gfx/gl/GLReadTexImageHelper.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* vim: set ts=8 sts=4 et sw=4 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef GLREADTEXIMAGEHELPER_H_
   8 #define GLREADTEXIMAGEHELPER_H_
   9
  10 #include "GLContextTypes.h"
  11 #include "mozilla/Attributes.h"
  12 #include "nsSize.h"
  13 #include "mozilla/RefPtr.h"
  14 #include "mozilla/gfx/Types.h"
  15
  16 namespace mozilla {
  17
  18 namespace gfx {
  19 class DataSourceSurface;
  20 } // namespace gfx
  21
  22 namespace gl {
  23
  24 // Returns true if the `dest{Format,Type}` are the same as the
  25 // `read{Format,Type}`.
  26 bool GetActualReadFormats(GLContext* gl,
  27                           GLenum destFormat, GLenum destType,
  28                           GLenum* out_readFormat, GLenum* out_readType);
  29
  30 void ReadPixelsIntoDataSurface(GLContext* aGL,
  31                                gfx::DataSourceSurface* aSurface);
  32
  33 already_AddRefed<gfx::DataSourceSurface>
  34 ReadBackSurface(GLContext* gl, GLuint aTexture, bool aYInvert, gfx::SurfaceFormat aFormat);
  35
  36 already_AddRefed<gfx::DataSourceSurface>
  37 YInvertImageSurface(gfx::DataSourceSurface* aSurf, uint32_t aStride);
  38
  39 void
  40 SwapRAndBComponents(gfx::DataSourceSurface* surf);
  41
  42 class GLReadTexImageHelper final
  43 {
  44     // The GLContext is the sole owner of the GLBlitHelper.
  45     GLContext* mGL;
  46
  47     GLuint mPrograms[4];
  48
  49     GLuint TextureImageProgramFor(GLenum aTextureTarget, int aShader);
  50
  51     bool DidGLErrorOccur(const char* str);
  52
  53 public:
  54
  55     explicit GLReadTexImageHelper(GLContext* gl);
  56     ~GLReadTexImageHelper();
  57
  58     /**
  59       * Read the image data contained in aTexture, and return it as an ImageSurface.
  60       * If GL_RGBA is given as the format, a SurfaceFormat::A8R8G8B8_UINT32 surface is returned.
  61       * Not implemented yet:
  62       * If GL_RGB is given as the format, a SurfaceFormat::X8R8G8B8_UINT32 surface is returned.
  63       * If GL_LUMINANCE is given as the format, a SurfaceFormat::A8 surface is returned.
  64       *
  65       * THIS IS EXPENSIVE.  It is ridiculously expensive.  Only do this
  66       * if you absolutely positively must, and never in any performance
  67       * critical path.
  68       *
  69       * NOTE: aShaderProgram is really mozilla::layers::ShaderProgramType. It is
  70       * passed as int to eliminate including LayerManagerOGLProgram.h here.
  71       */
  72     already_AddRefed<gfx::DataSourceSurface> ReadTexImage(GLuint aTextureId,
  73                                                           GLenum aTextureTarget,
  74                                                           const gfx::IntSize& aSize,
  75                                   /* ShaderProgramType */ int aShaderProgram,
  76                                                           bool aYInvert = false);
  77
  78     bool ReadTexImage(gfx::DataSourceSurface* aDest,
  79                       GLuint aTextureId,
  80                       GLenum aTextureTarget,
  81                       const gfx::IntSize& aSize,
  82                       int aShaderProgram,
  83                       bool aYInvert = false);
  84 };
  85
  86 } // namespace gl
  87 } // namespace mozilla
  88
  89 #endif