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(2, 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, foregroundBounds;
  65     background.getBounds(&bounds);
  66     bounds.offset(backgroundOffset);
  67     foreground.getBounds(&foregroundBounds);
  68     foregroundBounds.offset(foregroundOffset);
  69     bounds.join(foregroundBounds);
  70     if (!applyCropRect(&bounds, ctm)) {
  71         return false;
  72     }
  73
  74     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
  75     if (NULL == device.get()) {
  76         return false;
  77     }
  78     SkCanvas canvas(device);
  79     canvas.translate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
  80     SkPaint paint;
  81     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
  82     canvas.drawBitmap(background, SkIntToScalar(backgroundOffset.fX),
  83                       SkIntToScalar(backgroundOffset.fY), &paint);
  84     paint.setXfermode(fMode);
  85     canvas.drawBitmap(foreground, SkIntToScalar(foregroundOffset.fX),
  86                       SkIntToScalar(foregroundOffset.fY), &paint);
  87     canvas.clipRect(SkRect::Make(foregroundBounds), SkRegion::kDifference_Op);
  88     paint.setColor(SK_ColorTRANSPARENT);
  89     canvas.drawPaint(paint);
  90     *dst = device->accessBitmap(false);
  91     offset->fX = bounds.left();
  92     offset->fY = bounds.top();
  93     return true;
  94 }
  95
  96 #if SK_SUPPORT_GPU
  97
  98 bool SkXfermodeImageFilter::filterImageGPU(Proxy* proxy,
  99                                            const SkBitmap& src,
 100                                            const SkMatrix& ctm,
 101                                            SkBitmap* result,
 102                                            SkIPoint* offset) {
 103     SkBitmap background;
 104     SkIPoint backgroundOffset = SkIPoint::Make(0, 0);
 105     if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, ctm, &background,
 106                                                &backgroundOffset)) {
 107         return false;
 108     }
 109     GrTexture* backgroundTex = background.getTexture();
 110     SkBitmap foreground;
 111     SkIPoint foregroundOffset = SkIPoint::Make(0, 0);
 112     if (!SkImageFilterUtils::GetInputResultGPU(getInput(1), proxy, src, ctm, &foreground,
 113                                                &foregroundOffset)) {
 114         return false;
 115     }
 116     GrTexture* foregroundTex = foreground.getTexture();
 117     GrContext* context = foregroundTex->getContext();
 118
 119     GrEffectRef* xferEffect = NULL;
 120
 121     GrTextureDesc desc;
 122     desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
 123     desc.fWidth = src.width();
 124     desc.fHeight = src.height();
 125     desc.fConfig = kSkia8888_GrPixelConfig;
 126
 127     GrAutoScratchTexture ast(context, desc);
 128     SkAutoTUnref<GrTexture> dst(ast.detach());
 129
 130     GrContext::AutoRenderTarget art(context, dst->asRenderTarget());
 131
 132     SkXfermode::Coeff sm, dm;
 133     if (!SkXfermode::AsNewEffectOrCoeff(fMode, &xferEffect, &sm, &dm, backgroundTex)) {
 134         return false;
 135     }
 136
 137     SkMatrix foregroundMatrix = GrEffect::MakeDivByTextureWHMatrix(foregroundTex);
 138     foregroundMatrix.preTranslate(SkIntToScalar(backgroundOffset.fX-foregroundOffset.fX),
 139                                   SkIntToScalar(backgroundOffset.fY-foregroundOffset.fY));
 140
 141
 142     SkRect srcRect;
 143     src.getBounds(&srcRect);
 144     if (NULL != xferEffect) {
 145         GrPaint paint;
 146         paint.addColorTextureEffect(foregroundTex, foregroundMatrix);
 147         paint.addColorEffect(xferEffect)->unref();
 148         context->drawRect(paint, srcRect);
 149     } else {
 150         GrPaint backgroundPaint;
 151         SkMatrix backgroundMatrix = GrEffect::MakeDivByTextureWHMatrix(backgroundTex);
 152         backgroundPaint.addColorTextureEffect(backgroundTex, backgroundMatrix);
 153         context->drawRect(backgroundPaint, srcRect);
 154
 155         GrPaint foregroundPaint;
 156         foregroundPaint.setBlendFunc(sk_blend_to_grblend(sm), sk_blend_to_grblend(dm));
 157         foregroundPaint.addColorTextureEffect(foregroundTex, foregroundMatrix);
 158         context->drawRect(foregroundPaint, srcRect);
 159     }
 160     offset->fX = backgroundOffset.fX;
 161     offset->fY = backgroundOffset.fY;
 162     return SkImageFilterUtils::WrapTexture(dst, src.width(), src.height(), result);
 163 }
 164
 165 #endif