1 /* 2 * Copyright 2011 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 "GrAAHairLinePathRenderer.h" 9 10 #include "GrBatch.h" 11 #include "GrBatchTarget.h" 12 #include "GrBatchTest.h" 13 #include "GrContext.h" 14 #include "GrDefaultGeoProcFactory.h" 15 #include "GrDrawTargetCaps.h" 16 #include "GrIndexBuffer.h" 17 #include "GrPathUtils.h" 18 #include "GrPipelineBuilder.h" 19 #include "GrProcessor.h" 20 #include "GrResourceProvider.h" 21 #include "GrVertexBuffer.h" 22 #include "SkGeometry.h" 23 #include "SkStroke.h" 24 #include "SkTemplates.h" 25 26 #include "effects/GrBezierEffect.h" 27 28 #define PREALLOC_PTARRAY(N) SkSTArray<(N),SkPoint, true> 29 30 // quadratics are rendered as 5-sided polys in order to bound the 31 // AA stroke around the center-curve. See comments in push_quad_index_buffer and 32 // bloat_quad. Quadratics and conics share an index buffer 33 34 // lines are rendered as: 35 // *______________* 36 // |\ -_______ /| 37 // | \ \ / | 38 // | *--------* | 39 // | / ______/ \ | 40 // */_-__________\* 41 // For: 6 vertices and 18 indices (for 6 triangles) 42 43 // Each quadratic is rendered as a five sided polygon. This poly bounds 44 // the quadratic's bounding triangle but has been expanded so that the 45 // 1-pixel wide area around the curve is inside the poly. 46 // If a,b,c are the original control points then the poly a0,b0,c0,c1,a1 47 // that is rendered would look like this: 48 // b0 49 // b 50 // 51 // a0 c0 52 // a c 53 // a1 c1 54 // Each is drawn as three triangles ((a0,a1,b0), (b0,c1,c0), (a1,c1,b0)) 55 // specified by these 9 indices: 56 static const uint16_t kQuadIdxBufPattern[] = { 57 0, 1, 2, 58 2, 4, 3, 59 1, 4, 2 60 }; 61 62 static const int kIdxsPerQuad = SK_ARRAY_COUNT(kQuadIdxBufPattern); 63 static const int kQuadNumVertices = 5; 64 static const int kQuadsNumInIdxBuffer = 256; 65 GR_DECLARE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey); 66 67 static const GrIndexBuffer* ref_quads_index_buffer(GrResourceProvider* resourceProvider) { 68 GR_DEFINE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey); 69 return resourceProvider->refOrCreateInstancedIndexBuffer( 70 kQuadIdxBufPattern, kIdxsPerQuad, kQuadsNumInIdxBuffer, kQuadNumVertices, 71 gQuadsIndexBufferKey); 72 } 73 74 75 // Each line segment is rendered as two quads and two triangles. 76 // p0 and p1 have alpha = 1 while all other points have alpha = 0. 77 // The four external points are offset 1 pixel perpendicular to the 78 // line and half a pixel parallel to the line. 79 // 80 // p4 p5 81 // p0 p1 82 // p2 p3 83 // 84 // Each is drawn as six triangles specified by these 18 indices: 85 86 static const uint16_t kLineSegIdxBufPattern[] = { 87 0, 1, 3, 88 0, 3, 2, 89 0, 4, 5, 90 0, 5, 1, 91 0, 2, 4, 92 1, 5, 3 93 }; 94 95 static const int kIdxsPerLineSeg = SK_ARRAY_COUNT(kLineSegIdxBufPattern); 96 static const int kLineSegNumVertices = 6; 97 static const int kLineSegsNumInIdxBuffer = 256; 98 99 GR_DECLARE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey); 100 101 static const GrIndexBuffer* ref_lines_index_buffer(GrResourceProvider* resourceProvider) { 102 GR_DEFINE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey); 103 return resourceProvider->refOrCreateInstancedIndexBuffer( 104 kLineSegIdxBufPattern, kIdxsPerLineSeg, kLineSegsNumInIdxBuffer, kLineSegNumVertices, 105 gLinesIndexBufferKey); 106 } 107 108 // Takes 178th time of logf on Z600 / VC2010 109 static int get_float_exp(float x) { 110 GR_STATIC_ASSERT(sizeof(int) == sizeof(float)); 111 #ifdef SK_DEBUG 112 static bool tested; 113 if (!tested) { 114 tested = true; 115 SkASSERT(get_float_exp(0.25f) == -2); 116 SkASSERT(get_float_exp(0.3f) == -2); 117 SkASSERT(get_float_exp(0.5f) == -1); 118 SkASSERT(get_float_exp(1.f) == 0); 119 SkASSERT(get_float_exp(2.f) == 1); 120 SkASSERT(get_float_exp(2.5f) == 1); 121 SkASSERT(get_float_exp(8.f) == 3); 122 SkASSERT(get_float_exp(100.f) == 6); 123 SkASSERT(get_float_exp(1000.f) == 9); 124 SkASSERT(get_float_exp(1024.f) == 10); 125 SkASSERT(get_float_exp(3000000.f) == 21); 126 } 127 #endif 128 const int* iptr = (const int*)&x; 129 return (((*iptr) & 0x7f800000) >> 23) - 127; 130 } 131 132 // Uses the max curvature function for quads to estimate 133 // where to chop the conic. If the max curvature is not 134 // found along the curve segment it will return 1 and 135 // dst[0] is the original conic. If it returns 2 the dst[0] 136 // and dst[1] are the two new conics. 137 static int split_conic(const SkPoint src[3], SkConic dst[2], const SkScalar weight) { 138 SkScalar t = SkFindQuadMaxCurvature(src); 139 if (t == 0) { 140 if (dst) { 141 dst[0].set(src, weight); 142 } 143 return 1; 144 } else { 145 if (dst) { 146 SkConic conic; 147 conic.set(src, weight); 148 conic.chopAt(t, dst); 149 } 150 return 2; 151 } 152 } 153 154 // Calls split_conic on the entire conic and then once more on each subsection. 155 // Most cases will result in either 1 conic (chop point is not within t range) 156 // or 3 points (split once and then one subsection is split again). 157 static int chop_conic(const SkPoint src[3], SkConic dst[4], const SkScalar weight) { 158 SkConic dstTemp[2]; 159 int conicCnt = split_conic(src, dstTemp, weight); 160 if (2 == conicCnt) { 161 int conicCnt2 = split_conic(dstTemp[0].fPts, dst, dstTemp[0].fW); 162 conicCnt = conicCnt2 + split_conic(dstTemp[1].fPts, &dst[conicCnt2], dstTemp[1].fW); 163 } else { 164 dst[0] = dstTemp[0]; 165 } 166 return conicCnt; 167 } 168 169 // returns 0 if quad/conic is degen or close to it 170 // in this case approx the path with lines 171 // otherwise returns 1 172 static int is_degen_quad_or_conic(const SkPoint p[3], SkScalar* dsqd) { 173 static const SkScalar gDegenerateToLineTol = GrPathUtils::kDefaultTolerance; 174 static const SkScalar gDegenerateToLineTolSqd = 175 SkScalarMul(gDegenerateToLineTol, gDegenerateToLineTol); 176 177 if (p[0].distanceToSqd(p[1]) < gDegenerateToLineTolSqd || 178 p[1].distanceToSqd(p[2]) < gDegenerateToLineTolSqd) { 179 return 1; 180 } 181 182 *dsqd = p[1].distanceToLineBetweenSqd(p[0], p[2]); 183 if (*dsqd < gDegenerateToLineTolSqd) { 184 return 1; 185 } 186 187 if (p[2].distanceToLineBetweenSqd(p[1], p[0]) < gDegenerateToLineTolSqd) { 188 return 1; 189 } 190 return 0; 191 } 192 193 static int is_degen_quad_or_conic(const SkPoint p[3]) { 194 SkScalar dsqd; 195 return is_degen_quad_or_conic(p, &dsqd); 196 } 197 198 // we subdivide the quads to avoid huge overfill 199 // if it returns -1 then should be drawn as lines 200 static int num_quad_subdivs(const SkPoint p[3]) { 201 SkScalar dsqd; 202 if (is_degen_quad_or_conic(p, &dsqd)) { 203 return -1; 204 } 205 206 // tolerance of triangle height in pixels 207 // tuned on windows Quadro FX 380 / Z600 208 // trade off of fill vs cpu time on verts 209 // maybe different when do this using gpu (geo or tess shaders) 210 static const SkScalar gSubdivTol = 175 * SK_Scalar1; 211 212 if (dsqd <= SkScalarMul(gSubdivTol, gSubdivTol)) { 213 return 0; 214 } else { 215 static const int kMaxSub = 4; 216 // subdividing the quad reduces d by 4. so we want x = log4(d/tol) 217 // = log4(d*d/tol*tol)/2 218 // = log2(d*d/tol*tol) 219 220 // +1 since we're ignoring the mantissa contribution. 221 int log = get_float_exp(dsqd/(gSubdivTol*gSubdivTol)) + 1; 222 log = SkTMin(SkTMax(0, log), kMaxSub); 223 return log; 224 } 225 } 226 227 /** 228 * Generates the lines and quads to be rendered. Lines are always recorded in 229 * device space. We will do a device space bloat to account for the 1pixel 230 * thickness. 231 * Quads are recorded in device space unless m contains 232 * perspective, then in they are in src space. We do this because we will 233 * subdivide large quads to reduce over-fill. This subdivision has to be 234 * performed before applying the perspective matrix. 235 */ 236 static int gather_lines_and_quads(const SkPath& path, 237 const SkMatrix& m, 238 const SkIRect& devClipBounds, 239 GrAAHairLinePathRenderer::PtArray* lines, 240 GrAAHairLinePathRenderer::PtArray* quads, 241 GrAAHairLinePathRenderer::PtArray* conics, 242 GrAAHairLinePathRenderer::IntArray* quadSubdivCnts, 243 GrAAHairLinePathRenderer::FloatArray* conicWeights) { 244 SkPath::Iter iter(path, false); 245 246 int totalQuadCount = 0; 247 SkRect bounds; 248 SkIRect ibounds; 249 250 bool persp = m.hasPerspective(); 251 252 for (;;) { 253 SkPoint pathPts[4]; 254 SkPoint devPts[4]; 255 SkPath::Verb verb = iter.next(pathPts); 256 switch (verb) { 257 case SkPath::kConic_Verb: { 258 SkConic dst[4]; 259 // We chop the conics to create tighter clipping to hide error 260 // that appears near max curvature of very thin conics. Thin 261 // hyperbolas with high weight still show error. 262 int conicCnt = chop_conic(pathPts, dst, iter.conicWeight()); 263 for (int i = 0; i < conicCnt; ++i) { 264 SkPoint* chopPnts = dst[i].fPts; 265 m.mapPoints(devPts, chopPnts, 3); 266 bounds.setBounds(devPts, 3); 267 bounds.outset(SK_Scalar1, SK_Scalar1); 268 bounds.roundOut(&ibounds); 269 if (SkIRect::Intersects(devClipBounds, ibounds)) { 270 if (is_degen_quad_or_conic(devPts)) { 271 SkPoint* pts = lines->push_back_n(4); 272 pts[0] = devPts[0]; 273 pts[1] = devPts[1]; 274 pts[2] = devPts[1]; 275 pts[3] = devPts[2]; 276 } else { 277 // when in perspective keep conics in src space 278 SkPoint* cPts = persp ? chopPnts : devPts; 279 SkPoint* pts = conics->push_back_n(3); 280 pts[0] = cPts[0]; 281 pts[1] = cPts[1]; 282 pts[2] = cPts[2]; 283 conicWeights->push_back() = dst[i].fW; 284 } 285 } 286 } 287 break; 288 } 289 case SkPath::kMove_Verb: 290 break; 291 case SkPath::kLine_Verb: 292 m.mapPoints(devPts, pathPts, 2); 293 bounds.setBounds(devPts, 2); 294 bounds.outset(SK_Scalar1, SK_Scalar1); 295 bounds.roundOut(&ibounds); 296 if (SkIRect::Intersects(devClipBounds, ibounds)) { 297 SkPoint* pts = lines->push_back_n(2); 298 pts[0] = devPts[0]; 299 pts[1] = devPts[1]; 300 } 301 break; 302 case SkPath::kQuad_Verb: { 303 SkPoint choppedPts[5]; 304 // Chopping the quad helps when the quad is either degenerate or nearly degenerate. 305 // When it is degenerate it allows the approximation with lines to work since the 306 // chop point (if there is one) will be at the parabola's vertex. In the nearly 307 // degenerate the QuadUVMatrix computed for the points is almost singular which 308 // can cause rendering artifacts. 309 int n = SkChopQuadAtMaxCurvature(pathPts, choppedPts); 310 for (int i = 0; i < n; ++i) { 311 SkPoint* quadPts = choppedPts + i * 2; 312 m.mapPoints(devPts, quadPts, 3); 313 bounds.setBounds(devPts, 3); 314 bounds.outset(SK_Scalar1, SK_Scalar1); 315 bounds.roundOut(&ibounds); 316 317 if (SkIRect::Intersects(devClipBounds, ibounds)) { 318 int subdiv = num_quad_subdivs(devPts); 319 SkASSERT(subdiv >= -1); 320 if (-1 == subdiv) { 321 SkPoint* pts = lines->push_back_n(4); 322 pts[0] = devPts[0]; 323 pts[1] = devPts[1]; 324 pts[2] = devPts[1]; 325 pts[3] = devPts[2]; 326 } else { 327 // when in perspective keep quads in src space 328 SkPoint* qPts = persp ? quadPts : devPts; 329 SkPoint* pts = quads->push_back_n(3); 330 pts[0] = qPts[0]; 331 pts[1] = qPts[1]; 332 pts[2] = qPts[2]; 333 quadSubdivCnts->push_back() = subdiv; 334 totalQuadCount += 1 << subdiv; 335 } 336 } 337 } 338 break; 339 } 340 case SkPath::kCubic_Verb: 341 m.mapPoints(devPts, pathPts, 4); 342 bounds.setBounds(devPts, 4); 343 bounds.outset(SK_Scalar1, SK_Scalar1); 344 bounds.roundOut(&ibounds); 345 if (SkIRect::Intersects(devClipBounds, ibounds)) { 346 PREALLOC_PTARRAY(32) q; 347 // we don't need a direction if we aren't constraining the subdivision 348 static const SkPath::Direction kDummyDir = SkPath::kCCW_Direction; 349 // We convert cubics to quadratics (for now). 350 // In perspective have to do conversion in src space. 351 if (persp) { 352 SkScalar tolScale = 353 GrPathUtils::scaleToleranceToSrc(SK_Scalar1, m, 354 path.getBounds()); 355 GrPathUtils::convertCubicToQuads(pathPts, tolScale, false, kDummyDir, &q); 356 } else { 357 GrPathUtils::convertCubicToQuads(devPts, SK_Scalar1, false, kDummyDir, &q); 358 } 359 for (int i = 0; i < q.count(); i += 3) { 360 SkPoint* qInDevSpace; 361 // bounds has to be calculated in device space, but q is 362 // in src space when there is perspective. 363 if (persp) { 364 m.mapPoints(devPts, &q[i], 3); 365 bounds.setBounds(devPts, 3); 366 qInDevSpace = devPts; 367 } else { 368 bounds.setBounds(&q[i], 3); 369 qInDevSpace = &q[i]; 370 } 371 bounds.outset(SK_Scalar1, SK_Scalar1); 372 bounds.roundOut(&ibounds); 373 if (SkIRect::Intersects(devClipBounds, ibounds)) { 374 int subdiv = num_quad_subdivs(qInDevSpace); 375 SkASSERT(subdiv >= -1); 376 if (-1 == subdiv) { 377 SkPoint* pts = lines->push_back_n(4); 378 // lines should always be in device coords 379 pts[0] = qInDevSpace[0]; 380 pts[1] = qInDevSpace[1]; 381 pts[2] = qInDevSpace[1]; 382 pts[3] = qInDevSpace[2]; 383 } else { 384 SkPoint* pts = quads->push_back_n(3); 385 // q is already in src space when there is no 386 // perspective and dev coords otherwise. 387 pts[0] = q[0 + i]; 388 pts[1] = q[1 + i]; 389 pts[2] = q[2 + i]; 390 quadSubdivCnts->push_back() = subdiv; 391 totalQuadCount += 1 << subdiv; 392 } 393 } 394 } 395 } 396 break; 397 case SkPath::kClose_Verb: 398 break; 399 case SkPath::kDone_Verb: 400 return totalQuadCount; 401 } 402 } 403 } 404 405 struct LineVertex { 406 SkPoint fPos; 407 float fCoverage; 408 }; 409 410 struct BezierVertex { 411 SkPoint fPos; 412 union { 413 struct { 414 SkScalar fK; 415 SkScalar fL; 416 SkScalar fM; 417 } fConic; 418 SkVector fQuadCoord; 419 struct { 420 SkScalar fBogus[4]; 421 }; 422 }; 423 }; 424 425 GR_STATIC_ASSERT(sizeof(BezierVertex) == 3 * sizeof(SkPoint)); 426 427 static void intersect_lines(const SkPoint& ptA, const SkVector& normA, 428 const SkPoint& ptB, const SkVector& normB, 429 SkPoint* result) { 430 431 SkScalar lineAW = -normA.dot(ptA); 432 SkScalar lineBW = -normB.dot(ptB); 433 434 SkScalar wInv = SkScalarMul(normA.fX, normB.fY) - 435 SkScalarMul(normA.fY, normB.fX); 436 wInv = SkScalarInvert(wInv); 437 438 result->fX = SkScalarMul(normA.fY, lineBW) - SkScalarMul(lineAW, normB.fY); 439 result->fX = SkScalarMul(result->fX, wInv); 440 441 result->fY = SkScalarMul(lineAW, normB.fX) - SkScalarMul(normA.fX, lineBW); 442 result->fY = SkScalarMul(result->fY, wInv); 443 } 444 445 static void set_uv_quad(const SkPoint qpts[3], BezierVertex verts[kQuadNumVertices]) { 446 // this should be in the src space, not dev coords, when we have perspective 447 GrPathUtils::QuadUVMatrix DevToUV(qpts); 448 DevToUV.apply<kQuadNumVertices, sizeof(BezierVertex), sizeof(SkPoint)>(verts); 449 } 450 451 static void bloat_quad(const SkPoint qpts[3], const SkMatrix* toDevice, 452 const SkMatrix* toSrc, BezierVertex verts[kQuadNumVertices]) { 453 SkASSERT(!toDevice == !toSrc); 454 // original quad is specified by tri a,b,c 455 SkPoint a = qpts[0]; 456 SkPoint b = qpts[1]; 457 SkPoint c = qpts[2]; 458 459 if (toDevice) { 460 toDevice->mapPoints(&a, 1); 461 toDevice->mapPoints(&b, 1); 462 toDevice->mapPoints(&c, 1); 463 } 464 // make a new poly where we replace a and c by a 1-pixel wide edges orthog 465 // to edges ab and bc: 466 // 467 // before | after 468 // | b0 469 // b | 470 // | 471 // | a0 c0 472 // a c | a1 c1 473 // 474 // edges a0->b0 and b0->c0 are parallel to original edges a->b and b->c, 475 // respectively. 476 BezierVertex& a0 = verts[0]; 477 BezierVertex& a1 = verts[1]; 478 BezierVertex& b0 = verts[2]; 479 BezierVertex& c0 = verts[3]; 480 BezierVertex& c1 = verts[4]; 481 482 SkVector ab = b; 483 ab -= a; 484 SkVector ac = c; 485 ac -= a; 486 SkVector cb = b; 487 cb -= c; 488 489 // We should have already handled degenerates 490 SkASSERT(ab.length() > 0 && cb.length() > 0); 491 492 ab.normalize(); 493 SkVector abN; 494 abN.setOrthog(ab, SkVector::kLeft_Side); 495 if (abN.dot(ac) > 0) { 496 abN.negate(); 497 } 498 499 cb.normalize(); 500 SkVector cbN; 501 cbN.setOrthog(cb, SkVector::kLeft_Side); 502 if (cbN.dot(ac) < 0) { 503 cbN.negate(); 504 } 505 506 a0.fPos = a; 507 a0.fPos += abN; 508 a1.fPos = a; 509 a1.fPos -= abN; 510 511 c0.fPos = c; 512 c0.fPos += cbN; 513 c1.fPos = c; 514 c1.fPos -= cbN; 515 516 intersect_lines(a0.fPos, abN, c0.fPos, cbN, &b0.fPos); 517 518 if (toSrc) { 519 toSrc->mapPointsWithStride(&verts[0].fPos, sizeof(BezierVertex), kQuadNumVertices); 520 } 521 } 522 523 // Equations based off of Loop-Blinn Quadratic GPU Rendering 524 // Input Parametric: 525 // P(t) = (P0*(1-t)^2 + 2*w*P1*t*(1-t) + P2*t^2) / (1-t)^2 + 2*w*t*(1-t) + t^2) 526 // Output Implicit: 527 // f(x, y, w) = f(P) = K^2 - LM 528 // K = dot(k, P), L = dot(l, P), M = dot(m, P) 529 // k, l, m are calculated in function GrPathUtils::getConicKLM 530 static void set_conic_coeffs(const SkPoint p[3], BezierVertex verts[kQuadNumVertices], 531 const SkScalar weight) { 532 SkScalar klm[9]; 533 534 GrPathUtils::getConicKLM(p, weight, klm); 535 536 for (int i = 0; i < kQuadNumVertices; ++i) { 537 const SkPoint pnt = verts[i].fPos; 538 verts[i].fConic.fK = pnt.fX * klm[0] + pnt.fY * klm[1] + klm[2]; 539 verts[i].fConic.fL = pnt.fX * klm[3] + pnt.fY * klm[4] + klm[5]; 540 verts[i].fConic.fM = pnt.fX * klm[6] + pnt.fY * klm[7] + klm[8]; 541 } 542 } 543 544 static void add_conics(const SkPoint p[3], 545 const SkScalar weight, 546 const SkMatrix* toDevice, 547 const SkMatrix* toSrc, 548 BezierVertex** vert) { 549 bloat_quad(p, toDevice, toSrc, *vert); 550 set_conic_coeffs(p, *vert, weight); 551 *vert += kQuadNumVertices; 552 } 553 554 static void add_quads(const SkPoint p[3], 555 int subdiv, 556 const SkMatrix* toDevice, 557 const SkMatrix* toSrc, 558 BezierVertex** vert) { 559 SkASSERT(subdiv >= 0); 560 if (subdiv) { 561 SkPoint newP[5]; 562 SkChopQuadAtHalf(p, newP); 563 add_quads(newP + 0, subdiv-1, toDevice, toSrc, vert); 564 add_quads(newP + 2, subdiv-1, toDevice, toSrc, vert); 565 } else { 566 bloat_quad(p, toDevice, toSrc, *vert); 567 set_uv_quad(p, *vert); 568 *vert += kQuadNumVertices; 569 } 570 } 571 572 static void add_line(const SkPoint p[2], 573 const SkMatrix* toSrc, 574 uint8_t coverage, 575 LineVertex** vert) { 576 const SkPoint& a = p[0]; 577 const SkPoint& b = p[1]; 578 579 SkVector ortho, vec = b; 580 vec -= a; 581 582 if (vec.setLength(SK_ScalarHalf)) { 583 // Create a vector orthogonal to 'vec' and of unit length 584 ortho.fX = 2.0f * vec.fY; 585 ortho.fY = -2.0f * vec.fX; 586 587 float floatCoverage = GrNormalizeByteToFloat(coverage); 588 589 (*vert)[0].fPos = a; 590 (*vert)[0].fCoverage = floatCoverage; 591 (*vert)[1].fPos = b; 592 (*vert)[1].fCoverage = floatCoverage; 593 (*vert)[2].fPos = a - vec + ortho; 594 (*vert)[2].fCoverage = 0; 595 (*vert)[3].fPos = b + vec + ortho; 596 (*vert)[3].fCoverage = 0; 597 (*vert)[4].fPos = a - vec - ortho; 598 (*vert)[4].fCoverage = 0; 599 (*vert)[5].fPos = b + vec - ortho; 600 (*vert)[5].fCoverage = 0; 601 602 if (toSrc) { 603 toSrc->mapPointsWithStride(&(*vert)->fPos, 604 sizeof(LineVertex), 605 kLineSegNumVertices); 606 } 607 } else { 608 // just make it degenerate and likely offscreen 609 for (int i = 0; i < kLineSegNumVertices; ++i) { 610 (*vert)[i].fPos.set(SK_ScalarMax, SK_ScalarMax); 611 } 612 } 613 614 *vert += kLineSegNumVertices; 615 } 616 617 /////////////////////////////////////////////////////////////////////////////// 618 619 bool GrAAHairLinePathRenderer::canDrawPath(const GrDrawTarget* target, 620 const GrPipelineBuilder* pipelineBuilder, 621 const SkMatrix& viewMatrix, 622 const SkPath& path, 623 const GrStrokeInfo& stroke, 624 bool antiAlias) const { 625 if (!antiAlias) { 626 return false; 627 } 628 629 if (!IsStrokeHairlineOrEquivalent(stroke, viewMatrix, NULL)) { 630 return false; 631 } 632 633 if (SkPath::kLine_SegmentMask == path.getSegmentMasks() || 634 target->caps()->shaderCaps()->shaderDerivativeSupport()) { 635 return true; 636 } 637 return false; 638 } 639 640 template <class VertexType> 641 bool check_bounds(const SkMatrix& viewMatrix, const SkRect& devBounds, void* vertices, int vCount) 642 { 643 SkRect tolDevBounds = devBounds; 644 // The bounds ought to be tight, but in perspective the below code runs the verts 645 // through the view matrix to get back to dev coords, which can introduce imprecision. 646 if (viewMatrix.hasPerspective()) { 647 tolDevBounds.outset(SK_Scalar1 / 1000, SK_Scalar1 / 1000); 648 } else { 649 // Non-persp matrices cause this path renderer to draw in device space. 650 SkASSERT(viewMatrix.isIdentity()); 651 } 652 SkRect actualBounds; 653 654 VertexType* verts = reinterpret_cast<VertexType*>(vertices); 655 bool first = true; 656 for (int i = 0; i < vCount; ++i) { 657 SkPoint pos = verts[i].fPos; 658 // This is a hack to workaround the fact that we move some degenerate segments offscreen. 659 if (SK_ScalarMax == pos.fX) { 660 continue; 661 } 662 viewMatrix.mapPoints(&pos, 1); 663 if (first) { 664 actualBounds.set(pos.fX, pos.fY, pos.fX, pos.fY); 665 first = false; 666 } else { 667 actualBounds.growToInclude(pos.fX, pos.fY); 668 } 669 } 670 if (!first) { 671 return tolDevBounds.contains(actualBounds); 672 } 673 674 return true; 675 } 676 677 class AAHairlineBatch : public GrBatch { 678 public: 679 struct Geometry { 680 GrColor fColor; 681 uint8_t fCoverage; 682 SkMatrix fViewMatrix; 683 SkPath fPath; 684 SkIRect fDevClipBounds; 685 }; 686 687 static GrBatch* Create(const Geometry& geometry) { 688 return SkNEW_ARGS(AAHairlineBatch, (geometry)); 689 } 690 691 const char* name() const override { return "AAHairlineBatch"; } 692 693 void getInvariantOutputColor(GrInitInvariantOutput* out) const override { 694 // When this is called on a batch, there is only one geometry bundle 695 out->setKnownFourComponents(fGeoData[0].fColor); 696 } 697 void getInvariantOutputCoverage(GrInitInvariantOutput* out) const override { 698 out->setUnknownSingleComponent(); 699 } 700 701 void initBatchTracker(const GrPipelineInfo& init) override { 702 // Handle any color overrides 703 if (init.fColorIgnored) { 704 fGeoData[0].fColor = GrColor_ILLEGAL; 705 } else if (GrColor_ILLEGAL != init.fOverrideColor) { 706 fGeoData[0].fColor = init.fOverrideColor; 707 } 708 709 // setup batch properties 710 fBatch.fColorIgnored = init.fColorIgnored; 711 fBatch.fColor = fGeoData[0].fColor; 712 fBatch.fUsesLocalCoords = init.fUsesLocalCoords; 713 fBatch.fCoverageIgnored = init.fCoverageIgnored; 714 fBatch.fCoverage = fGeoData[0].fCoverage; 715 } 716 717 void generateGeometry(GrBatchTarget* batchTarget, const GrPipeline* pipeline) override; 718 719 SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; } 720 721 private: 722 typedef SkTArray<SkPoint, true> PtArray; 723 typedef SkTArray<int, true> IntArray; 724 typedef SkTArray<float, true> FloatArray; 725 726 AAHairlineBatch(const Geometry& geometry) { 727 this->initClassID<AAHairlineBatch>(); 728 fGeoData.push_back(geometry); 729 730 // compute bounds 731 fBounds = geometry.fPath.getBounds(); 732 geometry.fViewMatrix.mapRect(&fBounds); 733 734 // This is b.c. hairlines are notionally infinitely thin so without expansion 735 // two overlapping lines could be reordered even though they hit the same pixels. 736 fBounds.outset(0.5f, 0.5f); 737 } 738 739 bool onCombineIfPossible(GrBatch* t) override { 740 AAHairlineBatch* that = t->cast<AAHairlineBatch>(); 741 742 if (this->viewMatrix().hasPerspective() != that->viewMatrix().hasPerspective()) { 743 return false; 744 } 745 746 // We go to identity if we don't have perspective 747 if (this->viewMatrix().hasPerspective() && 748 !this->viewMatrix().cheapEqualTo(that->viewMatrix())) { 749 return false; 750 } 751 752 // TODO we can actually batch hairlines if they are the same color in a kind of bulk method 753 // but we haven't implemented this yet 754 // TODO investigate going to vertex color and coverage? 755 if (this->coverage() != that->coverage()) { 756 return false; 757 } 758 759 if (this->color() != that->color()) { 760 return false; 761 } 762 763 SkASSERT(this->usesLocalCoords() == that->usesLocalCoords()); 764 if (this->usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) { 765 return false; 766 } 767 768 fGeoData.push_back_n(that->geoData()->count(), that->geoData()->begin()); 769 this->joinBounds(that->bounds()); 770 return true; 771 } 772 773 GrColor color() const { return fBatch.fColor; } 774 uint8_t coverage() const { return fBatch.fCoverage; } 775 bool usesLocalCoords() const { return fBatch.fUsesLocalCoords; } 776 const SkMatrix& viewMatrix() const { return fGeoData[0].fViewMatrix; } 777 778 struct BatchTracker { 779 GrColor fColor; 780 uint8_t fCoverage; 781 SkRect fDevBounds; 782 bool fUsesLocalCoords; 783 bool fColorIgnored; 784 bool fCoverageIgnored; 785 }; 786 787 BatchTracker fBatch; 788 SkSTArray<1, Geometry, true> fGeoData; 789 }; 790 791 void AAHairlineBatch::generateGeometry(GrBatchTarget* batchTarget, const GrPipeline* pipeline) { 792 // Setup the viewmatrix and localmatrix for the GrGeometryProcessor. 793 SkMatrix invert; 794 if (!this->viewMatrix().invert(&invert)) { 795 return; 796 } 797 798 // we will transform to identity space if the viewmatrix does not have perspective 799 bool hasPerspective = this->viewMatrix().hasPerspective(); 800 const SkMatrix* geometryProcessorViewM = &SkMatrix::I(); 801 const SkMatrix* geometryProcessorLocalM = &invert; 802 const SkMatrix* toDevice = NULL; 803 const SkMatrix* toSrc = NULL; 804 if (hasPerspective) { 805 geometryProcessorViewM = &this->viewMatrix(); 806 geometryProcessorLocalM = &SkMatrix::I(); 807 toDevice = &this->viewMatrix(); 808 toSrc = &invert; 809 } 810 811 // Setup geometry processors for worst case 812 uint32_t gpFlags = GrDefaultGeoProcFactory::kPosition_GPType | 813 GrDefaultGeoProcFactory::kCoverage_GPType; 814 815 SkAutoTUnref<const GrGeometryProcessor> lineGP( 816 GrDefaultGeoProcFactory::Create(gpFlags, 817 this->color(), 818 *geometryProcessorViewM, 819 *geometryProcessorLocalM, 820 this->coverage())); 821 822 SkAutoTUnref<const GrGeometryProcessor> quadGP( 823 GrQuadEffect::Create(this->color(), 824 *geometryProcessorViewM, 825 kHairlineAA_GrProcessorEdgeType, 826 batchTarget->caps(), 827 *geometryProcessorLocalM, 828 this->coverage())); 829 830 SkAutoTUnref<const GrGeometryProcessor> conicGP( 831 GrConicEffect::Create(this->color(), 832 *geometryProcessorViewM, 833 kHairlineAA_GrProcessorEdgeType, 834 batchTarget->caps(), 835 *geometryProcessorLocalM, 836 this->coverage())); 837 838 // This is hand inlined for maximum performance. 839 PREALLOC_PTARRAY(128) lines; 840 PREALLOC_PTARRAY(128) quads; 841 PREALLOC_PTARRAY(128) conics; 842 IntArray qSubdivs; 843 FloatArray cWeights; 844 int quadCount = 0; 845 846 int instanceCount = fGeoData.count(); 847 for (int i = 0; i < instanceCount; i++) { 848 const Geometry& args = fGeoData[i]; 849 quadCount += gather_lines_and_quads(args.fPath, args.fViewMatrix, args.fDevClipBounds, 850 &lines, &quads, &conics, &qSubdivs, &cWeights); 851 } 852 853 int lineCount = lines.count() / 2; 854 int conicCount = conics.count() / 3; 855 856 // do lines first 857 if (lineCount) { 858 SkAutoTUnref<const GrIndexBuffer> linesIndexBuffer( 859 ref_lines_index_buffer(batchTarget->resourceProvider())); 860 batchTarget->initDraw(lineGP, pipeline); 861 862 // TODO remove this when batch is everywhere 863 GrPipelineInfo init; 864 init.fColorIgnored = fBatch.fColorIgnored; 865 init.fOverrideColor = GrColor_ILLEGAL; 866 init.fCoverageIgnored = fBatch.fCoverageIgnored; 867 init.fUsesLocalCoords = this->usesLocalCoords(); 868 lineGP->initBatchTracker(batchTarget->currentBatchTracker(), init); 869 870 const GrVertexBuffer* vertexBuffer; 871 int firstVertex; 872 873 size_t vertexStride = lineGP->getVertexStride(); 874 int vertexCount = kLineSegNumVertices * lineCount; 875 LineVertex* verts = reinterpret_cast<LineVertex*>( 876 batchTarget->makeVertSpace(vertexStride, vertexCount, &vertexBuffer, &firstVertex)); 877 878 if (!verts|| !linesIndexBuffer) { 879 SkDebugf("Could not allocate vertices\n"); 880 return; 881 } 882 883 SkASSERT(lineGP->getVertexStride() == sizeof(LineVertex)); 884 885 for (int i = 0; i < lineCount; ++i) { 886 add_line(&lines[2*i], toSrc, this->coverage(), &verts); 887 } 888 889 { 890 GrVertices vertices; 891 vertices.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, linesIndexBuffer, 892 firstVertex, kLineSegNumVertices, kIdxsPerLineSeg, lineCount, 893 kLineSegsNumInIdxBuffer); 894 batchTarget->draw(vertices); 895 } 896 } 897 898 if (quadCount || conicCount) { 899 const GrVertexBuffer* vertexBuffer; 900 int firstVertex; 901 902 SkAutoTUnref<const GrIndexBuffer> quadsIndexBuffer( 903 ref_quads_index_buffer(batchTarget->resourceProvider())); 904 905 size_t vertexStride = sizeof(BezierVertex); 906 int vertexCount = kQuadNumVertices * quadCount + kQuadNumVertices * conicCount; 907 void *vertices = batchTarget->makeVertSpace(vertexStride, vertexCount, 908 &vertexBuffer, &firstVertex); 909 910 if (!vertices || !quadsIndexBuffer) { 911 SkDebugf("Could not allocate vertices\n"); 912 return; 913 } 914 915 // Setup vertices 916 BezierVertex* verts = reinterpret_cast<BezierVertex*>(vertices); 917 918 int unsubdivQuadCnt = quads.count() / 3; 919 for (int i = 0; i < unsubdivQuadCnt; ++i) { 920 SkASSERT(qSubdivs[i] >= 0); 921 add_quads(&quads[3*i], qSubdivs[i], toDevice, toSrc, &verts); 922 } 923 924 // Start Conics 925 for (int i = 0; i < conicCount; ++i) { 926 add_conics(&conics[3*i], cWeights[i], toDevice, toSrc, &verts); 927 } 928 929 if (quadCount > 0) { 930 batchTarget->initDraw(quadGP, pipeline); 931 932 // TODO remove this when batch is everywhere 933 GrPipelineInfo init; 934 init.fColorIgnored = fBatch.fColorIgnored; 935 init.fOverrideColor = GrColor_ILLEGAL; 936 init.fCoverageIgnored = fBatch.fCoverageIgnored; 937 init.fUsesLocalCoords = this->usesLocalCoords(); 938 quadGP->initBatchTracker(batchTarget->currentBatchTracker(), init); 939 940 { 941 GrVertices verts; 942 verts.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, quadsIndexBuffer, 943 firstVertex, kQuadNumVertices, kIdxsPerQuad, quadCount, 944 kQuadsNumInIdxBuffer); 945 batchTarget->draw(verts); 946 firstVertex += quadCount * kQuadNumVertices; 947 } 948 } 949 950 if (conicCount > 0) { 951 batchTarget->initDraw(conicGP, pipeline); 952 953 // TODO remove this when batch is everywhere 954 GrPipelineInfo init; 955 init.fColorIgnored = fBatch.fColorIgnored; 956 init.fOverrideColor = GrColor_ILLEGAL; 957 init.fCoverageIgnored = fBatch.fCoverageIgnored; 958 init.fUsesLocalCoords = this->usesLocalCoords(); 959 conicGP->initBatchTracker(batchTarget->currentBatchTracker(), init); 960 961 { 962 GrVertices verts; 963 verts.initInstanced(kTriangles_GrPrimitiveType, vertexBuffer, quadsIndexBuffer, 964 firstVertex, kQuadNumVertices, kIdxsPerQuad, conicCount, 965 kQuadsNumInIdxBuffer); 966 batchTarget->draw(verts); 967 } 968 } 969 } 970 } 971 972 static GrBatch* create_hairline_batch(GrColor color, 973 const SkMatrix& viewMatrix, 974 const SkPath& path, 975 const GrStrokeInfo& stroke, 976 const SkIRect& devClipBounds) { 977 SkScalar hairlineCoverage; 978 uint8_t newCoverage = 0xff; 979 if (GrPathRenderer::IsStrokeHairlineOrEquivalent(stroke, viewMatrix, &hairlineCoverage)) { 980 newCoverage = SkScalarRoundToInt(hairlineCoverage * 0xff); 981 } 982 983 AAHairlineBatch::Geometry geometry; 984 geometry.fColor = color; 985 geometry.fCoverage = newCoverage; 986 geometry.fViewMatrix = viewMatrix; 987 geometry.fPath = path; 988 geometry.fDevClipBounds = devClipBounds; 989 990 return AAHairlineBatch::Create(geometry); 991 } 992 993 bool GrAAHairLinePathRenderer::onDrawPath(GrDrawTarget* target, 994 GrPipelineBuilder* pipelineBuilder, 995 GrColor color, 996 const SkMatrix& viewMatrix, 997 const SkPath& path, 998 const GrStrokeInfo& stroke, 999 bool) { 1000 SkIRect devClipBounds; 1001 pipelineBuilder->clip().getConservativeBounds(pipelineBuilder->getRenderTarget(), 1002 &devClipBounds); 1003 1004 SkAutoTUnref<GrBatch> batch(create_hairline_batch(color, viewMatrix, path, stroke, 1005 devClipBounds)); 1006 target->drawBatch(pipelineBuilder, batch); 1007 1008 return true; 1009 } 1010 1011 /////////////////////////////////////////////////////////////////////////////////////////////////// 1012 1013 #ifdef GR_TEST_UTILS 1014 1015 BATCH_TEST_DEFINE(AAHairlineBatch) { 1016 GrColor color = GrRandomColor(random); 1017 SkMatrix viewMatrix = GrTest::TestMatrix(random); 1018 GrStrokeInfo stroke(SkStrokeRec::kHairline_InitStyle); 1019 SkPath path = GrTest::TestPath(random); 1020 SkIRect devClipBounds; 1021 devClipBounds.setEmpty(); 1022 return create_hairline_batch(color, viewMatrix, path, stroke, devClipBounds); 1023 } 1024 1025 #endif 1026
