ImageBuffer-less SVG masking and clipping.

Source/core/platform/graphics/GraphicsContext.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * 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:
  * 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
@@ skipping 112 matching lines @@
 void GraphicsContext::restore()
 {
     if (paintingDisabled())
         return;
 
     if (m_stateStack.size() == 1) {
         LOG_ERROR("ERROR void GraphicsContext::restore() stack is empty");
         return;
     }
 
-    if (!m_state->m_imageBufferClip.empty()) {
-        applyClipFromImage(m_state->m_clip, m_state->m_imageBufferClip);
-        m_canvas->restore();
-    }
-
     m_stateStack.removeLast();
     m_state = m_stateStack.last().get();
 
     DeferredSaveState savedState = m_saveStateStack.last();
     m_saveStateStack.removeLast();
     m_deferredSaveFlags = savedState.m_flags;
     m_canvas->restoreToCount(savedState.m_restoreCount);
 }
 
 void GraphicsContext::saveLayer(const SkRect* bounds, const SkPaint* paint, SkCanvas::SaveFlags saveFlags)
@@ skipping 278 matching lines @@
         return;
 
     restoreLayer();
 
     ASSERT(m_transparencyCount > 0);
 #if !ASSERT_DISABLED
     --m_transparencyCount;
 #endif
 }
 
-void GraphicsContext::clipToImageBuffer(const ImageBuffer* imageBuffer, const FloatRect& rect)
-{
-    if (paintingDisabled())
-        return;
-
-    SkRect bounds = WebCoreFloatRectToSKRect(rect);
-
-    if (imageBuffer->internalSize().isEmpty()) {
-        clipRect(bounds);
-        return;
-    }
-
-    // Skia doesn't support clipping to an image, so we create a layer. The next
-    // time restore is invoked the layer and |imageBuffer| are combined to
-    // create the resulting image.
-    m_state->m_clip = bounds;
-
-    // Get the absolute coordinates of the stored clipping rectangle to make it
-    // independent of any transform changes.
-    getTotalMatrix().mapRect(&m_state->m_clip);
-
-    SkCanvas::SaveFlags saveFlags = static_cast<SkCanvas::SaveFlags>(SkCanvas::kHasAlphaLayer_SaveFlag | SkCanvas::kFullColorLayer_SaveFlag);
-    saveLayer(&bounds, 0, saveFlags);
-
-    const SkBitmap* bitmap = imageBuffer->context()->bitmap();
-
-    if (m_trackOpaqueRegion) {
-        SkRect opaqueRect = bitmap->isOpaque() ? m_state->m_clip : SkRect::MakeEmpty();
-        m_opaqueRegion.setImageMask(opaqueRect);
-    }
-
-    // Copy off the image as |imageBuffer| may be deleted before restore is invoked.
-    if (bitmap->isImmutable())
-        m_state->m_imageBufferClip = *bitmap;
-    else {
-        // We need to make a deep-copy of the pixels themselves, so they don't
-        // change on us between now and when we want to apply them in restore()
-        bitmap->copyTo(&m_state->m_imageBufferClip, SkBitmap::kARGB_8888_Config);
-    }
-}
-
 void GraphicsContext::setupPaintForFilling(SkPaint* paint) const
 {
     if (paintingDisabled())
         return;
 
     setupPaintCommon(paint);
 
     setupShader(paint, m_state->m_fillGradient.get(), m_state->m_fillPattern.get(), m_state->m_fillColor.rgb());
 }
 
@@ skipping 1376 matching lines @@
     } else if (pat) {
         shader = pat->shader();
         color = SK_ColorBLACK;
         paint->setFilterBitmap(imageInterpolationQuality() != InterpolationNone);
     }
 
     paint->setColor(m_state->applyAlpha(color));
     paint->setShader(shader.get());
 }
 
-
-void GraphicsContext::applyClipFromImage(const SkRect& rect, const SkBitmap& imageBuffer)
-{
-    if (paintingDisabled())
-        return;
-
-    // NOTE: this assumes the image mask contains opaque black for the portions that are to be shown, as such we
-    // only look at the alpha when compositing. I'm not 100% sure this is what WebKit expects for image clipping.
-    SkPaint paint;
-    paint.setXfermodeMode(SkXfermode::kDstIn_Mode);
-    realizeSave(SkCanvas::kMatrixClip_SaveFlag);
-    m_canvas->save(SkCanvas::kMatrix_SaveFlag);
-    m_canvas->resetMatrix();
-    m_canvas->drawBitmapRect(imageBuffer, 0, rect, &paint);
-    m_canvas->restore();
-}
-
 void GraphicsContext::didDrawTextInRect(const SkRect& textRect)
 {
     if (m_trackTextRegion) {
         TRACE_EVENT0("skia", "PlatformContextSkia::trackTextRegion");
         m_textRegion.join(textRect);
     }
 }
 
 }