text: //
  // Copyright (c) 2008-2021 the Urho3D project.
  //
  // 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 "../../Precompiled.h"
  
  #include "../../Core/Context.h"
  #include "../../Core/Profiler.h"
  #include "../../Graphics/Graphics.h"
  #include "../../Graphics/GraphicsEvents.h"
  #include "../../Graphics/GraphicsImpl.h"
  #include "../../Graphics/Renderer.h"
  #include "../../Graphics/TextureCube.h"
  #include "../../IO/FileSystem.h"
  #include "../../IO/Log.h"
  #include "../../Resource/ResourceCache.h"
  #include "../../Resource/XMLFile.h"
  
  #include "../../DebugNew.h"
  
  #ifdef _MSC_VER
  #pragma warning(disable:4355)
  #endif
  
  namespace Urho3D
  {
  
  void TextureCube::OnDeviceLost()
  {
      if (object_.name_ && !graphics_->IsDeviceLost())
          glDeleteTextures(1, &object_.name_);
  
      GPUObject::OnDeviceLost();
  
      for (auto& renderSurface : renderSurfaces_)
      {
          if (renderSurface)
              renderSurface->OnDeviceLost();
      }
  }
  
  void TextureCube::OnDeviceReset()
  {
      if (!object_.name_ || dataPending_)
      {
          // If has a resource file, reload through the resource cache. Otherwise just recreate.
          auto* cache = GetSubsystem<ResourceCache>();
          if (cache->Exists(GetName()))
              dataLost_ = !cache->ReloadResource(this);
  
          if (!object_.name_)
          {
              Create();
              dataLost_ = true;
          }
      }
  
      dataPending_ = false;
  }
  
  void TextureCube::Release()
  {
      if (object_.name_)
      {
          if (!graphics_)
              return;
  
          if (!graphics_->IsDeviceLost())
          {
              for (unsigned i = 0; i < MAX_TEXTURE_UNITS; ++i)
              {
                  if (graphics_->GetTexture(i) == this)
                      graphics_->SetTexture(i, nullptr);
              }
  
              glDeleteTextures(1, &object_.name_);
          }
  
          for (auto& renderSurface : renderSurfaces_)
          {
              if (renderSurface)
                  renderSurface->Release();
          }
  
          object_.name_ = 0;
      }
  
      resolveDirty_ = false;
      levelsDirty_ = false;
  }
  
  bool TextureCube::SetData(CubeMapFace face, unsigned level, int x, int y, int width, int height, const void* data)
  {
      URHO3D_PROFILE(SetTextureData);
  
      if (!object_.name_ || !graphics_)
      {
          URHO3D_LOGERROR("No texture created, can not set data");
          return false;
      }
  
      if (!data)
      {
          URHO3D_LOGERROR("Null source for setting data");
          return false;
      }
  
      if (level >= levels_)
      {
          URHO3D_LOGERROR("Illegal mip level for setting data");
          return false;
      }
  
      if (graphics_->IsDeviceLost())
      {
          URHO3D_LOGWARNING("Texture data assignment while device is lost");
          dataPending_ = true;
          return true;
      }
  
      if (IsCompressed())
      {
          x &= ~3u;
          y &= ~3u;
      }
  
      int levelWidth = GetLevelWidth(level);
      int levelHeight = GetLevelHeight(level);
      if (x < 0 || x + width > levelWidth || y < 0 || y + height > levelHeight || width <= 0 || height <= 0)
      {
          URHO3D_LOGERROR("Illegal dimensions for setting data");
          return false;
      }
  
      graphics_->SetTextureForUpdate(this);
  
      bool wholeLevel = x == 0 && y == 0 && width == levelWidth && height == levelHeight;
      unsigned format = GetSRGB() ? GetSRGBFormat(format_) : format_;
  
      if (!IsCompressed())
      {
          if (wholeLevel)
              glTexImage2D((GLenum)(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face), level, format, width, height, 0, GetExternalFormat(format_),
                  GetDataType(format_), data);
          else
              glTexSubImage2D((GLenum)(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face), level, x, y, width, height, GetExternalFormat(format_),
                  GetDataType(format_), data);
      }
      else
      {
          if (wholeLevel)
              glCompressedTexImage2D((GLenum)(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face), level, format, width, height, 0,
                  GetDataSize(width, height), data);
          else
              glCompressedTexSubImage2D((GLenum)(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face), level, x, y, width, height, format,
                  GetDataSize(width, height), data);
      }
  
      graphics_->SetTexture(0, nullptr);
      return true;
  }
  
  bool TextureCube::SetData(CubeMapFace face, Deserializer& source)
  {
      SharedPtr<Image> image(new Image(context_));
      if (!image->Load(source))
          return false;
  
      return SetData(face, image);
  }
  
  bool TextureCube::SetData(CubeMapFace face, Image* image, bool useAlpha)
  {
      if (!image)
      {
          URHO3D_LOGERROR("Null image, can not set face data");
          return false;
      }
  
      // Use a shared ptr for managing the temporary mip images created during this function
      SharedPtr<Image> mipImage;
      unsigned memoryUse = 0;
      MaterialQuality quality = QUALITY_HIGH;
      auto* renderer = GetSubsystem<Renderer>();
      if (renderer)
          quality = renderer->GetTextureQuality();
  
      if (!image->IsCompressed())
      {
          // Convert unsuitable formats to RGBA
          unsigned components = image->GetComponents();
          if (Graphics::GetGL3Support() && ((components == 1 && !useAlpha) || components == 2))
          {
              mipImage = image->ConvertToRGBA(); image = mipImage;
              if (!image)
                  return false;
              components = image->GetComponents();
          }
  
          unsigned char* levelData = image->GetData();
          int levelWidth = image->GetWidth();
          int levelHeight = image->GetHeight();
          unsigned format = 0;
  
          if (levelWidth != levelHeight)
          {
              URHO3D_LOGERROR("Cube texture width not equal to height");
              return false;
          }
  
          // Discard unnecessary mip levels
          for (unsigned i = 0; i < mipsToSkip_[quality]; ++i)
          {
              mipImage = image->GetNextLevel(); image = mipImage;
              levelData = image->GetData();
              levelWidth = image->GetWidth();
              levelHeight = image->GetHeight();
          }
  
          switch (components)
          {
          case 1:
              format = useAlpha ? Graphics::GetAlphaFormat() : Graphics::GetLuminanceFormat();
              break;
  
          case 2:
              format = Graphics::GetLuminanceAlphaFormat();
              break;
  
          case 3:
              format = Graphics::GetRGBFormat();
              break;
  
          case 4:
              format = Graphics::GetRGBAFormat();
              break;
  
          default:
              assert(false);  // Should not reach here
              break;
          }
  
          // Create the texture when face 0 is being loaded, check that rest of the faces are same size & format
          if (!face)
          {
              // If image was previously compressed, reset number of requested levels to avoid error if level count is too high for new size
              if (IsCompressed() && requestedLevels_ > 1)
                  requestedLevels_ = 0;
              SetSize(levelWidth, format);
          }
          else
          {
              if (!object_.name_)
              {
                  URHO3D_LOGERROR("Cube texture face 0 must be loaded first");
                  return false;
              }
              if (levelWidth != width_ || format != format_)
              {
                  URHO3D_LOGERROR("Cube texture face does not match size or format of face 0");
                  return false;
              }
          }
  
          for (unsigned i = 0; i < levels_; ++i)
          {
              SetData(face, i, 0, 0, levelWidth, levelHeight, levelData);
              memoryUse += levelWidth * levelHeight * components;
  
              if (i < levels_ - 1)
              {
                  mipImage = image->GetNextLevel(); image = mipImage;
                  levelData = image->GetData();
                  levelWidth = image->GetWidth();
                  levelHeight = image->GetHeight();
              }
          }
      }
      else
      {
          int width = image->GetWidth();
          int height = image->GetHeight();
          unsigned levels = image->GetNumCompressedLevels();
          unsigned format = graphics_->GetFormat(image->GetCompressedFormat());
          bool needDecompress = false;
  
          if (width != height)
          {
              URHO3D_LOGERROR("Cube texture width not equal to height");
              return false;
          }
  
          if (!format)
          {
              format = Graphics::GetRGBAFormat();
              needDecompress = true;
          }
  
          unsigned mipsToSkip = mipsToSkip_[quality];
          if (mipsToSkip >= levels)
              mipsToSkip = levels - 1;
          while (mipsToSkip && (width / (1u << mipsToSkip) < 4 || height / (1u << mipsToSkip) < 4))
              --mipsToSkip;
          width /= (1u << mipsToSkip);
          height /= (1u << mipsToSkip);
  
          // Create the texture when face 0 is being loaded, assume rest of the faces are same size & format
          if (!face)
          {
              SetNumLevels(Max((levels - mipsToSkip), 1U));
              SetSize(width, format);
          }
          else
          {
              if (!object_.name_)
              {
                  URHO3D_LOGERROR("Cube texture face 0 must be loaded first");
                  return false;
              }
              if (width != width_ || format != format_)
              {
                  URHO3D_LOGERROR("Cube texture face does not match size or format of face 0");
                  return false;
              }
          }
  
          for (unsigned i = 0; i < levels_ && i < levels - mipsToSkip; ++i)
          {
              CompressedLevel level = image->GetCompressedLevel(i + mipsToSkip);
              if (!needDecompress)
              {
                  SetData(face, i, 0, 0, level.width_, level.height_, level.data_);
                  memoryUse += level.rows_ * level.rowSize_;
              }
              else
              {
                  auto* rgbaData = new unsigned char[level.width_ * level.height_ * 4];
                  level.Decompress(rgbaData);
                  SetData(face, i, 0, 0, level.width_, level.height_, rgbaData);
                  memoryUse += level.width_ * level.height_ * 4;
                  delete[] rgbaData;
              }
          }
      }
  
      faceMemoryUse_[face] = memoryUse;
      unsigned totalMemoryUse = sizeof(TextureCube);
      for (unsigned memoryUse : faceMemoryUse_)
          totalMemoryUse += memoryUse;
      SetMemoryUse(totalMemoryUse);
      return true;
  }
  
  bool TextureCube::GetData(CubeMapFace face, unsigned level, void* dest) const
  {
      if (!object_.name_ || !graphics_)
      {
          URHO3D_LOGERROR("No texture created, can not get data");
          return false;
      }
  
  #ifndef GL_ES_VERSION_2_0
      if (!dest)
      {
          URHO3D_LOGERROR("Null destination for getting data");
          return false;
      }
  
      if (level >= levels_)
      {
          URHO3D_LOGERROR("Illegal mip level for getting data");
          return false;
      }
  
      if (graphics_->IsDeviceLost())
      {
          URHO3D_LOGWARNING("Getting texture data while device is lost");
          return false;
      }
  
      if (multiSample_ > 1 && !autoResolve_)
      {
          URHO3D_LOGERROR("Can not get data from multisampled texture without autoresolve");
          return false;
      }
  
      if (resolveDirty_)
          graphics_->ResolveToTexture(const_cast<TextureCube*>(this));
  
      graphics_->SetTextureForUpdate(const_cast<TextureCube*>(this));
  
      if (!IsCompressed())
          glGetTexImage((GLenum)(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face), level, GetExternalFormat(format_), GetDataType(format_), dest);
      else
          glGetCompressedTexImage((GLenum)(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face), level, dest);
  
      graphics_->SetTexture(0, nullptr);
      return true;
  #else
      // Special case on GLES: if the texture is a rendertarget, can make it current and use glReadPixels()
      if (usage_ == TEXTURE_RENDERTARGET)
      {
          graphics_->SetRenderTarget(0, renderSurfaces_[face]);
          // Ensure the FBO is current; this viewport is actually never rendered to
          graphics_->SetViewport(IntRect(0, 0, width_, height_));
          glReadPixels(0, 0, width_, height_, GetExternalFormat(format_), GetDataType(format_), dest);
          return true;
      }
  
      URHO3D_LOGERROR("Getting texture data not supported");
      return false;
  #endif
  }
  
  bool TextureCube::Create()
  {
      Release();
  
      if (!graphics_ || !width_ || !height_)
          return false;
  
      if (graphics_->IsDeviceLost())
      {
          URHO3D_LOGWARNING("Texture creation while device is lost");
          return true;
      }
  
  #ifdef GL_ES_VERSION_2_0
      if (multiSample_ > 1)
      {
          URHO3D_LOGWARNING("Multisampled texture is not supported on OpenGL ES");
          multiSample_ = 1;
          autoResolve_ = false;
      }
  #endif
  
      glGenTextures(1, &object_.name_);
  
      // Ensure that our texture is bound to OpenGL texture unit 0
      graphics_->SetTextureForUpdate(this);
  
      // If not compressed, create the initial level 0 texture with null data
      unsigned format = GetSRGB() ? GetSRGBFormat(format_) : format_;
      unsigned externalFormat = GetExternalFormat(format_);
      unsigned dataType = GetDataType(format_);
  
      // If multisample, create renderbuffers for each face
      if (multiSample_ > 1)
      {
          for (auto& renderSurface : renderSurfaces_)
              renderSurface->CreateRenderBuffer(width_, height_, format, multiSample_);
      }
  
      bool success = true;
      if (!IsCompressed())
      {
          glGetError();
          for (unsigned i = 0; i < MAX_CUBEMAP_FACES; ++i)
          {
              glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, format, width_, height_, 0, externalFormat, dataType, nullptr);
              if (glGetError())
                  success = false;
          }
      }
      if (!success)
          URHO3D_LOGERROR("Failed to create texture");
  
      // Set mipmapping
      if (usage_ == TEXTURE_DEPTHSTENCIL || usage_ == TEXTURE_DYNAMIC)
          requestedLevels_ = 1;
      else if (usage_ == TEXTURE_RENDERTARGET)
      {
  #if defined(__EMSCRIPTEN__) || defined(IOS) || defined(TVOS)
          // glGenerateMipmap appears to not be working on WebGL or iOS/tvOS, disable rendertarget mipmaps for now
          requestedLevels_ = 1;
  #else
          if (requestedLevels_ != 1)
          {
              // Generate levels for the first time now
              RegenerateLevels();
              // Determine max. levels automatically
              requestedLevels_ = 0;
          }
  #endif
      }
  
      levels_ = CheckMaxLevels(width_, height_, requestedLevels_);
  #ifndef GL_ES_VERSION_2_0
      glTexParameteri(target_, GL_TEXTURE_BASE_LEVEL, 0);
      glTexParameteri(target_, GL_TEXTURE_MAX_LEVEL, levels_ - 1);
  #endif
  
      // Set initial parameters, then unbind the texture
      UpdateParameters();
      graphics_->SetTexture(0, nullptr);
  
      return success;
  }
  
  }
  