Home | History | Annotate | Download | only in graphics 
      1 /*
      2  * Copyright (C) 2006, 2007, 2008 Apple Computer, Inc.  All rights reserved.
      3  * Copyright (C) 2008 Eric Seidel <eric (at) webkit.org>
      4  * Copyright (C) 2013 Google, Inc. All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     22  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     23  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     25  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include "config.h"
     29 #include "platform/graphics/Pattern.h"
     30 
     31 #include <v8.h>
     32 #include "SkCanvas.h"
     33 #include "SkColorShader.h"
     34 #include "platform/graphics/skia/SkiaUtils.h"
     35 
     36 namespace blink {
     37 
     38 PassRefPtr<Pattern> Pattern::createBitmapPattern(PassRefPtr<Image> tileImage, RepeatMode repeatMode)
     39 {
     40     return adoptRef(new Pattern(tileImage, repeatMode));
     41 }
     42 
     43 Pattern::Pattern(PassRefPtr<Image> image, RepeatMode repeatMode)
     44     : m_repeatMode(repeatMode)
     45     , m_externalMemoryAllocated(0)
     46 {
     47     if (image) {
     48         m_tileImage = image->nativeImageForCurrentFrame();
     49     }
     50 }
     51 
     52 Pattern::~Pattern()
     53 {
     54     if (m_externalMemoryAllocated)
     55         v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(-m_externalMemoryAllocated);
     56 }
     57 
     58 SkShader* Pattern::shader()
     59 {
     60     if (m_pattern)
     61         return m_pattern.get();
     62 
     63     SkMatrix localMatrix = affineTransformToSkMatrix(m_patternSpaceTransformation);
     64 
     65     // If we don't have a bitmap, return a transparent shader.
     66     if (!m_tileImage) {
     67         m_pattern = adoptRef(new SkColorShader(SK_ColorTRANSPARENT));
     68     } else if (m_repeatMode == RepeatModeXY) {
     69         m_pattern = adoptRef(SkShader::CreateBitmapShader(m_tileImage->bitmap(),
     70             SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &localMatrix));
     71     } else {
     72         // Skia does not have a "draw the tile only once" option. Clamp_TileMode
     73         // repeats the last line of the image after drawing one tile. To avoid
     74         // filling the space with arbitrary pixels, this workaround forces the
     75         // image to have a line of transparent pixels on the "repeated" edge(s),
     76         // thus causing extra space to be transparent filled.
     77         SkShader::TileMode tileModeX = (m_repeatMode & RepeatModeX)
     78             ? SkShader::kRepeat_TileMode
     79             : SkShader::kClamp_TileMode;
     80         SkShader::TileMode tileModeY = (m_repeatMode & RepeatModeY)
     81             ? SkShader::kRepeat_TileMode
     82             : SkShader::kClamp_TileMode;
     83         int expandW = (m_repeatMode & RepeatModeX) ? 0 : 1;
     84         int expandH = (m_repeatMode & RepeatModeY) ? 0 : 1;
     85 
     86         // Create a transparent bitmap 1 pixel wider and/or taller than the
     87         // original, then copy the orignal into it.
     88         // FIXME: Is there a better way to pad (not scale) an image in skia?
     89         SkImageInfo info = m_tileImage->bitmap().info();
     90         info.fWidth += expandW;
     91         info.fHeight += expandH;
     92         // we explicitly require non-opaquness, since we are going to add a transparent strip.
     93         info.fAlphaType = kPremul_SkAlphaType;
     94 
     95         SkBitmap bm2;
     96         bm2.allocPixels(info);
     97         bm2.eraseARGB(0x00, 0x00, 0x00, 0x00);
     98         SkCanvas canvas(bm2);
     99         canvas.drawBitmap(m_tileImage->bitmap(), 0, 0);
    100         bm2.setImmutable();
    101         m_pattern = adoptRef(SkShader::CreateBitmapShader(bm2, tileModeX, tileModeY, &localMatrix));
    102 
    103         // Clamp to int, since that's what the adjust function takes.
    104         m_externalMemoryAllocated = static_cast<int>(std::min(static_cast<size_t>(INT_MAX), bm2.getSafeSize()));
    105         v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(m_externalMemoryAllocated);
    106     }
    107     return m_pattern.get();
    108 }
    109 
    110 void Pattern::setPatternSpaceTransform(const AffineTransform& patternSpaceTransformation)
    111 {
    112     if (patternSpaceTransformation == m_patternSpaceTransformation)
    113         return;
    114 
    115     m_patternSpaceTransformation = patternSpaceTransformation;
    116     m_pattern.clear();
    117 }
    118 
    119 } // namespace blink
    120