gfx/gl/GLBlitTextureImageHelper.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 GLBLITTEXTUREIMAGEHELPER_H_
   8 #define GLBLITTEXTUREIMAGEHELPER_H_
   9
  10 #include "mozilla/Attributes.h"
  11 #include "GLContextTypes.h"
  12 #include "GLConsts.h"
  13
  14 struct nsIntRect;
  15
  16 namespace mozilla {
  17 namespace gl {
  18
  19 class GLContext;
  20 class TextureImage;
  21
  22 class GLBlitTextureImageHelper MOZ_FINAL
  23 {
  24     // The GLContext is the sole owner of the GLBlitTextureImageHelper.
  25     GLContext* mGL;
  26
  27     // lazy-initialized things
  28     GLuint mBlitProgram, mBlitFramebuffer;
  29     void UseBlitProgram();
  30     void SetBlitFramebufferForDestTexture(GLuint aTexture);
  31
  32 public:
  33
  34     explicit GLBlitTextureImageHelper(GLContext *gl);
  35     ~GLBlitTextureImageHelper();
  36
  37     /**
  38      * Copy a rectangle from one TextureImage into another.  The
  39      * source and destination are given in integer coordinates, and
  40      * will be converted to texture coordinates.
  41      *
  42      * For the source texture, the wrap modes DO apply -- it's valid
  43      * to use REPEAT or PAD and expect appropriate behaviour if the source
  44      * rectangle extends beyond its bounds.
  45      *
  46      * For the destination texture, the wrap modes DO NOT apply -- the
  47      * destination will be clipped by the bounds of the texture.
  48      *
  49      * Note: calling this function will cause the following OpenGL state
  50      * to be changed:
  51      *
  52      *   - current program
  53      *   - framebuffer binding
  54      *   - viewport
  55      *   - blend state (will be enabled at end)
  56      *   - scissor state (will be enabled at end)
  57      *   - vertex attrib 0 and 1 (pointer and enable state [enable state will be disabled at exit])
  58      *   - array buffer binding (will be 0)
  59      *   - active texture (will be 0)
  60      *   - texture 0 binding
  61      */
  62     void BlitTextureImage(TextureImage *aSrc, const nsIntRect& aSrcRect,
  63                           TextureImage *aDst, const nsIntRect& aDstRect);
  64 };
  65
  66 }
  67 }
  68
  69 #endif // GLBLITTEXTUREIMAGEHELPER_H_