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 "include/effects/SkOffsetImageFilter.h"
9
10#include "include/core/SkCanvas.h"
11#include "include/core/SkMatrix.h"
12#include "include/core/SkPaint.h"
13#include "src/core/SkImageFilter_Base.h"
14#include "src/core/SkPointPriv.h"
15#include "src/core/SkReadBuffer.h"
16#include "src/core/SkSpecialImage.h"
17#include "src/core/SkSpecialSurface.h"
18#include "src/core/SkWriteBuffer.h"
19
20namespace {
21
22class SkOffsetImageFilterImpl final : public SkImageFilter_Base {
23public:
24 SkOffsetImageFilterImpl(SkScalar dx, SkScalar dy, sk_sp<SkImageFilter> input,
25 const CropRect* cropRect)
26 : INHERITED(&input, 1, cropRect) {
27 fOffset.set(dx, dy);
28 }
29
30 SkRect computeFastBounds(const SkRect& src) const override;
31
32protected:
33 void flatten(SkWriteBuffer&) const override;
34 sk_sp<SkSpecialImage> onFilterImage(const Context&, SkIPoint* offset) const override;
35 SkIRect onFilterNodeBounds(const SkIRect&, const SkMatrix& ctm,
36 MapDirection, const SkIRect* inputRect) const override;
37
38private:
39 friend void SkOffsetImageFilter::RegisterFlattenables();
40 SK_FLATTENABLE_HOOKS(SkOffsetImageFilterImpl)
41
42 SkVector fOffset;
43
44 typedef SkImageFilter_Base INHERITED;
45};
46
47} // end namespace
48
49sk_sp<SkImageFilter> SkOffsetImageFilter::Make(SkScalar dx, SkScalar dy,
50 sk_sp<SkImageFilter> input,
51 const SkImageFilter::CropRect* cropRect) {
52 if (!SkScalarIsFinite(dx) || !SkScalarIsFinite(dy)) {
53 return nullptr;
54 }
55
56 return sk_sp<SkImageFilter>(new SkOffsetImageFilterImpl(dx, dy, std::move(input), cropRect));
57}
58
59void SkOffsetImageFilter::RegisterFlattenables() {
60 SK_REGISTER_FLATTENABLE(SkOffsetImageFilterImpl);
61 // TODO (michaelludwig) - Remove after grace period for SKPs to stop using old name
62 SkFlattenable::Register("SkOffsetImageFilter", SkOffsetImageFilterImpl::CreateProc);
63}
64
65///////////////////////////////////////////////////////////////////////////////////////////////////
66
67sk_sp<SkFlattenable> SkOffsetImageFilterImpl::CreateProc(SkReadBuffer& buffer) {
68 SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
69 SkPoint offset;
70 buffer.readPoint(&offset);
71 return SkOffsetImageFilter::Make(offset.x(), offset.y(), common.getInput(0),
72 &common.cropRect());
73}
74
75void SkOffsetImageFilterImpl::flatten(SkWriteBuffer& buffer) const {
76 this->INHERITED::flatten(buffer);
77 buffer.writePoint(fOffset);
78}
79
80static SkIPoint map_offset_vector(const SkMatrix& ctm, const SkVector& offset) {
81 SkVector vec = ctm.mapVector(offset.fX, offset.fY);
82 return SkIPoint::Make(SkScalarRoundToInt(vec.fX), SkScalarRoundToInt(vec.fY));
83}
84
85sk_sp<SkSpecialImage> SkOffsetImageFilterImpl::onFilterImage(const Context& ctx,
86 SkIPoint* offset) const {
87 SkIPoint srcOffset = SkIPoint::Make(0, 0);
88 sk_sp<SkSpecialImage> input(this->filterInput(0, ctx, &srcOffset));
89 if (!input) {
90 return nullptr;
91 }
92
93 SkIPoint vec = map_offset_vector(ctx.ctm(), fOffset);
94
95 if (!this->cropRectIsSet()) {
96 offset->fX = Sk32_sat_add(srcOffset.fX, vec.fX);
97 offset->fY = Sk32_sat_add(srcOffset.fY, vec.fY);
98 return input;
99 } else {
100 SkIRect bounds;
101 const SkIRect srcBounds = SkIRect::MakeXYWH(srcOffset.fX, srcOffset.fY,
102 input->width(), input->height());
103 if (!this->applyCropRect(ctx, srcBounds, &bounds)) {
104 return nullptr;
105 }
106
107 sk_sp<SkSpecialSurface> surf(ctx.makeSurface(bounds.size()));
108 if (!surf) {
109 return nullptr;
110 }
111
112 SkCanvas* canvas = surf->getCanvas();
113 SkASSERT(canvas);
114
115 // TODO: it seems like this clear shouldn't be necessary (see skbug.com/5075)
116 canvas->clear(0x0);
117
118 SkPaint paint;
119 paint.setBlendMode(SkBlendMode::kSrc);
120 canvas->translate(SkIntToScalar(srcOffset.fX - bounds.fLeft),
121 SkIntToScalar(srcOffset.fY - bounds.fTop));
122
123 input->draw(canvas, vec.fX, vec.fY, &paint);
124
125 offset->fX = bounds.fLeft;
126 offset->fY = bounds.fTop;
127 return surf->makeImageSnapshot();
128 }
129}
130
131SkRect SkOffsetImageFilterImpl::computeFastBounds(const SkRect& src) const {
132 SkRect bounds = this->getInput(0) ? this->getInput(0)->computeFastBounds(src) : src;
133 bounds.offset(fOffset.fX, fOffset.fY);
134 return bounds;
135}
136
137SkIRect SkOffsetImageFilterImpl::onFilterNodeBounds(
138 const SkIRect& src, const SkMatrix& ctm, MapDirection dir, const SkIRect* inputRect) const {
139 SkIPoint vec = map_offset_vector(ctm, fOffset);
140 if (kReverse_MapDirection == dir) {
141 SkPointPriv::Negate(vec);
142 }
143
144 return src.makeOffset(vec);
145}
146