1 /*
2  * Copyright 2012 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 "SkColorSpaceXformer.h"
9 #include "SkRadialGradient.h"
10 #include "SkRasterPipeline.h"
11 #include "SkReadBuffer.h"
12 #include "SkWriteBuffer.h"
13 
14 namespace {
15 
rad_to_unit_matrix(const SkPoint & center,SkScalar radius)16 SkMatrix rad_to_unit_matrix(const SkPoint& center, SkScalar radius) {
17     SkScalar    inv = SkScalarInvert(radius);
18 
19     SkMatrix matrix;
20     matrix.setTranslate(-center.fX, -center.fY);
21     matrix.postScale(inv, inv);
22     return matrix;
23 }
24 
25 }  // namespace
26 
27 /////////////////////////////////////////////////////////////////////
28 
SkRadialGradient(const SkPoint & center,SkScalar radius,const Descriptor & desc)29 SkRadialGradient::SkRadialGradient(const SkPoint& center, SkScalar radius, const Descriptor& desc)
30     : SkGradientShaderBase(desc, rad_to_unit_matrix(center, radius))
31     , fCenter(center)
32     , fRadius(radius) {
33 }
34 
asAGradient(GradientInfo * info) const35 SkShader::GradientType SkRadialGradient::asAGradient(GradientInfo* info) const {
36     if (info) {
37         commonAsAGradient(info);
38         info->fPoint[0] = fCenter;
39         info->fRadius[0] = fRadius;
40     }
41     return kRadial_GradientType;
42 }
43 
CreateProc(SkReadBuffer & buffer)44 sk_sp<SkFlattenable> SkRadialGradient::CreateProc(SkReadBuffer& buffer) {
45     DescriptorScope desc;
46     if (!desc.unflatten(buffer)) {
47         return nullptr;
48     }
49     const SkPoint center = buffer.readPoint();
50     const SkScalar radius = buffer.readScalar();
51     return SkGradientShader::MakeRadial(center, radius, desc.fColors, std::move(desc.fColorSpace),
52                                         desc.fPos, desc.fCount, desc.fTileMode, desc.fGradFlags,
53                                         desc.fLocalMatrix);
54 }
55 
flatten(SkWriteBuffer & buffer) const56 void SkRadialGradient::flatten(SkWriteBuffer& buffer) const {
57     this->INHERITED::flatten(buffer);
58     buffer.writePoint(fCenter);
59     buffer.writeScalar(fRadius);
60 }
61 
onMakeColorSpace(SkColorSpaceXformer * xformer) const62 sk_sp<SkShader> SkRadialGradient::onMakeColorSpace(SkColorSpaceXformer* xformer) const {
63     const AutoXformColors xformedColors(*this, xformer);
64     return SkGradientShader::MakeRadial(fCenter, fRadius, xformedColors.fColors.get(), fOrigPos,
65                                         fColorCount, fTileMode, fGradFlags,
66                                         &this->getLocalMatrix());
67 }
68 
appendGradientStages(SkArenaAlloc *,SkRasterPipeline * p,SkRasterPipeline *) const69 void SkRadialGradient::appendGradientStages(SkArenaAlloc*, SkRasterPipeline* p,
70                                             SkRasterPipeline*) const {
71     p->append(SkRasterPipeline::xy_to_radius);
72 }
73 
74 /////////////////////////////////////////////////////////////////////
75 
76 #if SK_SUPPORT_GPU
77 
78 #include "gradients/GrGradientShader.h"
79 
asFragmentProcessor(const GrFPArgs & args) const80 std::unique_ptr<GrFragmentProcessor> SkRadialGradient::asFragmentProcessor(
81         const GrFPArgs& args) const {
82     return GrGradientShader::MakeRadial(*this, args);
83 }
84 
85 #endif
86