1 /* 2 * Copyright (c) 2010, Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef DrawingBuffer_h 32 #define DrawingBuffer_h 33 34 #include "platform/PlatformExport.h" 35 #include "platform/geometry/IntSize.h" 36 #include "platform/graphics/GraphicsContext3D.h" 37 #include "platform/graphics/GraphicsTypes3D.h" 38 39 #include "public/platform/WebExternalTextureLayerClient.h" 40 #include "public/platform/WebExternalTextureMailbox.h" 41 #include "wtf/Noncopyable.h" 42 #include "wtf/OwnPtr.h" 43 #include "wtf/PassOwnPtr.h" 44 45 namespace blink { 46 class WebExternalBitmap; 47 class WebExternalTextureLayer; 48 class WebGraphicsContext3D; 49 class WebLayer; 50 } 51 52 namespace WebCore { 53 class GraphicsContext3D; 54 class ImageData; 55 56 // Abstract interface to allow basic context eviction management 57 class PLATFORM_EXPORT ContextEvictionManager : public RefCounted<ContextEvictionManager> { 58 public: ~ContextEvictionManager()59 virtual ~ContextEvictionManager() {}; 60 61 virtual void forciblyLoseOldestContext(const String& reason) = 0; 62 virtual IntSize oldestContextSize() = 0; 63 }; 64 65 // Manages a rendering target (framebuffer + attachment) for a canvas. Can publish its rendering 66 // results to a blink::WebLayer for compositing. 67 class PLATFORM_EXPORT DrawingBuffer : public RefCounted<DrawingBuffer>, public blink::WebExternalTextureLayerClient { 68 struct MailboxInfo : public RefCounted<MailboxInfo> { 69 blink::WebExternalTextureMailbox mailbox; 70 unsigned textureId; 71 IntSize size; 72 }; 73 public: 74 enum PreserveDrawingBuffer { 75 Preserve, 76 Discard 77 }; 78 79 static PassRefPtr<DrawingBuffer> create(GraphicsContext3D*, const IntSize&, PreserveDrawingBuffer, PassRefPtr<ContextEvictionManager>); 80 81 ~DrawingBuffer(); 82 83 // Clear all resources from this object, as well as context. Called when context is destroyed 84 // to prevent invalid accesses to the resources. 85 void releaseResources(); 86 87 // Issues a glClear() on all framebuffers associated with this DrawingBuffer. The caller is responsible for 88 // making the context current and setting the clear values and masks. Modifies the framebuffer binding. 89 void clearFramebuffers(GC3Dbitfield clearMask); 90 91 // Given the desired buffer size, provides the largest dimensions that will fit in the pixel budget. 92 IntSize adjustSize(const IntSize&); 93 void reset(const IntSize&); 94 void bind(); size()95 IntSize size() const { return m_size; } isZeroSized()96 bool isZeroSized() const { return m_size.isEmpty(); } 97 98 // Copies the multisample color buffer to the normal color buffer and leaves m_fbo bound. 99 void commit(long x = 0, long y = 0, long width = -1, long height = -1); 100 101 // commit should copy the full multisample buffer, and not respect the 102 // current scissor bounds. Track the state of the scissor test so that it 103 // can be disabled during calls to commit. setScissorEnabled(bool scissorEnabled)104 void setScissorEnabled(bool scissorEnabled) { m_scissorEnabled = scissorEnabled; } 105 106 // The DrawingBuffer needs to track the texture bound to texture unit 0. 107 // The bound texture is tracked to avoid costly queries during rendering. setTexture2DBinding(Platform3DObject texture)108 void setTexture2DBinding(Platform3DObject texture) { m_texture2DBinding = texture; } 109 110 // The DrawingBuffer needs to track the currently bound framebuffer so it 111 // restore the binding when needed. setFramebufferBinding(Platform3DObject fbo)112 void setFramebufferBinding(Platform3DObject fbo) { m_framebufferBinding = fbo; } 113 114 // Track the currently active texture unit. Texture unit 0 is used as host for a scratch 115 // texture. setActiveTextureUnit(GC3Dint textureUnit)116 void setActiveTextureUnit(GC3Dint textureUnit) { m_activeTextureUnit = textureUnit; } 117 118 bool multisample() const; 119 120 Platform3DObject framebuffer() const; 121 122 void markContentsChanged(); 123 124 blink::WebLayer* platformLayer(); 125 void paintCompositedResultsToCanvas(ImageBuffer*); 126 127 // WebExternalTextureLayerClient implementation. 128 virtual blink::WebGraphicsContext3D* context() OVERRIDE; 129 virtual bool prepareMailbox(blink::WebExternalTextureMailbox*, blink::WebExternalBitmap*) OVERRIDE; 130 virtual void mailboxReleased(const blink::WebExternalTextureMailbox&) OVERRIDE; 131 132 bool copyToPlatformTexture(GraphicsContext3D&, Platform3DObject texture, GC3Denum internalFormat, 133 GC3Denum destType, GC3Dint level, bool premultiplyAlpha, bool flipY); 134 135 private: 136 DrawingBuffer(GraphicsContext3D*, const IntSize&, bool multisampleExtensionSupported, 137 bool packedDepthStencilExtensionSupported, PreserveDrawingBuffer, PassRefPtr<ContextEvictionManager>); 138 139 void initialize(const IntSize&); 140 141 Platform3DObject frontColorBuffer() const; colorBuffer()142 Platform3DObject colorBuffer() const { return m_colorBuffer; } 143 144 unsigned createColorTexture(const IntSize& size = IntSize()); 145 // Create the depth/stencil and multisample buffers, if needed. 146 void createSecondaryBuffers(); 147 bool resizeFramebuffer(const IntSize&); 148 bool resizeMultisampleFramebuffer(const IntSize&); 149 void resizeDepthStencil(const IntSize&, int sampleCount); 150 151 // Bind to the m_framebufferBinding if it's not 0. 152 void restoreFramebufferBinding(); 153 154 void clearPlatformLayer(); 155 156 PassRefPtr<MailboxInfo> recycledMailbox(); 157 PassRefPtr<MailboxInfo> createNewMailbox(unsigned); 158 159 // Updates the current size of the buffer, ensuring that s_currentResourceUsePixels is updated. 160 void setSize(const IntSize& size); 161 162 // Calculates the difference in pixels between the current buffer size and the proposed size. 163 int pixelDelta(const IntSize& size); 164 165 // Given the desired buffer size, provides the largest dimensions that will fit in the pixel budget 166 // Returns true if the buffer will only fit if the oldest WebGL context is forcibly lost 167 IntSize adjustSizeWithContextEviction(const IntSize&, bool& evictContext); 168 169 PreserveDrawingBuffer m_preserveDrawingBuffer; 170 bool m_scissorEnabled; 171 Platform3DObject m_texture2DBinding; 172 Platform3DObject m_framebufferBinding; 173 GC3Denum m_activeTextureUnit; 174 175 RefPtr<GraphicsContext3D> m_context; 176 IntSize m_size; 177 bool m_multisampleExtensionSupported; 178 bool m_packedDepthStencilExtensionSupported; 179 Platform3DObject m_fbo; 180 Platform3DObject m_colorBuffer; 181 Platform3DObject m_frontColorBuffer; 182 183 // This is used when we have OES_packed_depth_stencil. 184 Platform3DObject m_depthStencilBuffer; 185 186 // These are used when we don't. 187 Platform3DObject m_depthBuffer; 188 Platform3DObject m_stencilBuffer; 189 190 // For multisampling. 191 Platform3DObject m_multisampleFBO; 192 Platform3DObject m_multisampleColorBuffer; 193 194 // True if our contents have been modified since the last presentation of this buffer. 195 bool m_contentsChanged; 196 197 // True if commit() has been called since the last time markContentsChanged() had been called. 198 bool m_contentsChangeCommitted; 199 200 GraphicsContext3D::Attributes m_attributes; 201 unsigned m_internalColorFormat; 202 unsigned m_colorFormat; 203 unsigned m_internalRenderbufferFormat; 204 int m_maxTextureSize; 205 206 OwnPtr<blink::WebExternalTextureLayer> m_layer; 207 208 // All of the mailboxes that this DrawingBuffer has ever created. 209 Vector<RefPtr<MailboxInfo> > m_textureMailboxes; 210 // Mailboxes that were released by the compositor and can be used again by this DrawingBuffer. 211 Vector<RefPtr<MailboxInfo> > m_recycledMailboxes; 212 RefPtr<MailboxInfo> m_lastColorBuffer; 213 214 RefPtr<ContextEvictionManager> m_contextEvictionManager; 215 }; 216 217 } // namespace WebCore 218 219 #endif // DrawingBuffer_h 220