text: /*
   * 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 "sky/engine/config.h"
  #include "sky/engine/platform/graphics/Pattern.h"
  
  #include "sky/engine/platform/graphics/skia/SkiaUtils.h"
  #include "third_party/skia/include/core/SkCanvas.h"
  #include "third_party/skia/include/core/SkColorShader.h"
  #include "v8/include/v8.h"
  
  namespace blink {
  
  PassRefPtr<Pattern> Pattern::createBitmapPattern(PassRefPtr<Image> tileImage, RepeatMode repeatMode)
  {
      return adoptRef(new Pattern(tileImage, repeatMode));
  }
  
  Pattern::Pattern(PassRefPtr<Image> image, RepeatMode repeatMode)
      : m_repeatMode(repeatMode)
      , m_externalMemoryAllocated(0)
  {
      if (image) {
          m_tileImage = image->nativeImageForCurrentFrame();
      }
  }
  
  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_repeatMode == RepeatModeXY) {
          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_repeatMode & RepeatModeX)
              ? SkShader::kRepeat_TileMode
              : SkShader::kClamp_TileMode;
          SkShader::TileMode tileModeY = (m_repeatMode & RepeatModeY)
              ? SkShader::kRepeat_TileMode
              : SkShader::kClamp_TileMode;
          int expandW = (m_repeatMode & RepeatModeX) ? 0 : 1;
          int expandH = (m_repeatMode & RepeatModeY) ? 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();
  }
  
  void Pattern::setPatternSpaceTransform(const AffineTransform& patternSpaceTransformation)
  {
      if (patternSpaceTransformation == m_patternSpaceTransformation)
          return;
  
      m_patternSpaceTransformation = patternSpaceTransformation;
      m_pattern.clear();
  }
  
  } // namespace blink
  