Use newImageSnapshot() to get an image from a Canvas

Source/platform/graphics/Pattern.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2013 Google, Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-
 #include "config.h"
 #include "platform/graphics/Pattern.h"
 
+#include "platform/graphics/BitmapPattern.h"
+#include "platform/graphics/StaticBitmapPattern.h"
+#include "platform/graphics/skia/SkiaUtils.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkImage.h"
 #include <v8.h>
-#include "SkCanvas.h"
-#include "SkColorShader.h"
-#include "platform/graphics/skia/SkiaUtils.h"
-
 
 namespace blink {
 
-Pattern::Pattern(PassRefPtr<Image> image, bool repeatX, bool repeatY)
-    : m_repeatX(repeatX)
-    , m_repeatY(repeatY)
-    , m_externalMemoryAllocated(0)
+PassRefPtr<Pattern> Pattern::create(PassRefPtr<Image> tileImage, bool repeatX, bool repeatY)
 {
-    if (image) {
-        m_tileImage = image->nativeImageForCurrentFrame();
-    }
+    if (tileImage->image())
+        return StaticBitmapPattern::create(tileImage, repeatX, repeatY);
+
+    return BitmapPattern::create(tileImage, repeatX, repeatY);
 }
 
 Pattern::~Pattern()
 {
-    if (m_externalMemoryAllocated)
-        v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(-m_externalMemoryAllocated);
-}
-
-SkShader* Pattern::shader()
-{
-    if (m_pattern)
-        return m_pattern.get();
-
-    SkMatrix localMatrix = affineTransformToSkMatrix(m_patternSpaceTransformation);
-
-    // If we don't have a bitmap, return a transparent shader.
-    if (!m_tileImage)
-        m_pattern = adoptRef(new SkColorShader(SK_ColorTRANSPARENT));
-    else if (m_repeatX && m_repeatY)
-        m_pattern = adoptRef(SkShader::CreateBitmapShader(m_tileImage->bitmap(), SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &localMatrix));
-    else {
-        // Skia does not have a "draw the tile only once" option. Clamp_TileMode
-        // repeats the last line of the image after drawing one tile. To avoid
-        // filling the space with arbitrary pixels, this workaround forces the
-        // image to have a line of transparent pixels on the "repeated" edge(s),
-        // thus causing extra space to be transparent filled.
-        SkShader::TileMode tileModeX = m_repeatX ? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
-        SkShader::TileMode tileModeY = m_repeatY ? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
-        int expandW = m_repeatX ? 0 : 1;
-        int expandH = m_repeatY ? 0 : 1;
-
-        // Create a transparent bitmap 1 pixel wider and/or taller than the
-        // original, then copy the orignal into it.
-        // FIXME: Is there a better way to pad (not scale) an image in skia?
-        SkImageInfo info = m_tileImage->bitmap().info();
-        info.fWidth += expandW;
-        info.fHeight += expandH;
-        // we explicitly require non-opaquness, since we are going to add a transparent strip.
-        info.fAlphaType = kPremul_SkAlphaType;
-
-        SkBitmap bm2;
-        bm2.allocPixels(info);
-        bm2.eraseARGB(0x00, 0x00, 0x00, 0x00);
-        SkCanvas canvas(bm2);
-        canvas.drawBitmap(m_tileImage->bitmap(), 0, 0);
-        bm2.setImmutable();
-        m_pattern = adoptRef(SkShader::CreateBitmapShader(bm2, tileModeX, tileModeY, &localMatrix));
-
-        // Clamp to int, since that's what the adjust function takes.
-        m_externalMemoryAllocated = static_cast<int>(std::min(static_cast<size_t>(INT_MAX), bm2.getSafeSize()));
-        v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(m_externalMemoryAllocated);
-    }
-    return m_pattern.get();
+    adjustExternalMemoryAllocated(-m_externalMemoryAllocated);
 }
 
 void Pattern::setPatternSpaceTransform(const AffineTransform& patternSpaceTransformation)
 {
     m_patternSpaceTransformation = patternSpaceTransformation;
     if (m_pattern)
         m_pattern.clear();
 }
 
+SkShader* Pattern::shader(SkShader::ShaderLocation preferredLocation)
+{
+    if (!m_pattern) {
+        m_pattern = createShader(preferredLocation);
+    }
+
+    return m_pattern.get();
 }
+
+void Pattern::adjustExternalMemoryAllocated(int64_t delta)
+{
+    delta = std::max(-m_externalMemoryAllocated, delta);
+
+    v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(delta);
+
+    m_externalMemoryAllocated += delta;
+}
+
+BitmapBackedPattern::BitmapBackedPattern(bool repeatX, bool repeatY, int64_t externalMemoryAllocated) : Pattern(repeatX, repeatY, externalMemoryAllocated) { }
+
+BitmapBackedPattern::~BitmapBackedPattern() { }
+
+PassRefPtr<SkShader> BitmapBackedPattern::createShader(SkShader::ShaderLocation preferredLocation)

[Justin Novosad, 2014/08/05 17:31:26]

unused argument should be commented-out

[Rémi Piotaix, 2014/08/06 18:09:14]

Done.

+{
+    // Skia does not have a "draw the tile only once" option. Clamp_TileMode
+    // repeats the last line of the image after drawing one tile. To avoid
+    // filling the space with arbitrary pixels, this workaround forces the
+    // image to have a line of transparent pixels on the "repeated" edge(s),
+    // thus causing extra space to be transparent filled.
+    SkShader::TileMode tileModeX = m_repeatX ? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
+    SkShader::TileMode tileModeY = m_repeatY ? SkShader::kRepeat_TileMode : SkShader::kClamp_TileMode;
+    int expandW = m_repeatX ? 0 : 1;
+    int expandH = m_repeatY ? 0 : 1;
+
+    // Create a transparent bitmap 1 pixel wider and/or taller than the
+    // original, then copy the orignal into it.
+    // FIXME: Is there a better way to pad (not scale) an image in skia?
+    SkImageInfo info = this->getBitmapInfo();
+    info.fWidth = info.width() + expandW;
+    info.fHeight = info.height() + expandH;
+    // we explicitly require non-opaquness, since we are going to add a transparent strip.
+    info.fAlphaType = kPremul_SkAlphaType;
+
+    SkBitmap bm2;
+    bm2.allocPixels(info);
+    SkCanvas canvas(bm2);
+
+    SkPaint paint;
+    paint.setXfermode(SkXfermode::Create(SkXfermode::kSrc_Mode))->unref();

[Justin Novosad, 2014/08/05 17:31:26]

You should use the version of setXfermode that takes a SkXfermode::Mode instead
of creating an SkXfermode

[Rémi Piotaix, 2014/08/06 18:09:14]

Done.

+
+    this->drawBitmapToCanvas(canvas, paint);
+
+    paint.setARGB(0x00, 0x00, 0x00, 0x00);
+    paint.setStyle(SkPaint::kFill_Style);
+
+    if (!m_repeatX)
+        canvas.drawRect(SkRect::MakeXYWH(info.width() - 1, 0, 1, info.height()), paint);
+
+    if (!m_repeatY)
+        canvas.drawRect(SkRect::MakeXYWH(0, info.height()-1, info.width(), 1), paint);
+
+    bm2.setImmutable();
+
+    // Clamp to int, since that's what the adjust function takes.
+    adjustExternalMemoryAllocated(bm2.getSafeSize());
+
+    SkMatrix localMatrix = affineTransformToSkMatrix(m_patternSpaceTransformation);
+
+    return adoptRef(SkShader::CreateBitmapShader(bm2, tileModeX, tileModeY, &localMatrix));
+}
+
+}