1/*
2 * Copyright 2013 Google Inc.
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 "SkTileImageFilter.h"
9#include "SkBitmap.h"
10#include "SkCanvas.h"
11#include "SkDevice.h"
12#include "SkReadBuffer.h"
13#include "SkWriteBuffer.h"
14#include "SkMatrix.h"
15#include "SkPaint.h"
16#include "SkShader.h"
17#include "SkValidationUtils.h"
18
19SkTileImageFilter* SkTileImageFilter::Create(const SkRect& srcRect, const SkRect& dstRect,
20                                             SkImageFilter* input, uint32_t uniqueID) {
21    if (!SkIsValidRect(srcRect) || !SkIsValidRect(dstRect)) {
22        return NULL;
23    }
24    return SkNEW_ARGS(SkTileImageFilter, (srcRect, dstRect, input, uniqueID));
25}
26
27bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
28                                      const Context& ctx,
29                                      SkBitmap* dst, SkIPoint* offset) const {
30    SkBitmap source = src;
31    SkImageFilter* input = getInput(0);
32    SkIPoint srcOffset = SkIPoint::Make(0, 0);
33    if (input && !input->filterImage(proxy, src, ctx, &source, &srcOffset)) {
34        return false;
35    }
36
37    SkRect dstRect;
38    ctx.ctm().mapRect(&dstRect, fDstRect);
39    SkIRect dstIRect;
40    dstRect.roundOut(&dstIRect);
41    int w = dstIRect.width();
42    int h = dstIRect.height();
43    if (!fSrcRect.width() || !fSrcRect.height() || !w || !h) {
44        return false;
45    }
46
47    SkRect srcRect;
48    ctx.ctm().mapRect(&srcRect, fSrcRect);
49    SkIRect srcIRect;
50    srcRect.roundOut(&srcIRect);
51    srcIRect.offset(-srcOffset);
52    SkBitmap subset;
53    SkIRect bounds;
54    source.getBounds(&bounds);
55
56    if (!srcIRect.intersect(bounds)) {
57        offset->fX = offset->fY = 0;
58        return true;
59    } else if (!source.extractSubset(&subset, srcIRect)) {
60        return false;
61    }
62
63    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(w, h));
64    if (NULL == device.get()) {
65        return false;
66    }
67    SkCanvas canvas(device);
68    SkPaint paint;
69    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
70
71    SkMatrix shaderMatrix;
72    shaderMatrix.setTranslate(SkIntToScalar(srcOffset.fX),
73                              SkIntToScalar(srcOffset.fY));
74    SkAutoTUnref<SkShader> shader(SkShader::CreateBitmapShader(subset,
75                                  SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode,
76                                  &shaderMatrix));
77    paint.setShader(shader);
78    canvas.translate(-dstRect.fLeft, -dstRect.fTop);
79    canvas.drawRect(dstRect, paint);
80    *dst = device->accessBitmap(false);
81    offset->fX = dstIRect.fLeft;
82    offset->fY = dstIRect.fTop;
83    return true;
84}
85
86bool SkTileImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
87                                       SkIRect* dst) const {
88    SkRect srcRect;
89    ctm.mapRect(&srcRect, fSrcRect);
90    SkIRect srcIRect;
91    srcRect.roundOut(&srcIRect);
92    srcIRect.join(src);
93    *dst = srcIRect;
94    return true;
95}
96
97#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
98SkTileImageFilter::SkTileImageFilter(SkReadBuffer& buffer)
99  : INHERITED(1, buffer) {
100    buffer.readRect(&fSrcRect);
101    buffer.readRect(&fDstRect);
102    buffer.validate(buffer.isValid() && SkIsValidRect(fSrcRect) && SkIsValidRect(fDstRect));
103}
104#endif
105
106SkFlattenable* SkTileImageFilter::CreateProc(SkReadBuffer& buffer) {
107    SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
108    SkRect src, dst;
109    buffer.readRect(&src);
110    buffer.readRect(&dst);
111    return Create(src, dst, common.getInput(0), common.uniqueID());
112}
113
114void SkTileImageFilter::flatten(SkWriteBuffer& buffer) const {
115    this->INHERITED::flatten(buffer);
116    buffer.writeRect(fSrcRect);
117    buffer.writeRect(fDstRect);
118}
119