DrawingBuffer clean-up: Aesthetic changes

third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.h

 /*
  * Copyright (c) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 285 matching lines @@
 
   // Shared memory bitmaps that were released by the compositor and can be used
   // again by this DrawingBuffer.
   struct RecycledBitmap {
     std::unique_ptr<cc::SharedBitmap> bitmap;
     IntSize size;
   };
   Vector<RecycledBitmap> m_recycledBitmaps;
 
  private:
-  // All parameters necessary to generate the texture that will be passed to
-  // prepareMailbox.
-  struct TextureParameters {
+  // All parameters necessary to generate the texture for the ColorBuffer.
+  struct ColorBufferParameters {
     DISALLOW_NEW();
     GLenum target = 0;
     GLenum internalColorFormat = 0;
 
     // The internal color format used when allocating storage for the
     // texture. This may be different from internalColorFormat if RGB
     // emulation is required.
     GLenum creationInternalColorFormat = 0;
     GLenum colorFormat = 0;
   };
 
   struct ColorBuffer : public RefCounted<ColorBuffer> {
-    ColorBuffer(DrawingBuffer*, const TextureParameters&, const IntSize&);
+    ColorBuffer(DrawingBuffer*,
+                const ColorBufferParameters&,
+                const IntSize&,
+                GLuint textureId,
+                GLuint imageId);
     ~ColorBuffer();
 
     // The owning DrawingBuffer. Note that DrawingBuffer is explicitly destroyed
     // by the beginDestruction method, which will eventually drain all of its
     // ColorBuffers.
     RefPtr<DrawingBuffer> drawingBuffer;
 
-    const TextureParameters parameters;
+    const ColorBufferParameters parameters;
     const IntSize size;
 
-    GLuint textureId = 0;
-    GLuint imageId = 0;
+    const GLuint textureId = 0;
+    const GLuint imageId = 0;
 
     // The mailbox used to send this buffer to the compositor.
     gpu::Mailbox mailbox;
 
     // The sync token for when this buffer was sent to the compositor.
     gpu::SyncToken produceSyncToken;
 
     // The sync token for when this buffer was received back from the
     // compositor.
     gpu::SyncToken receiveSyncToken;
 
    private:
     WTF_MAKE_NONCOPYABLE(ColorBuffer);
   };
 
   bool prepareTextureMailboxInternal(
       cc::TextureMailbox* outMailbox,
       std::unique_ptr<cc::SingleReleaseCallback>* outReleaseCallback,
       bool forceGpuResult);
 
-  // Callbacks for mailboxes given to the compositor from PrepareTextureMailbox.
-  void gpuMailboxReleased(RefPtr<ColorBuffer>,
+  // Helper functions to be called only by prepareTextureMailboxInternal.
+  bool finishPrepareTextureMailboxGpu(
+      cc::TextureMailbox* outMailbox,
+      std::unique_ptr<cc::SingleReleaseCallback>* outReleaseCallback);
+  bool finishPrepareTextureMailboxSoftware(
+      cc::TextureMailbox* outMailbox,
+      std::unique_ptr<cc::SingleReleaseCallback>* outReleaseCallback);
+
+  // Callbacks for mailboxes given to the compositor from
+  // finishPrepareTextureMailboxGpu and finishPrepareTextureMailboxSoftware.
+  void mailboxReleasedGpu(RefPtr<ColorBuffer>,
                           const gpu::SyncToken&,
                           bool lostResource);
-  void softwareMailboxReleased(std::unique_ptr<cc::SharedBitmap>,
+  void mailboxReleasedSoftware(std::unique_ptr<cc::SharedBitmap>,
                                const IntSize&,
                                const gpu::SyncToken&,
                                bool lostResource);
 
   // The texture parameters to use for a texture that will be backed by a
-  // CHROMIUM_image.
-  TextureParameters chromiumImageTextureParameters();
+  // CHROMIUM_image, backed by a GpuMemoryBuffer.
+  ColorBufferParameters gpuMemoryBufferColorBufferParameters();
 
-  // The texture parameters to use for a default texture.
-  TextureParameters defaultTextureParameters();
-
-  // Creates and binds a texture with the given parameters. Returns 0 on
-  // failure, or the newly created texture id on success. The caller takes
-  // ownership of the newly created texture.
-  GLuint createColorTexture(const TextureParameters&);
+  // The texture parameters to use for an ordinary GL texture.
+  ColorBufferParameters textureColorBufferParameters();
 
   // Attempts to allocator storage for, or resize all buffers. Returns whether
   // the operation was successful.
   bool resizeDefaultFramebuffer(const IntSize&);
 
   void clearPlatformLayer();
 
-  PassRefPtr<ColorBuffer> takeRecycledMailbox();
-
   std::unique_ptr<cc::SharedBitmap> createOrRecycleBitmap();
 
   // Updates the current size of the buffer, ensuring that
   // s_currentResourceUsePixels is updated.
   void setSize(const IntSize& size);
 
   // This is the order of bytes to use when doing a readback.
   enum ReadbackOrder { ReadbackRGBA, ReadbackSkia };
 
   // Helper function which does a readback from the currently-bound
   // framebuffer into a buffer of a certain size with 4-byte pixels.
   void readBackFramebuffer(unsigned char* pixels,
                            int width,
                            int height,
                            ReadbackOrder,
                            WebGLImageConversion::AlphaOp);
 
   // Helper function to flip a bitmap vertically.
   void flipVertically(uint8_t* data, int width, int height);
 
-  // Allocate a storage texture if possible. Otherwise, allocate a regular
-  // texture.
-  void allocateConditionallyImmutableTexture(GLenum target,
-                                             GLenum internalformat,
-                                             GLsizei width,
-                                             GLsizei height,
-                                             GLint border,
-                                             GLenum format,
-                                             GLenum type);
-
   // If RGB emulation is required, then the CHROMIUM image's alpha channel
   // must be immediately cleared after it is bound to a texture. Nothing
   // should be allowed to change the alpha channel after this.
   void clearChromiumImageAlpha(const ColorBuffer&);
 
   // Tries to create a CHROMIUM_image backed texture if
   // RuntimeEnabledFeatures::webGLImageChromiumEnabled() is true. On failure,
-  // or if the flag is false, creates a default texture.
-  RefPtr<ColorBuffer> createTextureAndAllocateMemory(const IntSize&);
+  // or if the flag is false, creates a default texture. Always returns a valid
+  // ColorBuffer.
+  RefPtr<ColorBuffer> createColorBuffer(const IntSize&);
 
-  // Creates and allocates space for a default texture.
-  RefPtr<ColorBuffer> createDefaultTextureAndAllocateMemory(const IntSize&);
+  // Creates or recycles a ColorBuffer of size |m_size|.
+  PassRefPtr<ColorBuffer> createOrRecycleColorBuffer();
 
   // Attaches |m_backColorBuffer| to |m_fbo|, which is always the source for
   // read operations.
   void attachColorBufferToReadFramebuffer();
 
   // Whether the WebGL client desires an explicit resolve. This is
   // implemented by forwarding all draw operations to a multisample
   // renderbuffer, which is resolved before any read operations or swaps.
   bool wantExplicitResolve();
 
@@ skipping 20 matching lines @@
   gpu::gles2::GLES2Interface* m_gl;
   std::unique_ptr<Extensions3DUtil> m_extensionsUtil;
   IntSize m_size = {-1, -1};
   const bool m_discardFramebufferSupported;
   const bool m_wantAlphaChannel;
   const bool m_premultipliedAlpha;
   const bool m_softwareRendering;
   bool m_hasImplicitStencilBuffer = false;
   bool m_storageTextureSupported = false;
 
-  // This is the ColorBuffer that was most recently presented to the compositor
-  // by prepareTextureMailboxInternal.
-  RefPtr<ColorBuffer> m_frontColorBuffer;
-
   std::unique_ptr<WTF::Closure> m_newMailboxCallback;
 
   // This is used when the user requests either a depth or stencil buffer.
   GLuint m_depthStencilBuffer = 0;
 
   // When wantExplicitResolve() returns true, the target of all draw
   // operations.
   GLuint m_multisampleFBO = 0;
 
   // The id of the renderbuffer storage for |m_multisampleFBO|.
   GLuint m_multisampleRenderbuffer = 0;
 
   // When wantExplicitResolve() returns false, the target of all draw and
   // read operations. When wantExplicitResolve() returns true, the target of
-  // all read operations. A swap is performed by exchanging |m_backColorBuffer|
-  // with |m_frontColorBuffer|.
+  // all read operations.
   GLuint m_fbo = 0;
 
-  // All information about the texture storage for |m_fbo|.
+  // The ColorBuffer that backs |m_fbo|.
   RefPtr<ColorBuffer> m_backColorBuffer;
 
+  // The ColorBuffer that was most recently presented to the compositor by
+  // prepareTextureMailboxInternal.
+  RefPtr<ColorBuffer> m_frontColorBuffer;
+
   // True if our contents have been modified since the last presentation of this
   // buffer.
   bool m_contentsChanged = true;
 
   // True if commit() has been called since the last time markContentsChanged()
   // had been called.
   bool m_contentsChangeCommitted = false;
   bool m_bufferClearNeeded = false;
 
   // Whether the client wants a depth or stencil buffer.
@@ skipping 13 matching lines @@
   int m_sampleCount = 0;
   int m_packAlignment = 4;
   bool m_destructionInProgress = false;
   bool m_isHidden = false;
   SkFilterQuality m_filterQuality = kLow_SkFilterQuality;
 
   std::unique_ptr<WebExternalTextureLayer> m_layer;
 
   // Mailboxes that were released by the compositor can be used again by this
   // DrawingBuffer.
-  Deque<RefPtr<ColorBuffer>> m_recycledMailboxQueue;
+  Deque<RefPtr<ColorBuffer>> m_recycledColorBufferQueue;
 
   // If the width and height of the Canvas's backing store don't
   // match those that we were given in the most recent call to
   // reshape(), then we need an intermediate bitmap to read back the
   // frame buffer into. This seems to happen when CSS styles are
   // used to resize the Canvas.
   SkBitmap m_resizingBitmap;
 
-  // Used to flip a bitmap vertically.
-  Vector<uint8_t> m_scanline;
-
   // In the case of OffscreenCanvas, we do not want to enable the
   // WebGLImageChromium flag, so we replace all the
   // RuntimeEnabledFeatures::webGLImageChromiumEnabled() call with
   // shouldUseChromiumImage() calls, and set m_chromiumImageUsage to
   // DisallowChromiumImage in the case of OffscreenCanvas.
   ChromiumImageUsage m_chromiumImageUsage;
   bool shouldUseChromiumImage();
 };
 
 }  // namespace blink
 
 #endif  // DrawingBuffer_h