text: /*
   * Copyright 2015 Google Inc.
   *
   * Use of this source code is governed by a BSD-style license that can be
   * found in the LICENSE file.
   */
  
  #include "src/gpu/gl/GrGLUniformHandler.h"
  
  #include "src/gpu/GrTexturePriv.h"
  #include "src/gpu/gl/GrGLCaps.h"
  #include "src/gpu/gl/GrGLGpu.h"
  #include "src/gpu/gl/builders/GrGLProgramBuilder.h"
  #include "src/sksl/SkSLCompiler.h"
  
  #define GL_CALL(X) GR_GL_CALL(this->glGpu()->glInterface(), X)
  #define GL_CALL_RET(R, X) GR_GL_CALL_RET(this->glGpu()->glInterface(), R, X)
  
  bool valid_name(const char* name) {
      // disallow unknown names that start with "sk_"
      if (!strncmp(name, GR_NO_MANGLE_PREFIX, strlen(GR_NO_MANGLE_PREFIX))) {
          return !strcmp(name, SkSL::Compiler::RTADJUST_NAME);
      }
      return true;
  }
  
  GrGLSLUniformHandler::UniformHandle GrGLUniformHandler::internalAddUniformArray(
                                                                              uint32_t visibility,
                                                                              GrSLType type,
                                                                              const char* name,
                                                                              bool mangleName,
                                                                              int arrayCount,
                                                                              const char** outName) {
      SkASSERT(name && strlen(name));
      SkASSERT(valid_name(name));
      SkASSERT(0 != visibility);
  
      UniformInfo& uni = fUniforms.push_back();
      uni.fVariable.setType(type);
      uni.fVariable.setTypeModifier(GrShaderVar::kUniform_TypeModifier);
      // TODO this is a bit hacky, lets think of a better way.  Basically we need to be able to use
      // the uniform view matrix name in the GP, and the GP is immutable so it has to tell the PB
      // exactly what name it wants to use for the uniform view matrix.  If we prefix anythings, then
      // the names will mismatch.  I think the correct solution is to have all GPs which need the
      // uniform view matrix, they should upload the view matrix in their setData along with regular
      // uniforms.
      char prefix = 'u';
      if ('u' == name[0] || !strncmp(name, GR_NO_MANGLE_PREFIX, strlen(GR_NO_MANGLE_PREFIX))) {
          prefix = '\0';
      }
      fProgramBuilder->nameVariable(uni.fVariable.accessName(), prefix, name, mangleName);
      uni.fVariable.setArrayCount(arrayCount);
      uni.fVisibility = visibility;
      uni.fLocation = -1;
  
      if (outName) {
          *outName = uni.fVariable.c_str();
      }
      return GrGLSLUniformHandler::UniformHandle(fUniforms.count() - 1);
  }
  
  GrGLSLUniformHandler::SamplerHandle GrGLUniformHandler::addSampler(const GrSurfaceProxy* texture,
                                                                     GrSamplerState,
                                                                     const GrSwizzle& swizzle,
                                                                     const char* name,
                                                                     const GrShaderCaps* shaderCaps) {
      SkASSERT(name && strlen(name));
      SkASSERT(texture->asTextureProxy());
  
      SkString mangleName;
      char prefix = 'u';
      fProgramBuilder->nameVariable(&mangleName, prefix, name, true);
  
      GrTextureType type = texture->backendFormat().textureType();
  
      UniformInfo& sampler = fSamplers.push_back();
      sampler.fVariable.setType(GrSLCombinedSamplerTypeForTextureType(type));
      sampler.fVariable.setTypeModifier(GrShaderVar::kUniform_TypeModifier);
      sampler.fVariable.setName(mangleName);
      sampler.fLocation = -1;
      sampler.fVisibility = kFragment_GrShaderFlag;
      if (shaderCaps->textureSwizzleAppliedInShader()) {
          fSamplerSwizzles.push_back(swizzle);
          SkASSERT(fSamplers.count() == fSamplerSwizzles.count());
      }
      return GrGLSLUniformHandler::SamplerHandle(fSamplers.count() - 1);
  }
  
  void GrGLUniformHandler::appendUniformDecls(GrShaderFlags visibility, SkString* out) const {
      for (int i = 0; i < fUniforms.count(); ++i) {
          if (fUniforms[i].fVisibility & visibility) {
              fUniforms[i].fVariable.appendDecl(fProgramBuilder->shaderCaps(), out);
              out->append(";");
          }
      }
      for (int i = 0; i < fSamplers.count(); ++i) {
          if (fSamplers[i].fVisibility & visibility) {
              fSamplers[i].fVariable.appendDecl(fProgramBuilder->shaderCaps(), out);
              out->append(";\n");
          }
      }
  }
  
  void GrGLUniformHandler::bindUniformLocations(GrGLuint programID, const GrGLCaps& caps) {
      if (caps.bindUniformLocationSupport()) {
          int currUniform = 0;
          for (int i = 0; i < fUniforms.count(); ++i, ++currUniform) {
              GL_CALL(BindUniformLocation(programID, currUniform, fUniforms[i].fVariable.c_str()));
              fUniforms[i].fLocation = currUniform;
          }
          for (int i = 0; i < fSamplers.count(); ++i, ++currUniform) {
              GL_CALL(BindUniformLocation(programID, currUniform, fSamplers[i].fVariable.c_str()));
              fSamplers[i].fLocation = currUniform;
          }
      }
  }
  
  void GrGLUniformHandler::getUniformLocations(GrGLuint programID, const GrGLCaps& caps, bool force) {
      if (!caps.bindUniformLocationSupport() || force) {
          int count = fUniforms.count();
          for (int i = 0; i < count; ++i) {
              GrGLint location;
              GL_CALL_RET(location, GetUniformLocation(programID, fUniforms[i].fVariable.c_str()));
              fUniforms[i].fLocation = location;
          }
          for (int i = 0; i < fSamplers.count(); ++i) {
              GrGLint location;
              GL_CALL_RET(location, GetUniformLocation(programID, fSamplers[i].fVariable.c_str()));
              fSamplers[i].fLocation = location;
          }
      }
  }
  
  const GrGLGpu* GrGLUniformHandler::glGpu() const {
      GrGLProgramBuilder* glPB = (GrGLProgramBuilder*) fProgramBuilder;
      return glPB->gpu();
  }
  