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| 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 "SkTwoPointRadialGradient.h" | |
| 10 | |
| 11 /* Two-point radial gradients are specified by two circles, each with a center | |
| 12 point and radius. The gradient can be considered to be a series of | |
| 13 concentric circles, with the color interpolated from the start circle | |
| 14 (at t=0) to the end circle (at t=1). | |
| 15 | |
| 16 For each point (x, y) in the span, we want to find the | |
| 17 interpolated circle that intersects that point. The center | |
| 18 of the desired circle (Cx, Cy) falls at some distance t | |
| 19 along the line segment between the start point (Sx, Sy) and | |
| 20 end point (Ex, Ey): | |
| 21 | |
| 22 Cx = (1 - t) * Sx + t * Ex (0 <= t <= 1) | |
| 23 Cy = (1 - t) * Sy + t * Ey | |
| 24 | |
| 25 The radius of the desired circle (r) is also a linear interpolation t | |
| 26 between the start and end radii (Sr and Er): | |
| 27 | |
| 28 r = (1 - t) * Sr + t * Er | |
| 29 | |
| 30 But | |
| 31 | |
| 32 (x - Cx)^2 + (y - Cy)^2 = r^2 | |
| 33 | |
| 34 so | |
| 35 | |
| 36 (x - ((1 - t) * Sx + t * Ex))^2 | |
| 37 + (y - ((1 - t) * Sy + t * Ey))^2 | |
| 38 = ((1 - t) * Sr + t * Er)^2 | |
| 39 | |
| 40 Solving for t yields | |
| 41 | |
| 42 [(Sx - Ex)^2 + (Sy - Ey)^2 - (Er - Sr)^2)] * t^2 | |
| 43 + [2 * (Sx - Ex)(x - Sx) + 2 * (Sy - Ey)(y - Sy) - 2 * (Er - Sr) * Sr] * t | |
| 44 + [(x - Sx)^2 + (y - Sy)^2 - Sr^2] = 0 | |
| 45 | |
| 46 To simplify, let Dx = Sx - Ex, Dy = Sy - Ey, Dr = Er - Sr, dx = x - Sx, dy =
y - Sy | |
| 47 | |
| 48 [Dx^2 + Dy^2 - Dr^2)] * t^2 | |
| 49 + 2 * [Dx * dx + Dy * dy - Dr * Sr] * t | |
| 50 + [dx^2 + dy^2 - Sr^2] = 0 | |
| 51 | |
| 52 A quadratic in t. The two roots of the quadratic reflect the two | |
| 53 possible circles on which the point may fall. Solving for t yields | |
| 54 the gradient value to use. | |
| 55 | |
| 56 If a<0, the start circle is entirely contained in the | |
| 57 end circle, and one of the roots will be <0 or >1 (off the line | |
| 58 segment). If a>0, the start circle falls at least partially | |
| 59 outside the end circle (or vice versa), and the gradient | |
| 60 defines a "tube" where a point may be on one circle (on the | |
| 61 inside of the tube) or the other (outside of the tube). We choose | |
| 62 one arbitrarily. | |
| 63 | |
| 64 In order to keep the math to within the limits of fixed point, | |
| 65 we divide the entire quadratic by Dr^2, and replace | |
| 66 (x - Sx)/Dr with x' and (y - Sy)/Dr with y', giving | |
| 67 | |
| 68 [Dx^2 / Dr^2 + Dy^2 / Dr^2 - 1)] * t^2 | |
| 69 + 2 * [x' * Dx / Dr + y' * Dy / Dr - Sr / Dr] * t | |
| 70 + [x'^2 + y'^2 - Sr^2/Dr^2] = 0 | |
| 71 | |
| 72 (x' and y' are computed by appending the subtract and scale to the | |
| 73 fDstToIndex matrix in the constructor). | |
| 74 | |
| 75 Since the 'A' component of the quadratic is independent of x' and y', it | |
| 76 is precomputed in the constructor. Since the 'B' component is linear in | |
| 77 x' and y', if x and y are linear in the span, 'B' can be computed | |
| 78 incrementally with a simple delta (db below). If it is not (e.g., | |
| 79 a perspective projection), it must be computed in the loop. | |
| 80 | |
| 81 */ | |
| 82 | |
| 83 namespace { | |
| 84 | |
| 85 inline SkFixed two_point_radial(SkScalar b, SkScalar fx, SkScalar fy, | |
| 86 SkScalar sr2d2, SkScalar foura, | |
| 87 SkScalar oneOverTwoA, bool posRoot) { | |
| 88 SkScalar c = SkScalarSquare(fx) + SkScalarSquare(fy) - sr2d2; | |
| 89 if (0 == foura) { | |
| 90 return SkScalarToFixed(SkScalarDiv(-c, b)); | |
| 91 } | |
| 92 | |
| 93 SkScalar discrim = SkScalarSquare(b) - SkScalarMul(foura, c); | |
| 94 if (discrim < 0) { | |
| 95 discrim = -discrim; | |
| 96 } | |
| 97 SkScalar rootDiscrim = SkScalarSqrt(discrim); | |
| 98 SkScalar result; | |
| 99 if (posRoot) { | |
| 100 result = SkScalarMul(-b + rootDiscrim, oneOverTwoA); | |
| 101 } else { | |
| 102 result = SkScalarMul(-b - rootDiscrim, oneOverTwoA); | |
| 103 } | |
| 104 return SkScalarToFixed(result); | |
| 105 } | |
| 106 | |
| 107 typedef void (* TwoPointRadialShadeProc)(SkScalar fx, SkScalar dx, | |
| 108 SkScalar fy, SkScalar dy, | |
| 109 SkScalar b, SkScalar db, | |
| 110 SkScalar fSr2D2, SkScalar foura, SkScalar fOneOverTwoA, bool posRoot, | |
| 111 SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, | |
| 112 int count); | |
| 113 | |
| 114 void shadeSpan_twopoint_clamp(SkScalar fx, SkScalar dx, | |
| 115 SkScalar fy, SkScalar dy, | |
| 116 SkScalar b, SkScalar db, | |
| 117 SkScalar fSr2D2, SkScalar foura, SkScalar fOneOverTwoA, bool posRoot, | |
| 118 SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, | |
| 119 int count) { | |
| 120 for (; count > 0; --count) { | |
| 121 SkFixed t = two_point_radial(b, fx, fy, fSr2D2, foura, | |
| 122 fOneOverTwoA, posRoot); | |
| 123 SkFixed index = SkClampMax(t, 0xFFFF); | |
| 124 SkASSERT(index <= 0xFFFF); | |
| 125 *dstC++ = cache[index >> SkGradientShaderBase::kCache32Shift]; | |
| 126 fx += dx; | |
| 127 fy += dy; | |
| 128 b += db; | |
| 129 } | |
| 130 } | |
| 131 void shadeSpan_twopoint_mirror(SkScalar fx, SkScalar dx, | |
| 132 SkScalar fy, SkScalar dy, | |
| 133 SkScalar b, SkScalar db, | |
| 134 SkScalar fSr2D2, SkScalar foura, SkScalar fOneOverTwoA, bool posRoot, | |
| 135 SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, | |
| 136 int count) { | |
| 137 for (; count > 0; --count) { | |
| 138 SkFixed t = two_point_radial(b, fx, fy, fSr2D2, foura, | |
| 139 fOneOverTwoA, posRoot); | |
| 140 SkFixed index = mirror_tileproc(t); | |
| 141 SkASSERT(index <= 0xFFFF); | |
| 142 *dstC++ = cache[index >> SkGradientShaderBase::kCache32Shift]; | |
| 143 fx += dx; | |
| 144 fy += dy; | |
| 145 b += db; | |
| 146 } | |
| 147 } | |
| 148 | |
| 149 void shadeSpan_twopoint_repeat(SkScalar fx, SkScalar dx, | |
| 150 SkScalar fy, SkScalar dy, | |
| 151 SkScalar b, SkScalar db, | |
| 152 SkScalar fSr2D2, SkScalar foura, SkScalar fOneOverTwoA, bool posRoot, | |
| 153 SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache, | |
| 154 int count) { | |
| 155 for (; count > 0; --count) { | |
| 156 SkFixed t = two_point_radial(b, fx, fy, fSr2D2, foura, | |
| 157 fOneOverTwoA, posRoot); | |
| 158 SkFixed index = repeat_tileproc(t); | |
| 159 SkASSERT(index <= 0xFFFF); | |
| 160 *dstC++ = cache[index >> SkGradientShaderBase::kCache32Shift]; | |
| 161 fx += dx; | |
| 162 fy += dy; | |
| 163 b += db; | |
| 164 } | |
| 165 } | |
| 166 } | |
| 167 | |
| 168 ///////////////////////////////////////////////////////////////////// | |
| 169 | |
| 170 static SkMatrix pts_to_unit(const SkPoint& start, SkScalar diffRadius) { | |
| 171 SkScalar inv = diffRadius ? SkScalarInvert(diffRadius) : 0; | |
| 172 SkMatrix matrix; | |
| 173 matrix.setTranslate(-start.fX, -start.fY); | |
| 174 matrix.postScale(inv, inv); | |
| 175 return matrix; | |
| 176 } | |
| 177 | |
| 178 SkTwoPointRadialGradient::SkTwoPointRadialGradient(const SkPoint& start, SkScala
r startRadius, | |
| 179 const SkPoint& end, SkScalar
endRadius, | |
| 180 const Descriptor& desc) | |
| 181 : SkGradientShaderBase(desc, pts_to_unit(start, endRadius - startRadius)) | |
| 182 , fCenter1(start) | |
| 183 , fCenter2(end) | |
| 184 , fRadius1(startRadius) | |
| 185 , fRadius2(endRadius) | |
| 186 { | |
| 187 fDiff = fCenter1 - fCenter2; | |
| 188 fDiffRadius = fRadius2 - fRadius1; | |
| 189 // hack to avoid zero-divide for now | |
| 190 SkScalar inv = fDiffRadius ? SkScalarInvert(fDiffRadius) : 0; | |
| 191 fDiff.fX = SkScalarMul(fDiff.fX, inv); | |
| 192 fDiff.fY = SkScalarMul(fDiff.fY, inv); | |
| 193 fStartRadius = SkScalarMul(fRadius1, inv); | |
| 194 fSr2D2 = SkScalarSquare(fStartRadius); | |
| 195 fA = SkScalarSquare(fDiff.fX) + SkScalarSquare(fDiff.fY) - SK_Scalar1; | |
| 196 fOneOverTwoA = fA ? SkScalarInvert(fA * 2) : 0; | |
| 197 } | |
| 198 | |
| 199 SkShader::BitmapType SkTwoPointRadialGradient::asABitmap( | |
| 200 SkBitmap* bitmap, | |
| 201 SkMatrix* matrix, | |
| 202 SkShader::TileMode* xy) const { | |
| 203 if (bitmap) { | |
| 204 this->getGradientTableBitmap(bitmap); | |
| 205 } | |
| 206 SkScalar diffL = 0; // just to avoid gcc warning | |
| 207 if (matrix) { | |
| 208 diffL = SkScalarSqrt(SkScalarSquare(fDiff.fX) + | |
| 209 SkScalarSquare(fDiff.fY)); | |
| 210 } | |
| 211 if (matrix) { | |
| 212 if (diffL) { | |
| 213 SkScalar invDiffL = SkScalarInvert(diffL); | |
| 214 matrix->setSinCos(-SkScalarMul(invDiffL, fDiff.fY), | |
| 215 SkScalarMul(invDiffL, fDiff.fX)); | |
| 216 } else { | |
| 217 matrix->reset(); | |
| 218 } | |
| 219 matrix->preConcat(fPtsToUnit); | |
| 220 } | |
| 221 if (xy) { | |
| 222 xy[0] = fTileMode; | |
| 223 xy[1] = kClamp_TileMode; | |
| 224 } | |
| 225 return kTwoPointRadial_BitmapType; | |
| 226 } | |
| 227 | |
| 228 SkShader::GradientType SkTwoPointRadialGradient::asAGradient( | |
| 229 SkShader::GradientInfo* info) const { | |
| 230 if (info) { | |
| 231 commonAsAGradient(info); | |
| 232 info->fPoint[0] = fCenter1; | |
| 233 info->fPoint[1] = fCenter2; | |
| 234 info->fRadius[0] = fRadius1; | |
| 235 info->fRadius[1] = fRadius2; | |
| 236 } | |
| 237 return kRadial2_GradientType; | |
| 238 } | |
| 239 | |
| 240 size_t SkTwoPointRadialGradient::contextSize() const { | |
| 241 return sizeof(TwoPointRadialGradientContext); | |
| 242 } | |
| 243 | |
| 244 SkShader::Context* SkTwoPointRadialGradient::onCreateContext(const ContextRec& r
ec, | |
| 245 void* storage) cons
t { | |
| 246 // For now, we might have divided by zero, so detect that. | |
| 247 if (0 == fDiffRadius) { | |
| 248 return NULL; | |
| 249 } | |
| 250 return SkNEW_PLACEMENT_ARGS(storage, TwoPointRadialGradientContext, (*this,
rec)); | |
| 251 } | |
| 252 | |
| 253 SkTwoPointRadialGradient::TwoPointRadialGradientContext::TwoPointRadialGradientC
ontext( | |
| 254 const SkTwoPointRadialGradient& shader, const ContextRec& rec) | |
| 255 : INHERITED(shader, rec) | |
| 256 { | |
| 257 // we don't have a span16 proc | |
| 258 fFlags &= ~kHasSpan16_Flag; | |
| 259 } | |
| 260 | |
| 261 void SkTwoPointRadialGradient::TwoPointRadialGradientContext::shadeSpan( | |
| 262 int x, int y, SkPMColor* dstCParam, int count) { | |
| 263 SkASSERT(count > 0); | |
| 264 | |
| 265 const SkTwoPointRadialGradient& twoPointRadialGradient = | |
| 266 static_cast<const SkTwoPointRadialGradient&>(fShader); | |
| 267 | |
| 268 SkPMColor* SK_RESTRICT dstC = dstCParam; | |
| 269 | |
| 270 // Zero difference between radii: fill with transparent black. | |
| 271 if (twoPointRadialGradient.fDiffRadius == 0) { | |
| 272 sk_bzero(dstC, count * sizeof(*dstC)); | |
| 273 return; | |
| 274 } | |
| 275 SkMatrix::MapXYProc dstProc = fDstToIndexProc; | |
| 276 TileProc proc = twoPointRadialGradient.fTileProc; | |
| 277 const SkPMColor* SK_RESTRICT cache = fCache->getCache32(); | |
| 278 | |
| 279 SkScalar foura = twoPointRadialGradient.fA * 4; | |
| 280 bool posRoot = twoPointRadialGradient.fDiffRadius < 0; | |
| 281 if (fDstToIndexClass != kPerspective_MatrixClass) { | |
| 282 SkPoint srcPt; | |
| 283 dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf, | |
| 284 SkIntToScalar(y) + SK_ScalarHalf, &srcPt); | |
| 285 SkScalar dx, fx = srcPt.fX; | |
| 286 SkScalar dy, fy = srcPt.fY; | |
| 287 | |
| 288 if (fDstToIndexClass == kFixedStepInX_MatrixClass) { | |
| 289 SkFixed fixedX, fixedY; | |
| 290 (void)fDstToIndex.fixedStepInX(SkIntToScalar(y), &fixedX, &fixedY); | |
| 291 dx = SkFixedToScalar(fixedX); | |
| 292 dy = SkFixedToScalar(fixedY); | |
| 293 } else { | |
| 294 SkASSERT(fDstToIndexClass == kLinear_MatrixClass); | |
| 295 dx = fDstToIndex.getScaleX(); | |
| 296 dy = fDstToIndex.getSkewY(); | |
| 297 } | |
| 298 SkScalar b = (SkScalarMul(twoPointRadialGradient.fDiff.fX, fx) + | |
| 299 SkScalarMul(twoPointRadialGradient.fDiff.fY, fy) - | |
| 300 twoPointRadialGradient.fStartRadius) * 2; | |
| 301 SkScalar db = (SkScalarMul(twoPointRadialGradient.fDiff.fX, dx) + | |
| 302 SkScalarMul(twoPointRadialGradient.fDiff.fY, dy)) * 2; | |
| 303 | |
| 304 TwoPointRadialShadeProc shadeProc = shadeSpan_twopoint_repeat; | |
| 305 if (SkShader::kClamp_TileMode == twoPointRadialGradient.fTileMode) { | |
| 306 shadeProc = shadeSpan_twopoint_clamp; | |
| 307 } else if (SkShader::kMirror_TileMode == twoPointRadialGradient.fTileMod
e) { | |
| 308 shadeProc = shadeSpan_twopoint_mirror; | |
| 309 } else { | |
| 310 SkASSERT(SkShader::kRepeat_TileMode == twoPointRadialGradient.fTileM
ode); | |
| 311 } | |
| 312 (*shadeProc)(fx, dx, fy, dy, b, db, | |
| 313 twoPointRadialGradient.fSr2D2, foura, | |
| 314 twoPointRadialGradient.fOneOverTwoA, posRoot, | |
| 315 dstC, cache, count); | |
| 316 } else { // perspective case | |
| 317 SkScalar dstX = SkIntToScalar(x); | |
| 318 SkScalar dstY = SkIntToScalar(y); | |
| 319 for (; count > 0; --count) { | |
| 320 SkPoint srcPt; | |
| 321 dstProc(fDstToIndex, dstX, dstY, &srcPt); | |
| 322 SkScalar fx = srcPt.fX; | |
| 323 SkScalar fy = srcPt.fY; | |
| 324 SkScalar b = (SkScalarMul(twoPointRadialGradient.fDiff.fX, fx) + | |
| 325 SkScalarMul(twoPointRadialGradient.fDiff.fY, fy) - | |
| 326 twoPointRadialGradient.fStartRadius) * 2; | |
| 327 SkFixed t = two_point_radial(b, fx, fy, twoPointRadialGradient.fSr2D
2, foura, | |
| 328 twoPointRadialGradient.fOneOverTwoA, po
sRoot); | |
| 329 SkFixed index = proc(t); | |
| 330 SkASSERT(index <= 0xFFFF); | |
| 331 *dstC++ = cache[index >> SkGradientShaderBase::kCache32Shift]; | |
| 332 dstX += SK_Scalar1; | |
| 333 } | |
| 334 } | |
| 335 } | |
| 336 | |
| 337 #ifndef SK_IGNORE_TO_STRING | |
| 338 void SkTwoPointRadialGradient::toString(SkString* str) const { | |
| 339 str->append("SkTwoPointRadialGradient: ("); | |
| 340 | |
| 341 str->append("center1: ("); | |
| 342 str->appendScalar(fCenter1.fX); | |
| 343 str->append(", "); | |
| 344 str->appendScalar(fCenter1.fY); | |
| 345 str->append(") radius1: "); | |
| 346 str->appendScalar(fRadius1); | |
| 347 str->append(" "); | |
| 348 | |
| 349 str->append("center2: ("); | |
| 350 str->appendScalar(fCenter2.fX); | |
| 351 str->append(", "); | |
| 352 str->appendScalar(fCenter2.fY); | |
| 353 str->append(") radius2: "); | |
| 354 str->appendScalar(fRadius2); | |
| 355 str->append(" "); | |
| 356 | |
| 357 this->INHERITED::toString(str); | |
| 358 | |
| 359 str->append(")"); | |
| 360 } | |
| 361 #endif | |
| 362 | |
| 363 SkFlattenable* SkTwoPointRadialGradient::CreateProc(SkReadBuffer& buffer) { | |
| 364 DescriptorScope desc; | |
| 365 if (!desc.unflatten(buffer)) { | |
| 366 return NULL; | |
| 367 } | |
| 368 const SkPoint c1 = buffer.readPoint(); | |
| 369 const SkPoint c2 = buffer.readPoint(); | |
| 370 const SkScalar r1 = buffer.readScalar(); | |
| 371 const SkScalar r2 = buffer.readScalar(); | |
| 372 return SkGradientShader::CreateTwoPointRadial(c1, r1, c2, r2, desc.fColors,
desc.fPos, | |
| 373 desc.fCount, desc.fTileMode, d
esc.fGradFlags, | |
| 374 desc.fLocalMatrix); | |
| 375 } | |
| 376 | |
| 377 void SkTwoPointRadialGradient::flatten( | |
| 378 SkWriteBuffer& buffer) const { | |
| 379 this->INHERITED::flatten(buffer); | |
| 380 buffer.writePoint(fCenter1); | |
| 381 buffer.writePoint(fCenter2); | |
| 382 buffer.writeScalar(fRadius1); | |
| 383 buffer.writeScalar(fRadius2); | |
| 384 } | |
| 385 | |
| 386 ///////////////////////////////////////////////////////////////////// | |
| 387 | |
| 388 #if SK_SUPPORT_GPU | |
| 389 | |
| 390 #include "SkGr.h" | |
| 391 #include "gl/builders/GrGLProgramBuilder.h" | |
| 392 | |
| 393 // For brevity | |
| 394 typedef GrGLProgramDataManager::UniformHandle UniformHandle; | |
| 395 | |
| 396 class GrGLRadial2Gradient : public GrGLGradientEffect { | |
| 397 | |
| 398 public: | |
| 399 | |
| 400 GrGLRadial2Gradient(const GrProcessor&); | |
| 401 virtual ~GrGLRadial2Gradient() { } | |
| 402 | |
| 403 virtual void emitCode(GrGLFPBuilder*, | |
| 404 const GrFragmentProcessor&, | |
| 405 const char* outputColor, | |
| 406 const char* inputColor, | |
| 407 const TransformedCoordsArray&, | |
| 408 const TextureSamplerArray&) override; | |
| 409 void setData(const GrGLProgramDataManager&, const GrProcessor&) override; | |
| 410 | |
| 411 static void GenKey(const GrProcessor&, const GrGLSLCaps& caps, GrProcessorKe
yBuilder* b); | |
| 412 | |
| 413 protected: | |
| 414 | |
| 415 UniformHandle fParamUni; | |
| 416 | |
| 417 const char* fVSVaryingName; | |
| 418 const char* fFSVaryingName; | |
| 419 | |
| 420 bool fIsDegenerate; | |
| 421 | |
| 422 // @{ | |
| 423 /// Values last uploaded as uniforms | |
| 424 | |
| 425 SkScalar fCachedCenter; | |
| 426 SkScalar fCachedRadius; | |
| 427 bool fCachedPosRoot; | |
| 428 | |
| 429 // @} | |
| 430 | |
| 431 private: | |
| 432 | |
| 433 typedef GrGLGradientEffect INHERITED; | |
| 434 | |
| 435 }; | |
| 436 | |
| 437 ///////////////////////////////////////////////////////////////////// | |
| 438 | |
| 439 class GrRadial2Gradient : public GrGradientEffect { | |
| 440 public: | |
| 441 static GrFragmentProcessor* Create(GrContext* ctx, | |
| 442 const SkTwoPointRadialGradient& shader, | |
| 443 const SkMatrix& matrix, | |
| 444 SkShader::TileMode tm) { | |
| 445 return SkNEW_ARGS(GrRadial2Gradient, (ctx, shader, matrix, tm)); | |
| 446 } | |
| 447 | |
| 448 virtual ~GrRadial2Gradient() { } | |
| 449 | |
| 450 const char* name() const override { return "Two-Point Radial Gradient"; } | |
| 451 | |
| 452 virtual void getGLProcessorKey(const GrGLSLCaps& caps, | |
| 453 GrProcessorKeyBuilder* b) const override { | |
| 454 GrGLRadial2Gradient::GenKey(*this, caps, b); | |
| 455 } | |
| 456 | |
| 457 GrGLFragmentProcessor* createGLInstance() const override { | |
| 458 return SkNEW_ARGS(GrGLRadial2Gradient, (*this)); | |
| 459 } | |
| 460 | |
| 461 // The radial gradient parameters can collapse to a linear (instead of quadr
atic) equation. | |
| 462 bool isDegenerate() const { return SK_Scalar1 == fCenterX1; } | |
| 463 SkScalar center() const { return fCenterX1; } | |
| 464 SkScalar radius() const { return fRadius0; } | |
| 465 bool isPosRoot() const { return SkToBool(fPosRoot); } | |
| 466 | |
| 467 private: | |
| 468 bool onIsEqual(const GrFragmentProcessor& sBase) const override { | |
| 469 const GrRadial2Gradient& s = sBase.cast<GrRadial2Gradient>(); | |
| 470 return (INHERITED::onIsEqual(sBase) && | |
| 471 this->fCenterX1 == s.fCenterX1 && | |
| 472 this->fRadius0 == s.fRadius0 && | |
| 473 this->fPosRoot == s.fPosRoot); | |
| 474 } | |
| 475 | |
| 476 GrRadial2Gradient(GrContext* ctx, | |
| 477 const SkTwoPointRadialGradient& shader, | |
| 478 const SkMatrix& matrix, | |
| 479 SkShader::TileMode tm) | |
| 480 : INHERITED(ctx, shader, matrix, tm) | |
| 481 , fCenterX1(shader.getCenterX1()) | |
| 482 , fRadius0(shader.getStartRadius()) | |
| 483 , fPosRoot(shader.getDiffRadius() < 0) { | |
| 484 this->initClassID<GrRadial2Gradient>(); | |
| 485 // We pass the linear part of the quadratic as a varying. | |
| 486 // float b = 2.0 * (fCenterX1 * x - fRadius0 * z) | |
| 487 fBTransform = this->getCoordTransform(); | |
| 488 SkMatrix& bMatrix = *fBTransform.accessMatrix(); | |
| 489 bMatrix[SkMatrix::kMScaleX] = 2 * (SkScalarMul(fCenterX1, bMatrix[SkMatr
ix::kMScaleX]) - | |
| 490 SkScalarMul(fRadius0, bMatrix[SkMatri
x::kMPersp0])); | |
| 491 bMatrix[SkMatrix::kMSkewX] = 2 * (SkScalarMul(fCenterX1, bMatrix[SkMatri
x::kMSkewX]) - | |
| 492 SkScalarMul(fRadius0, bMatrix[SkMatrix
::kMPersp1])); | |
| 493 bMatrix[SkMatrix::kMTransX] = 2 * (SkScalarMul(fCenterX1, bMatrix[SkMatr
ix::kMTransX]) - | |
| 494 SkScalarMul(fRadius0, bMatrix[SkMatri
x::kMPersp2])); | |
| 495 this->addCoordTransform(&fBTransform); | |
| 496 } | |
| 497 | |
| 498 GR_DECLARE_FRAGMENT_PROCESSOR_TEST; | |
| 499 | |
| 500 // @{ | |
| 501 // Cache of values - these can change arbitrarily, EXCEPT | |
| 502 // we shouldn't change between degenerate and non-degenerate?! | |
| 503 | |
| 504 GrCoordTransform fBTransform; | |
| 505 SkScalar fCenterX1; | |
| 506 SkScalar fRadius0; | |
| 507 SkBool8 fPosRoot; | |
| 508 | |
| 509 // @} | |
| 510 | |
| 511 typedef GrGradientEffect INHERITED; | |
| 512 }; | |
| 513 | |
| 514 ///////////////////////////////////////////////////////////////////// | |
| 515 | |
| 516 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrRadial2Gradient); | |
| 517 | |
| 518 GrFragmentProcessor* GrRadial2Gradient::TestCreate(SkRandom* random, | |
| 519 GrContext* context, | |
| 520 const GrDrawTargetCaps&, | |
| 521 GrTexture**) { | |
| 522 SkPoint center1 = {random->nextUScalar1(), random->nextUScalar1()}; | |
| 523 SkScalar radius1 = random->nextUScalar1(); | |
| 524 SkPoint center2; | |
| 525 SkScalar radius2; | |
| 526 do { | |
| 527 center2.set(random->nextUScalar1(), random->nextUScalar1()); | |
| 528 radius2 = random->nextUScalar1 (); | |
| 529 // There is a bug in two point radial gradients with identical radii | |
| 530 } while (radius1 == radius2); | |
| 531 | |
| 532 SkColor colors[kMaxRandomGradientColors]; | |
| 533 SkScalar stopsArray[kMaxRandomGradientColors]; | |
| 534 SkScalar* stops = stopsArray; | |
| 535 SkShader::TileMode tm; | |
| 536 int colorCount = RandomGradientParams(random, colors, &stops, &tm); | |
| 537 SkAutoTUnref<SkShader> shader(SkGradientShader::CreateTwoPointRadial(center1
, radius1, | |
| 538 center2
, radius2, | |
| 539 colors,
stops, colorCount, | |
| 540 tm)); | |
| 541 SkPaint paint; | |
| 542 GrFragmentProcessor* fp; | |
| 543 GrColor paintColor; | |
| 544 SkAssertResult(shader->asFragmentProcessor(context, paint, | |
| 545 GrTest::TestMatrix(random), NULL, | |
| 546 &paintColor, &fp)); | |
| 547 return fp; | |
| 548 } | |
| 549 | |
| 550 ///////////////////////////////////////////////////////////////////// | |
| 551 | |
| 552 GrGLRadial2Gradient::GrGLRadial2Gradient(const GrProcessor& processor) | |
| 553 : fVSVaryingName(NULL) | |
| 554 , fFSVaryingName(NULL) | |
| 555 , fCachedCenter(SK_ScalarMax) | |
| 556 , fCachedRadius(-SK_ScalarMax) | |
| 557 , fCachedPosRoot(0) { | |
| 558 | |
| 559 const GrRadial2Gradient& data = processor.cast<GrRadial2Gradient>(); | |
| 560 fIsDegenerate = data.isDegenerate(); | |
| 561 } | |
| 562 | |
| 563 void GrGLRadial2Gradient::emitCode(GrGLFPBuilder* builder, | |
| 564 const GrFragmentProcessor& fp, | |
| 565 const char* outputColor, | |
| 566 const char* inputColor, | |
| 567 const TransformedCoordsArray& coords, | |
| 568 const TextureSamplerArray& samplers) { | |
| 569 const GrRadial2Gradient& ge = fp.cast<GrRadial2Gradient>(); | |
| 570 this->emitUniforms(builder, ge); | |
| 571 fParamUni = builder->addUniformArray(GrGLProgramBuilder::kFragment_Visibilit
y, | |
| 572 kFloat_GrSLType, kDefault_GrSLPrecision
, | |
| 573 "Radial2FSParams", 6); | |
| 574 | |
| 575 SkString cName("c"); | |
| 576 SkString ac4Name("ac4"); | |
| 577 SkString rootName("root"); | |
| 578 SkString t; | |
| 579 SkString p0; | |
| 580 SkString p1; | |
| 581 SkString p2; | |
| 582 SkString p3; | |
| 583 SkString p4; | |
| 584 SkString p5; | |
| 585 builder->getUniformVariable(fParamUni).appendArrayAccess(0, &p0); | |
| 586 builder->getUniformVariable(fParamUni).appendArrayAccess(1, &p1); | |
| 587 builder->getUniformVariable(fParamUni).appendArrayAccess(2, &p2); | |
| 588 builder->getUniformVariable(fParamUni).appendArrayAccess(3, &p3); | |
| 589 builder->getUniformVariable(fParamUni).appendArrayAccess(4, &p4); | |
| 590 builder->getUniformVariable(fParamUni).appendArrayAccess(5, &p5); | |
| 591 | |
| 592 GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder(); | |
| 593 // We interpolate the linear component in coords[1]. | |
| 594 SkASSERT(coords[0].getType() == coords[1].getType()); | |
| 595 const char* coords2D; | |
| 596 SkString bVar; | |
| 597 if (kVec3f_GrSLType == coords[0].getType()) { | |
| 598 fsBuilder->codeAppendf("\tvec3 interpolants = vec3(%s.xy, %s.x) / %s.z;\
n", | |
| 599 coords[0].c_str(), coords[1].c_str(), coords[0].c
_str()); | |
| 600 coords2D = "interpolants.xy"; | |
| 601 bVar = "interpolants.z"; | |
| 602 } else { | |
| 603 coords2D = coords[0].c_str(); | |
| 604 bVar.printf("%s.x", coords[1].c_str()); | |
| 605 } | |
| 606 | |
| 607 // c = (x^2)+(y^2) - params[4] | |
| 608 fsBuilder->codeAppendf("\tfloat %s = dot(%s, %s) - %s;\n", | |
| 609 cName.c_str(), coords2D, coords2D, p4.c_str()); | |
| 610 | |
| 611 // If we aren't degenerate, emit some extra code, and accept a slightly | |
| 612 // more complex coord. | |
| 613 if (!fIsDegenerate) { | |
| 614 | |
| 615 // ac4 = 4.0 * params[0] * c | |
| 616 fsBuilder->codeAppendf("\tfloat %s = %s * 4.0 * %s;\n", | |
| 617 ac4Name.c_str(), p0.c_str(), | |
| 618 cName.c_str()); | |
| 619 | |
| 620 // root = sqrt(b^2-4ac) | |
| 621 // (abs to avoid exception due to fp precision) | |
| 622 fsBuilder->codeAppendf("\tfloat %s = sqrt(abs(%s*%s - %s));\n", | |
| 623 rootName.c_str(), bVar.c_str(), bVar.c_str(), | |
| 624 ac4Name.c_str()); | |
| 625 | |
| 626 // t is: (-b + params[5] * sqrt(b^2-4ac)) * params[1] | |
| 627 t.printf("(-%s + %s * %s) * %s", bVar.c_str(), p5.c_str(), | |
| 628 rootName.c_str(), p1.c_str()); | |
| 629 } else { | |
| 630 // t is: -c/b | |
| 631 t.printf("-%s / %s", cName.c_str(), bVar.c_str()); | |
| 632 } | |
| 633 | |
| 634 this->emitColor(builder, ge, t.c_str(), outputColor, inputColor, samplers); | |
| 635 } | |
| 636 | |
| 637 void GrGLRadial2Gradient::setData(const GrGLProgramDataManager& pdman, | |
| 638 const GrProcessor& processor) { | |
| 639 INHERITED::setData(pdman, processor); | |
| 640 const GrRadial2Gradient& data = processor.cast<GrRadial2Gradient>(); | |
| 641 SkASSERT(data.isDegenerate() == fIsDegenerate); | |
| 642 SkScalar centerX1 = data.center(); | |
| 643 SkScalar radius0 = data.radius(); | |
| 644 if (fCachedCenter != centerX1 || | |
| 645 fCachedRadius != radius0 || | |
| 646 fCachedPosRoot != data.isPosRoot()) { | |
| 647 | |
| 648 SkScalar a = SkScalarMul(centerX1, centerX1) - SK_Scalar1; | |
| 649 | |
| 650 // When we're in the degenerate (linear) case, the second | |
| 651 // value will be INF but the program doesn't read it. (We | |
| 652 // use the same 6 uniforms even though we don't need them | |
| 653 // all in the linear case just to keep the code complexity | |
| 654 // down). | |
| 655 float values[6] = { | |
| 656 SkScalarToFloat(a), | |
| 657 1 / (2.f * SkScalarToFloat(a)), | |
| 658 SkScalarToFloat(centerX1), | |
| 659 SkScalarToFloat(radius0), | |
| 660 SkScalarToFloat(SkScalarMul(radius0, radius0)), | |
| 661 data.isPosRoot() ? 1.f : -1.f | |
| 662 }; | |
| 663 | |
| 664 pdman.set1fv(fParamUni, 6, values); | |
| 665 fCachedCenter = centerX1; | |
| 666 fCachedRadius = radius0; | |
| 667 fCachedPosRoot = data.isPosRoot(); | |
| 668 } | |
| 669 } | |
| 670 | |
| 671 void GrGLRadial2Gradient::GenKey(const GrProcessor& processor, | |
| 672 const GrGLSLCaps&, GrProcessorKeyBuilder* b) { | |
| 673 uint32_t* key = b->add32n(2); | |
| 674 key[0] = GenBaseGradientKey(processor); | |
| 675 key[1] = processor.cast<GrRadial2Gradient>().isDegenerate(); | |
| 676 } | |
| 677 | |
| 678 ///////////////////////////////////////////////////////////////////// | |
| 679 | |
| 680 bool SkTwoPointRadialGradient::asFragmentProcessor(GrContext* context, const SkP
aint& paint, | |
| 681 const SkMatrix&, | |
| 682 const SkMatrix* localMatrix,
GrColor* paintColor, | |
| 683 GrFragmentProcessor** fp) co
nst { | |
| 684 SkASSERT(context); | |
| 685 | |
| 686 // invert the localM, translate to center1 (fPtsToUni), rotate so center2 is
on x axis. | |
| 687 SkMatrix matrix; | |
| 688 if (!this->getLocalMatrix().invert(&matrix)) { | |
| 689 return false; | |
| 690 } | |
| 691 if (localMatrix) { | |
| 692 SkMatrix inv; | |
| 693 if (!localMatrix->invert(&inv)) { | |
| 694 return false; | |
| 695 } | |
| 696 matrix.postConcat(inv); | |
| 697 } | |
| 698 matrix.postConcat(fPtsToUnit); | |
| 699 | |
| 700 SkScalar diffLen = fDiff.length(); | |
| 701 if (0 != diffLen) { | |
| 702 SkScalar invDiffLen = SkScalarInvert(diffLen); | |
| 703 SkMatrix rot; | |
| 704 rot.setSinCos(-SkScalarMul(invDiffLen, fDiff.fY), | |
| 705 SkScalarMul(invDiffLen, fDiff.fX)); | |
| 706 matrix.postConcat(rot); | |
| 707 } | |
| 708 | |
| 709 *paintColor = SkColor2GrColorJustAlpha(paint.getColor()); | |
| 710 *fp = GrRadial2Gradient::Create(context, *this, matrix, fTileMode); | |
| 711 | |
| 712 return true; | |
| 713 } | |
| 714 | |
| 715 #else | |
| 716 | |
| 717 bool SkTwoPointRadialGradient::asFragmentProcessor(GrContext*, const SkPaint&, c
onst SkMatrix&, | |
| 718 const SkMatrix*, | |
| 719 GrColor*, GrFragmentProcessor
**) const { | |
| 720 SkDEBUGFAIL("Should not call in GPU-less build"); | |
| 721 return false; | |
| 722 } | |
| 723 | |
| 724 #endif | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1114243005:
remove (redundant) twopointradial shader (Closed)
Base URL: https://skia.googlesource.com/skia.git@master