Support canvas size as default object size

third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp

 // Copyright 2016 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 "modules/canvas2d/BaseRenderingContext2D.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/css/parser/CSSParser.h"
@@ skipping 838 matching lines @@
         return value.getAsHTMLCanvasElement().get();
     if (value.isImageBitmap())
         return value.getAsImageBitmap().get();
     ASSERT_NOT_REACHED();
     return nullptr;
 }
 
 void BaseRenderingContext2D::drawImage(const CanvasImageSourceUnion& imageSource, double x, double y, ExceptionState& exceptionState)
 {
     CanvasImageSource* imageSourceInternal = toImageSourceInternal(imageSource);
-    FloatSize sourceRectSize = imageSourceInternal->elementSize();
-    FloatSize destRectSize = imageSourceInternal->defaultDestinationSize();
+    FloatSize defaultObjectSize(width(), height());
+    FloatSize sourceRectSize = imageSourceInternal->elementSize(defaultObjectSize);
+    FloatSize destRectSize = imageSourceInternal->defaultDestinationSize(defaultObjectSize);
     drawImage(imageSourceInternal, 0, 0, sourceRectSize.width(), sourceRectSize.height(), x, y, destRectSize.width(), destRectSize.height(), exceptionState);
 }
 
 void BaseRenderingContext2D::drawImage(const CanvasImageSourceUnion& imageSource,
     double x, double y, double width, double height, ExceptionState& exceptionState)
 {
     CanvasImageSource* imageSourceInternal = toImageSourceInternal(imageSource);
-    FloatSize sourceRectSize = imageSourceInternal->elementSize();
+    FloatSize defaultObjectSize(this->width(), this->height());
+    FloatSize sourceRectSize = imageSourceInternal->elementSize(defaultObjectSize);
     drawImage(imageSourceInternal, 0, 0, sourceRectSize.width(), sourceRectSize.height(), x, y, width, height, exceptionState);
 }
 
 void BaseRenderingContext2D::drawImage(const CanvasImageSourceUnion& imageSource,
     double sx, double sy, double sw, double sh,
     double dx, double dy, double dw, double dh, ExceptionState& exceptionState)
 {
     CanvasImageSource* imageSourceInternal = toImageSourceInternal(imageSource);
     drawImage(imageSourceInternal, sx, sy, sw, sh, dx, dy, dw, dh, exceptionState);
 }
@@ skipping 85 matching lines @@
 }
 
 void BaseRenderingContext2D::drawImage(CanvasImageSource* imageSource,
     double sx, double sy, double sw, double sh,
     double dx, double dy, double dw, double dh, ExceptionState& exceptionState)
 {
     if (!drawingCanvas())
         return;
 
     RefPtr<Image> image;
+    FloatSize defaultObjectSize(width(), height());
     SourceImageStatus sourceImageStatus = InvalidSourceImageStatus;
     if (!imageSource->isVideoElement()) {
         AccelerationHint hint = imageBuffer()->isAccelerated() ? PreferAcceleration : PreferNoAcceleration;
-        image = imageSource->getSourceImageForCanvas(&sourceImageStatus, hint, SnapshotReasonDrawImage);
+        image = imageSource->getSourceImageForCanvas(&sourceImageStatus, hint, SnapshotReasonDrawImage, defaultObjectSize);
         if (sourceImageStatus == UndecodableSourceImageStatus)
             exceptionState.throwDOMException(InvalidStateError, "The HTMLImageElement provided is in the 'broken' state.");
         if (!image || !image->width() || !image->height())
             return;
     } else {
         if (!static_cast<HTMLVideoElement*>(imageSource)->hasAvailableVideoFrame())
             return;
     }
 
     if (!std::isfinite(dx) || !std::isfinite(dy) || !std::isfinite(dw) || !std::isfinite(dh)
         || !std::isfinite(sx) || !std::isfinite(sy) || !std::isfinite(sw) || !std::isfinite(sh)
         || !dw || !dh || !sw || !sh)
         return;
 
     FloatRect srcRect = normalizeRect(FloatRect(sx, sy, sw, sh));
     FloatRect dstRect = normalizeRect(FloatRect(dx, dy, dw, dh));
 
-    clipRectsToImageRect(FloatRect(FloatPoint(), imageSource->elementSize()), &srcRect, &dstRect);
+    clipRectsToImageRect(FloatRect(FloatPoint(), imageSource->elementSize(defaultObjectSize)), &srcRect, &dstRect);
 
     imageSource->adjustDrawRects(&srcRect, &dstRect);
 
     if (srcRect.isEmpty())
         return;
 
     DisableDeferralReason reason = DisableDeferralReasonUnknown;
     if (shouldDisableDeferral(imageSource, &reason) || image->isTextureBacked())
         disableDeferral(reason);
 
@@ skipping 10 matching lines @@
         }, dstRect, CanvasRenderingContext2DState::ImagePaintType,
         imageSource->isOpaque() ? CanvasRenderingContext2DState::OpaqueImage : CanvasRenderingContext2DState::NonOpaqueImage);
 
     validateStateStack();
 
     bool isExpensive = false;
 
     if (ExpensiveCanvasHeuristicParameters::SVGImageSourcesAreExpensive && imageSource->isSVGSource())
         isExpensive = true;
 
-    if (imageSource->elementSize().width() * imageSource->elementSize().height() > width() * height() * ExpensiveCanvasHeuristicParameters::ExpensiveImageSizeRatio)
+    if (imageSource->elementSize(defaultObjectSize).width() * imageSource->elementSize(defaultObjectSize).height() > width() * height() * ExpensiveCanvasHeuristicParameters::ExpensiveImageSizeRatio)

[fs, 2016/03/04 14:31:26]

Nit: Maybe store the result of imageSource->elementSize(...) (explicitly) on the
stack on first use to avoid recomputing it three times? (And simplify this
expression somewhat too.)

[Justin Novosad, 2016/03/04 14:38:59]

+1

[davve, 2016/03/04 15:10:36]

Done.

         isExpensive = true;
 
     if (isExpensive) {
         ImageBuffer* buffer = imageBuffer();
         if (buffer)
             buffer->setHasExpensiveOp();
     }
 
     if (imageSource->isCanvasElement() && static_cast<HTMLCanvasElement*>(imageSource)->is3D()) {
         // WebGL to 2D canvas: must flush graphics context to prevent a race
@@ skipping 39 matching lines @@
 }
 
 CanvasPattern* BaseRenderingContext2D::createPattern(const CanvasImageSourceUnion& imageSource, const String& repetitionType, ExceptionState& exceptionState)
 {
     Pattern::RepeatMode repeatMode = CanvasPattern::parseRepetitionType(repetitionType, exceptionState);
     if (exceptionState.hadException())
         return nullptr;
 
     SourceImageStatus status;
     CanvasImageSource* imageSourceInternal = toImageSourceInternal(imageSource);
-    RefPtr<Image> imageForRendering = imageSourceInternal->getSourceImageForCanvas(&status, PreferNoAcceleration, SnapshotReasonCreatePattern);
+    FloatSize defaultObjectSize(width(), height());
+    RefPtr<Image> imageForRendering = imageSourceInternal->getSourceImageForCanvas(&status, PreferNoAcceleration, SnapshotReasonCreatePattern, defaultObjectSize);
 
     switch (status) {
     case NormalSourceImageStatus:
         break;
     case ZeroSizeCanvasSourceImageStatus:
-        exceptionState.throwDOMException(InvalidStateError, String::format("The canvas %s is 0.", imageSourceInternal->elementSize().width() ? "height" : "width"));
+        exceptionState.throwDOMException(InvalidStateError, String::format("The canvas %s is 0.", imageSourceInternal->elementSize(defaultObjectSize).width() ? "height" : "width"));
         return nullptr;
     case UndecodableSourceImageStatus:
         exceptionState.throwDOMException(InvalidStateError, "Source image is in the 'broken' state.");
         return nullptr;
     case InvalidSourceImageStatus:
         imageForRendering = Image::nullImage();
         break;
     case IncompleteSourceImageStatus:
         return nullptr;
     default:
@@ skipping 254 matching lines @@
 
     imageBuffer()->willOverwriteCanvas();
 }
 
 DEFINE_TRACE(BaseRenderingContext2D)
 {
     visitor->trace(m_stateStack);
 }
 
 } // namespace blink