2011-04-13 Brian Salomon <bsalomon@google.com>
[WebKit-https.git] / Source / WebCore / platform / graphics / chromium / DrawingBufferChromium.cpp
1 /*
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30
31 #include "config.h"
32
33 #include "DrawingBuffer.h"
34
35 #include "Extensions3DChromium.h"
36 #include "GraphicsContext3D.h"
37 #include "SharedGraphicsContext3D.h"
38
39 #if ENABLE(SKIA_GPU)
40 #include "GrContext.h"
41 #endif
42
43 #if USE(ACCELERATED_COMPOSITING)
44 #include "Canvas2DLayerChromium.h"
45 #endif
46
47 namespace WebCore {
48
49 struct DrawingBufferInternal {
50     unsigned offscreenColorTexture;
51 #if USE(ACCELERATED_COMPOSITING)
52     RefPtr<Canvas2DLayerChromium> platformLayer;
53 #endif
54 };
55
56 static unsigned generateColorTexture(GraphicsContext3D* context, const IntSize& size)
57 {
58     unsigned offscreenColorTexture = context->createTexture();
59     if (!offscreenColorTexture)
60         return 0;
61
62     context->bindTexture(GraphicsContext3D::TEXTURE_2D, offscreenColorTexture);
63     context->texParameteri(GraphicsContext3D::TEXTURE_2D, GraphicsContext3D::TEXTURE_MAG_FILTER, GraphicsContext3D::NEAREST);
64     context->texParameteri(GraphicsContext3D::TEXTURE_2D, GraphicsContext3D::TEXTURE_MIN_FILTER, GraphicsContext3D::NEAREST);
65     context->texParameteri(GraphicsContext3D::TEXTURE_2D, GraphicsContext3D::TEXTURE_WRAP_S, GraphicsContext3D::CLAMP_TO_EDGE);
66     context->texParameteri(GraphicsContext3D::TEXTURE_2D, GraphicsContext3D::TEXTURE_WRAP_T, GraphicsContext3D::CLAMP_TO_EDGE);
67     context->texImage2DResourceSafe(GraphicsContext3D::TEXTURE_2D, 0, GraphicsContext3D::RGBA, size.width(), size.height(), 0, GraphicsContext3D::RGBA, GraphicsContext3D::UNSIGNED_BYTE);
68     context->framebufferTexture2D(GraphicsContext3D::FRAMEBUFFER, GraphicsContext3D::COLOR_ATTACHMENT0, GraphicsContext3D::TEXTURE_2D, offscreenColorTexture, 0);
69
70     return offscreenColorTexture;
71 }
72
73
74 DrawingBuffer::DrawingBuffer(GraphicsContext3D* context,
75                              const IntSize& size,
76                              bool multisampleExtensionSupported,
77                              bool packedDepthStencilExtensionSupported)
78     : m_context(context)
79     , m_size(size)
80     , m_multisampleExtensionSupported(multisampleExtensionSupported)
81     , m_packedDepthStencilExtensionSupported(packedDepthStencilExtensionSupported)
82     , m_fbo(0)
83     , m_colorBuffer(0)
84     , m_depthStencilBuffer(0)
85     , m_depthBuffer(0)
86     , m_stencilBuffer(0)
87     , m_multisampleFBO(0)
88     , m_multisampleColorBuffer(0)
89     , m_internal(new DrawingBufferInternal)
90 #if ENABLE(SKIA_GPU)
91     , m_grContext(0)
92 #endif
93 {
94     if (!m_context->getExtensions()->supports("GL_CHROMIUM_copy_texture_to_parent_texture")) {
95         m_context.clear();
96         return;
97     }
98     m_fbo = context->createFramebuffer();
99     context->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, m_fbo);
100     m_colorBuffer = generateColorTexture(context, size);
101     createSecondaryBuffers();
102     reset(size);
103 }
104
105 DrawingBuffer::~DrawingBuffer()
106 {
107 #if USE(ACCELERATED_COMPOSITING)
108     if (m_internal->platformLayer)
109         m_internal->platformLayer->setDrawingBuffer(0);
110 #endif
111
112     if (!m_context)
113         return;
114         
115     m_context->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, m_fbo);
116     m_context->deleteTexture(m_colorBuffer);
117
118     clear();
119 }
120
121 #if USE(ACCELERATED_COMPOSITING)
122 void DrawingBuffer::publishToPlatformLayer()
123 {
124     if (!m_context)
125         return;
126         
127     if (m_callback)
128         m_callback->willPublish();
129     if (multisample())
130         commit();
131     unsigned parentTexture = m_internal->platformLayer->textureId();
132     // FIXME: We do the copy in the canvas' (child) context so that it executes in the correct order relative to
133     // other commands in the child context.  This ensures that the parent texture always contains a complete
134     // frame and not some intermediate result.  However, there is no synchronization to ensure that this copy
135     // happens before the compositor draws.  This means we might draw stale frames sometimes.  Ideally this
136     // would insert a fence into the child command stream that the compositor could wait for.
137     m_context->makeContextCurrent();
138 #if ENABLE(SKIA_GPU)
139     if (m_grContext)
140         m_grContext->flush(0);
141 #endif
142     static_cast<Extensions3DChromium*>(m_context->getExtensions())->copyTextureToParentTextureCHROMIUM(m_colorBuffer, parentTexture);
143     m_context->flush();
144 }
145 #endif
146
147 void DrawingBuffer::didReset()
148 {
149 #if USE(ACCELERATED_COMPOSITING)
150     if (m_internal->platformLayer)
151         m_internal->platformLayer->setTextureChanged();
152 #endif
153 }
154
155 #if USE(ACCELERATED_COMPOSITING)
156 PlatformLayer* DrawingBuffer::platformLayer()
157 {
158     if (!m_internal->platformLayer)
159         m_internal->platformLayer = Canvas2DLayerChromium::create(this, 0);
160     return m_internal->platformLayer.get();
161 }
162 #endif
163
164 Platform3DObject DrawingBuffer::platformColorBuffer() const
165 {
166     return m_colorBuffer;
167 }
168
169 #if ENABLE(SKIA_GPU)
170 void DrawingBuffer::setGrContext(GrContext* context)
171 {
172     // We just take a ptr without referencing it, as we require that we never outlive
173     // the SharedGraphicsContext3D object that is giving us the context.
174     m_grContext = context;
175 }
176
177 void DrawingBuffer::getGrPlatformSurfaceDesc(GrPlatformSurfaceDesc* desc)
178 {
179     desc->fSurfaceType = kTextureRenderTarget_GrPlatformSurfaceType;
180
181     desc->fPlatformTexture = m_colorBuffer;
182     if (multisample()) {
183         desc->fRenderTargetFlags = kIsMultisampled_GrPlatformRenderTargetFlagBit | kGrCanResolve_GrPlatformRenderTargetFlagBit;
184         desc->fPlatformRenderTarget = m_multisampleFBO;
185         desc->fPlatformResolveDestination = m_fbo;
186     } else {
187         desc->fRenderTargetFlags = kNone_GrPlatformRenderTargetFlagBit;
188         desc->fPlatformRenderTarget = m_fbo;
189         desc->fPlatformResolveDestination = 0;
190     }
191
192     desc->fWidth = m_size.width();
193     desc->fHeight = m_size.height();
194     desc->fConfig = kRGBA_8888_GrPixelConfig;
195
196     desc->fStencilBits = (m_depthStencilBuffer || m_stencilBuffer) ? 8 : 0;
197 }
198
199 #endif
200
201 }