuffer, NULL);
    m_pDriver->vkFreeMemory(m_Device, readbackMem, NULL);
  
    if(uniqIdxBuf != VK_NULL_HANDLE)
    {
      m_pDriver->vkDestroyBuffer(m_Device, uniqIdxBuf, NULL);
      m_pDriver->vkFreeMemory(m_Device, uniqIdxBufMem, NULL);
    }
  
    // fill out m_PostVS.Data
    m_PostVS.Data[eventId].vsin.topo = state.primitiveTopology;
    m_PostVS.Data[eventId].vsout.topo = state.primitiveTopology;
    m_PostVS.Data[eventId].vsout.buf = meshBuffer;
    m_PostVS.Data[eventId].vsout.bufmem = meshMem;
  
    m_PostVS.Data[eventId].vsout.baseVertex = 0;
  
    m_PostVS.Data[eventId].vsout.numViews = numViews;
  
    m_PostVS.Data[eventId].vsout.vertStride = bufStride;
    m_PostVS.Data[eventId].vsout.nearPlane = nearp;
    m_PostVS.Data[eventId].vsout.farPlane = farp;
  
    m_PostVS.Data[eventId].vsout.useIndices = bool(action->flags & ActionFlags::Indexed);
    m_PostVS.Data[eventId].vsout.numVerts = action->numIndices;
  
    m_PostVS.Data[eventId].vsout.instStride = 0;
    if(action->flags & ActionFlags::Instanced)
      m_PostVS.Data[eventId].vsout.instStride = uint32_t(bufSize / (action->numInstances * numViews));
  
    m_PostVS.Data[eventId].vsout.idxbuf = VK_NULL_HANDLE;
    if(m_PostVS.Data[eventId].vsout.useIndices && state.ibuffer.buf != ResourceId())
    {
      VkIndexType type = VK_INDEX_TYPE_UINT16;
      if(idxsize == 4)
        type = VK_INDEX_TYPE_UINT32;
      else if(idxsize == 1)
        type = VK_INDEX_TYPE_UINT8_EXT;
  
      m_PostVS.Data[eventId].vsout.idxbuf = rebasedIdxBuf;
      m_PostVS.Data[eventId].vsout.idxbufmem = rebasedIdxBufMem;
      m_PostVS.Data[eventId].vsout.idxFmt = type;
    }
  
    m_PostVS.Data[eventId].vsout.hasPosOut =
        refl->outputSignature[0].systemValue == ShaderBuiltin::Position;
    m_PostVS.Data[eventId].vsout.flipY = state.views.empty() ? false : state.views[0].height < 0.0f;
  
    if(descpool != VK_NULL_HANDLE)
    {
      // delete descriptors. Technically we don't have to free the descriptor sets, but our tracking
      // on replay doesn't handle destroying children of pooled objects so we do it explicitly anyway.
      m_pDriver->vkFreeDescriptorSets(dev, descpool, (uint32_t)descSets.size(), descSets.data());
  
      m_pDriver->vkDestroyDescriptorPool(dev, descpool, NULL);
  
      for(VkDescriptorSetLayout layout : setLayouts)
        m_pDriver->vkDestroyDescriptorSetLayout(dev, layout, NULL);
    }
  
    // delete pipeline layout
    m_pDriver->vkDestroyPipelineLayout(dev, pipeLayout, NULL);
  
    // delete pipeline
    m_pDriver->vkDestroyPipeline(dev, pipe, NULL);
  
    // delete shader/shader module
    m_pDriver->vkDestroyShaderModule(dev, module, NULL);
  }
  
  void VulkanReplay::FetchTessGSOut(uint32_t eventId, VulkanRenderState &state)
  {
    VulkanCreationInfo &creationInfo = m_pDriver->m_CreationInfo;
  
    const VulkanCreationInfo::Pipeline &pipeInfo = creationInfo.m_Pipeline[state.graphics.pipeline];
  
    const ActionDescription *action = m_pDriver->GetAction(eventId);
  
    // set defaults so that we don't try to fetch this output again if something goes wrong and the
    // same event is selected again
    {
      m_PostVS.Data[eventId].gsout.buf = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].gsout.bufmem = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].gsout.instStride = 0;
      m_PostVS.Data[eventId].gsout.vertStride = 0;
      m_PostVS.Data[eventId].gsout.numViews = 1;
      m_PostVS.Data[eventId].gsout.nearPlane = 0.0f;
      m_PostVS.Data[eventId].gsout.farPlane = 0.0f;
      m_PostVS.Data[eventId].gsout.useIndices = false;
      m_PostVS.Data[eventId].gsout.hasPosOut = false;
      m_PostVS.Data[eventId].gsout.flipY = false;
      m_PostVS.Data[eventId].gsout.idxbuf = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].gsout.idxbufmem = VK_NULL_HANDLE;
    }
  
    if(!creationInfo.m_RenderPass[state.renderPass].subpasses[state.subpass].multiviews.empty())
    {
      RDCWARN("Multipass is active for this draw, no GS/Tess mesh output is available");
      return;
    }
  
    // first try geometry stage
    int stageIndex = 3;
  
    // if there is no such shader bound, try tessellation
    if(!pipeInfo.shaders[stageIndex].refl)
      stageIndex = 2;
  
    // if still nothing, do vertex
    if(!pipeInfo.shaders[stageIndex].refl)
      stageIndex = 0;
  
    ShaderReflection *lastRefl = pipeInfo.shaders[stageIndex].refl;
  
    RDCASSERT(lastRefl);
  
    uint32_t primitiveMultiplier = 1;
  
    // transform feedback expands strips to lists
    switch(pipeInfo.shaders[stageIndex].patchData->outTopo)
    {
      case Topology::PointList:
        m_PostVS.Data[eventId].gsout.topo = VK_PRIMITIVE_TOPOLOGY_POINT_LIST;
        break;
      case Topology::LineList:
      case Topology::LineStrip:
        m_PostVS.Data[eventId].gsout.topo = VK_PRIMITIVE_TOPOLOGY_LINE_LIST;
        primitiveMultiplier = 2;
        break;
      default:
        RDCERR("Unexpected output topology %s",
               ToStr(pipeInfo.shaders[stageIndex].patchData->outTopo).c_str());
        DELIBERATE_FALLTHROUGH();
      case Topology::TriangleList:
      case Topology::TriangleStrip:
        m_PostVS.Data[eventId].gsout.topo = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
        primitiveMultiplier = 3;
        break;
    }
  
    if(lastRefl->outputSignature.empty())
    {
      // empty vertex output signature
      m_PostVS.Data[eventId].gsout.buf = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].gsout.bufmem = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].gsout.instStride = 0;
      m_PostVS.Data[eventId].gsout.vertStride = 0;
      m_PostVS.Data[eventId].gsout.numViews = 1;
      m_PostVS.Data[eventId].gsout.nearPlane = 0.0f;
      m_PostVS.Data[eventId].gsout.farPlane = 0.0f;
      m_PostVS.Data[eventId].gsout.useIndices = false;
      m_PostVS.Data[eventId].gsout.hasPosOut = false;
      m_PostVS.Data[eventId].gsout.flipY = false;
      m_PostVS.Data[eventId].gsout.idxbuf = VK_NULL_HANDLE;
      m_PostVS.Data[eventId].gsout.idxbufmem = VK_NULL_HANDLE;
      return;
    }
  
    if(!ObjDisp(m_Device)->CmdBeginTransformFeedbackEXT)
    {
      RDCLOG(
          "VK_EXT_transform_feedback extension not available, can't fetch tessellation/geometry "
          "output");
      return;
    }
  
    const VulkanCreationInfo::ShaderModule &moduleInfo =
        creationInfo.m_ShaderModule[pipeInfo.shaders[stageIndex].module];
  
    rdcarray<uint32_t> modSpirv = moduleInfo.spirv.GetSPIRV();
  
    uint32_t xfbStride = 0;
  
    // adds XFB annotations in order of the output signature (with the position first)
    AddXFBAnnotations(*lastRefl, *pipeInfo.shaders[stageIndex].patchData,
                      pipeInfo.shaders[stageIndex].entryPoint.c_str(), modSpirv, xfbStride);
  
    // create vertex shader with modified code
    VkShaderModuleCreateInfo moduleCreateInfo = {
        VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO, NULL,         0,
        modSpirv.size() * sizeof(uint32_t),          &modSpirv[0],
    };
  
    VkResult vkr = VK_SUCCESS;
    VkDevice dev = m_Device;
  
    VkShaderModule module;
    vkr = m_pDriver->vkCreateShaderModule(dev, &moduleCreateInfo, NULL, &module);
    CheckVkResult(vkr);
  
    VkGraphicsPipelineCreateInfo pipeCreateInfo;
  
    // get pipeline create info
    m_pDriver->GetShaderCache()->MakeGraphicsPipelineInfo(pipeCreateInfo, state.graphics.pipeline);
  
    VkPipelineRasterizationStateCreateInfo *rs =
        (VkPipelineRasterizationStateCreateInfo *)pipeCreateInfo.pRasterizationState;
    rs->rasterizerDiscardEnable = true;
  
    for(uint32_t i = 0; i < pipeCreateInfo.stageCount; i++)
    {
      VkPipelineShaderStageCreateInfo &stage =
          (VkPipelineShaderStageCreateInfo &)pipeCreateInfo.pStages[i];
  
      if(StageIndex(stage.stage) == stageIndex)
      {
        stage.module = module;
        break;
      }
    }
  
    // create a empty renderpass and framebuffer so we can draw
    VkFramebuffer fb = VK_NULL_HANDLE;
    VkRenderPass rp = VK_NULL_HANDLE;
  
    VkSubpassDescription sub = {0, VK_PIPELINE_BIND_POINT_GRAPHICS};
    VkRenderPassCreateInfo rpinfo = {
        VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO, NULL, 0, 0, NULL, 1, &sub,
    };
  
    vkr = m_pDriver->vkCreateRenderPass(m_Device, &rpinfo, NULL, &rp);
    CheckVkResult(vkr);
  
    VkFramebufferCreateInfo fbinfo = {
        VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO, NULL, 0, rp, 0, NULL, 16U, 16U, 1,
    };
  
    vkr = m_pDriver->vkCreateFramebuffer(m_Device, &fbinfo, NULL, &fb);
    CheckVkResult(vkr);
  
    pipeCreateInfo.renderPass = rp;
    pipeCreateInfo.subpass = 0;
  
    VkPipeline pipe = VK_NULL_HANDLE;
    vkr = m_pDriver->vkCreateGraphicsPipelines(m_Device, VK_NULL_HANDLE, 1, &pipeCreateInfo, NULL,
                                               &pipe);
    CheckVkResult(vkr);
  
    state.graphics.pipeline = GetResID(pipe);
    state.SetFramebuffer(m_pDriver, GetResID(fb));
    state.renderPass = GetResID(rp);
    state.subpass = 0;
    state.renderArea.offset.x = 0;
    state.renderArea.offset.y = 0;
    state.renderArea.extent.width = 16;
    state.renderArea.extent.height = 16;
  
    // disable any existing XFB
    state.xfbbuffers.clear();
    state.xfbcounters.clear();
  
    if(m_PostVS.XFBQueryPoolSize < action->numInstances)
    {
      if(m_PostVS.XFBQueryPoolSize != VK_NULL_HANDLE)
        m_pDriver->vkDestroyQueryPool(m_Device, m_PostVS.XFBQueryPool, NULL);
  
      VkQueryPoolCreateInfo info = {
          VK_STRUCTURE_TYPE_QUERY_POOL_CREATE_INFO,
          NULL,
          0,
          VK_QUERY_TYPE_TRANSFORM_FEEDBACK_STREAM_EXT,
          action->numInstances,
          0,
      };
  
      vkr = m_pDriver->vkCreateQueryPool(m_Device, &info, NULL, &m_PostVS.XFBQueryPool);
      CheckVkResult(vkr);
  
      m_PostVS.XFBQueryPoolSize = action->numInstances;
    }
  
    VkBuffer meshBuffer = VK_NULL_HANDLE;
    VkDeviceMemory meshMem = VK_NULL_HANDLE;
  
    // start with bare minimum size, which might be enough if no expansion happens
    VkDeviceSize bufferSize = 0;
    VkDeviceSize dataSize =
        uint64_t(action->numIndices) * uint64_t(action->numInstances) * uint64_t(xfbStride);
  
    VkXfbQueryResult queryResult = {};
  
    while(bufferSize < dataSize)
    {
      bufferSize = dataSize;
  
      if(meshBuffer != VK_NULL_HANDLE)
      {
        m_pDriver->vkDestroyBuffer(dev, meshBuffer, NULL);
        m_pDriver->vkFreeMemory(dev, meshMem, NULL);
  
        meshBuffer = VK_NULL_HANDLE;
        meshMem = VK_NULL_HANDLE;
      }
  
      VkBufferCreateInfo bufInfo = {VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO};
  
      bufInfo.size = bufferSize;
  
      bufInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
      bufInfo.usage |= VK_BUFFER_USAGE_TRANSFER_DST_BIT;
      bufInfo.usage |= VK_BUFFER_USAGE_TRANSFORM_FEEDBACK_BUFFER_BIT_EXT;
      bufInfo.usage |= VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
  
      vkr = m_pDriver->vkCreateBuffer(dev, &bufInfo, NULL, &meshBuffer);
      CheckVkResult(vkr);
  
      VkMemoryRequirements mrq = {0};
      m_pDriver->vkGetBufferMemoryRequirements(dev, meshBuffer, &mrq);
  
      VkMemoryAllocateInfo allocInfo = {
          VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO, NULL, mrq.size,
          m_pDriver->GetGPULocalMemoryIndex(mrq.memoryTypeBits),
      };
  
      vkr = m_pDriver->vkAllocateMemory(dev, &allocInfo, NULL, &meshMem);
  
      if(vkr == VK_ERROR_OUT_OF_DEVICE_MEMORY || vkr == VK_ERROR_OUT_OF_HOST_MEMORY)
      {
        RDCWARN("Output allocation for %llu bytes failed fetching tessellation/geometry output.",
                mrq.size);
  
        m_pDriver->vkDestroyBuffer(dev, meshBuffer, NULL);
  
        // delete framebuffer and renderpass
        m_pDriver->vkDestroyFramebuffer(dev, fb, NULL);
        m_pDriver->vkDestroyRenderPass(dev, rp, NULL);
  
        // delete pipeline
        m_pDriver->vkDestroyPipeline(dev, pipe, NULL);
  
        // delete shader/shader module
        m_pDriver->vkDestroyShaderModule(dev, module, NULL);
        return;
      }
  
      CheckVkResult(vkr);
  
      vkr = m_pDriver->vkBindBufferMemory(dev, meshBuffer, meshMem, 0);
      CheckVkResult(vkr);
  
      VkCommandBuffer cmd = m_pDriver->GetNextCmd();
  
      if(cmd == VK_NULL_HANDLE)
        return;
  
      VkCommandBufferBeginInfo beginInfo = {VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO, NULL,
                                            VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT};
  
      vkr = ObjDisp(dev)->BeginCommandBuffer(Unwrap(cmd), &beginInfo);
      CheckVkResult(vkr);
  
      ObjDisp(dev)->CmdResetQueryPool(Unwrap(cmd), Unwrap(m_PostVS.XFBQueryPool), 0, 1);
  
      // fill destination buffer with 0s to ensure unwritten vertices have sane data
      ObjDisp(dev)->CmdFillBuffer(Unwrap(cmd), Unwrap(meshBuffer), 0, bufInfo.size, 0);
  
      VkBufferMemoryBarrier meshbufbarrier = {
          VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER,
          NULL,
          VK_ACCESS_TRANSFER_WRITE_BIT,
          VK_ACCESS_TRANSFORM_FEEDBACK_WRITE_BIT_EXT,
          VK_QUEUE_FAMILY_IGNORED,
          VK_QUEUE_FAMILY_IGNORED,
          Unwrap(meshBuffer),
          0,
          bufInfo.size,
      };
  
      // wait for the above fill to finish.
      DoPipelineBarrier(cmd, 1, &meshbufbarrier);
  
      state.BeginRenderPassAndApplyState(m_pDriver, cmd, VulkanRenderState::BindGraphics);
  
      ObjDisp(cmd)->CmdBeginQuery(Unwrap(cmd), Unwrap(m_PostVS.XFBQueryPool), 0, 0);
  
      ObjDisp(cmd)->CmdBindTransformFeedbackBuffersEXT(Unwrap(cmd), 0, 1, UnwrapPtr(meshBuffer),
                                                       &meshbufbarrier.offset, &meshbufbarrier.size);
  
      ObjDisp(cmd)->CmdBeginTransformFeedbackEXT(Unwrap(cmd), 0, 1, NULL, NULL);
  
      m_pDriver->ReplayDraw(cmd, *action);
  
      ObjDisp(cmd)->CmdEndTransformFeedbackEXT(Unwrap(cmd), 0, 1, NULL, NULL);
  
      ObjDisp(cmd)->CmdEndQuery(Unwrap(cmd), Unwrap(m_PostVS.XFBQueryPool), 0);
  
      state.EndRenderPass(cmd);
  
      vkr = ObjDisp(dev)->EndCommandBuffer(Unwrap(cmd));
      CheckVkResult(vkr);
  
      m_pDriver->SubmitCmds();
      m_pDriver->FlushQ();
  
      vkr = ObjDisp(dev)->GetQueryPoolResults(
          Unwrap(dev), Unwrap(m_PostVS.XFBQueryPool), 0, 1, sizeof(VkXfbQueryResult), &queryResult,
          sizeof(VkXfbQueryResult), VK_QUERY_RESULT_64_BIT | VK_QUERY_RESULT_WAIT_BIT);
      CheckVkResult(vkr);
  
      VkDeviceSize generatedSize = queryResult.numPrimitivesGenerated * 3 * xfbStride;
  
      // output buffer isn't big enough, delete it and re-run so we recreate it larger
      if(generatedSize > dataSize)
        dataSize = generatedSize;
    }
  
    rdcarray<VulkanPostVSData::InstData> instData;
  
    // instanced draws must be replayed one at a time so we can record the number of primitives from
    // each drawcall, as due to expansion this can vary per-instance.
    if(action->flags & ActionFlags::Instanced && action->numInstances > 1)
    {
      VkCommandBuffer cmd = m_pDriver->GetNextCmd();
  
      if(cmd == VK_NULL_HANDLE)
        return;
  
      VkCommandBufferBeginInfo beginInfo = {VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO, NULL,
                                            VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT};
  
      vkr = ObjDisp(dev)->BeginCommandBuffer(Unwrap(cmd), &beginInfo);
      CheckVkResult(vkr);
  
      ObjDisp(dev)->CmdResetQueryPool(Unwrap(cmd), Unwrap(m_PostVS.XFBQueryPool), 0,
                                      action->numInstances);
  
      state.BeginRenderPassAndApplyState(m_pDriver, cmd, VulkanRenderState::BindGraphics);
  
      ActionDescription act = *action;
  
      // do incremental draws to get the output size. We have to do this O(N^2) style because
      // there's no way to replay only a single instance. We have to replay 1, 2, 3, ... N
      // instances and count the total number of verts each time, then we can see from the
      // difference how much each instance wrote.
      for(uint32_t inst = 1; inst <= action->numInstances; inst++)
      {
        ObjDisp(cmd)->CmdBeginQuery(Unwrap(cmd), Unwrap(m_PostVS.XFBQueryPool), inst - 1, 0);
  
        VkDeviceSize offset = 0;
        ObjDisp(cmd)->CmdBindTransformFeedbackBuffersEXT(Unwrap(cmd), 0, 1, UnwrapPtr(meshBuffer),
                                                         &offset, &bufferSize);
  
        ObjDisp(cmd)->CmdBeginTransformFeedbackEXT(Unwrap(cmd), 0, 1, NULL, NULL);
  
        act.numInstances = inst;
        m_pDriver->ReplayDraw(cmd, act);
  
        ObjDisp(cmd)->CmdEndTransformFeedbackEXT(Unwrap(cmd), 0, 1, NULL, NULL);
  
        ObjDisp(cmd)->CmdEndQuery(Unwrap(cmd), Unwrap(m_PostVS.XFBQueryPool), inst - 1);
      }
  
      state.EndRenderPass(cmd);
  
      vkr = ObjDisp(dev)->EndCommandBuffer(Unwrap(cmd));
      CheckVkResult(vkr);
  
      m_pDriver->SubmitCmds();
      m_pDriver->FlushQ();
  
      rdcarray<VkXfbQueryResult> queryResults;
      queryResults.resize(action->numInstances);
      vkr = ObjDisp(dev)->GetQueryPoolResults(
          Unwrap(dev), Unwrap(m_PostVS.XFBQueryPool), 0, action->numInstances,
          sizeof(VkXfbQueryResult) * action->numInstances, queryResults.data(),
          sizeof(VkXfbQueryResult), VK_QUERY_RESULT_64_BIT | VK_QUERY_RESULT_WAIT_BIT);
      CheckVkResult(vkr);
  
      uint64_t prevVertCount = 0;
  
      for(uint32_t inst = 0; inst < action->numInstances; inst++)
      {
        uint64_t vertCount = queryResults[inst].numPrimitivesWritten * primitiveMultiplier;
  
        VulkanPostVSData::InstData d;
        d.numVerts = uint32_t(vertCount - prevVertCount);
        d.bufOffset = uint32_t(xfbStride * prevVertCount);
        prevVertCount = vertCount;
  
        instData.push_back(d);
      }
    }
  
    float nearp = 0.1f;
    float farp = 100.0f;
  
    Vec4f pos0;
  
    bool found = false;
  
    // we read back the buffer in chunks, since we're likely to find a match in the first few
    // vertices.
  
    VkDeviceSize readbackoffset = 0;
    const VkDeviceSize readbacksize = 1024 * 1024;
  
    while(readbackoffset < bufferSize)
    {
      bytebuf data;
      GetBufferData(GetResID(meshBuffer), readbackoffset, readbacksize, data);
  
      if(data.empty())
        break;
  
      if(readbackoffset == 0)
        memcpy(&pos0, data.data(), sizeof(pos0));
  
      for(uint32_t i = 0; i < data.size() / xfbStride; i++)
      {
        //////////////////////////////////////////////////////////////////////////////////
        // derive near/far, assuming a standard perspective matrix
        //
        // the transformation from from pre-projection {Z,W} to post-projection {Z,W}
        // is linear. So we can say Zpost = Zpre*m + c . Here we assume Wpre = 1
        // and we know Wpost = Zpre from the perspective matrix.
        // we can then see from the perspective matrix that
        // m = F/(F-N)
        // c = -(F*N)/(F-N)
        //
        // with re-arranging and substitution, we then get:
        // N = -c/m
        // F = c/(1-m)
        //
        // so if we can derive m and c then we can determine N and F. We can do this with
        // two points, and we pick them reasonably distinct on z to reduce floating-point
        // error
  
        Vec4f *pos = (Vec4f *)(data.data() + xfbStride * i);
  
        // skip invalid vertices (w=0)
        if(pos->w != 0.0f && fabs(pos->w - pos0.w) > 0.01f && fabs(pos->z - pos0.z) > 0.01f)
        {
          Vec2f A(pos0.w, pos0.z);
          Vec2f B(pos->w, pos->z);
  
          float m = (B.y - A.y) / (B.x - A.x);
          float c = B.y - B.x * m;
  
          if(m == 1.0f)
            continue;
  
          if(-c / m <= 0.000001f)
            continue;
  
          nearp = -c / m;
          farp = c / (1 - m);
  
          found = true;
  
          break;
        }
      }
  
      if(found)
        break;
  
      // read the next segment
      readbackoffset += readbacksize;
    }
  
    // if we didn't find anything, all z's and w's were identical.
    // If the z is positive and w greater for the first element then
    // we detect this projection as reversed z with infinite far plane
    if(!found && pos0.z > 0.0f && pos0.w > pos0.z)
    {
      nearp = pos0.z;
      farp = FLT_MAX;
    }
  
    // fill out m_PostVS.Data
    m_PostVS.Data[eventId].gsout.buf = meshBuffer;
    m_PostVS.Data[eventId].gsout.bufmem = meshMem;
  
    m_PostVS.Data[eventId].gsout.baseVertex = 0;
  
    m_PostVS.Data[eventId].gsout.numViews = 1;
  
    m_PostVS.Data[eventId].gsout.vertStride = xfbStride;
    m_PostVS.Data[eventId].gsout.nearPlane = nearp;
    m_PostVS.Data[eventId].gsout.farPlane = farp;
  
    m_PostVS.Data[eventId].gsout.useIndices = false;
  
    m_PostVS.Data[eventId].gsout.numVerts =
        uint32_t(queryResult.numPrimitivesWritten) * primitiveMultiplier;
  
    // set instance stride to 0. If there's any stride needed, it will be calculated using instData
    m_PostVS.Data[eventId].gsout.instStride = 0;
    m_PostVS.Data[eventId].gsout.instData = instData;
  
    m_PostVS.Data[eventId].gsout.idxbuf = VK_NULL_HANDLE;
    m_PostVS.Data[eventId].gsout.idxbufmem = VK_NULL_HANDLE;
  
    m_PostVS.Data[eventId].gsout.hasPosOut = true;
    m_PostVS.Data[eventId].gsout.flipY = state.views.empty() ? false : state.views[0].height < 0.0f;
  
    // delete framebuffer and renderpass
    m_pDriver->vkDestroyFramebuffer(dev, fb, NULL);
    m_pDriver->vkDestroyRenderPass(dev, rp, NULL);
  
    // delete pipeline
    m_pDriver->vkDestroyPipeline(dev, pipe, NULL);
  
    // delete shader/shader module
    m_pDriver->vkDestroyShaderModule(dev, module, NULL);
  }
  
  void VulkanReplay::InitPostVSBuffers(uint32_t eventId, VulkanRenderState state)
  {
    // go through any aliasing
    if(m_PostVS.Alias.find(eventId) != m_PostVS.Alias.end())
      eventId = m_PostVS.Alias[eventId];
  
    if(m_PostVS.Data.find(eventId) != m_PostVS.Data.end())
      return;
  
    VulkanCreationInfo &creationInfo = m_pDriver->m_CreationInfo;
  
    if(state.graphics.pipeline == ResourceId() || state.renderPass == ResourceId())
      return;
  
    const VulkanCreationInfo::Pipeline &pipeInfo = creationInfo.m_Pipeline[state.graphics.pipeline];
  
    if(pipeInfo.shaders[0].module == ResourceId())
      return;
  
    const ActionDescription *action = m_pDriver->GetAction(eventId);
  
    if(action == NULL || action->numIndices == 0 || action->numInstances == 0)
      return;
  
    VkMarkerRegion::Begin(StringFormat::Fmt("FetchVSOut for %u", eventId));
  
    FetchVSOut(eventId, state);
  
    VkMarkerRegion::End();
  
    // if there's no tessellation or geometry shader active, bail out now
    if(pipeInfo.shaders[2].module == ResourceId() && pipeInfo.shaders[3].module == ResourceId())
      return;
  
    VkMarkerRegion::Begin(StringFormat::Fmt("FetchTessGSOut for %u", eventId));
  
    FetchTessGSOut(eventId, state);
  
    VkMarkerRegion::End();
  }
  
  void VulkanReplay::InitPostVSBuffers(uint32_t eventId)
  {
    InitPostVSBuffers(eventId, m_pDriver->GetRenderState());
  }
  
  struct VulkanInitPostVSCallback : public VulkanActionCallback
  {
    VulkanInitPostVSCallback(WrappedVulkan *vk, const rdcarray<uint32_t> &events)
        : m_pDriver(vk), m_Events(events)
    {
      m_pDriver->SetActionCB(this);
    }
    ~VulkanInitPostVSCallback() { m_pDriver->SetActionCB(NULL); }
    void PreDraw(uint32_t eid, VkCommandBuffer cmd)
    {
      if(m_Events.contains(eid))
        m_pDriver->GetReplay()->InitPostVSBuffers(eid, m_pDriver->GetCmdRenderState());
    }
  
    bool PostDraw(uint32_t eid, VkCommandBuffer cmd) { return false; }
    void PostRedraw(uint32_t eid, VkCommandBuffer cmd) {}
    // Dispatches don't rasterize, so do nothing
    void PreDispatch(uint32_t eid, VkCommandBuffer cmd) {}
    bool PostDispatch(uint32_t eid, VkCommandBuffer cmd) { return false; }
    void PostRedispatch(uint32_t eid, VkCommandBuffer cmd) {}
    // Ditto copy/etc
    void PreMisc(uint32_t eid, ActionFlags flags, VkCommandBuffer cmd) {}
    bool PostMisc(uint32_t eid, ActionFlags flags, VkCommandBuffer cmd) { return false; }
    void PostRemisc(uint32_t eid, ActionFlags flags, VkCommandBuffer cmd) {}
    void PreEndCommandBuffer(VkCommandBuffer cmd) {}
    void AliasEvent(uint32_t primary, uint32_t alias)
    {
      if(m_Events.contains(primary))
        m_pDriver->GetReplay()->AliasPostVSBuffers(primary, alias);
    }
    bool SplitSecondary() { return false; }
    void PreCmdExecute(uint32_t baseEid, uint32_t secondaryFirst, uint32_t secondaryLast,
                       VkCommandBuffer cmd)
    {
    }
    void PostCmdExecute(uint32_t baseEid, uint32_t secondaryFirst, uint32_t secondaryLast,
                        VkCommandBuffer cmd)
    {
    }
  
    WrappedVulkan *m_pDriver;
    const rdcarray<uint32_t> &m_Events;
  };
  
  void VulkanReplay::InitPostVSBuffers(const rdcarray<uint32_t> &events)
  {
    size_t first = 0;
  
    for(; first < events.size(); first++)
    {
      const ActionDescription *action = m_pDriver->GetAction(events[first]);
      if(action->flags & ActionFlags::PassBoundary)
        continue;
      break;
    }
  
    // first we must replay up to the first event without replaying it. This ensures any
    // non-command buffer calls like memory unmaps etc all happen correctly before this
    // command buffer
    m_pDriver->ReplayLog(0, events[first], eReplay_WithoutDraw);
  
    VulkanInitPostVSCallback cb(m_pDriver, events);
  
    // now we replay the events, which are guaranteed (because we generated them in
    // GetPassEvents above) to come from the same command buffer, so the event IDs are
    // still locally continuous, even if we jump into replaying.
    m_pDriver->ReplayLog(events[first], events.back(), eReplay_Full);
  }
  
  MeshFormat VulkanReplay::GetPostVSBuffers(uint32_t eventId, uint32_t instID, uint32_t viewID,
                                            MeshDataStage stage)
  {
    // go through any aliasing
    if(m_PostVS.Alias.find(eventId) != m_PostVS.Alias.end())
      eventId = m_PostVS.Alias[eventId];
  
    VulkanPostVSData postvs;
    RDCEraseEl(postvs);
  
    if(m_PostVS.Data.find(eventId) != m_PostVS.Data.end())
      postvs = m_PostVS.Data[eventId];
  
    const ActionDescription *action = m_pDriver->GetAction(eventId);
  
    uint32_t numInstances = 1;
    if(action && (action->flags & ActionFlags::Instanced))
      numInstances = action->numInstances;
  
    VulkanPostVSData::StageData s = postvs.GetStage(stage);
  
    // clamp viewID
    if(s.numViews > 1)
      viewID = RDCMIN(viewID, s.numViews - 1);
    else
      viewID = 0;
  
    MeshFormat ret;
  
    if(s.useIndices && s.idxbuf != VK_NULL_HANDLE)
    {
      ret.indexResourceId = GetResID(s.idxbuf);
      if(s.idxFmt == VK_INDEX_TYPE_UINT32)
        ret.indexByteStride = 4;
      else if(s.idxFmt == VK_INDEX_TYPE_UINT8_EXT)
        ret.indexByteStride = 1;
      else
        ret.indexByteStride = 2;
      ret.indexByteSize = ~0ULL;
    }
    else
    {
      ret.indexResourceId = ResourceId();
      ret.indexByteStride = 0;
    }
    ret.indexByteOffset = 0;
    ret.baseVertex = s.baseVertex;
  
    if(s.buf != VK_NULL_HANDLE)
    {
      ret.vertexResourceId = GetResID(s.buf);
      ret.vertexByteSize = ~0ULL;
    }
    else
    {
      ret.vertexResourceId = ResourceId();
    }
  
    ret.vertexByteOffset = s.instStride * (instID + viewID * numInstances);
    ret.vertexByteStride = s.vertStride;
  
    ret.format.compCount = 4;
    ret.format.compByteWidth = 4;
    ret.format.compType = CompType::Float;
    ret.format.type = ResourceFormatType::Regular;
  
    ret.showAlpha = false;
  
    ret.topology = MakePrimitiveTopology(s.topo, 1);
    ret.numIndices = s.numVerts;
  
    ret.unproject = s.hasPosOut;
    ret.nearPlane = s.nearPlane;
    ret.farPlane = s.farPlane;
    ret.flipY = s.flipY;
  
    if(instID < s.instData.size())
    {
      VulkanPostVSData::InstData inst = s.instData[instID];
  
      ret.vertexByteOffset = inst.bufOffset;
      ret.numIndices = inst.numVerts;
    }
  
    return ret;
  }
  