Implement InterpolationMedium to filter animated images

Source/platform/graphics/GraphicsContext.cpp

Index: Source/platform/graphics/GraphicsContext.cpp
diff --git a/Source/platform/graphics/GraphicsContext.cpp b/Source/platform/graphics/GraphicsContext.cpp
index 9f62b29a780eb6f06ee663c9839aeaec46aa7def..db62b8c5886660e6ddc880727b5fa4b783b4fbe5 100644
--- a/Source/platform/graphics/GraphicsContext.cpp
+++ b/Source/platform/graphics/GraphicsContext.cpp
@@ -1027,16 +1027,16 @@ void GraphicsContext::drawImage(Image* image, const IntPoint& p, CompositeOperat
     drawImage(image, FloatRect(IntRect(p, image->size())), FloatRect(FloatPoint(), FloatSize(image->size())), op, shouldRespectImageOrientation);
 }
 
-void GraphicsContext::drawImage(Image* image, const IntRect& r, CompositeOperator op, RespectImageOrientationEnum shouldRespectImageOrientation, bool useLowQualityScale)
+void GraphicsContext::drawImage(Image* image, const IntRect& r, CompositeOperator op, RespectImageOrientationEnum shouldRespectImageOrientation, InterpolationQuality interpolationQuality)
 {
     if (!image)
         return;
-    drawImage(image, FloatRect(r), FloatRect(FloatPoint(), FloatSize(image->size())), op, shouldRespectImageOrientation, useLowQualityScale);
+    drawImage(image, FloatRect(r), FloatRect(FloatPoint(), FloatSize(image->size())), op, shouldRespectImageOrientation, interpolationQuality);
 }
 
-void GraphicsContext::drawImage(Image* image, const FloatRect& dest, const FloatRect& src, CompositeOperator op, RespectImageOrientationEnum shouldRespectImageOrientation, bool useLowQualityScale)
+void GraphicsContext::drawImage(Image* image, const FloatRect& dest, const FloatRect& src, CompositeOperator op, RespectImageOrientationEnum shouldRespectImageOrientation, InterpolationQuality interpolationQuality)
 {
-    drawImage(image, dest, src, op, blink::WebBlendModeNormal, shouldRespectImageOrientation, useLowQualityScale);
+    drawImage(image, dest, src, op, blink::WebBlendModeNormal, shouldRespectImageOrientation, interpolationQuality);
 }
 
 void GraphicsContext::drawImage(Image* image, const FloatRect& dest)
@@ -1046,31 +1046,29 @@ void GraphicsContext::drawImage(Image* image, const FloatRect& dest)
     drawImage(image, dest, FloatRect(IntRect(IntPoint(), image->size())));
 }
 
-void GraphicsContext::drawImage(Image* image, const FloatRect& dest, const FloatRect& src, CompositeOperator op, WebBlendMode blendMode, RespectImageOrientationEnum shouldRespectImageOrientation, bool useLowQualityScale)
-{    if (paintingDisabled() || !image)
+void GraphicsContext::drawImage(Image* image, const FloatRect& dest, const FloatRect& src, CompositeOperator op, WebBlendMode blendMode, RespectImageOrientationEnum shouldRespectImageOrientation, InterpolationQuality interpolationQuality)
+{
+    if (paintingDisabled() || !image)
         return;
 
-    InterpolationQuality previousInterpolationQuality = InterpolationDefault;
-
-    if (useLowQualityScale) {
-        previousInterpolationQuality = imageInterpolationQuality();
-        setImageInterpolationQuality(InterpolationLow);
-    }
-
-    image->draw(this, dest, src, op, blendMode, shouldRespectImageOrientation);
-
-    if (useLowQualityScale)
+    if (interpolationQuality != InterpolationDefault) {

[Stephen White, 2014/03/18 17:26:43]

Shouldn't this check be against imageInterpolationQuality(), not
InterpolationDefault?

[Alpha Left Google, 2014/03/18 22:59:13]

Done.

+        InterpolationQuality previousInterpolationQuality = imageInterpolationQuality();
+        setImageInterpolationQuality(interpolationQuality);
+        image->draw(this, dest, src, op, blendMode, shouldRespectImageOrientation);
         setImageInterpolationQuality(previousInterpolationQuality);
+    } else {
+        image->draw(this, dest, src, op, blendMode, shouldRespectImageOrientation);
+    }
 }
 
-void GraphicsContext::drawTiledImage(Image* image, const IntRect& destRect, const IntPoint& srcPoint, const IntSize& tileSize, CompositeOperator op, bool useLowQualityScale, WebBlendMode blendMode, const IntSize& repeatSpacing)
+void GraphicsContext::drawTiledImage(Image* image, const IntRect& destRect, const IntPoint& srcPoint, const IntSize& tileSize, CompositeOperator op, InterpolationQuality interpolationQuality, WebBlendMode blendMode, const IntSize& repeatSpacing)
 {
     if (paintingDisabled() || !image)
         return;
 
-    if (useLowQualityScale) {
+    if (interpolationQuality != InterpolationDefault) {

[Stephen White, 2014/03/18 17:26:43]

Same here.

[Alpha Left Google, 2014/03/18 22:59:13]

Done.

         InterpolationQuality previousInterpolationQuality = imageInterpolationQuality();
-        setImageInterpolationQuality(InterpolationLow);
+        setImageInterpolationQuality(interpolationQuality);
         image->drawTiled(this, destRect, srcPoint, tileSize, op, blendMode, repeatSpacing);
         setImageInterpolationQuality(previousInterpolationQuality);
     } else {
@@ -1079,7 +1077,7 @@ void GraphicsContext::drawTiledImage(Image* image, const IntRect& destRect, cons
 }
 
 void GraphicsContext::drawTiledImage(Image* image, const IntRect& dest, const IntRect& srcRect,
-    const FloatSize& tileScaleFactor, Image::TileRule hRule, Image::TileRule vRule, CompositeOperator op, bool useLowQualityScale)
+    const FloatSize& tileScaleFactor, Image::TileRule hRule, Image::TileRule vRule, CompositeOperator op, InterpolationQuality interpolationQuality)
 {
     if (paintingDisabled() || !image)
         return;
@@ -1090,9 +1088,9 @@ void GraphicsContext::drawTiledImage(Image* image, const IntRect& dest, const In
         return;
     }
 
-    if (useLowQualityScale) {
+    if (interpolationQuality != InterpolationDefault) {

[Stephen White, 2014/03/18 17:26:43]

Same here.

[Alpha Left Google, 2014/03/18 22:59:13]

Done.

         InterpolationQuality previousInterpolationQuality = imageInterpolationQuality();
-        setImageInterpolationQuality(InterpolationLow);
+        setImageInterpolationQuality(interpolationQuality);
         image->drawTiled(this, dest, srcRect, tileScaleFactor, hRule, vRule, op);
         setImageInterpolationQuality(previousInterpolationQuality);
     } else {
@@ -1107,11 +1105,11 @@ void GraphicsContext::drawImageBuffer(ImageBuffer* image, const IntPoint& p, Com
     drawImageBuffer(image, FloatRect(IntRect(p, image->size())), FloatRect(FloatPoint(), FloatSize(image->size())), op, blendMode);
 }
 
-void GraphicsContext::drawImageBuffer(ImageBuffer* image, const IntRect& r, CompositeOperator op, WebBlendMode blendMode, bool useLowQualityScale)
+void GraphicsContext::drawImageBuffer(ImageBuffer* image, const IntRect& r, CompositeOperator op, WebBlendMode blendMode, InterpolationQuality interpolationQuality)
 {
     if (!image)
         return;
-    drawImageBuffer(image, FloatRect(r), FloatRect(FloatPoint(), FloatSize(image->size())), op, blendMode, useLowQualityScale);
+    drawImageBuffer(image, FloatRect(r), FloatRect(FloatPoint(), FloatSize(image->size())), op, blendMode, interpolationQuality);
 }
 
 void GraphicsContext::drawImageBuffer(ImageBuffer* image, const IntPoint& dest, const IntRect& srcRect, CompositeOperator op, WebBlendMode blendMode)
@@ -1119,9 +1117,9 @@ void GraphicsContext::drawImageBuffer(ImageBuffer* image, const IntPoint& dest,
     drawImageBuffer(image, FloatRect(IntRect(dest, srcRect.size())), FloatRect(srcRect), op, blendMode);
 }
 
-void GraphicsContext::drawImageBuffer(ImageBuffer* image, const IntRect& dest, const IntRect& srcRect, CompositeOperator op, WebBlendMode blendMode, bool useLowQualityScale)
+void GraphicsContext::drawImageBuffer(ImageBuffer* image, const IntRect& dest, const IntRect& srcRect, CompositeOperator op, WebBlendMode blendMode, InterpolationQuality interpolationQuality)
 {
-    drawImageBuffer(image, FloatRect(dest), FloatRect(srcRect), op, blendMode, useLowQualityScale);
+    drawImageBuffer(image, FloatRect(dest), FloatRect(srcRect), op, blendMode, interpolationQuality);
 }
 
 void GraphicsContext::drawImageBuffer(ImageBuffer* image, const FloatRect& dest)
@@ -1131,18 +1129,18 @@ void GraphicsContext::drawImageBuffer(ImageBuffer* image, const FloatRect& dest)
     drawImageBuffer(image, dest, FloatRect(IntRect(IntPoint(), image->size())));
 }
 
-void GraphicsContext::drawImageBuffer(ImageBuffer* image, const FloatRect& dest, const FloatRect& src, CompositeOperator op, WebBlendMode blendMode, bool useLowQualityScale)
+void GraphicsContext::drawImageBuffer(ImageBuffer* image, const FloatRect& dest, const FloatRect& src, CompositeOperator op, WebBlendMode blendMode, InterpolationQuality interpolationQuality)
 {
     if (paintingDisabled() || !image)
         return;
 
-    if (useLowQualityScale) {
+    if (interpolationQuality != InterpolationDefault) {

[Stephen White, 2014/03/18 17:26:43]

Same here. (Tangentially, I wonder if these functions could be templated and/or
refactored.)

[Alpha Left Google, 2014/03/18 22:59:13]

Done. Yeah I'll leave that refactoring as a separate change.

         InterpolationQuality previousInterpolationQuality = imageInterpolationQuality();
-        setImageInterpolationQuality(InterpolationLow);
-        image->draw(this, dest, src, op, blendMode, useLowQualityScale);
+        setImageInterpolationQuality(interpolationQuality);
+        image->draw(this, dest, src, op, blendMode, interpolationQuality);

[Stephen White, 2014/03/18 17:26:43]

(Not new to this patch, but it seems odd that we have to both set the
interpolation quality, and pass it to image->draw() as well.)

[Alpha Left Google, 2014/03/18 22:59:13]

Indeed. :(

         setImageInterpolationQuality(previousInterpolationQuality);
     } else {
-        image->draw(this, dest, src, op, blendMode, useLowQualityScale);
+        image->draw(this, dest, src, op, blendMode, interpolationQuality);
     }
 }