1 files changed, 85 insertions, 0 deletions
diff --git a/gfx/gl/GLReadTexImageHelper.h b/gfx/gl/GLReadTexImageHelper.h
new file mode 100644
index 0000000000..c5b631fc1a
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+++ b/gfx/gl/GLReadTexImageHelper.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef GLREADTEXIMAGEHELPER_H_
+#define GLREADTEXIMAGEHELPER_H_
+
+#include "GLContextTypes.h"
+#include "mozilla/Attributes.h"
+#include "nsSize.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/gfx/Types.h"
+
+namespace mozilla {
+
+namespace gfx {
+class DataSourceSurface;
+}  // namespace gfx
+
+namespace gl {
+
+// Returns true if the `dest{Format,Type}` are the same as the
+// `read{Format,Type}`.
+bool GetActualReadFormats(GLContext* gl, GLenum destFormat, GLenum destType,
+                          GLenum* out_readFormat, GLenum* out_readType);
+
+void ReadPixelsIntoBuffer(GLContext* gl, uint8_t* aData, int32_t aStride,
+                          const gfx::IntSize& aSize,
+                          gfx::SurfaceFormat aFormat);
+
+void ReadPixelsIntoDataSurface(GLContext* aGL,
+                               gfx::DataSourceSurface* aSurface);
+
+already_AddRefed<gfx::DataSourceSurface> ReadBackSurface(
+    GLContext* gl, GLuint aTexture, bool aYInvert, gfx::SurfaceFormat aFormat);
+
+already_AddRefed<gfx::DataSourceSurface> YInvertImageSurface(
+    gfx::DataSourceSurface* aSurf, uint32_t aStride);
+
+void SwapRAndBComponents(gfx::DataSourceSurface* surf);
+
+class GLReadTexImageHelper final {
+  // The GLContext is the sole owner of the GLBlitHelper.
+  GLContext* mGL;
+
+  GLuint mPrograms[4];
+
+  GLuint TextureImageProgramFor(GLenum aTextureTarget, int aShader);
+
+  bool DidGLErrorOccur(const char* str);
+
+ public:
+  explicit GLReadTexImageHelper(GLContext* gl);
+  ~GLReadTexImageHelper();
+
+  /**
+   * Read the image data contained in aTexture, and return it as an
+   * ImageSurface. If GL_RGBA is given as the format, a
+   * SurfaceFormat::A8R8G8B8_UINT32 surface is returned. Not implemented yet: If
+   * GL_RGB is given as the format, a SurfaceFormat::X8R8G8B8_UINT32 surface is
+   * returned. If GL_LUMINANCE is given as the format, a SurfaceFormat::A8
+   * surface is returned.
+   *
+   * THIS IS EXPENSIVE.  It is ridiculously expensive.  Only do this
+   * if you absolutely positively must, and never in any performance
+   * critical path.
+   *
+   * NOTE: aShaderProgram is really mozilla::layers::ShaderProgramType. It is
+   * passed as int to eliminate including LayerManagerOGLProgram.h here.
+   */
+  already_AddRefed<gfx::DataSourceSurface> ReadTexImage(
+      GLuint aTextureId, GLenum aTextureTarget, const gfx::IntSize& aSize,
+      /* ShaderProgramType */ int aShaderProgram, bool aYInvert = false);
+
+  bool ReadTexImage(gfx::DataSourceSurface* aDest, GLuint aTextureId,
+                    GLenum aTextureTarget, const gfx::IntSize& aSize,
+                    int aShaderProgram, bool aYInvert = false);
+};
+
+}  // namespace gl
+}  // namespace mozilla
+
+#endif