1 2 /* 3 * Copyright 2012 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 #include "SkSweepGradient.h" 10 11 SkSweepGradient::SkSweepGradient(SkScalar cx, SkScalar cy, 12 const Descriptor& desc, const SkMatrix* localMatrix) 13 : SkGradientShaderBase(desc, localMatrix) 14 , fCenter(SkPoint::Make(cx, cy)) 15 { 16 fPtsToUnit.setTranslate(-cx, -cy); 17 18 // overwrite the tilemode to a canonical value (since sweep ignores it) 19 fTileMode = SkShader::kClamp_TileMode; 20 } 21 22 SkShader::BitmapType SkSweepGradient::asABitmap(SkBitmap* bitmap, 23 SkMatrix* matrix, SkShader::TileMode* xy) const { 24 if (bitmap) { 25 this->getGradientTableBitmap(bitmap); 26 } 27 if (matrix) { 28 *matrix = fPtsToUnit; 29 } 30 if (xy) { 31 xy[0] = fTileMode; 32 xy[1] = kClamp_TileMode; 33 } 34 return kSweep_BitmapType; 35 } 36 37 SkShader::GradientType SkSweepGradient::asAGradient(GradientInfo* info) const { 38 if (info) { 39 commonAsAGradient(info); 40 info->fPoint[0] = fCenter; 41 } 42 return kSweep_GradientType; 43 } 44 45 SkSweepGradient::SkSweepGradient(SkReadBuffer& buffer) 46 : INHERITED(buffer), 47 fCenter(buffer.readPoint()) { 48 } 49 50 void SkSweepGradient::flatten(SkWriteBuffer& buffer) const { 51 this->INHERITED::flatten(buffer); 52 buffer.writePoint(fCenter); 53 } 54 55 size_t SkSweepGradient::contextSize() const { 56 return sizeof(SweepGradientContext); 57 } 58 59 SkShader::Context* SkSweepGradient::onCreateContext(const ContextRec& rec, void* storage) const { 60 return SkNEW_PLACEMENT_ARGS(storage, SweepGradientContext, (*this, rec)); 61 } 62 63 SkSweepGradient::SweepGradientContext::SweepGradientContext( 64 const SkSweepGradient& shader, const ContextRec& rec) 65 : INHERITED(shader, rec) {} 66 67 // returns angle in a circle [0..2PI) -> [0..255] 68 static unsigned SkATan2_255(float y, float x) { 69 // static const float g255Over2PI = 255 / (2 * SK_ScalarPI); 70 static const float g255Over2PI = 40.584510488433314f; 71 72 float result = sk_float_atan2(y, x); 73 if (result < 0) { 74 result += 2 * SK_ScalarPI; 75 } 76 SkASSERT(result >= 0); 77 // since our value is always >= 0, we can cast to int, which is faster than 78 // calling floorf() 79 int ir = (int)(result * g255Over2PI); 80 SkASSERT(ir >= 0 && ir <= 255); 81 return ir; 82 } 83 84 void SkSweepGradient::SweepGradientContext::shadeSpan(int x, int y, SkPMColor* SK_RESTRICT dstC, 85 int count) { 86 SkMatrix::MapXYProc proc = fDstToIndexProc; 87 const SkMatrix& matrix = fDstToIndex; 88 const SkPMColor* SK_RESTRICT cache = fCache->getCache32(); 89 int toggle = init_dither_toggle(x, y); 90 SkPoint srcPt; 91 92 if (fDstToIndexClass != kPerspective_MatrixClass) { 93 proc(matrix, SkIntToScalar(x) + SK_ScalarHalf, 94 SkIntToScalar(y) + SK_ScalarHalf, &srcPt); 95 SkScalar dx, fx = srcPt.fX; 96 SkScalar dy, fy = srcPt.fY; 97 98 if (fDstToIndexClass == kFixedStepInX_MatrixClass) { 99 SkFixed storage[2]; 100 (void)matrix.fixedStepInX(SkIntToScalar(y) + SK_ScalarHalf, 101 &storage[0], &storage[1]); 102 dx = SkFixedToScalar(storage[0]); 103 dy = SkFixedToScalar(storage[1]); 104 } else { 105 SkASSERT(fDstToIndexClass == kLinear_MatrixClass); 106 dx = matrix.getScaleX(); 107 dy = matrix.getSkewY(); 108 } 109 110 for (; count > 0; --count) { 111 *dstC++ = cache[toggle + SkATan2_255(fy, fx)]; 112 fx += dx; 113 fy += dy; 114 toggle = next_dither_toggle(toggle); 115 } 116 } else { // perspective case 117 for (int stop = x + count; x < stop; x++) { 118 proc(matrix, SkIntToScalar(x) + SK_ScalarHalf, 119 SkIntToScalar(y) + SK_ScalarHalf, &srcPt); 120 *dstC++ = cache[toggle + SkATan2_255(srcPt.fY, srcPt.fX)]; 121 toggle = next_dither_toggle(toggle); 122 } 123 } 124 } 125 126 void SkSweepGradient::SweepGradientContext::shadeSpan16(int x, int y, uint16_t* SK_RESTRICT dstC, 127 int count) { 128 SkMatrix::MapXYProc proc = fDstToIndexProc; 129 const SkMatrix& matrix = fDstToIndex; 130 const uint16_t* SK_RESTRICT cache = fCache->getCache16(); 131 int toggle = init_dither_toggle16(x, y); 132 SkPoint srcPt; 133 134 if (fDstToIndexClass != kPerspective_MatrixClass) { 135 proc(matrix, SkIntToScalar(x) + SK_ScalarHalf, 136 SkIntToScalar(y) + SK_ScalarHalf, &srcPt); 137 SkScalar dx, fx = srcPt.fX; 138 SkScalar dy, fy = srcPt.fY; 139 140 if (fDstToIndexClass == kFixedStepInX_MatrixClass) { 141 SkFixed storage[2]; 142 (void)matrix.fixedStepInX(SkIntToScalar(y) + SK_ScalarHalf, 143 &storage[0], &storage[1]); 144 dx = SkFixedToScalar(storage[0]); 145 dy = SkFixedToScalar(storage[1]); 146 } else { 147 SkASSERT(fDstToIndexClass == kLinear_MatrixClass); 148 dx = matrix.getScaleX(); 149 dy = matrix.getSkewY(); 150 } 151 152 for (; count > 0; --count) { 153 int index = SkATan2_255(fy, fx) >> (8 - kCache16Bits); 154 *dstC++ = cache[toggle + index]; 155 toggle = next_dither_toggle16(toggle); 156 fx += dx; 157 fy += dy; 158 } 159 } else { // perspective case 160 for (int stop = x + count; x < stop; x++) { 161 proc(matrix, SkIntToScalar(x) + SK_ScalarHalf, 162 SkIntToScalar(y) + SK_ScalarHalf, &srcPt); 163 164 int index = SkATan2_255(srcPt.fY, srcPt.fX); 165 index >>= (8 - kCache16Bits); 166 *dstC++ = cache[toggle + index]; 167 toggle = next_dither_toggle16(toggle); 168 } 169 } 170 } 171 172 ///////////////////////////////////////////////////////////////////// 173 174 #if SK_SUPPORT_GPU 175 176 #include "GrTBackendEffectFactory.h" 177 #include "SkGr.h" 178 179 class GrGLSweepGradient : public GrGLGradientEffect { 180 public: 181 182 GrGLSweepGradient(const GrBackendEffectFactory& factory, 183 const GrDrawEffect&) : INHERITED (factory) { } 184 virtual ~GrGLSweepGradient() { } 185 186 virtual void emitCode(GrGLShaderBuilder*, 187 const GrDrawEffect&, 188 EffectKey, 189 const char* outputColor, 190 const char* inputColor, 191 const TransformedCoordsArray&, 192 const TextureSamplerArray&) SK_OVERRIDE; 193 194 static EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) { 195 return GenBaseGradientKey(drawEffect); 196 } 197 198 private: 199 200 typedef GrGLGradientEffect INHERITED; 201 202 }; 203 204 ///////////////////////////////////////////////////////////////////// 205 206 class GrSweepGradient : public GrGradientEffect { 207 public: 208 static GrEffectRef* Create(GrContext* ctx, 209 const SkSweepGradient& shader, 210 const SkMatrix& matrix) { 211 AutoEffectUnref effect(SkNEW_ARGS(GrSweepGradient, (ctx, shader, matrix))); 212 return CreateEffectRef(effect); 213 } 214 virtual ~GrSweepGradient() { } 215 216 static const char* Name() { return "Sweep Gradient"; } 217 virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE { 218 return GrTBackendEffectFactory<GrSweepGradient>::getInstance(); 219 } 220 221 typedef GrGLSweepGradient GLEffect; 222 223 private: 224 GrSweepGradient(GrContext* ctx, 225 const SkSweepGradient& shader, 226 const SkMatrix& matrix) 227 : INHERITED(ctx, shader, matrix, SkShader::kClamp_TileMode) { } 228 GR_DECLARE_EFFECT_TEST; 229 230 typedef GrGradientEffect INHERITED; 231 }; 232 233 ///////////////////////////////////////////////////////////////////// 234 235 GR_DEFINE_EFFECT_TEST(GrSweepGradient); 236 237 GrEffectRef* GrSweepGradient::TestCreate(SkRandom* random, 238 GrContext* context, 239 const GrDrawTargetCaps&, 240 GrTexture**) { 241 SkPoint center = {random->nextUScalar1(), random->nextUScalar1()}; 242 243 SkColor colors[kMaxRandomGradientColors]; 244 SkScalar stopsArray[kMaxRandomGradientColors]; 245 SkScalar* stops = stopsArray; 246 SkShader::TileMode tmIgnored; 247 int colorCount = RandomGradientParams(random, colors, &stops, &tmIgnored); 248 SkAutoTUnref<SkShader> shader(SkGradientShader::CreateSweep(center.fX, center.fY, 249 colors, stops, colorCount)); 250 SkPaint paint; 251 GrEffectRef* effect; 252 GrColor grColor; 253 shader->asNewEffect(context, paint, NULL, &grColor, &effect); 254 return effect; 255 } 256 257 ///////////////////////////////////////////////////////////////////// 258 259 void GrGLSweepGradient::emitCode(GrGLShaderBuilder* builder, 260 const GrDrawEffect&, 261 EffectKey key, 262 const char* outputColor, 263 const char* inputColor, 264 const TransformedCoordsArray& coords, 265 const TextureSamplerArray& samplers) { 266 this->emitUniforms(builder, key); 267 SkString coords2D = builder->ensureFSCoords2D(coords, 0); 268 const GrGLContextInfo ctxInfo = builder->ctxInfo(); 269 SkString t; 270 // 0.1591549430918 is 1/(2*pi), used since atan returns values [-pi, pi] 271 // On Intel GPU there is an issue where it reads the second arguement to atan "- %s.x" as an int 272 // thus must us -1.0 * %s.x to work correctly 273 if (kIntel_GrGLVendor != ctxInfo.vendor()){ 274 t.printf("atan(- %s.y, - %s.x) * 0.1591549430918 + 0.5", 275 coords2D.c_str(), coords2D.c_str()); 276 } else { 277 t.printf("atan(- %s.y, -1.0 * %s.x) * 0.1591549430918 + 0.5", 278 coords2D.c_str(), coords2D.c_str()); 279 } 280 this->emitColor(builder, t.c_str(), key, 281 outputColor, inputColor, samplers); 282 } 283 284 ///////////////////////////////////////////////////////////////////// 285 286 bool SkSweepGradient::asNewEffect(GrContext* context, const SkPaint& paint, 287 const SkMatrix* localMatrix, GrColor* grColor, 288 GrEffectRef** grEffect) const { 289 290 SkMatrix matrix; 291 if (!this->getLocalMatrix().invert(&matrix)) { 292 return false; 293 } 294 if (localMatrix) { 295 SkMatrix inv; 296 if (!localMatrix->invert(&inv)) { 297 return false; 298 } 299 matrix.postConcat(inv); 300 } 301 matrix.postConcat(fPtsToUnit); 302 303 *grEffect = GrSweepGradient::Create(context, *this, matrix); 304 *grColor = SkColor2GrColorJustAlpha(paint.getColor()); 305 306 return true; 307 } 308 309 #else 310 311 bool SkSweepGradient::asNewEffect(GrContext* context, const SkPaint& paint, 312 const SkMatrix* localMatrix, GrColor* grColor, 313 GrEffectRef** grEffect) const { 314 SkDEBUGFAIL("Should not call in GPU-less build"); 315 return false; 316 } 317 318 #endif 319 320 #ifndef SK_IGNORE_TO_STRING 321 void SkSweepGradient::toString(SkString* str) const { 322 str->append("SkSweepGradient: ("); 323 324 str->append("center: ("); 325 str->appendScalar(fCenter.fX); 326 str->append(", "); 327 str->appendScalar(fCenter.fY); 328 str->append(") "); 329 330 this->INHERITED::toString(str); 331 332 str->append(")"); 333 } 334 #endif 335
