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 "nsAutoPtr.h"
  14 #include "mozilla/RefPtr.h"
  15 #include "mozilla/gfx/Types.h"
  16
  17 namespace mozilla {
  18
  19 namespace gfx {
  20 class DataSourceSurface;
  21 }
  22
  23 namespace gl {
  24
  25 void ReadPixelsIntoDataSurface(GLContext* aGL,
  26                                gfx::DataSourceSurface* aSurface);
  27
  28 TemporaryRef<gfx::DataSourceSurface>
  29 ReadBackSurface(GLContext* gl, GLuint aTexture, bool aYInvert, gfx::SurfaceFormat aFormat);
  30
  31 class GLReadTexImageHelper MOZ_FINAL
  32 {
  33     // The GLContext is the sole owner of the GLBlitHelper.
  34     GLContext* mGL;
  35
  36     GLuint mPrograms[4];
  37
  38     GLuint TextureImageProgramFor(GLenum aTextureTarget, int aShader);
  39
  40     bool DidGLErrorOccur(const char* str);
  41
  42 public:
  43
  44     GLReadTexImageHelper(GLContext* gl);
  45     ~GLReadTexImageHelper();
  46
  47     /**
  48       * Read the image data contained in aTexture, and return it as an ImageSurface.
  49       * If GL_RGBA is given as the format, a gfxImageFormat::ARGB32 surface is returned.
  50       * Not implemented yet:
  51       * If GL_RGB is given as the format, a gfxImageFormat::RGB24 surface is returned.
  52       * If GL_LUMINANCE is given as the format, a gfxImageFormat::A8 surface is returned.
  53       *
  54       * THIS IS EXPENSIVE.  It is ridiculously expensive.  Only do this
  55       * if you absolutely positively must, and never in any performance
  56       * critical path.
  57       *
  58       * NOTE: aShaderProgram is really mozilla::layers::ShaderProgramType. It is
  59       * passed as int to eliminate including LayerManagerOGLProgram.h here.
  60       */
  61     TemporaryRef<gfx::DataSourceSurface> ReadTexImage(GLuint aTextureId,
  62                                                       GLenum aTextureTarget,
  63                                                       const gfx::IntSize& aSize,
  64                               /* ShaderProgramType */ int aShaderProgram,
  65                                                       bool aYInvert = false);
  66
  67
  68 };
  69
  70 }
  71 }
  72
  73 #endif