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 "SkMergeImageFilter.h"
9#include "SkCanvas.h"
10#include "SkDevice.h"
11#include "SkReadBuffer.h"
12#include "SkWriteBuffer.h"
13#include "SkValidationUtils.h"
14
15///////////////////////////////////////////////////////////////////////////////
16
17void SkMergeImageFilter::initAllocModes() {
18    int inputCount = countInputs();
19    if (inputCount) {
20        size_t size = sizeof(uint8_t) * inputCount;
21        if (size <= sizeof(fStorage)) {
22            fModes = SkTCast<uint8_t*>(fStorage);
23        } else {
24            fModes = SkTCast<uint8_t*>(sk_malloc_throw(size));
25        }
26    } else {
27        fModes = NULL;
28    }
29}
30
31void SkMergeImageFilter::initModes(const SkXfermode::Mode modes[]) {
32    if (modes) {
33        this->initAllocModes();
34        int inputCount = countInputs();
35        for (int i = 0; i < inputCount; ++i) {
36            fModes[i] = SkToU8(modes[i]);
37        }
38    } else {
39        fModes = NULL;
40    }
41}
42
43SkMergeImageFilter::SkMergeImageFilter(SkImageFilter* first, SkImageFilter* second,
44                                       SkXfermode::Mode mode,
45                                       const CropRect* cropRect) : INHERITED(first, second, cropRect) {
46    if (SkXfermode::kSrcOver_Mode != mode) {
47        SkXfermode::Mode modes[] = { mode, mode };
48        this->initModes(modes);
49    } else {
50        fModes = NULL;
51    }
52}
53
54SkMergeImageFilter::SkMergeImageFilter(SkImageFilter* filters[], int count,
55                                       const SkXfermode::Mode modes[],
56                                       const CropRect* cropRect) : INHERITED(count, filters, cropRect) {
57    SkASSERT(count >= 0);
58    this->initModes(modes);
59}
60
61SkMergeImageFilter::~SkMergeImageFilter() {
62
63    if (fModes != SkTCast<uint8_t*>(fStorage)) {
64        sk_free(fModes);
65    }
66}
67
68bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
69                                       const Context& ctx,
70                                       SkBitmap* result, SkIPoint* offset) const {
71    if (countInputs() < 1) {
72        return false;
73    }
74
75    SkIRect bounds;
76    if (!this->applyCropRect(ctx, src, SkIPoint::Make(0, 0), &bounds)) {
77        return false;
78    }
79
80    const int x0 = bounds.left();
81    const int y0 = bounds.top();
82
83    SkAutoTUnref<SkBaseDevice> dst(proxy->createDevice(bounds.width(), bounds.height()));
84    if (NULL == dst) {
85        return false;
86    }
87    SkCanvas canvas(dst);
88    SkPaint paint;
89
90    int inputCount = countInputs();
91    for (int i = 0; i < inputCount; ++i) {
92        SkBitmap tmp;
93        const SkBitmap* srcPtr;
94        SkIPoint pos = SkIPoint::Make(0, 0);
95        SkImageFilter* filter = getInput(i);
96        if (filter) {
97            if (!filter->filterImage(proxy, src, ctx, &tmp, &pos)) {
98                return false;
99            }
100            srcPtr = &tmp;
101        } else {
102            srcPtr = &src;
103        }
104
105        if (fModes) {
106            paint.setXfermodeMode((SkXfermode::Mode)fModes[i]);
107        } else {
108            paint.setXfermode(NULL);
109        }
110        canvas.drawSprite(*srcPtr, pos.x() - x0, pos.y() - y0, &paint);
111    }
112
113    offset->fX = bounds.left();
114    offset->fY = bounds.top();
115    *result = dst->accessBitmap(false);
116    return true;
117}
118
119void SkMergeImageFilter::flatten(SkWriteBuffer& buffer) const {
120    this->INHERITED::flatten(buffer);
121
122    buffer.writeBool(fModes != NULL);
123    if (fModes) {
124        buffer.writeByteArray(fModes, countInputs() * sizeof(fModes[0]));
125    }
126}
127
128SkMergeImageFilter::SkMergeImageFilter(SkReadBuffer& buffer)
129  : INHERITED(-1, buffer) {
130    bool hasModes = buffer.readBool();
131    if (hasModes) {
132        this->initAllocModes();
133        int nbInputs = countInputs();
134        size_t size = nbInputs * sizeof(fModes[0]);
135        SkASSERT(buffer.getArrayCount() == size);
136        if (buffer.validate(buffer.getArrayCount() == size) &&
137            buffer.readByteArray(fModes, size)) {
138            for (int i = 0; i < nbInputs; ++i) {
139                buffer.validate(SkIsValidMode((SkXfermode::Mode)fModes[i]));
140            }
141        }
142    } else {
143        fModes = 0;
144    }
145}
146