src/third_party/WebKit/Source/core/paint/HTMLCanvasPainter.cpp

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "config.h"
   6 #include "core/paint/HTMLCanvasPainter.h"
   7
   8 #include "core/html/HTMLCanvasElement.h"
   9 #include "core/rendering/PaintInfo.h"
  10 #include "core/rendering/RenderHTMLCanvas.h"
  11 #include "platform/geometry/LayoutPoint.h"
  12
  13 namespace blink {
  14
  15 void HTMLCanvasPainter::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
  16 {
  17     GraphicsContext* context = paintInfo.context;
  18
  19     LayoutRect contentRect = m_renderHTMLCanvas.contentBoxRect();
  20     contentRect.moveBy(paintOffset);
  21     LayoutRect paintRect = m_renderHTMLCanvas.replacedContentRect();
  22     paintRect.moveBy(paintOffset);
  23
  24     bool clip = !contentRect.contains(paintRect);
  25     if (clip) {
  26         // Not allowed to overflow the content box.
  27         paintInfo.context->save();
  28         paintInfo.context->clip(pixelSnappedIntRect(contentRect));
  29     }
  30
  31     // FIXME: InterpolationNone should be used if ImageRenderingOptimizeContrast is set.
  32     // See bug for more details: crbug.com/353716.
  33     InterpolationQuality interpolationQuality = m_renderHTMLCanvas.style()->imageRendering() == ImageRenderingOptimizeContrast ? InterpolationLow : CanvasDefaultInterpolationQuality;
  34
  35     HTMLCanvasElement* canvas = toHTMLCanvasElement(m_renderHTMLCanvas.node());
  36     LayoutSize layoutSize = contentRect.size();
  37     if (m_renderHTMLCanvas.style()->imageRendering() == ImageRenderingPixelated
  38         && (layoutSize.width() > canvas->width() || layoutSize.height() > canvas->height() || layoutSize == canvas->size())) {
  39         interpolationQuality = InterpolationNone;
  40     }
  41
  42     InterpolationQuality previousInterpolationQuality = context->imageInterpolationQuality();
  43     context->setImageInterpolationQuality(interpolationQuality);
  44     canvas->paint(context, paintRect);
  45     context->setImageInterpolationQuality(previousInterpolationQuality);
  46
  47     if (clip)
  48         context->restore();
  49 }
  50
  51 } // namespace blink