Removing the dependency on GraphicsContext for drawing images in 2D canvas

Source/core/html/canvas/CanvasRenderingContext2DState.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 
 #include "core/html/canvas/CanvasRenderingContext2DState.h"
 
 #include "core/css/CSSFontSelector.h"
 #include "core/html/canvas/CanvasGradient.h"
@@ skipping 23 matching lines @@
     , m_realizedFont(false)
     , m_isTransformInvertible(true)
     , m_hasClip(false)
     , m_hasComplexClip(false)
     , m_fillStyleDirty(true)
     , m_strokeStyleDirty(true)
     , m_lineDashDirty(false)
 {
     m_fillPaint.setStyle(SkPaint::kFill_Style);
     m_fillPaint.setAntiAlias(true);
+    m_imagePaint.setStyle(SkPaint::kFill_Style);
+    m_imagePaint.setAntiAlias(true);
     m_strokePaint.setStyle(SkPaint::kStroke_Style);
     m_strokePaint.setStrokeWidth(1);
     m_strokePaint.setStrokeCap(SkPaint::kButt_Cap);
     m_strokePaint.setStrokeMiter(10);
     m_strokePaint.setStrokeJoin(SkPaint::kMiter_Join);
     m_strokePaint.setAntiAlias(true);
     setImageSmoothingEnabled(true);
 }
 
 CanvasRenderingContext2DState::CanvasRenderingContext2DState(const CanvasRenderingContext2DState& other, ClipListCopyMode mode)
     : CSSFontSelectorClient()
     , m_unrealizedSaveCount(other.m_unrealizedSaveCount)
     , m_unparsedStrokeColor(other.m_unparsedStrokeColor)
     , m_unparsedFillColor(other.m_unparsedFillColor)
     , m_strokeStyle(other.m_strokeStyle)
     , m_fillStyle(other.m_fillStyle)
     , m_strokePaint(other.m_strokePaint)
     , m_fillPaint(other.m_fillPaint)
+    , m_imagePaint(other.m_imagePaint)
     , m_shadowOffset(other.m_shadowOffset)
     , m_shadowBlur(other.m_shadowBlur)
     , m_shadowColor(other.m_shadowColor)
     , m_emptyDrawLooper(other.m_emptyDrawLooper)
     , m_shadowOnlyDrawLooper(other.m_shadowOnlyDrawLooper)
     , m_shadowAndForegroundDrawLooper(other.m_shadowAndForegroundDrawLooper)
     , m_shadowOnlyImageFilter(other.m_shadowOnlyImageFilter)
     , m_shadowAndForegroundImageFilter(other.m_shadowAndForegroundImageFilter)
     , m_globalAlpha(other.m_globalAlpha)
     , m_transform(other.m_transform)
@@ skipping 28 matching lines @@
         static_cast<CSSFontSelector*>(m_font.fontSelector())->unregisterForInvalidationCallbacks(this);
 #endif
 
     m_unrealizedSaveCount = other.m_unrealizedSaveCount;
     m_unparsedStrokeColor = other.m_unparsedStrokeColor;
     m_unparsedFillColor = other.m_unparsedFillColor;
     m_strokeStyle = other.m_strokeStyle;
     m_fillStyle = other.m_fillStyle;
     m_strokePaint = other.m_strokePaint;
     m_fillPaint = other.m_fillPaint;
+    m_imagePaint = other.m_imagePaint;
     m_shadowOffset = other.m_shadowOffset;
     m_shadowBlur = other.m_shadowBlur;
     m_shadowColor = other.m_shadowColor;
     m_emptyDrawLooper = other.m_emptyDrawLooper;
     m_shadowOnlyDrawLooper = other.m_shadowOnlyDrawLooper;
     m_shadowAndForegroundDrawLooper = other.m_shadowAndForegroundDrawLooper;
     m_shadowOnlyImageFilter = other.m_shadowOnlyImageFilter;
     m_shadowAndForegroundImageFilter = other.m_shadowAndForegroundImageFilter;
     m_globalAlpha = other.m_globalAlpha;
     m_transform = other.m_transform;
@@ skipping 108 matching lines @@
     m_fillStyleDirty = false;
 }
 
 CanvasStyle* CanvasRenderingContext2DState::style(PaintType paintType) const
 {
     switch (paintType) {
     case FillPaintType:
         return fillStyle();
     case StrokePaintType:
         return strokeStyle();
+    case ImagePaintType:
+        return nullptr;
     }
     ASSERT_NOT_REACHED();
     return nullptr;
 }
 
 void CanvasRenderingContext2DState::setGlobalAlpha(float alpha)
 {
     m_globalAlpha = alpha;
     m_strokeStyleDirty = true;
     m_fillStyleDirty = true;
+    m_imagePaint.setColor(scaleAlpha(SK_ColorBLACK, clampedAlphaForBlending(m_globalAlpha)));
 }
 
 void CanvasRenderingContext2DState::clipPath(const SkPath& path, AntiAliasingMode antiAliasingMode)
 {
     m_clipList.clipPath(path, antiAliasingMode, affineTransformToSkMatrix(m_transform));
     m_hasClip = true;
     if (!path.isRect(0))
         m_hasComplexClip = true;
 }
 
@@ skipping 104 matching lines @@
 void CanvasRenderingContext2DState::setShadowColor(SkColor shadowColor)
 {
     m_shadowColor = shadowColor;
     shadowParameterChanged();
 }
 
 void CanvasRenderingContext2DState::setGlobalComposite(SkXfermode::Mode mode)
 {
     m_strokePaint.setXfermodeMode(mode);
     m_fillPaint.setXfermodeMode(mode);
+    m_imagePaint.setXfermodeMode(mode);
 }
 
 SkXfermode::Mode CanvasRenderingContext2DState::globalComposite() const
 {
     SkXfermode* xferMode = m_strokePaint.getXfermode();
     SkXfermode::Mode mode;
     if (!xferMode || !xferMode->asMode(&mode))
         return SkXfermode::kSrcOver_Mode;
     return mode;
 }
 
 void CanvasRenderingContext2DState::setImageSmoothingEnabled(bool enabled)
 {
     SkFilterQuality filterQuality = enabled ? kLow_SkFilterQuality : kNone_SkFilterQuality;
     m_strokePaint.setFilterQuality(filterQuality);
     m_fillPaint.setFilterQuality(filterQuality);
+    m_imagePaint.setFilterQuality(filterQuality);
 }
 
 bool CanvasRenderingContext2DState::imageSmoothingEnabled() const
 {
-    return m_strokePaint.getFilterQuality() == kLow_SkFilterQuality;
+    return m_imagePaint.getFilterQuality() == kLow_SkFilterQuality;
 }
 
 bool CanvasRenderingContext2DState::shouldDrawShadows() const
 {
     return alphaChannel(m_shadowColor) && (m_shadowBlur || !m_shadowOffset.isZero());
 }
 
 const SkPaint* CanvasRenderingContext2DState::getPaint(PaintType paintType, ShadowMode shadowMode, ImageType imageType) const
 {
     SkPaint* paint;
-    if (paintType == StrokePaintType) {
+    switch (paintType) {
+    case StrokePaintType:
         updateLineDash();
         updateStrokeStyle();
         paint = &m_strokePaint;
-    } else {
+        break;
+    case FillPaintType:
         updateFillStyle();
         paint = &m_fillPaint;
+        break;
+    case ImagePaintType:
+        paint = &m_imagePaint;
+        break;
+    default:
+        ASSERT_NOT_REACHED();
     }
 
     if ((!shouldDrawShadows() && shadowMode == DrawShadowAndForeground) || shadowMode == DrawForegroundOnly) {
         paint->setLooper(0);
         paint->setImageFilter(0);
         return paint;
     }
 
     if (!shouldDrawShadows() && shadowMode == DrawShadowOnly) {
         paint->setLooper(emptyDrawLooper()); // draw nothing
@@ skipping 17 matching lines @@
         paint->setLooper(0);
         paint->setImageFilter(shadowAndForegroundImageFilter());
         return paint;
     }
     paint->setLooper(shadowAndForegroundDrawLooper());
     paint->setImageFilter(0);
     return paint;
 }
 
 } // blink