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 "SkOffsetImageFilter.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 
onFilterImage(Proxy * proxy,const SkBitmap & source,const Context & ctx,SkBitmap * result,SkIPoint * offset) const17 bool SkOffsetImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source,
18                                         const Context& ctx,
19                                         SkBitmap* result,
20                                         SkIPoint* offset) const {
21     SkImageFilter* input = getInput(0);
22     SkBitmap src = source;
23     SkIPoint srcOffset = SkIPoint::Make(0, 0);
24 #ifdef SK_DISABLE_OFFSETIMAGEFILTER_OPTIMIZATION
25     if (false) {
26 #else
27     if (!cropRectIsSet()) {
28 #endif
29         if (input && !input->filterImage(proxy, source, ctx, &src, &srcOffset)) {
30             return false;
31         }
32 
33         SkVector vec;
34         ctx.ctm().mapVectors(&vec, &fOffset, 1);
35 
36         offset->fX = srcOffset.fX + SkScalarRoundToInt(vec.fX);
37         offset->fY = srcOffset.fY + SkScalarRoundToInt(vec.fY);
38         *result = src;
39     } else {
40         if (input && !input->filterImage(proxy, source, ctx, &src, &srcOffset)) {
41             return false;
42         }
43 
44         SkIRect bounds;
45         if (!this->applyCropRect(ctx, src, srcOffset, &bounds)) {
46             return false;
47         }
48 
49         SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
50         if (NULL == device.get()) {
51             return false;
52         }
53         SkCanvas canvas(device);
54         SkPaint paint;
55         paint.setXfermodeMode(SkXfermode::kSrc_Mode);
56         canvas.translate(SkIntToScalar(srcOffset.fX - bounds.fLeft),
57                          SkIntToScalar(srcOffset.fY - bounds.fTop));
58         SkVector vec;
59         ctx.ctm().mapVectors(&vec, &fOffset, 1);
60         canvas.drawBitmap(src, vec.x(), vec.y(), &paint);
61         *result = device->accessBitmap(false);
62         offset->fX = bounds.fLeft;
63         offset->fY = bounds.fTop;
64     }
65     return true;
66 }
67 
68 void SkOffsetImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
69     if (getInput(0)) {
70         getInput(0)->computeFastBounds(src, dst);
71     } else {
72         *dst = src;
73     }
74     SkRect copy = *dst;
75     dst->offset(fOffset.fX, fOffset.fY);
76     dst->join(copy);
77 }
78 
79 bool SkOffsetImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
80                                          SkIRect* dst) const {
81     SkVector vec;
82     ctm.mapVectors(&vec, &fOffset, 1);
83 
84     SkIRect bounds = src;
85     bounds.offset(-SkScalarCeilToInt(vec.fX), -SkScalarCeilToInt(vec.fY));
86     bounds.join(src);
87     if (getInput(0)) {
88         return getInput(0)->filterBounds(bounds, ctm, dst);
89     }
90     *dst = bounds;
91     return true;
92 }
93 
94 SkFlattenable* SkOffsetImageFilter::CreateProc(SkReadBuffer& buffer) {
95     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
96     SkPoint offset;
97     buffer.readPoint(&offset);
98     return Create(offset.x(), offset.y(), common.getInput(0), &common.cropRect());
99 }
100 
101 void SkOffsetImageFilter::flatten(SkWriteBuffer& buffer) const {
102     this->INHERITED::flatten(buffer);
103     buffer.writePoint(fOffset);
104 }
105 
106 SkOffsetImageFilter::SkOffsetImageFilter(SkScalar dx, SkScalar dy, SkImageFilter* input,
107                                          const CropRect* cropRect)
108   : INHERITED(1, &input, cropRect) {
109     fOffset.set(dx, dy);
110 }
111 
112 #ifndef SK_IGNORE_TO_STRING
113 void SkOffsetImageFilter::toString(SkString* str) const {
114     str->appendf("SkOffsetImageFilter: (");
115     str->appendf("offset: (%f, %f) ", fOffset.fX, fOffset.fY);
116     str->append("input: (");
117     if (this->getInput(0)) {
118         this->getInput(0)->toString(str);
119     }
120     str->append("))");
121 }
122 #endif
123