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