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