OLD | NEW |
(Empty) | |
| 1 /* |
| 2 * Copyright 2014 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 "GrConvexPolyEffect.h" |
| 9 |
| 10 #include "gl/GrGLEffect.h" |
| 11 #include "gl/GrGLSL.h" |
| 12 #include "gl/GrGLVertexEffect.h" |
| 13 #include "GrTBackendEffectFactory.h" |
| 14 |
| 15 #include "SkPath.h" |
| 16 |
| 17 class GrGLConvexPolyEffect : public GrGLEffect { |
| 18 public: |
| 19 GrGLConvexPolyEffect(const GrBackendEffectFactory&, const GrDrawEffect&); |
| 20 |
| 21 virtual void emitCode(GrGLShaderBuilder* builder, |
| 22 const GrDrawEffect& drawEffect, |
| 23 EffectKey key, |
| 24 const char* outputColor, |
| 25 const char* inputColor, |
| 26 const TransformedCoordsArray&, |
| 27 const TextureSamplerArray&) SK_OVERRIDE; |
| 28 |
| 29 static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&); |
| 30 |
| 31 virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVER
RIDE; |
| 32 |
| 33 private: |
| 34 GrGLUniformManager::UniformHandle fEdgeUniform; |
| 35 SkScalar fPrevEdges[3 * GrConvexPolyEffect::kMaxE
dges]; |
| 36 typedef GrGLEffect INHERITED; |
| 37 }; |
| 38 |
| 39 GrGLConvexPolyEffect::GrGLConvexPolyEffect(const GrBackendEffectFactory& factory
, |
| 40 const GrDrawEffect& drawEffect) |
| 41 : INHERITED (factory) { |
| 42 fPrevEdges[0] = SK_ScalarNaN; |
| 43 } |
| 44 |
| 45 void GrGLConvexPolyEffect::emitCode(GrGLShaderBuilder* builder, |
| 46 const GrDrawEffect& drawEffect, |
| 47 EffectKey key, |
| 48 const char* outputColor, |
| 49 const char* inputColor, |
| 50 const TransformedCoordsArray&, |
| 51 const TextureSamplerArray& samplers) { |
| 52 const GrConvexPolyEffect& cpe = drawEffect.castEffect<GrConvexPolyEffect>(); |
| 53 |
| 54 const char *edgeArrayName; |
| 55 fEdgeUniform = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibil
ity, |
| 56 kVec3f_GrSLType, |
| 57 "edges", |
| 58 cpe.getEdgeCount(), |
| 59 &edgeArrayName); |
| 60 builder->fsCodeAppend("\t\tfloat alpha = 1.0;\n"); |
| 61 builder->fsCodeAppend("\t\tfloat edge;\n"); |
| 62 const char* fragmentPos = builder->fragmentPosition(); |
| 63 for (int i = 0; i < cpe.getEdgeCount(); ++i) { |
| 64 builder->fsCodeAppendf("\t\tedge = dot(%s[%d], vec3(%s.x, %s.y, 1));\n", |
| 65 edgeArrayName, i, fragmentPos, fragmentPos); |
| 66 switch (cpe.getEdgeType()) { |
| 67 case GrConvexPolyEffect::kFillAA_EdgeType: |
| 68 builder->fsCodeAppend("\t\tedge = clamp(edge, 0.0, 1.0);\n"); |
| 69 builder->fsCodeAppend("\t\talpha *= edge;\n"); |
| 70 break; |
| 71 case GrConvexPolyEffect::kFillNoAA_EdgeType: |
| 72 builder->fsCodeAppend("\t\tedge = edge >= 0.5 ? 1.0 : 0.0;\n"); |
| 73 builder->fsCodeAppend("\t\talpha *= edge;\n"); |
| 74 break; |
| 75 } |
| 76 } |
| 77 |
| 78 builder->fsCodeAppendf("\t%s = %s;\n", outputColor, |
| 79 (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_st
r()); |
| 80 } |
| 81 |
| 82 void GrGLConvexPolyEffect::setData(const GrGLUniformManager& uman, const GrDrawE
ffect& drawEffect) { |
| 83 const GrConvexPolyEffect& cpe = drawEffect.castEffect<GrConvexPolyEffect>(); |
| 84 size_t byteSize = 3 * cpe.getEdgeCount() * sizeof(SkScalar); |
| 85 if (0 != memcmp(fPrevEdges, cpe.getEdges(), byteSize)) { |
| 86 uman.set3fv(fEdgeUniform, cpe.getEdgeCount(), cpe.getEdges()); |
| 87 memcpy(fPrevEdges, cpe.getEdges(), byteSize); |
| 88 } |
| 89 } |
| 90 |
| 91 GrGLEffect::EffectKey GrGLConvexPolyEffect::GenKey(const GrDrawEffect& drawEffec
t, |
| 92 const GrGLCaps&) { |
| 93 const GrConvexPolyEffect& cpe = drawEffect.castEffect<GrConvexPolyEffect>(); |
| 94 GR_STATIC_ASSERT(GrConvexPolyEffect::kEdgeTypeCnt <= 4); |
| 95 return (cpe.getEdgeCount() << 2) | cpe.getEdgeType(); |
| 96 } |
| 97 |
| 98 ////////////////////////////////////////////////////////////////////////////// |
| 99 |
| 100 GrEffectRef* GrConvexPolyEffect::Create(EdgeType type, const SkPath& path) { |
| 101 if (path.getSegmentMasks() != SkPath::kLine_SegmentMask || |
| 102 !path.isConvex() || |
| 103 path.isInverseFillType()) { |
| 104 return NULL; |
| 105 } |
| 106 |
| 107 if (path.countPoints() > kMaxEdges) { |
| 108 return NULL; |
| 109 } |
| 110 |
| 111 SkPoint pts[kMaxEdges]; |
| 112 SkScalar edges[3 * kMaxEdges]; |
| 113 |
| 114 SkPath::Direction dir; |
| 115 SkAssertResult(path.cheapComputeDirection(&dir)); |
| 116 |
| 117 int count = path.getPoints(pts, kMaxEdges); |
| 118 int n = 0; |
| 119 for (int lastPt = count - 1, i = 0; i < count; lastPt = i++) { |
| 120 if (pts[lastPt] != pts[i]) { |
| 121 SkVector v = pts[i] - pts[lastPt]; |
| 122 v.normalize(); |
| 123 if (SkPath::kCCW_Direction == dir) { |
| 124 edges[3 * n] = v.fY; |
| 125 edges[3 * n + 1] = -v.fX; |
| 126 } else { |
| 127 edges[3 * n] = -v.fY; |
| 128 edges[3 * n + 1] = v.fX; |
| 129 } |
| 130 edges[3 * n + 2] = -(edges[3 * n] * pts[i].fX + edges[3 * n + 1] * p
ts[i].fY); |
| 131 ++n; |
| 132 } |
| 133 } |
| 134 return Create(type, n, edges); |
| 135 } |
| 136 |
| 137 GrConvexPolyEffect::~GrConvexPolyEffect() {} |
| 138 |
| 139 void GrConvexPolyEffect::getConstantColorComponents(GrColor* color, uint32_t* va
lidFlags) const { |
| 140 *validFlags = 0; |
| 141 } |
| 142 |
| 143 const GrBackendEffectFactory& GrConvexPolyEffect::getFactory() const { |
| 144 return GrTBackendEffectFactory<GrConvexPolyEffect>::getInstance(); |
| 145 } |
| 146 |
| 147 GrConvexPolyEffect::GrConvexPolyEffect(EdgeType edgeType, int n, const SkScalar
edges[]) |
| 148 : fEdgeType(edgeType) |
| 149 , fEdgeCount(n) { |
| 150 // Factory function should have already ensured this. |
| 151 SkASSERT(n <= kMaxEdges); |
| 152 memcpy(fEdges, edges, 3 * n * sizeof(SkScalar)); |
| 153 // Outset the edges by 0.5 so that a pixel with center on an edge is 50% cov
ered in the AA case |
| 154 // and 100% covered in the non-AA case. |
| 155 for (int i = 0; i < n; ++i) { |
| 156 fEdges[3 * i + 2] += SK_ScalarHalf; |
| 157 } |
| 158 this->setWillReadFragmentPosition(); |
| 159 } |
| 160 |
| 161 bool GrConvexPolyEffect::onIsEqual(const GrEffect& other) const { |
| 162 const GrConvexPolyEffect& cpe = CastEffect<GrConvexPolyEffect>(other); |
| 163 // ignore the fact that 0 == -0 and just use memcmp. |
| 164 return (cpe.fEdgeType == fEdgeType && cpe.fEdgeCount == fEdgeCount && |
| 165 0 == memcmp(cpe.fEdges, fEdges, 3 * fEdgeCount * sizeof(SkScalar))); |
| 166 } |
| 167 |
| 168 ////////////////////////////////////////////////////////////////////////////// |
| 169 |
| 170 GR_DEFINE_EFFECT_TEST(GrConvexPolyEffect); |
| 171 |
| 172 GrEffectRef* GrConvexPolyEffect::TestCreate(SkRandom* random, |
| 173 GrContext*, |
| 174 const GrDrawTargetCaps& caps, |
| 175 GrTexture*[]) { |
| 176 EdgeType edgeType = static_cast<EdgeType>(random->nextULessThan(kEdgeTypeCnt
)); |
| 177 int count = random->nextULessThan(kMaxEdges + 1); |
| 178 SkScalar edges[kMaxEdges * 3]; |
| 179 for (int i = 0; i < 3 * count; ++i) { |
| 180 edges[i] = random->nextSScalar1(); |
| 181 } |
| 182 |
| 183 return GrConvexPolyEffect::Create(edgeType, count, edges); |
| 184 } |
| 185 |
OLD | NEW |