SkMatrixImageFilter.cpp revision daa57bfd4204f5a7d304c580bcf5ad99d0121e1f 
1/*
2 * Copyright 2014 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 "SkMatrixImageFilter.h"
9#include "SkBitmap.h"
10#include "SkCanvas.h"
11#include "SkDevice.h"
12#include "SkColorPriv.h"
13#include "SkReadBuffer.h"
14#include "SkWriteBuffer.h"
15#include "SkMatrix.h"
16#include "SkRect.h"
17
18SkMatrixImageFilter::SkMatrixImageFilter(const SkMatrix& transform,
19                                         SkFilterQuality filterQuality,
20                                         SkImageFilter* input)
21  : INHERITED(1, &input),
22    fTransform(transform),
23    fFilterQuality(filterQuality) {
24}
25
26SkMatrixImageFilter* SkMatrixImageFilter::Create(const SkMatrix& transform,
27                                                 SkFilterQuality filterQuality,
28                                                 SkImageFilter* input) {
29    return SkNEW_ARGS(SkMatrixImageFilter, (transform, filterQuality, input));
30}
31
32SkFlattenable* SkMatrixImageFilter::CreateProc(SkReadBuffer& buffer) {
33    SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
34    SkMatrix matrix;
35    buffer.readMatrix(&matrix);
36    SkFilterQuality quality = static_cast<SkFilterQuality>(buffer.readInt());
37    return Create(matrix, quality, common.getInput(0));
38}
39
40void SkMatrixImageFilter::flatten(SkWriteBuffer& buffer) const {
41    this->INHERITED::flatten(buffer);
42    buffer.writeMatrix(fTransform);
43    buffer.writeInt(fFilterQuality);
44}
45
46SkMatrixImageFilter::~SkMatrixImageFilter() {
47}
48
49bool SkMatrixImageFilter::onFilterImage(Proxy* proxy,
50                                        const SkBitmap& source,
51                                        const Context& ctx,
52                                        SkBitmap* result,
53                                        SkIPoint* offset) const {
54    SkBitmap src = source;
55    SkIPoint srcOffset = SkIPoint::Make(0, 0);
56    if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctx, &src, &srcOffset)) {
57        return false;
58    }
59
60    SkRect dstRect;
61    SkIRect srcBounds, dstBounds;
62    src.getBounds(&srcBounds);
63    srcBounds.offset(srcOffset);
64    SkRect srcRect = SkRect::Make(srcBounds);
65    SkMatrix matrix;
66    if (!ctx.ctm().invert(&matrix)) {
67        return false;
68    }
69    matrix.postConcat(fTransform);
70    matrix.postConcat(ctx.ctm());
71    matrix.mapRect(&dstRect, srcRect);
72    dstRect.roundOut(&dstBounds);
73
74    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(dstBounds.width(), dstBounds.height()));
75    if (NULL == device.get()) {
76        return false;
77    }
78
79    SkCanvas canvas(device.get());
80    canvas.translate(-SkIntToScalar(dstBounds.x()), -SkIntToScalar(dstBounds.y()));
81    canvas.concat(matrix);
82    SkPaint paint;
83
84    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
85    paint.setFilterQuality(fFilterQuality);
86    canvas.drawBitmap(src, srcRect.x(), srcRect.y(), &paint);
87
88    *result = device.get()->accessBitmap(false);
89    offset->fX = dstBounds.fLeft;
90    offset->fY = dstBounds.fTop;
91    return true;
92}
93
94void SkMatrixImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
95    SkRect bounds = src;
96    if (getInput(0)) {
97        getInput(0)->computeFastBounds(src, &bounds);
98    }
99    fTransform.mapRect(dst, bounds);
100    dst->join(bounds);   // Work around for skia:3194
101}
102
103bool SkMatrixImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
104                                         SkIRect* dst) const {
105    SkMatrix transformInverse;
106    if (!fTransform.invert(&transformInverse)) {
107        return false;
108    }
109    SkMatrix matrix;
110    if (!ctm.invert(&matrix)) {
111        return false;
112    }
113    matrix.postConcat(transformInverse);
114    matrix.postConcat(ctm);
115    SkRect floatBounds;
116    matrix.mapRect(&floatBounds, SkRect::Make(src));
117    SkIRect bounds = floatBounds.roundOut();
118    if (getInput(0) && !getInput(0)->filterBounds(bounds, ctm, &bounds)) {
119        return false;
120    }
121
122    *dst = bounds;
123    return true;
124}
125
126#ifndef SK_IGNORE_TO_STRING
127void SkMatrixImageFilter::toString(SkString* str) const {
128    str->appendf("SkMatrixImageFilter: (");
129
130    str->appendf("transform: (%f %f %f %f %f %f %f %f %f)",
131                 fTransform[SkMatrix::kMScaleX],
132                 fTransform[SkMatrix::kMSkewX],
133                 fTransform[SkMatrix::kMTransX],
134                 fTransform[SkMatrix::kMSkewY],
135                 fTransform[SkMatrix::kMScaleY],
136                 fTransform[SkMatrix::kMTransY],
137                 fTransform[SkMatrix::kMPersp0],
138                 fTransform[SkMatrix::kMPersp1],
139                 fTransform[SkMatrix::kMPersp2]);
140
141    str->append("<dt>FilterLevel:</dt><dd>");
142    static const char* gFilterLevelStrings[] = { "None", "Low", "Medium", "High" };
143    str->append(gFilterLevelStrings[fFilterQuality]);
144    str->append("</dd>");
145
146    str->appendf(")");
147}
148#endif
149