1 /*
2 * Copyright 2020 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 "modules/svg/include/SkSVGFeDisplacementMap.h"
9
10 #include "include/core/SkImageFilter.h"
11 #include "include/core/SkM44.h"
12 #include "include/core/SkRect.h"
13 #include "include/core/SkScalar.h"
14 #include "include/effects/SkImageFilters.h"
15 #include "modules/svg/include/SkSVGAttributeParser.h"
16 #include "modules/svg/include/SkSVGFilterContext.h"
17 #include "modules/svg/include/SkSVGRenderContext.h"
18
19 #include <tuple>
20
parseAndSetAttribute(const char * name,const char * value)21 bool SkSVGFeDisplacementMap::parseAndSetAttribute(const char* name, const char* value) {
22 return INHERITED::parseAndSetAttribute(name, value) ||
23 this->setIn2(SkSVGAttributeParser::parse<SkSVGFeInputType>("in2", name, value)) ||
24 this->setXChannelSelector(
25 SkSVGAttributeParser::parse<SkSVGFeDisplacementMap::ChannelSelector>(
26 "xChannelSelector", name, value)) ||
27 this->setYChannelSelector(
28 SkSVGAttributeParser::parse<SkSVGFeDisplacementMap::ChannelSelector>(
29 "yChannelSelector", name, value)) ||
30 this->setScale(SkSVGAttributeParser::parse<SkSVGNumberType>("scale", name, value));
31 }
32
onMakeImageFilter(const SkSVGRenderContext & ctx,const SkSVGFilterContext & fctx) const33 sk_sp<SkImageFilter> SkSVGFeDisplacementMap::onMakeImageFilter(
34 const SkSVGRenderContext& ctx, const SkSVGFilterContext& fctx) const {
35 const SkRect cropRect = this->resolveFilterSubregion(ctx, fctx);
36 const SkSVGColorspace colorspace = this->resolveColorspace(ctx, fctx);
37
38 // According to spec https://www.w3.org/TR/SVG11/filters.html#feDisplacementMapElement,
39 // the 'in' source image must remain in its current colorspace.
40 sk_sp<SkImageFilter> in = fctx.resolveInput(ctx, this->getIn());
41 sk_sp<SkImageFilter> in2 = fctx.resolveInput(ctx, this->getIn2(), colorspace);
42
43 SkScalar scale = fScale;
44 if (fctx.primitiveUnits().type() == SkSVGObjectBoundingBoxUnits::Type::kObjectBoundingBox) {
45 const auto obbt = ctx.transformForCurrentOBB(fctx.primitiveUnits());
46 scale = SkSVGLengthContext({obbt.scale.x, obbt.scale.y})
47 .resolve(SkSVGLength(scale, SkSVGLength::Unit::kPercentage),
48 SkSVGLengthContext::LengthType::kOther);
49 }
50
51 return SkImageFilters::DisplacementMap(
52 fXChannelSelector, fYChannelSelector, scale, in2, in, cropRect);
53 }
54
resolveColorspace(const SkSVGRenderContext & ctx,const SkSVGFilterContext & fctx) const55 SkSVGColorspace SkSVGFeDisplacementMap::resolveColorspace(const SkSVGRenderContext& ctx,
56 const SkSVGFilterContext& fctx) const {
57 // According to spec https://www.w3.org/TR/SVG11/filters.html#feDisplacementMapElement,
58 // the 'in' source image must remain in its current colorspace, which means the colorspace of
59 // this FE node is the same as the input.
60 return fctx.resolveInputColorspace(ctx, this->getIn());
61 }
62
63 template <>
parse(SkSVGFeDisplacementMap::ChannelSelector * channel)64 bool SkSVGAttributeParser::parse<SkSVGFeDisplacementMap::ChannelSelector>(
65 SkSVGFeDisplacementMap::ChannelSelector* channel) {
66 static constexpr std::tuple<const char*, SkSVGFeDisplacementMap::ChannelSelector> gMap[] = {
67 { "R", SkSVGFeDisplacementMap::ChannelSelector::kR },
68 { "G", SkSVGFeDisplacementMap::ChannelSelector::kG },
69 { "B", SkSVGFeDisplacementMap::ChannelSelector::kB },
70 { "A", SkSVGFeDisplacementMap::ChannelSelector::kA },
71 };
72
73 return this->parseEnumMap(gMap, channel) && this->parseEOSToken();
74 }
75