Initial import attempt, just to play with. Many things disabled/removed

ui/cc/LayerTextureSubImage.cpp

Index: ui/cc/LayerTextureSubImage.cpp
diff --git a/ui/cc/LayerTextureSubImage.cpp b/ui/cc/LayerTextureSubImage.cpp
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index 0000000000000000000000000000000000000000..c560b8918ec57fc6b476865e40f92cd5039499f9
--- /dev/null
+++ b/ui/cc/LayerTextureSubImage.cpp
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+/*
+ * Copyright (C) 2011 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:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS 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 APPLE OR ITS 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.
+ */
+
+#include "config.h"
+
+#if USE(ACCELERATED_COMPOSITING)
+
+#include "LayerTextureSubImage.h"
+
+#include "Extensions3DChromium.h"
+#include "LayerRendererChromium.h" // For GLC() macro
+#include "TraceEvent.h"
+#include "cc/CCGraphicsContext.h"
+
+namespace WebCore {
+
+LayerTextureSubImage::LayerTextureSubImage(bool useMapTexSubImage)
+    : m_useMapTexSubImage(useMapTexSubImage)
+{
+}
+
+LayerTextureSubImage::~LayerTextureSubImage()
+{
+}
+
+void LayerTextureSubImage::setSubImageSize(const IntSize& subImageSize)
+{
+    if (subImageSize == m_subImageSize)
+        return;
+
+    m_subImageSize = subImageSize;
+    m_subImage.clear();
+}
+
+void LayerTextureSubImage::upload(const uint8_t* image, const IntRect& imageRect,
+                                  const IntRect& sourceRect, const IntRect& destRect,
+                                  GC3Denum format, CCGraphicsContext* context)
+{
+    if (m_useMapTexSubImage)
+        uploadWithMapTexSubImage(image, imageRect, sourceRect, destRect, format, context);
+    else
+        uploadWithTexSubImage(image, imageRect, sourceRect, destRect, format, context);
+}
+
+void LayerTextureSubImage::uploadWithTexSubImage(const uint8_t* image, const IntRect& imageRect,
+                                                 const IntRect& sourceRect, const IntRect& destRect,
+                                                 GC3Denum format, CCGraphicsContext* context)
+{
+    TRACE_EVENT0("cc", "LayerTextureSubImage::uploadWithTexSubImage");
+    if (!m_subImage)
+        m_subImage = adoptArrayPtr(new uint8_t[m_subImageSize.width() * m_subImageSize.height() * 4]);
+
+    // Offset from image-rect to source-rect.
+    IntPoint offset(sourceRect.x() - imageRect.x(), sourceRect.y() - imageRect.y());
+
+    const uint8_t* pixelSource;
+    if (imageRect.width() == sourceRect.width() && !offset.x())
+        pixelSource = &image[4 * offset.y() * imageRect.width()];
+    else {
+        // Strides not equal, so do a row-by-row memcpy from the
+        // paint results into a temp buffer for uploading.
+        for (int row = 0; row < destRect.height(); ++row)
+            memcpy(&m_subImage[destRect.width() * 4 * row],
+                   &image[4 * (offset.x() + (offset.y() + row) * imageRect.width())],
+                   destRect.width() * 4);
+
+        pixelSource = &m_subImage[0];
+    }
+
+    WebKit::WebGraphicsContext3D* context3d = context->context3D();
+    if (!context3d) {
+        // FIXME: Implement this path for software compositing.
+        return;
+    }
+    GLC(context3d, context3d->texSubImage2D(GL_TEXTURE_2D, 0, destRect.x(), destRect.y(), destRect.width(), destRect.height(), format, GL_UNSIGNED_BYTE, pixelSource));
+}
+
+void LayerTextureSubImage::uploadWithMapTexSubImage(const uint8_t* image, const IntRect& imageRect,
+                                                    const IntRect& sourceRect, const IntRect& destRect,
+                                                    GC3Denum format, CCGraphicsContext* context)
+{
+    TRACE_EVENT0("cc", "LayerTextureSubImage::uploadWithMapTexSubImage");
+    WebKit::WebGraphicsContext3D* context3d = context->context3D();
+    if (!context3d) {
+        // FIXME: Implement this path for software compositing.
+        return;
+    }
+
+    // Offset from image-rect to source-rect.
+    IntPoint offset(sourceRect.x() - imageRect.x(), sourceRect.y() - imageRect.y());
+
+    // Upload tile data via a mapped transfer buffer
+    uint8_t* pixelDest = static_cast<uint8_t*>(context3d->mapTexSubImage2DCHROMIUM(GL_TEXTURE_2D, 0, destRect.x(), destRect.y(), destRect.width(), destRect.height(), format, GL_UNSIGNED_BYTE, GL_WRITE_ONLY));
+
+    if (!pixelDest) {
+        uploadWithTexSubImage(image, imageRect, sourceRect, destRect, format, context);
+        return;
+    }
+
+    unsigned int componentsPerPixel = 4;
+    unsigned int bytesPerComponent = 1;
+
+    if (imageRect.width() == sourceRect.width() && !offset.x())
+        memcpy(pixelDest, &image[offset.y() * imageRect.width() * componentsPerPixel * bytesPerComponent], imageRect.width() * destRect.height() * componentsPerPixel * bytesPerComponent);
+    else {
+        // Strides not equal, so do a row-by-row memcpy from the
+        // paint results into the pixelDest
+        for (int row = 0; row < destRect.height(); ++row)
+            memcpy(&pixelDest[destRect.width() * row * componentsPerPixel * bytesPerComponent],
+                   &image[4 * (offset.x() + (offset.y() + row) * imageRect.width())],
+                   destRect.width() * componentsPerPixel * bytesPerComponent);
+    }
+    GLC(context3d, context3d->unmapTexSubImage2DCHROMIUM(pixelDest));
+}
+
+} // namespace WebCore
+
+#endif // USE(ACCELERATED_COMPOSITING)