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
23SkXfermodeImageFilter::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
31SkXfermodeImageFilter::~SkXfermodeImageFilter() {
32    SkSafeUnref(fMode);
33}
34
35SkXfermodeImageFilter::SkXfermodeImageFilter(SkFlattenableReadBuffer& buffer)
36  : INHERITED(2, buffer) {
37    fMode = buffer.readXfermode();
38}
39
40void SkXfermodeImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
41    this->INHERITED::flatten(buffer);
42    buffer.writeFlattenable(fMode);
43}
44
45bool 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
98bool 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
166