Implement resize option for createImageBitmap(HTMLVideoElement)

third_party/WebKit/Source/core/frame/ImageBitmap.cpp

Index: third_party/WebKit/Source/core/frame/ImageBitmap.cpp
diff --git a/third_party/WebKit/Source/core/frame/ImageBitmap.cpp b/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
index 5efe36d700f3086ad7703144f1c644e6524496b2..17588768c78a2c1319ac2e0a949a344e040f8734 100644
--- a/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
+++ b/third_party/WebKit/Source/core/frame/ImageBitmap.cpp
@@ -28,6 +28,8 @@ struct ParsedOptions {
     bool shouldScaleInput = false;
     unsigned resizeWidth = 0;
     unsigned resizeHeight = 0;
+    float scaleRatioX = 1;
+    float scaleRatioY = 1;
     IntRect cropRect;
     SkFilterQuality resizeQuality = kLow_SkFilterQuality;
 };
@@ -47,7 +49,7 @@ static bool frameIsValid(const SkBitmap& frameBitmap)
     return frameBitmap.colorType() == kN32_SkColorType;
 }
 
-ParsedOptions parseOptions(const ImageBitmapOptions& options, Optional<IntRect> cropRect, IntSize sourceSize)
+ParsedOptions parseOptions(const ImageBitmapOptions& options, Optional<IntRect> cropRect, IntSize sourceSize, bool shouldCalculateRatio)
 {
     ParsedOptions parsedOptions;
     if (options.imageOrientation() == imageOrientationFlipY) {
@@ -88,6 +90,10 @@ ParsedOptions parseOptions(const ImageBitmapOptions& options, Optional<IntRect>
         return parsedOptions;
     }
     parsedOptions.shouldScaleInput = true;
+    if (shouldCalculateRatio) {
+        parsedOptions.scaleRatioX = static_cast<float>(parsedOptions.resizeWidth) / parsedOptions.cropRect.width();
+        parsedOptions.scaleRatioY = static_cast<float>(parsedOptions.resizeHeight) / parsedOptions.cropRect.height();
+    }
 
     if (options.resizeQuality() == "high")
         parsedOptions.resizeQuality = kHigh_SkFilterQuality;
@@ -282,7 +288,7 @@ static PassRefPtr<StaticBitmapImage> cropImage(Image* image, const ParsedOptions
 ImageBitmap::ImageBitmap(HTMLImageElement* image, Optional<IntRect> cropRect, Document* document, const ImageBitmapOptions& options)
 {
     RefPtr<Image> input = image->cachedImage()->getImage();
-    ParsedOptions parsedOptions = parseOptions(options, cropRect, image->bitmapSourceSize());
+    ParsedOptions parsedOptions = parseOptions(options, cropRect, image->bitmapSourceSize(), false);
 
     if (options.colorSpaceConversion() == "none")
         m_image = cropImage(input.get(), parsedOptions, PremultiplyAlpha, ImageDecoder::GammaAndColorProfileIgnored);
@@ -308,13 +314,11 @@ ImageBitmap::ImageBitmap(HTMLVideoElement* video, Optional<IntRect> cropRect, Do
     IntSize playerSize;
     if (video->webMediaPlayer())
         playerSize = video->webMediaPlayer()->naturalSize();
-
-    // TODO(xidachen); implement the resize option.
-    ParsedOptions parsedOptions = parseOptions(options, cropRect, video->bitmapSourceSize());
+    ParsedOptions parsedOptions = parseOptions(options, cropRect, video->bitmapSourceSize(), true);
 
     IntRect videoRect = IntRect(IntPoint(), playerSize);
     IntRect srcRect = intersection(parsedOptions.cropRect, videoRect);
-    std::unique_ptr<ImageBuffer> buffer = ImageBuffer::create(parsedOptions.cropRect.size(), NonOpaque, DoNotInitializeImagePixels);
+    std::unique_ptr<ImageBuffer> buffer = ImageBuffer::create(IntSize(parsedOptions.resizeWidth, parsedOptions.resizeHeight), NonOpaque, DoNotInitializeImagePixels);
     if (!buffer)
         return;
 
@@ -323,7 +327,14 @@ ImageBitmap::ImageBitmap(HTMLVideoElement* video, Optional<IntRect> cropRect, Do
         buffer->canvas()->scale(1, -1);
     }
     IntPoint dstPoint = IntPoint(std::max(0, -parsedOptions.cropRect.x()), std::max(0, -parsedOptions.cropRect.y()));
-    video->paintCurrentFrame(buffer->canvas(), IntRect(dstPoint, srcRect.size()), nullptr);
+    IntSize dstSize = srcRect.size();
+    SkPaint paint;
+    if (parsedOptions.shouldScaleInput) {
+        dstPoint.scale(parsedOptions.scaleRatioX, parsedOptions.scaleRatioY);

[Justin Novosad, 2016/07/29 15:08:52]

putting the scaleRAtion in parsedOptions is overkill IMHO.  they should just be
locals in this function. It adds unnecessary complexity to the shared parsing
function.  Not to mention that the bool arg is bad for readability.

[xidachen, 2016/07/29 17:22:10]

Yes, that makes perfect sense. Changed in the new PS.

+        paint.setFilterQuality(parsedOptions.resizeQuality);
+        dstSize.scale(parsedOptions.scaleRatioX, parsedOptions.scaleRatioY);
+    }
+    video->paintCurrentFrame(buffer->canvas(), IntRect(dstPoint, dstSize), parsedOptions.shouldScaleInput ? &paint : nullptr);
 
     RefPtr<SkImage> skiaImage = buffer->newSkImageSnapshot(PreferNoAcceleration, SnapshotReasonUnknown);
     if (!parsedOptions.premultiplyAlpha)
@@ -337,7 +348,7 @@ ImageBitmap::ImageBitmap(HTMLCanvasElement* canvas, Optional<IntRect> cropRect,
 {
     ASSERT(canvas->isPaintable());
     RefPtr<Image> input = canvas->copiedImage(BackBuffer, PreferAcceleration);
-    ParsedOptions parsedOptions = parseOptions(options, cropRect, canvas->bitmapSourceSize());
+    ParsedOptions parsedOptions = parseOptions(options, cropRect, canvas->bitmapSourceSize(), false);
 
     bool isPremultiplyAlphaReverted = false;
     if (!parsedOptions.premultiplyAlpha) {
@@ -379,7 +390,7 @@ ImageBitmap::ImageBitmap(ImageData* data, Optional<IntRect> cropRect, const Imag
 {
     // TODO(xidachen): implement the resize option
     IntRect dataSrcRect = IntRect(IntPoint(), data->size());
-    ParsedOptions parsedOptions = parseOptions(options, cropRect, data->bitmapSourceSize());
+    ParsedOptions parsedOptions = parseOptions(options, cropRect, data->bitmapSourceSize(), false);
     IntRect srcRect = cropRect ? intersection(parsedOptions.cropRect, dataSrcRect) : dataSrcRect;
 
     // treat non-premultiplyAlpha as a special case
@@ -480,7 +491,7 @@ ImageBitmap::ImageBitmap(ImageBitmap* bitmap, Optional<IntRect> cropRect, const
     RefPtr<Image> input = bitmap->bitmapImage();
     if (!input)
         return;
-    ParsedOptions parsedOptions = parseOptions(options, cropRect, input->size());
+    ParsedOptions parsedOptions = parseOptions(options, cropRect, input->size(), false);
 
     m_image = cropImage(input.get(), parsedOptions, bitmap->isPremultiplied() ? PremultiplyAlpha : DontPremultiplyAlpha);
     if (!m_image)
@@ -493,7 +504,7 @@ ImageBitmap::ImageBitmap(PassRefPtr<StaticBitmapImage> image, Optional<IntRect>
 {
     bool originClean = image->originClean();
     RefPtr<Image> input = image;
-    ParsedOptions parsedOptions = parseOptions(options, cropRect, input->size());
+    ParsedOptions parsedOptions = parseOptions(options, cropRect, input->size(), false);
 
     m_image = cropImage(input.get(), parsedOptions, DontPremultiplyAlpha);
     if (!m_image)