1/*
2 * Copyright 2012 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 "SkColorFilterImageFilter.h"
9
10#include "SkCanvas.h"
11#include "SkColorFilter.h"
12#include "SkColorSpaceXformer.h"
13#include "SkImageFilterPriv.h"
14#include "SkReadBuffer.h"
15#include "SkSpecialImage.h"
16#include "SkSpecialSurface.h"
17#include "SkWriteBuffer.h"
18
19sk_sp<SkImageFilter> SkColorFilterImageFilter::Make(sk_sp<SkColorFilter> cf,
20                                                    sk_sp<SkImageFilter> input,
21                                                    const CropRect* cropRect) {
22    if (!cf) {
23        return nullptr;
24    }
25
26    SkColorFilter* inputCF;
27    if (input && input->isColorFilterNode(&inputCF)) {
28        // This is an optimization, as it collapses the hierarchy by just combining the two
29        // colorfilters into a single one, which the new imagefilter will wrap.
30        sk_sp<SkColorFilter> newCF(SkColorFilter::MakeComposeFilter(cf,// can't move bc of fallthru
31                                                                    sk_sp<SkColorFilter>(inputCF)));
32        if (newCF) {
33            return sk_sp<SkImageFilter>(new SkColorFilterImageFilter(std::move(newCF),
34                                                                     sk_ref_sp(input->getInput(0)),
35                                                                     cropRect));
36        }
37    }
38
39    return sk_sp<SkImageFilter>(new SkColorFilterImageFilter(std::move(cf),
40                                                             std::move(input),
41                                                             cropRect));
42}
43
44SkColorFilterImageFilter::SkColorFilterImageFilter(sk_sp<SkColorFilter> cf,
45                                                   sk_sp<SkImageFilter> input,
46                                                   const CropRect* cropRect)
47    : INHERITED(&input, 1, cropRect)
48    , fColorFilter(std::move(cf)) {
49}
50
51sk_sp<SkFlattenable> SkColorFilterImageFilter::CreateProc(SkReadBuffer& buffer) {
52    SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
53    sk_sp<SkColorFilter> cf(buffer.readColorFilter());
54    return Make(std::move(cf), common.getInput(0), &common.cropRect());
55}
56
57void SkColorFilterImageFilter::flatten(SkWriteBuffer& buffer) const {
58    this->INHERITED::flatten(buffer);
59    buffer.writeFlattenable(fColorFilter.get());
60}
61
62sk_sp<SkSpecialImage> SkColorFilterImageFilter::onFilterImage(SkSpecialImage* source,
63                                                              const Context& ctx,
64                                                              SkIPoint* offset) const {
65    SkIPoint inputOffset = SkIPoint::Make(0, 0);
66    sk_sp<SkSpecialImage> input(this->filterInput(0, source, ctx, &inputOffset));
67
68    SkIRect inputBounds;
69    if (fColorFilter->affectsTransparentBlack()) {
70        // If the color filter affects transparent black, the bounds are the entire clip.
71        inputBounds = ctx.clipBounds();
72    } else if (!input) {
73        return nullptr;
74    } else {
75        inputBounds = SkIRect::MakeXYWH(inputOffset.x(), inputOffset.y(),
76                                        input->width(), input->height());
77    }
78
79    SkIRect bounds;
80    if (!this->applyCropRect(ctx, inputBounds, &bounds)) {
81        return nullptr;
82    }
83
84    sk_sp<SkSpecialSurface> surf(source->makeSurface(ctx.outputProperties(), bounds.size()));
85    if (!surf) {
86        return nullptr;
87    }
88
89    SkCanvas* canvas = surf->getCanvas();
90    SkASSERT(canvas);
91
92    SkPaint paint;
93
94    paint.setBlendMode(SkBlendMode::kSrc);
95    paint.setColorFilter(fColorFilter);
96
97    // TODO: it may not be necessary to clear or drawPaint inside the input bounds
98    // (see skbug.com/5075)
99    if (fColorFilter->affectsTransparentBlack()) {
100        // The subsequent input->draw() call may not fill the entire canvas. For filters which
101        // affect transparent black, ensure that the filter is applied everywhere.
102        paint.setColor(SK_ColorTRANSPARENT);
103        canvas->drawPaint(paint);
104        paint.setColor(SK_ColorBLACK);
105    } else {
106        canvas->clear(0x0);
107    }
108
109    if (input) {
110        input->draw(canvas,
111                    SkIntToScalar(inputOffset.fX - bounds.fLeft),
112                    SkIntToScalar(inputOffset.fY - bounds.fTop),
113                    &paint);
114    }
115
116    offset->fX = bounds.fLeft;
117    offset->fY = bounds.fTop;
118    return surf->makeImageSnapshot();
119}
120
121sk_sp<SkImageFilter> SkColorFilterImageFilter::onMakeColorSpace(SkColorSpaceXformer* xformer)
122const {
123    SkASSERT(1 == this->countInputs());
124
125    sk_sp<SkImageFilter> input = xformer->apply(this->getInput(0));
126    auto colorFilter = xformer->apply(fColorFilter.get());
127    if (this->getInput(0) != input.get() || fColorFilter != colorFilter) {
128        return SkColorFilterImageFilter::Make(std::move(colorFilter), std::move(input),
129                                              this->getCropRectIfSet());
130    }
131    return this->refMe();
132}
133
134bool SkColorFilterImageFilter::onIsColorFilterNode(SkColorFilter** filter) const {
135    SkASSERT(1 == this->countInputs());
136    if (!this->cropRectIsSet()) {
137        if (filter) {
138            *filter = SkRef(fColorFilter.get());
139        }
140        return true;
141    }
142    return false;
143}
144
145bool SkColorFilterImageFilter::affectsTransparentBlack() const {
146    return fColorFilter->affectsTransparentBlack();
147}
148
149#ifndef SK_IGNORE_TO_STRING
150void SkColorFilterImageFilter::toString(SkString* str) const {
151    str->appendf("SkColorFilterImageFilter: (");
152
153    str->appendf("input: (");
154
155    if (this->getInput(0)) {
156        this->getInput(0)->toString(str);
157    }
158
159    str->appendf(") color filter: ");
160    fColorFilter->toString(str);
161
162    str->append(")");
163}
164#endif
165