Initial implementation of display list backed 2D canvases

Source/platform/graphics/RecordingImageBufferSurface.cpp

+/*
+ * Copyright (c) 2013, 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
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */

[dshwang, 2014/07/14 11:45:40]

nits: Use brand-new license.

[Stephen White, 2014/07/14 15:19:15]

Good point; see http://www.chromium.org/blink/coding-style#TOC-License.

[Justin Novosad, 2014/07/17 18:34:14]

Done.

+
+#include "config.h"
+
+#include "platform/graphics/RecordingImageBufferSurface.h"
+
+#include "platform/graphics/GraphicsContext.h"
+#include "platform/graphics/ImageBuffer.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkPictureRecorder.h"
+#include "wtf/PassOwnPtr.h"
+#include "wtf/PassRefPtr.h"
+
+namespace WebCore {
+
+RecordingImageBufferSurface::RecordingImageBufferSurface(const IntSize& size, OpacityMode opacityMode)
+    : ImageBufferSurface(size, opacityMode)
+    , m_imageBuffer(0)
+    , m_frameWasCleared(true)
+{
+    initializeCurrentFrame();
+}
+
+RecordingImageBufferSurface::~RecordingImageBufferSurface()
+{ }
+
+void RecordingImageBufferSurface::initializeCurrentFrame()
+{
+    static SkRTreeFactory rTreeFactory;
+    m_currentFrame = adoptPtr(new SkPictureRecorder);
+    m_currentFrame->beginRecording(size().width(), size().height(), &rTreeFactory);
+    if (m_imageBuffer) {
+        m_imageBuffer->context()->resetCanvas(m_currentFrame->getRecordingCanvas());
+        m_imageBuffer->context()->setTrackOpaqueRegion(true);
+    }
+}
+
+void RecordingImageBufferSurface::setImageBuffer(ImageBuffer* imageBuffer)
+{
+    m_imageBuffer = imageBuffer;
+    if (m_currentFrame) {
+        m_imageBuffer->context()->setTrackOpaqueRegion(true);
+        m_imageBuffer->context()->resetCanvas(m_currentFrame->getRecordingCanvas());
+    }
+}
+
+
+void RecordingImageBufferSurface::willReadback()
+{
+    fallBackToRasterCanvas();
+}
+
+void RecordingImageBufferSurface::fallBackToRasterCanvas()
+{
+    if (m_rasterCanvas)

[dshwang, 2014/07/14 11:45:40]

How about adding ASSERT(!m_currentFrame);?

[Justin Novosad, 2014/07/17 18:34:14]

Done.

+        return;
+
+    m_rasterCanvas = adoptPtr(SkCanvas::NewRasterN32(size().width(), size().height()));
+
+    if (m_previousFrame) {
+        m_previousFrame->draw(m_rasterCanvas.get());
+        m_previousFrame.clear();
+    }
+    if (m_currentFrame) {
+        RefPtr<SkPicture> currentPicture = adoptRef(m_currentFrame->endRecording());
+        currentPicture->draw(m_rasterCanvas.get());
+        m_currentFrame.clear();
+    }
+
+    if (m_imageBuffer) {
+        m_imageBuffer->context()->setTrackOpaqueRegion(false);
+        m_imageBuffer->context()->resetCanvas(m_rasterCanvas.get());
+    }
+}
+
+SkCanvas* RecordingImageBufferSurface::canvas() const
+{
+    if (m_rasterCanvas)
+        return m_rasterCanvas.get();
+
+    ASSERT(m_currentFrame->getRecordingCanvas());
+    return m_currentFrame->getRecordingCanvas();
+}
+
+PassRefPtr<SkPicture> RecordingImageBufferSurface::getPicture()
+{
+    if (handleOpaqueFrame())
+        return m_previousFrame;
+
+    if (!m_rasterCanvas)
+        fallBackToRasterCanvas();
+    return nullptr;
+}
+
+void RecordingImageBufferSurface::didClearCanvas()
+{
+    m_frameWasCleared = true;
+}
+
+bool RecordingImageBufferSurface::handleOpaqueFrame()
+{
+    if (!m_currentFrame)
+        return false;
+    IntRect canvasRect(IntPoint(0, 0), size());
+    if (!m_frameWasCleared && !m_imageBuffer->context()->opaqueRegion().asRect().contains(canvasRect))
+        return false;
+
+    SkCanvas* oldCanvas = m_currentFrame->getRecordingCanvas(); // Could be raster or picture
+
+    // FIXME(crbug.com/392614): handle transferring complex state from the current picture to the new one.
+    if (oldCanvas->getSaveCount())
+        return false;
+    if (!oldCanvas->isClipRect() || oldCanvas->)
+        return false;
+
+    SkMatrix ctm = oldCanvas->getTotalMatrix();
+    SkRect clip;
+    oldCanvas->getClipBounds(&clip);
+
+    m_previousFrame = adoptRef(m_currentFrame->endRecording());
+    initializeCurrentFrame();
+
+    SkCanvas* newCanvas = m_currentFrame->getRecordingCanvas();
+    newCanvas->concat(ctm);
+    newCanvas->clipRect(clip);
+
+    m_frameWasCleared = false;
+    return true;
+}
+
+} // namespace WebCore