xref: /aosp_15_r20/external/skia/modules/svg/src/SkSVGRadialGradient.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2017 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/SkSVGRadialGradient.h"
9 
10 #include "include/core/SkColorSpace.h"
11 #include "include/core/SkPoint.h"
12 #include "include/core/SkShader.h"
13 #include "include/effects/SkGradientShader.h"
14 #include "modules/svg/include/SkSVGAttributeParser.h"
15 #include "modules/svg/include/SkSVGRenderContext.h"
16 
17 class SkMatrix;
18 enum class SkTileMode;
19 
SkSVGRadialGradient()20 SkSVGRadialGradient::SkSVGRadialGradient() : INHERITED(SkSVGTag::kRadialGradient) {}
21 
parseAndSetAttribute(const char * name,const char * value)22 bool SkSVGRadialGradient::parseAndSetAttribute(const char* name, const char* value) {
23     return INHERITED::parseAndSetAttribute(name, value) ||
24            this->setCx(SkSVGAttributeParser::parse<SkSVGLength>("cx", name, value)) ||
25            this->setCy(SkSVGAttributeParser::parse<SkSVGLength>("cy", name, value)) ||
26            this->setR(SkSVGAttributeParser::parse<SkSVGLength>("r", name, value)) ||
27            this->setFx(SkSVGAttributeParser::parse<SkSVGLength>("fx", name, value)) ||
28            this->setFy(SkSVGAttributeParser::parse<SkSVGLength>("fy", name, value));
29 }
30 
onMakeShader(const SkSVGRenderContext & ctx,const SkColor4f * colors,const SkScalar * pos,int count,SkTileMode tm,const SkMatrix & m) const31 sk_sp<SkShader> SkSVGRadialGradient::onMakeShader(const SkSVGRenderContext& ctx,
32                                                   const SkColor4f* colors, const SkScalar* pos,
33                                                   int count, SkTileMode tm,
34                                                   const SkMatrix& m) const {
35     const SkSVGLengthContext lctx =
36             this->getGradientUnits().type() == SkSVGObjectBoundingBoxUnits::Type::kObjectBoundingBox
37                     ? SkSVGLengthContext({1, 1})
38                     : ctx.lengthContext();
39 
40     const auto      r = lctx.resolve(fR , SkSVGLengthContext::LengthType::kOther);
41     const auto center = SkPoint::Make(
42             lctx.resolve(fCx, SkSVGLengthContext::LengthType::kHorizontal),
43             lctx.resolve(fCy, SkSVGLengthContext::LengthType::kVertical));
44     const auto  focal = SkPoint::Make(
45         fFx.isValid() ? lctx.resolve(*fFx, SkSVGLengthContext::LengthType::kHorizontal)
46                       : center.x(),
47         fFy.isValid() ? lctx.resolve(*fFy, SkSVGLengthContext::LengthType::kVertical)
48                       : center.y());
49 
50     if (r == 0) {
51         const auto last_color = count > 0 ? colors[count - 1] : SkColors::kBlack;
52         return SkShaders::Color(last_color, nullptr);
53     }
54 
55     return center == focal
56         ? SkGradientShader::MakeRadial(center, r, colors, nullptr, pos, count, tm, 0, &m)
57         : SkGradientShader::MakeTwoPointConical(focal, 0, center, r, colors, nullptr, pos,
58                                                 count, tm, 0, &m);
59 }
60