src/third_party/skia/src/effects/SkXfermodeImageFilter.cpp

   1 /*
   2  * Copyright 2013 The Android Open Source Project
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7
   8 #include "SkXfermodeImageFilter.h"
   9 #include "SkCanvas.h"
  10 #include "SkDevice.h"
  11 #include "SkColorPriv.h"
  12 #include "SkReadBuffer.h"
  13 #include "SkWriteBuffer.h"
  14 #include "SkXfermode.h"
  15 #if SK_SUPPORT_GPU
  16 #include "GrContext.h"
  17 #include "effects/GrSimpleTextureEffect.h"
  18 #include "SkGr.h"
  19 #include "SkImageFilterUtils.h"
  20 #endif
  21
  22 ///////////////////////////////////////////////////////////////////////////////
  23
  24 SkXfermodeImageFilter::SkXfermodeImageFilter(SkXfermode* mode,
  25                                              SkImageFilter* background,
  26                                              SkImageFilter* foreground,
  27                                              const CropRect* cropRect)
  28   : INHERITED(background, foreground, cropRect), fMode(mode) {
  29     SkSafeRef(fMode);
  30 }
  31
  32 SkXfermodeImageFilter::~SkXfermodeImageFilter() {
  33     SkSafeUnref(fMode);
  34 }
  35
  36 SkXfermodeImageFilter::SkXfermodeImageFilter(SkReadBuffer& buffer)
  37   : INHERITED(2, buffer) {
  38     fMode = buffer.readXfermode();
  39 }
  40
  41 void SkXfermodeImageFilter::flatten(SkWriteBuffer& buffer) const {
  42     this->INHERITED::flatten(buffer);
  43     buffer.writeFlattenable(fMode);
  44 }
  45
  46 bool SkXfermodeImageFilter::onFilterImage(Proxy* proxy,
  47                                             const SkBitmap& src,
  48                                             const SkMatrix& ctm,
  49                                             SkBitmap* dst,
  50                                             SkIPoint* offset) const {
  51     SkBitmap background = src, foreground = src;
  52     SkImageFilter* backgroundInput = getInput(0);
  53     SkImageFilter* foregroundInput = getInput(1);
  54     SkIPoint backgroundOffset = SkIPoint::Make(0, 0);
  55     if (backgroundInput &&
  56         !backgroundInput->filterImage(proxy, src, ctm, &background, &backgroundOffset)) {
  57         return false;
  58     }
  59     SkIPoint foregroundOffset = SkIPoint::Make(0, 0);
  60     if (foregroundInput &&
  61         !foregroundInput->filterImage(proxy, src, ctm, &foreground, &foregroundOffset)) {
  62         return false;
  63     }
  64
  65     SkIRect bounds, foregroundBounds;
  66     background.getBounds(&bounds);
  67     bounds.offset(backgroundOffset);
  68     foreground.getBounds(&foregroundBounds);
  69     foregroundBounds.offset(foregroundOffset);
  70     bounds.join(foregroundBounds);
  71     if (!applyCropRect(&bounds, ctm)) {
  72         return false;
  73     }
  74
  75     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
  76     if (NULL == device.get()) {
  77         return false;
  78     }
  79     SkCanvas canvas(device);
  80     canvas.translate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
  81     SkPaint paint;
  82     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
  83     canvas.drawBitmap(background, SkIntToScalar(backgroundOffset.fX),
  84                       SkIntToScalar(backgroundOffset.fY), &paint);
  85     paint.setXfermode(fMode);
  86     canvas.drawBitmap(foreground, SkIntToScalar(foregroundOffset.fX),
  87                       SkIntToScalar(foregroundOffset.fY), &paint);
  88     canvas.clipRect(SkRect::Make(foregroundBounds), SkRegion::kDifference_Op);
  89     paint.setColor(SK_ColorTRANSPARENT);
  90     canvas.drawPaint(paint);
  91     *dst = device->accessBitmap(false);
  92     offset->fX = bounds.left();
  93     offset->fY = bounds.top();
  94     return true;
  95 }
  96
  97 #if SK_SUPPORT_GPU
  98
  99 bool SkXfermodeImageFilter::filterImageGPU(Proxy* proxy,
 100                                            const SkBitmap& src,
 101                                            const SkMatrix& ctm,
 102                                            SkBitmap* result,
 103                                            SkIPoint* offset) const {
 104     SkBitmap background;
 105     SkIPoint backgroundOffset = SkIPoint::Make(0, 0);
 106     if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, ctm, &background,
 107                                                &backgroundOffset)) {
 108         return false;
 109     }
 110     GrTexture* backgroundTex = background.getTexture();
 111     SkBitmap foreground;
 112     SkIPoint foregroundOffset = SkIPoint::Make(0, 0);
 113     if (!SkImageFilterUtils::GetInputResultGPU(getInput(1), proxy, src, ctm, &foreground,
 114                                                &foregroundOffset)) {
 115         return false;
 116     }
 117     GrTexture* foregroundTex = foreground.getTexture();
 118     GrContext* context = foregroundTex->getContext();
 119
 120     GrEffectRef* xferEffect = NULL;
 121
 122     GrTextureDesc desc;
 123     desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
 124     desc.fWidth = src.width();
 125     desc.fHeight = src.height();
 126     desc.fConfig = kSkia8888_GrPixelConfig;
 127
 128     GrAutoScratchTexture ast(context, desc);
 129     SkAutoTUnref<GrTexture> dst(ast.detach());
 130
 131     GrContext::AutoRenderTarget art(context, dst->asRenderTarget());
 132
 133     SkXfermode::Coeff sm, dm;
 134     if (!SkXfermode::AsNewEffectOrCoeff(fMode, &xferEffect, &sm, &dm, backgroundTex)) {
 135         return false;
 136     }
 137
 138     SkMatrix foregroundMatrix = GrEffect::MakeDivByTextureWHMatrix(foregroundTex);
 139     foregroundMatrix.preTranslate(SkIntToScalar(backgroundOffset.fX-foregroundOffset.fX),
 140                                   SkIntToScalar(backgroundOffset.fY-foregroundOffset.fY));
 141
 142
 143     SkRect srcRect;
 144     src.getBounds(&srcRect);
 145     if (NULL != xferEffect) {
 146         GrPaint paint;
 147         paint.addColorTextureEffect(foregroundTex, foregroundMatrix);
 148         paint.addColorEffect(xferEffect)->unref();
 149         context->drawRect(paint, srcRect);
 150     } else {
 151         GrPaint backgroundPaint;
 152         SkMatrix backgroundMatrix = GrEffect::MakeDivByTextureWHMatrix(backgroundTex);
 153         backgroundPaint.addColorTextureEffect(backgroundTex, backgroundMatrix);
 154         context->drawRect(backgroundPaint, srcRect);
 155
 156         GrPaint foregroundPaint;
 157         foregroundPaint.setBlendFunc(sk_blend_to_grblend(sm), sk_blend_to_grblend(dm));
 158         foregroundPaint.addColorTextureEffect(foregroundTex, foregroundMatrix);
 159         context->drawRect(foregroundPaint, srcRect);
 160     }
 161     offset->fX = backgroundOffset.fX;
 162     offset->fY = backgroundOffset.fY;
 163     return SkImageFilterUtils::WrapTexture(dst, src.width(), src.height(), result);
 164 }
 165
 166 #endif