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 "src/gpu/ops/AAHairLinePathRenderer.h"
9 
10 #include "include/core/SkPoint3.h"
11 #include "include/private/SkTemplates.h"
12 #include "src/core/SkGeometry.h"
13 #include "src/core/SkMatrixPriv.h"
14 #include "src/core/SkPointPriv.h"
15 #include "src/core/SkRectPriv.h"
16 #include "src/core/SkStroke.h"
17 #include "src/gpu/GrAuditTrail.h"
18 #include "src/gpu/GrBuffer.h"
19 #include "src/gpu/GrCaps.h"
20 #include "src/gpu/GrDefaultGeoProcFactory.h"
21 #include "src/gpu/GrDrawOpTest.h"
22 #include "src/gpu/GrOpFlushState.h"
23 #include "src/gpu/GrProcessor.h"
24 #include "src/gpu/GrProgramInfo.h"
25 #include "src/gpu/GrResourceProvider.h"
26 #include "src/gpu/GrStyle.h"
27 #include "src/gpu/GrUtil.h"
28 #include "src/gpu/effects/GrBezierEffect.h"
29 #include "src/gpu/geometry/GrPathUtils.h"
30 #include "src/gpu/geometry/GrStyledShape.h"
31 #include "src/gpu/ops/GrMeshDrawOp.h"
32 #include "src/gpu/ops/GrSimpleMeshDrawOpHelperWithStencil.h"
33 #include "src/gpu/v1/SurfaceDrawContext_v1.h"
34 
35 #define PREALLOC_PTARRAY(N) SkSTArray<(N),SkPoint, true>
36 
37 using PtArray = SkTArray<SkPoint, true>;
38 using IntArray = SkTArray<int, true>;
39 using FloatArray = SkTArray<float, true>;
40 
41 namespace {
42 
43 // quadratics are rendered as 5-sided polys in order to bound the
44 // AA stroke around the center-curve. See comments in push_quad_index_buffer and
45 // bloat_quad. Quadratics and conics share an index buffer
46 
47 // lines are rendered as:
48 //      *______________*
49 //      |\ -_______   /|
50 //      | \        \ / |
51 //      |  *--------*  |
52 //      | /  ______/ \ |
53 //      */_-__________\*
54 // For: 6 vertices and 18 indices (for 6 triangles)
55 
56 // Each quadratic is rendered as a five sided polygon. This poly bounds
57 // the quadratic's bounding triangle but has been expanded so that the
58 // 1-pixel wide area around the curve is inside the poly.
59 // If a,b,c are the original control points then the poly a0,b0,c0,c1,a1
60 // that is rendered would look like this:
61 //              b0
62 //              b
63 //
64 //     a0              c0
65 //      a            c
66 //       a1       c1
67 // Each is drawn as three triangles ((a0,a1,b0), (b0,c1,c0), (a1,c1,b0))
68 // specified by these 9 indices:
69 static const uint16_t kQuadIdxBufPattern[] = {
70     0, 1, 2,
71     2, 4, 3,
72     1, 4, 2
73 };
74 
75 static const int kIdxsPerQuad = SK_ARRAY_COUNT(kQuadIdxBufPattern);
76 static const int kQuadNumVertices = 5;
77 static const int kQuadsNumInIdxBuffer = 256;
78 GR_DECLARE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey);
79 
get_quads_index_buffer(GrResourceProvider* resourceProvider)80 sk_sp<const GrBuffer> get_quads_index_buffer(GrResourceProvider* resourceProvider) {
81     GR_DEFINE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey);
82     return resourceProvider->findOrCreatePatternedIndexBuffer(
83         kQuadIdxBufPattern, kIdxsPerQuad, kQuadsNumInIdxBuffer, kQuadNumVertices,
84         gQuadsIndexBufferKey);
85 }
86 
87 
88 // Each line segment is rendered as two quads and two triangles.
89 // p0 and p1 have alpha = 1 while all other points have alpha = 0.
90 // The four external points are offset 1 pixel perpendicular to the
91 // line and half a pixel parallel to the line.
92 //
93 // p4                  p5
94 //      p0         p1
95 // p2                  p3
96 //
97 // Each is drawn as six triangles specified by these 18 indices:
98 
99 static const uint16_t kLineSegIdxBufPattern[] = {
100     0, 1, 3,
101     0, 3, 2,
102     0, 4, 5,
103     0, 5, 1,
104     0, 2, 4,
105     1, 5, 3
106 };
107 
108 static const int kIdxsPerLineSeg = SK_ARRAY_COUNT(kLineSegIdxBufPattern);
109 static const int kLineSegNumVertices = 6;
110 static const int kLineSegsNumInIdxBuffer = 256;
111 
112 GR_DECLARE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey);
113 
get_lines_index_buffer(GrResourceProvider* resourceProvider)114 sk_sp<const GrBuffer> get_lines_index_buffer(GrResourceProvider* resourceProvider) {
115     GR_DEFINE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey);
116     return resourceProvider->findOrCreatePatternedIndexBuffer(
117         kLineSegIdxBufPattern, kIdxsPerLineSeg,  kLineSegsNumInIdxBuffer, kLineSegNumVertices,
118         gLinesIndexBufferKey);
119 }
120 
121 // Takes 178th time of logf on Z600 / VC2010
get_float_exp(float x)122 int get_float_exp(float x) {
123     static_assert(sizeof(int) == sizeof(float));
124 #ifdef SK_DEBUG
125     static bool tested;
126     if (!tested) {
127         tested = true;
128         SkASSERT(get_float_exp(0.25f) == -2);
129         SkASSERT(get_float_exp(0.3f) == -2);
130         SkASSERT(get_float_exp(0.5f) == -1);
131         SkASSERT(get_float_exp(1.f) == 0);
132         SkASSERT(get_float_exp(2.f) == 1);
133         SkASSERT(get_float_exp(2.5f) == 1);
134         SkASSERT(get_float_exp(8.f) == 3);
135         SkASSERT(get_float_exp(100.f) == 6);
136         SkASSERT(get_float_exp(1000.f) == 9);
137         SkASSERT(get_float_exp(1024.f) == 10);
138         SkASSERT(get_float_exp(3000000.f) == 21);
139     }
140 #endif
141     const int* iptr = (const int*)&x;
142     return (((*iptr) & 0x7f800000) >> 23) - 127;
143 }
144 
145 // Uses the max curvature function for quads to estimate
146 // where to chop the conic. If the max curvature is not
147 // found along the curve segment it will return 1 and
148 // dst[0] is the original conic. If it returns 2 the dst[0]
149 // and dst[1] are the two new conics.
split_conic(const SkPoint src[3], SkConic dst[2], const SkScalar weight)150 int split_conic(const SkPoint src[3], SkConic dst[2], const SkScalar weight) {
151     SkScalar t = SkFindQuadMaxCurvature(src);
152     if (t == 0 || t == 1) {
153         if (dst) {
154             dst[0].set(src, weight);
155         }
156         return 1;
157     } else {
158         if (dst) {
159             SkConic conic;
160             conic.set(src, weight);
161             if (!conic.chopAt(t, dst)) {
162                 dst[0].set(src, weight);
163                 return 1;
164             }
165         }
166         return 2;
167     }
168 }
169 
170 // Calls split_conic on the entire conic and then once more on each subsection.
171 // Most cases will result in either 1 conic (chop point is not within t range)
172 // or 3 points (split once and then one subsection is split again).
chop_conic(const SkPoint src[3], SkConic dst[4], const SkScalar weight)173 int chop_conic(const SkPoint src[3], SkConic dst[4], const SkScalar weight) {
174     SkConic dstTemp[2];
175     int conicCnt = split_conic(src, dstTemp, weight);
176     if (2 == conicCnt) {
177         int conicCnt2 = split_conic(dstTemp[0].fPts, dst, dstTemp[0].fW);
178         conicCnt = conicCnt2 + split_conic(dstTemp[1].fPts, &dst[conicCnt2], dstTemp[1].fW);
179     } else {
180         dst[0] = dstTemp[0];
181     }
182     return conicCnt;
183 }
184 
185 // returns 0 if quad/conic is degen or close to it
186 // in this case approx the path with lines
187 // otherwise returns 1
is_degen_quad_or_conic(const SkPoint p[3], SkScalar* dsqd)188 int is_degen_quad_or_conic(const SkPoint p[3], SkScalar* dsqd) {
189     static const SkScalar gDegenerateToLineTol = GrPathUtils::kDefaultTolerance;
190     static const SkScalar gDegenerateToLineTolSqd =
191         gDegenerateToLineTol * gDegenerateToLineTol;
192 
193     if (SkPointPriv::DistanceToSqd(p[0], p[1]) < gDegenerateToLineTolSqd ||
194         SkPointPriv::DistanceToSqd(p[1], p[2]) < gDegenerateToLineTolSqd) {
195         return 1;
196     }
197 
198     *dsqd = SkPointPriv::DistanceToLineBetweenSqd(p[1], p[0], p[2]);
199     if (*dsqd < gDegenerateToLineTolSqd) {
200         return 1;
201     }
202 
203     if (SkPointPriv::DistanceToLineBetweenSqd(p[2], p[1], p[0]) < gDegenerateToLineTolSqd) {
204         return 1;
205     }
206     return 0;
207 }
208 
is_degen_quad_or_conic(const SkPoint p[3])209 int is_degen_quad_or_conic(const SkPoint p[3]) {
210     SkScalar dsqd;
211     return is_degen_quad_or_conic(p, &dsqd);
212 }
213 
214 // we subdivide the quads to avoid huge overfill
215 // if it returns -1 then should be drawn as lines
num_quad_subdivs(const SkPoint p[3])216 int num_quad_subdivs(const SkPoint p[3]) {
217     SkScalar dsqd;
218     if (is_degen_quad_or_conic(p, &dsqd)) {
219         return -1;
220     }
221 
222     // tolerance of triangle height in pixels
223     // tuned on windows  Quadro FX 380 / Z600
224     // trade off of fill vs cpu time on verts
225     // maybe different when do this using gpu (geo or tess shaders)
226     static const SkScalar gSubdivTol = 175 * SK_Scalar1;
227 
228     if (dsqd <= gSubdivTol * gSubdivTol) {
229         return 0;
230     } else {
231         static const int kMaxSub = 4;
232         // subdividing the quad reduces d by 4. so we want x = log4(d/tol)
233         // = log4(d*d/tol*tol)/2
234         // = log2(d*d/tol*tol)
235 
236         // +1 since we're ignoring the mantissa contribution.
237         int log = get_float_exp(dsqd/(gSubdivTol*gSubdivTol)) + 1;
238         log = std::min(std::max(0, log), kMaxSub);
239         return log;
240     }
241 }
242 
243 /**
244  * Generates the lines and quads to be rendered. Lines are always recorded in
245  * device space. We will do a device space bloat to account for the 1pixel
246  * thickness.
247  * Quads are recorded in device space unless m contains
248  * perspective, then in they are in src space. We do this because we will
249  * subdivide large quads to reduce over-fill. This subdivision has to be
250  * performed before applying the perspective matrix.
251  */
gather_lines_and_quads(const SkPath& path, const SkMatrix& m, const SkIRect& devClipBounds, SkScalar capLength, bool convertConicsToQuads, PtArray* lines, PtArray* quads, PtArray* conics, IntArray* quadSubdivCnts, FloatArray* conicWeights)252 int gather_lines_and_quads(const SkPath& path,
253                            const SkMatrix& m,
254                            const SkIRect& devClipBounds,
255                            SkScalar capLength,
256                            bool convertConicsToQuads,
257                            PtArray* lines,
258                            PtArray* quads,
259                            PtArray* conics,
260                            IntArray* quadSubdivCnts,
261                            FloatArray* conicWeights) {
262     SkPath::Iter iter(path, false);
263 
264     int totalQuadCount = 0;
265     SkRect bounds;
266     SkIRect ibounds;
267 
268     bool persp = m.hasPerspective();
269 
270     // Whenever a degenerate, zero-length contour is encountered, this code will insert a
271     // 'capLength' x-aligned line segment. Since this is rendering hairlines it is hoped this will
272     // suffice for AA square & circle capping.
273     int verbsInContour = 0; // Does not count moves
274     bool seenZeroLengthVerb = false;
275     SkPoint zeroVerbPt;
276 
277     // Adds a quad that has already been chopped to the list and checks for quads that are close to
278     // lines. Also does a bounding box check. It takes points that are in src space and device
279     // space. The src points are only required if the view matrix has perspective.
280     auto addChoppedQuad = [&](const SkPoint srcPts[3], const SkPoint devPts[4],
281                               bool isContourStart) {
282         SkRect bounds;
283         SkIRect ibounds;
284         bounds.setBounds(devPts, 3);
285         bounds.outset(SK_Scalar1, SK_Scalar1);
286         bounds.roundOut(&ibounds);
287         // We only need the src space space pts when not in perspective.
288         SkASSERT(srcPts || !persp);
289         if (SkIRect::Intersects(devClipBounds, ibounds)) {
290             int subdiv = num_quad_subdivs(devPts);
291             SkASSERT(subdiv >= -1);
292             if (-1 == subdiv) {
293                 SkPoint* pts = lines->push_back_n(4);
294                 pts[0] = devPts[0];
295                 pts[1] = devPts[1];
296                 pts[2] = devPts[1];
297                 pts[3] = devPts[2];
298                 if (isContourStart && pts[0] == pts[1] && pts[2] == pts[3]) {
299                     seenZeroLengthVerb = true;
300                     zeroVerbPt = pts[0];
301                 }
302             } else {
303                 // when in perspective keep quads in src space
304                 const SkPoint* qPts = persp ? srcPts : devPts;
305                 SkPoint* pts = quads->push_back_n(3);
306                 pts[0] = qPts[0];
307                 pts[1] = qPts[1];
308                 pts[2] = qPts[2];
309                 quadSubdivCnts->push_back() = subdiv;
310                 totalQuadCount += 1 << subdiv;
311             }
312         }
313     };
314 
315     // Applies the view matrix to quad src points and calls the above helper.
316     auto addSrcChoppedQuad = [&](const SkPoint srcSpaceQuadPts[3], bool isContourStart) {
317         SkPoint devPts[3];
318         m.mapPoints(devPts, srcSpaceQuadPts, 3);
319         addChoppedQuad(srcSpaceQuadPts, devPts, isContourStart);
320     };
321 
322     for (;;) {
323         SkPoint pathPts[4];
324         SkPath::Verb verb = iter.next(pathPts);
325         switch (verb) {
326             case SkPath::kConic_Verb:
327                 if (convertConicsToQuads) {
328                     SkScalar weight = iter.conicWeight();
329                     SkAutoConicToQuads converter;
330                     const SkPoint* quadPts = converter.computeQuads(pathPts, weight, 0.25f);
331                     for (int i = 0; i < converter.countQuads(); ++i) {
332                         addSrcChoppedQuad(quadPts + 2 * i, !verbsInContour && 0 == i);
333                     }
334                 } else {
335                     SkConic dst[4];
336                     // We chop the conics to create tighter clipping to hide error
337                     // that appears near max curvature of very thin conics. Thin
338                     // hyperbolas with high weight still show error.
339                     int conicCnt = chop_conic(pathPts, dst, iter.conicWeight());
340                     for (int i = 0; i < conicCnt; ++i) {
341                         SkPoint devPts[4];
342                         SkPoint* chopPnts = dst[i].fPts;
343                         m.mapPoints(devPts, chopPnts, 3);
344                         bounds.setBounds(devPts, 3);
345                         bounds.outset(SK_Scalar1, SK_Scalar1);
346                         bounds.roundOut(&ibounds);
347                         if (SkIRect::Intersects(devClipBounds, ibounds)) {
348                             if (is_degen_quad_or_conic(devPts)) {
349                                 SkPoint* pts = lines->push_back_n(4);
350                                 pts[0] = devPts[0];
351                                 pts[1] = devPts[1];
352                                 pts[2] = devPts[1];
353                                 pts[3] = devPts[2];
354                                 if (verbsInContour == 0 && i == 0 && pts[0] == pts[1] &&
355                                     pts[2] == pts[3]) {
356                                     seenZeroLengthVerb = true;
357                                     zeroVerbPt = pts[0];
358                                 }
359                             } else {
360                                 // when in perspective keep conics in src space
361                                 SkPoint* cPts = persp ? chopPnts : devPts;
362                                 SkPoint* pts = conics->push_back_n(3);
363                                 pts[0] = cPts[0];
364                                 pts[1] = cPts[1];
365                                 pts[2] = cPts[2];
366                                 conicWeights->push_back() = dst[i].fW;
367                             }
368                         }
369                     }
370                 }
371                 verbsInContour++;
372                 break;
373             case SkPath::kMove_Verb:
374                 // New contour (and last one was unclosed). If it was just a zero length drawing
375                 // operation, and we're supposed to draw caps, then add a tiny line.
376                 if (seenZeroLengthVerb && verbsInContour == 1 && capLength > 0) {
377                     SkPoint* pts = lines->push_back_n(2);
378                     pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY);
379                     pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY);
380                 }
381                 verbsInContour = 0;
382                 seenZeroLengthVerb = false;
383                 break;
384             case SkPath::kLine_Verb: {
385                 SkPoint devPts[2];
386                 m.mapPoints(devPts, pathPts, 2);
387                 bounds.setBounds(devPts, 2);
388                 bounds.outset(SK_Scalar1, SK_Scalar1);
389                 bounds.roundOut(&ibounds);
390                 if (SkIRect::Intersects(devClipBounds, ibounds)) {
391                     SkPoint* pts = lines->push_back_n(2);
392                     pts[0] = devPts[0];
393                     pts[1] = devPts[1];
394                     if (verbsInContour == 0 && pts[0] == pts[1]) {
395                         seenZeroLengthVerb = true;
396                         zeroVerbPt = pts[0];
397                     }
398                 }
399                 verbsInContour++;
400                 break;
401             }
402             case SkPath::kQuad_Verb: {
403                 SkPoint choppedPts[5];
404                 // Chopping the quad helps when the quad is either degenerate or nearly degenerate.
405                 // When it is degenerate it allows the approximation with lines to work since the
406                 // chop point (if there is one) will be at the parabola's vertex. In the nearly
407                 // degenerate the QuadUVMatrix computed for the points is almost singular which
408                 // can cause rendering artifacts.
409                 int n = SkChopQuadAtMaxCurvature(pathPts, choppedPts);
410                 for (int i = 0; i < n; ++i) {
411                     addSrcChoppedQuad(choppedPts + i * 2, !verbsInContour && 0 == i);
412                 }
413                 verbsInContour++;
414                 break;
415             }
416             case SkPath::kCubic_Verb: {
417                 SkPoint devPts[4];
418                 m.mapPoints(devPts, pathPts, 4);
419                 bounds.setBounds(devPts, 4);
420                 bounds.outset(SK_Scalar1, SK_Scalar1);
421                 bounds.roundOut(&ibounds);
422                 if (SkIRect::Intersects(devClipBounds, ibounds)) {
423                     PREALLOC_PTARRAY(32) q;
424                     // We convert cubics to quadratics (for now).
425                     // In perspective have to do conversion in src space.
426                     if (persp) {
427                         SkScalar tolScale =
428                             GrPathUtils::scaleToleranceToSrc(SK_Scalar1, m, path.getBounds());
429                         GrPathUtils::convertCubicToQuads(pathPts, tolScale, &q);
430                     } else {
431                         GrPathUtils::convertCubicToQuads(devPts, SK_Scalar1, &q);
432                     }
433                     for (int i = 0; i < q.count(); i += 3) {
434                         if (persp) {
435                             addSrcChoppedQuad(&q[i], !verbsInContour && 0 == i);
436                         } else {
437                             addChoppedQuad(nullptr, &q[i], !verbsInContour && 0 == i);
438                         }
439                     }
440                 }
441                 verbsInContour++;
442                 break;
443             }
444             case SkPath::kClose_Verb:
445                 // Contour is closed, so we don't need to grow the starting line, unless it's
446                 // *just* a zero length subpath. (SVG Spec 11.4, 'stroke').
447                 if (capLength > 0) {
448                     if (seenZeroLengthVerb && verbsInContour == 1) {
449                         SkPoint* pts = lines->push_back_n(2);
450                         pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY);
451                         pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY);
452                     } else if (verbsInContour == 0) {
453                         // Contour was (moveTo, close). Add a line.
454                         SkPoint devPts[2];
455                         m.mapPoints(devPts, pathPts, 1);
456                         devPts[1] = devPts[0];
457                         bounds.setBounds(devPts, 2);
458                         bounds.outset(SK_Scalar1, SK_Scalar1);
459                         bounds.roundOut(&ibounds);
460                         if (SkIRect::Intersects(devClipBounds, ibounds)) {
461                             SkPoint* pts = lines->push_back_n(2);
462                             pts[0] = SkPoint::Make(devPts[0].fX - capLength, devPts[0].fY);
463                             pts[1] = SkPoint::Make(devPts[1].fX + capLength, devPts[1].fY);
464                         }
465                     }
466                 }
467                 break;
468             case SkPath::kDone_Verb:
469                 if (seenZeroLengthVerb && verbsInContour == 1 && capLength > 0) {
470                     // Path ended with a dangling (moveTo, line|quad|etc). If the final verb is
471                     // degenerate, we need to draw a line.
472                     SkPoint* pts = lines->push_back_n(2);
473                     pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY);
474                     pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY);
475                 }
476                 return totalQuadCount;
477         }
478     }
479 }
480 
481 struct LineVertex {
482     SkPoint fPos;
483     float fCoverage;
484 };
485 
486 struct BezierVertex {
487     SkPoint fPos;
488     union {
489         struct {
490             SkScalar fKLM[3];
491         } fConic;
492         SkVector   fQuadCoord;
493         struct {
494             SkScalar fBogus[4];
495         };
496     };
497 };
498 
499 static_assert(sizeof(BezierVertex) == 3 * sizeof(SkPoint));
500 
intersect_lines(const SkPoint& ptA, const SkVector& normA, const SkPoint& ptB, const SkVector& normB, SkPoint* result)501 void intersect_lines(const SkPoint& ptA, const SkVector& normA,
502                      const SkPoint& ptB, const SkVector& normB,
503                      SkPoint* result) {
504 
505     SkScalar lineAW = -normA.dot(ptA);
506     SkScalar lineBW = -normB.dot(ptB);
507 
508     SkScalar wInv = normA.fX * normB.fY - normA.fY * normB.fX;
509     wInv = SkScalarInvert(wInv);
510     if (!SkScalarIsFinite(wInv)) {
511         // lines are parallel, pick the point in between
512         *result = (ptA + ptB)*SK_ScalarHalf;
513         *result += normA;
514     } else {
515         result->fX = normA.fY * lineBW - lineAW * normB.fY;
516         result->fX *= wInv;
517 
518         result->fY = lineAW * normB.fX - normA.fX * lineBW;
519         result->fY *= wInv;
520     }
521 }
522 
set_uv_quad(const SkPoint qpts[3], BezierVertex verts[kQuadNumVertices])523 void set_uv_quad(const SkPoint qpts[3], BezierVertex verts[kQuadNumVertices]) {
524     // this should be in the src space, not dev coords, when we have perspective
525     GrPathUtils::QuadUVMatrix DevToUV(qpts);
526     DevToUV.apply(verts, kQuadNumVertices, sizeof(BezierVertex), sizeof(SkPoint));
527 }
528 
bloat_quad(const SkPoint qpts[3], const SkMatrix* toDevice, const SkMatrix* toSrc, BezierVertex verts[kQuadNumVertices])529 void bloat_quad(const SkPoint qpts[3],
530                 const SkMatrix* toDevice,
531                 const SkMatrix* toSrc,
532                 BezierVertex verts[kQuadNumVertices]) {
533     SkASSERT(!toDevice == !toSrc);
534     // original quad is specified by tri a,b,c
535     SkPoint a = qpts[0];
536     SkPoint b = qpts[1];
537     SkPoint c = qpts[2];
538 
539     if (toDevice) {
540         toDevice->mapPoints(&a, 1);
541         toDevice->mapPoints(&b, 1);
542         toDevice->mapPoints(&c, 1);
543     }
544     // make a new poly where we replace a and c by a 1-pixel wide edges orthog
545     // to edges ab and bc:
546     //
547     //   before       |        after
548     //                |              b0
549     //         b      |
550     //                |
551     //                |     a0            c0
552     // a         c    |        a1       c1
553     //
554     // edges a0->b0 and b0->c0 are parallel to original edges a->b and b->c,
555     // respectively.
556     BezierVertex& a0 = verts[0];
557     BezierVertex& a1 = verts[1];
558     BezierVertex& b0 = verts[2];
559     BezierVertex& c0 = verts[3];
560     BezierVertex& c1 = verts[4];
561 
562     SkVector ab = b;
563     ab -= a;
564     SkVector ac = c;
565     ac -= a;
566     SkVector cb = b;
567     cb -= c;
568 
569     // After the transform (or due to floating point math) we might have a line,
570     // try to do something reasonable
571     if (SkPointPriv::LengthSqd(ab) <= SK_ScalarNearlyZero*SK_ScalarNearlyZero) {
572         ab = cb;
573     }
574     if (SkPointPriv::LengthSqd(cb) <= SK_ScalarNearlyZero*SK_ScalarNearlyZero) {
575         cb = ab;
576     }
577 
578     // We should have already handled degenerates
579     SkASSERT(ab.length() > 0 && cb.length() > 0);
580 
581     ab.normalize();
582     SkVector abN = SkPointPriv::MakeOrthog(ab, SkPointPriv::kLeft_Side);
583     if (abN.dot(ac) > 0) {
584         abN.negate();
585     }
586 
587     cb.normalize();
588     SkVector cbN = SkPointPriv::MakeOrthog(cb, SkPointPriv::kLeft_Side);
589     if (cbN.dot(ac) < 0) {
590         cbN.negate();
591     }
592 
593     a0.fPos = a;
594     a0.fPos += abN;
595     a1.fPos = a;
596     a1.fPos -= abN;
597 
598     if (toDevice && SkPointPriv::LengthSqd(ac) <= SK_ScalarNearlyZero*SK_ScalarNearlyZero) {
599         c = b;
600     }
601     c0.fPos = c;
602     c0.fPos += cbN;
603     c1.fPos = c;
604     c1.fPos -= cbN;
605 
606     intersect_lines(a0.fPos, abN, c0.fPos, cbN, &b0.fPos);
607 
608     if (toSrc) {
609         SkMatrixPriv::MapPointsWithStride(*toSrc, &verts[0].fPos, sizeof(BezierVertex),
610                                           kQuadNumVertices);
611     }
612 }
613 
614 // Equations based off of Loop-Blinn Quadratic GPU Rendering
615 // Input Parametric:
616 // 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)
617 // Output Implicit:
618 // f(x, y, w) = f(P) = K^2 - LM
619 // K = dot(k, P), L = dot(l, P), M = dot(m, P)
620 // k, l, m are calculated in function GrPathUtils::getConicKLM
set_conic_coeffs(const SkPoint p[3], BezierVertex verts[kQuadNumVertices], const SkScalar weight)621 void set_conic_coeffs(const SkPoint p[3],
622                       BezierVertex verts[kQuadNumVertices],
623                       const SkScalar weight) {
624     SkMatrix klm;
625 
626     GrPathUtils::getConicKLM(p, weight, &klm);
627 
628     for (int i = 0; i < kQuadNumVertices; ++i) {
629         const SkPoint3 pt3 = {verts[i].fPos.x(), verts[i].fPos.y(), 1.f};
630         klm.mapHomogeneousPoints((SkPoint3* ) verts[i].fConic.fKLM, &pt3, 1);
631     }
632 }
633 
add_conics(const SkPoint p[3], const SkScalar weight, const SkMatrix* toDevice, const SkMatrix* toSrc, BezierVertex** vert)634 void add_conics(const SkPoint p[3],
635                 const SkScalar weight,
636                 const SkMatrix* toDevice,
637                 const SkMatrix* toSrc,
638                 BezierVertex** vert) {
639     bloat_quad(p, toDevice, toSrc, *vert);
640     set_conic_coeffs(p, *vert, weight);
641     *vert += kQuadNumVertices;
642 }
643 
add_quads(const SkPoint p[3], int subdiv, const SkMatrix* toDevice, const SkMatrix* toSrc, BezierVertex** vert)644 void add_quads(const SkPoint p[3],
645                int subdiv,
646                const SkMatrix* toDevice,
647                const SkMatrix* toSrc,
648                BezierVertex** vert) {
649     SkASSERT(subdiv >= 0);
650     // temporary vertex storage to avoid reading the vertex buffer
651     BezierVertex outVerts[kQuadNumVertices] = {};
652 
653     // storage for the chopped quad
654     // pts 0,1,2 are the first quad, and 2,3,4 the second quad
655     SkPoint choppedQuadPts[5];
656     // start off with our original curve in the second quad slot
657     memcpy(&choppedQuadPts[2], p, 3*sizeof(SkPoint));
658 
659     int stepCount = 1 << subdiv;
660     while (stepCount > 1) {
661         // The general idea is:
662         // * chop the quad using pts 2,3,4 as the input
663         // * write out verts using pts 0,1,2
664         // * now 2,3,4 is the remainder of the curve, chop again until all subdivisions are done
665         SkScalar h = 1.f / stepCount;
666         SkChopQuadAt(&choppedQuadPts[2], choppedQuadPts, h);
667 
668         bloat_quad(choppedQuadPts, toDevice, toSrc, outVerts);
669         set_uv_quad(choppedQuadPts, outVerts);
670         memcpy(*vert, outVerts, kQuadNumVertices*sizeof(BezierVertex));
671         *vert += kQuadNumVertices;
672         --stepCount;
673     }
674 
675     // finish up, write out the final quad
676     bloat_quad(&choppedQuadPts[2], toDevice, toSrc, outVerts);
677     set_uv_quad(&choppedQuadPts[2], outVerts);
678     memcpy(*vert, outVerts, kQuadNumVertices * sizeof(BezierVertex));
679     *vert += kQuadNumVertices;
680 }
681 
add_line(const SkPoint p[2], const SkMatrix* toSrc, uint8_t coverage, LineVertex** vert)682 void add_line(const SkPoint p[2],
683               const SkMatrix* toSrc,
684               uint8_t coverage,
685               LineVertex** vert) {
686     const SkPoint& a = p[0];
687     const SkPoint& b = p[1];
688 
689     SkVector ortho, vec = b;
690     vec -= a;
691 
692     SkScalar lengthSqd = SkPointPriv::LengthSqd(vec);
693 
694     if (vec.setLength(SK_ScalarHalf)) {
695         // Create a vector orthogonal to 'vec' and of unit length
696         ortho.fX = 2.0f * vec.fY;
697         ortho.fY = -2.0f * vec.fX;
698 
699         float floatCoverage = GrNormalizeByteToFloat(coverage);
700 
701         if (lengthSqd >= 1.0f) {
702             // Relative to points a and b:
703             // The inner vertices are inset half a pixel along the line a,b
704             (*vert)[0].fPos = a + vec;
705             (*vert)[0].fCoverage = floatCoverage;
706             (*vert)[1].fPos = b - vec;
707             (*vert)[1].fCoverage = floatCoverage;
708         } else {
709             // The inner vertices are inset a distance of length(a,b) from the outer edge of
710             // geometry. For the "a" inset this is the same as insetting from b by half a pixel.
711             // The coverage is then modulated by the length. This gives us the correct
712             // coverage for rects shorter than a pixel as they get translated subpixel amounts
713             // inside of a pixel.
714             SkScalar length = SkScalarSqrt(lengthSqd);
715             (*vert)[0].fPos = b - vec;
716             (*vert)[0].fCoverage = floatCoverage * length;
717             (*vert)[1].fPos = a + vec;
718             (*vert)[1].fCoverage = floatCoverage * length;
719         }
720         // Relative to points a and b:
721         // The outer vertices are outset half a pixel along the line a,b and then a whole pixel
722         // orthogonally.
723         (*vert)[2].fPos = a - vec + ortho;
724         (*vert)[2].fCoverage = 0;
725         (*vert)[3].fPos = b + vec + ortho;
726         (*vert)[3].fCoverage = 0;
727         (*vert)[4].fPos = a - vec - ortho;
728         (*vert)[4].fCoverage = 0;
729         (*vert)[5].fPos = b + vec - ortho;
730         (*vert)[5].fCoverage = 0;
731 
732         if (toSrc) {
733             SkMatrixPriv::MapPointsWithStride(*toSrc, &(*vert)->fPos, sizeof(LineVertex),
734                                               kLineSegNumVertices);
735         }
736     } else {
737         // just make it degenerate and likely offscreen
738         for (int i = 0; i < kLineSegNumVertices; ++i) {
739             (*vert)[i].fPos.set(SK_ScalarMax, SK_ScalarMax);
740         }
741     }
742 
743     *vert += kLineSegNumVertices;
744 }
745 
746 ///////////////////////////////////////////////////////////////////////////////
747 
748 class AAHairlineOp final : public GrMeshDrawOp {
749 private:
750     using Helper = GrSimpleMeshDrawOpHelperWithStencil;
751 
752 public:
753     DEFINE_OP_CLASS_ID
754 
Make(GrRecordingContext* context, GrPaint&& paint, const SkMatrix& viewMatrix, const SkPath& path, const GrStyle& style, const SkIRect& devClipBounds, const GrUserStencilSettings* stencilSettings)755     static GrOp::Owner Make(GrRecordingContext* context,
756                             GrPaint&& paint,
757                             const SkMatrix& viewMatrix,
758                             const SkPath& path,
759                             const GrStyle& style,
760                             const SkIRect& devClipBounds,
761                             const GrUserStencilSettings* stencilSettings) {
762         SkScalar hairlineCoverage;
763         uint8_t newCoverage = 0xff;
764         if (GrIsStrokeHairlineOrEquivalent(style, viewMatrix, &hairlineCoverage)) {
765             newCoverage = SkScalarRoundToInt(hairlineCoverage * 0xff);
766         }
767 
768         const SkStrokeRec& stroke = style.strokeRec();
769         SkScalar capLength = SkPaint::kButt_Cap != stroke.getCap() ? hairlineCoverage * 0.5f : 0.0f;
770 
771         return Helper::FactoryHelper<AAHairlineOp>(context, std::move(paint), newCoverage,
772                                                    viewMatrix, path,
773                                                    devClipBounds, capLength, stencilSettings);
774     }
775 
AAHairlineOp(GrProcessorSet* processorSet, const SkPMColor4f& color, uint8_t coverage, const SkMatrix& viewMatrix, const SkPath& path, SkIRect devClipBounds, SkScalar capLength, const GrUserStencilSettings* stencilSettings)776     AAHairlineOp(GrProcessorSet* processorSet,
777                  const SkPMColor4f& color,
778                  uint8_t coverage,
779                  const SkMatrix& viewMatrix,
780                  const SkPath& path,
781                  SkIRect devClipBounds,
782                  SkScalar capLength,
783                  const GrUserStencilSettings* stencilSettings)
784             : INHERITED(ClassID())
785             , fHelper(processorSet, GrAAType::kCoverage, stencilSettings)
786             , fColor(color)
787             , fCoverage(coverage) {
788         fPaths.emplace_back(PathData{viewMatrix, path, devClipBounds, capLength});
789 
790         this->setTransformedBounds(path.getBounds(), viewMatrix, HasAABloat::kYes,
791                                    IsHairline::kYes);
792     }
793 
794     const char* name() const override { return "AAHairlineOp"; }
795 
796     void visitProxies(const GrVisitProxyFunc& func) const override {
797 
798         bool visited = false;
799         for (int i = 0; i < 3; ++i) {
800             if (fProgramInfos[i]) {
801                 fProgramInfos[i]->visitFPProxies(func);
802                 visited = true;
803             }
804         }
805 
806         if (!visited) {
807             fHelper.visitProxies(func);
808         }
809     }
810 
811     FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }
812 
813     GrProcessorSet::Analysis finalize(const GrCaps& caps, const GrAppliedClip* clip,
814                                       GrClampType clampType) override {
815         // This Op uses uniform (not vertex) color, so doesn't need to track wide color.
816         return fHelper.finalizeProcessors(caps, clip, clampType,
817                                           GrProcessorAnalysisCoverage::kSingleChannel, &fColor,
818                                           nullptr);
819     }
820 
821     enum class Program : uint8_t {
822         kNone  = 0x0,
823         kLine  = 0x1,
824         kQuad  = 0x2,
825         kConic = 0x4,
826     };
827 
828 private:
829     void makeLineProgramInfo(const GrCaps&, SkArenaAlloc*, const GrPipeline*,
830                              const GrSurfaceProxyView& writeView,
831                              bool usesMSAASurface,
832                              const SkMatrix* geometryProcessorViewM,
833                              const SkMatrix* geometryProcessorLocalM,
834                              GrXferBarrierFlags renderPassXferBarriers,
835                              GrLoadOp colorLoadOp);
836     void makeQuadProgramInfo(const GrCaps&, SkArenaAlloc*, const GrPipeline*,
837                              const GrSurfaceProxyView& writeView,
838                              bool usesMSAASurface,
839                              const SkMatrix* geometryProcessorViewM,
840                              const SkMatrix* geometryProcessorLocalM,
841                              GrXferBarrierFlags renderPassXferBarriers,
842                              GrLoadOp colorLoadOp);
843     void makeConicProgramInfo(const GrCaps&, SkArenaAlloc*, const GrPipeline*,
844                               const GrSurfaceProxyView& writeView,
845                               bool usesMSAASurface,
846                               const SkMatrix* geometryProcessorViewM,
847                               const SkMatrix* geometryProcessorLocalM,
848                               GrXferBarrierFlags renderPassXferBarriers,
849                               GrLoadOp colorLoadOp);
850 
851     GrProgramInfo* programInfo() override {
852         // This Op has 3 programInfos and implements its own onPrePrepareDraws so this entry point
853         // should really never be called.
854         SkASSERT(0);
855         return nullptr;
856     }
857 
858     Program predictPrograms(const GrCaps*) const;
859 
860     void onCreateProgramInfo(const GrCaps*,
861                              SkArenaAlloc*,
862                              const GrSurfaceProxyView& writeView,
863                              bool usesMSAASurface,
864                              GrAppliedClip&&,
865                              const GrDstProxyView&,
866                              GrXferBarrierFlags renderPassXferBarriers,
867                              GrLoadOp colorLoadOp) override;
868 
869     void onPrePrepareDraws(GrRecordingContext*,
870                            const GrSurfaceProxyView& writeView,
871                            GrAppliedClip*,
872                            const GrDstProxyView&,
873                            GrXferBarrierFlags renderPassXferBarriers,
874                            GrLoadOp colorLoadOp) override;
875 
876     void onPrepareDraws(GrMeshDrawTarget*) override;
877     void onExecute(GrOpFlushState*, const SkRect& chainBounds) override;
878 
879     CombineResult onCombineIfPossible(GrOp* t, SkArenaAlloc*, const GrCaps& caps) override {
880         AAHairlineOp* that = t->cast<AAHairlineOp>();
881 
882         if (!fHelper.isCompatible(that->fHelper, caps, this->bounds(), that->bounds())) {
883             return CombineResult::kCannotCombine;
884         }
885 
886         if (this->viewMatrix().hasPerspective() != that->viewMatrix().hasPerspective()) {
887             return CombineResult::kCannotCombine;
888         }
889 
890         // We go to identity if we don't have perspective
891         if (this->viewMatrix().hasPerspective() &&
892             !SkMatrixPriv::CheapEqual(this->viewMatrix(), that->viewMatrix())) {
893             return CombineResult::kCannotCombine;
894         }
895 
896         // TODO we can actually combine hairlines if they are the same color in a kind of bulk
897         // method but we haven't implemented this yet
898         // TODO investigate going to vertex color and coverage?
899         if (this->coverage() != that->coverage()) {
900             return CombineResult::kCannotCombine;
901         }
902 
903         if (this->color() != that->color()) {
904             return CombineResult::kCannotCombine;
905         }
906 
907         if (fHelper.usesLocalCoords() && !SkMatrixPriv::CheapEqual(this->viewMatrix(),
908                                                                    that->viewMatrix())) {
909             return CombineResult::kCannotCombine;
910         }
911 
912         fPaths.push_back_n(that->fPaths.count(), that->fPaths.begin());
913         return CombineResult::kMerged;
914     }
915 
916 #if GR_TEST_UTILS
917     SkString onDumpInfo() const override {
918         return SkStringPrintf("Color: 0x%08x Coverage: 0x%02x, Count: %d\n%s",
919                               fColor.toBytes_RGBA(), fCoverage, fPaths.count(),
920                               fHelper.dumpInfo().c_str());
921     }
922 #endif
923 
color() const924     const SkPMColor4f& color() const { return fColor; }
coverage() const925     uint8_t coverage() const { return fCoverage; }
viewMatrix() const926     const SkMatrix& viewMatrix() const { return fPaths[0].fViewMatrix; }
927 
928     struct PathData {
929         SkMatrix fViewMatrix;
930         SkPath fPath;
931         SkIRect fDevClipBounds;
932         SkScalar fCapLength;
933     };
934 
935     SkSTArray<1, PathData, true> fPaths;
936     Helper fHelper;
937     SkPMColor4f fColor;
938     uint8_t fCoverage;
939 
940     Program        fCharacterization = Program::kNone;       // holds a mask of required programs
941     GrSimpleMesh*  fMeshes[3] = { nullptr };
942     GrProgramInfo* fProgramInfos[3] = { nullptr };
943 
944     using INHERITED = GrMeshDrawOp;
945 };
946 
947 GR_MAKE_BITFIELD_CLASS_OPS(AAHairlineOp::Program)
948 
makeLineProgramInfo(const GrCaps& caps, SkArenaAlloc* arena, const GrPipeline* pipeline, const GrSurfaceProxyView& writeView, bool usesMSAASurface, const SkMatrix* geometryProcessorViewM, const SkMatrix* geometryProcessorLocalM, GrXferBarrierFlags renderPassXferBarriers, GrLoadOp colorLoadOp)949 void AAHairlineOp::makeLineProgramInfo(const GrCaps& caps, SkArenaAlloc* arena,
950                                        const GrPipeline* pipeline,
951                                        const GrSurfaceProxyView& writeView,
952                                        bool usesMSAASurface,
953                                        const SkMatrix* geometryProcessorViewM,
954                                        const SkMatrix* geometryProcessorLocalM,
955                                        GrXferBarrierFlags renderPassXferBarriers,
956                                        GrLoadOp colorLoadOp) {
957     if (fProgramInfos[0]) {
958         return;
959     }
960 
961     GrGeometryProcessor* lineGP;
962     {
963         using namespace GrDefaultGeoProcFactory;
964 
965         Color color(this->color());
966         LocalCoords localCoords(fHelper.usesLocalCoords() ? LocalCoords::kUsePosition_Type
967                                                           : LocalCoords::kUnused_Type);
968         localCoords.fMatrix = geometryProcessorLocalM;
969 
970         lineGP = GrDefaultGeoProcFactory::Make(arena,
971                                                color,
972                                                Coverage::kAttribute_Type,
973                                                localCoords,
974                                                *geometryProcessorViewM);
975         SkASSERT(sizeof(LineVertex) == lineGP->vertexStride());
976     }
977 
978     fProgramInfos[0] = GrSimpleMeshDrawOpHelper::CreateProgramInfo(
979             &caps, arena, pipeline, writeView, usesMSAASurface, lineGP, GrPrimitiveType::kTriangles,
980             renderPassXferBarriers, colorLoadOp, fHelper.stencilSettings());
981 }
982 
makeQuadProgramInfo(const GrCaps& caps, SkArenaAlloc* arena, const GrPipeline* pipeline, const GrSurfaceProxyView& writeView, bool usesMSAASurface, const SkMatrix* geometryProcessorViewM, const SkMatrix* geometryProcessorLocalM, GrXferBarrierFlags renderPassXferBarriers, GrLoadOp colorLoadOp)983 void AAHairlineOp::makeQuadProgramInfo(const GrCaps& caps, SkArenaAlloc* arena,
984                                        const GrPipeline* pipeline,
985                                        const GrSurfaceProxyView& writeView,
986                                        bool usesMSAASurface,
987                                        const SkMatrix* geometryProcessorViewM,
988                                        const SkMatrix* geometryProcessorLocalM,
989                                        GrXferBarrierFlags renderPassXferBarriers,
990                                        GrLoadOp colorLoadOp) {
991     if (fProgramInfos[1]) {
992         return;
993     }
994 
995     GrGeometryProcessor* quadGP = GrQuadEffect::Make(arena,
996                                                      this->color(),
997                                                      *geometryProcessorViewM,
998                                                      caps,
999                                                      *geometryProcessorLocalM,
1000                                                      fHelper.usesLocalCoords(),
1001                                                      this->coverage());
1002     SkASSERT(sizeof(BezierVertex) == quadGP->vertexStride());
1003 
1004     fProgramInfos[1] = GrSimpleMeshDrawOpHelper::CreateProgramInfo(
1005             &caps, arena, pipeline, writeView, usesMSAASurface, quadGP, GrPrimitiveType::kTriangles,
1006             renderPassXferBarriers, colorLoadOp, fHelper.stencilSettings());
1007 }
1008 
makeConicProgramInfo(const GrCaps& caps, SkArenaAlloc* arena, const GrPipeline* pipeline, const GrSurfaceProxyView& writeView, bool usesMSAASurface, const SkMatrix* geometryProcessorViewM, const SkMatrix* geometryProcessorLocalM, GrXferBarrierFlags renderPassXferBarriers, GrLoadOp colorLoadOp)1009 void AAHairlineOp::makeConicProgramInfo(const GrCaps& caps, SkArenaAlloc* arena,
1010                                         const GrPipeline* pipeline,
1011                                         const GrSurfaceProxyView& writeView,
1012                                         bool usesMSAASurface,
1013                                         const SkMatrix* geometryProcessorViewM,
1014                                         const SkMatrix* geometryProcessorLocalM,
1015                                         GrXferBarrierFlags renderPassXferBarriers,
1016                                         GrLoadOp colorLoadOp) {
1017     if (fProgramInfos[2]) {
1018         return;
1019     }
1020 
1021     GrGeometryProcessor* conicGP = GrConicEffect::Make(arena,
1022                                                        this->color(),
1023                                                        *geometryProcessorViewM,
1024                                                        caps,
1025                                                        *geometryProcessorLocalM,
1026                                                        fHelper.usesLocalCoords(),
1027                                                        this->coverage());
1028     SkASSERT(sizeof(BezierVertex) == conicGP->vertexStride());
1029 
1030     fProgramInfos[2] = GrSimpleMeshDrawOpHelper::CreateProgramInfo(
1031             &caps, arena, pipeline, writeView, usesMSAASurface, conicGP,
1032             GrPrimitiveType::kTriangles, renderPassXferBarriers, colorLoadOp,
1033             fHelper.stencilSettings());
1034 }
1035 
predictPrograms(const GrCaps* caps) const1036 AAHairlineOp::Program AAHairlineOp::predictPrograms(const GrCaps* caps) const {
1037     bool convertConicsToQuads = !caps->shaderCaps()->floatIs32Bits();
1038 
1039     // When predicting the programs we always include the lineProgram bc it is used as a fallback
1040     // for quads and conics. In non-DDL mode there are cases where it sometimes isn't needed for a
1041     // given path.
1042     Program neededPrograms = Program::kLine;
1043 
1044     for (int i = 0; i < fPaths.count(); i++) {
1045         uint32_t mask = fPaths[i].fPath.getSegmentMasks();
1046 
1047         if (mask & (SkPath::kQuad_SegmentMask | SkPath::kCubic_SegmentMask)) {
1048             neededPrograms |= Program::kQuad;
1049         }
1050         if (mask & SkPath::kConic_SegmentMask) {
1051             if (convertConicsToQuads) {
1052                 neededPrograms |= Program::kQuad;
1053             } else {
1054                 neededPrograms |= Program::kConic;
1055             }
1056         }
1057     }
1058 
1059     return neededPrograms;
1060 }
1061 
onCreateProgramInfo(const GrCaps* caps, SkArenaAlloc* arena, const GrSurfaceProxyView& writeView, bool usesMSAASurface, GrAppliedClip&& appliedClip, const GrDstProxyView& dstProxyView, GrXferBarrierFlags renderPassXferBarriers, GrLoadOp colorLoadOp)1062 void AAHairlineOp::onCreateProgramInfo(const GrCaps* caps,
1063                                        SkArenaAlloc* arena,
1064                                        const GrSurfaceProxyView& writeView,
1065                                        bool usesMSAASurface,
1066                                        GrAppliedClip&& appliedClip,
1067                                        const GrDstProxyView& dstProxyView,
1068                                        GrXferBarrierFlags renderPassXferBarriers,
1069                                        GrLoadOp colorLoadOp) {
1070     // Setup the viewmatrix and localmatrix for the GrGeometryProcessor.
1071     SkMatrix invert;
1072     if (!this->viewMatrix().invert(&invert)) {
1073         return;
1074     }
1075 
1076     // we will transform to identity space if the viewmatrix does not have perspective
1077     bool hasPerspective = this->viewMatrix().hasPerspective();
1078     const SkMatrix* geometryProcessorViewM = &SkMatrix::I();
1079     const SkMatrix* geometryProcessorLocalM = &invert;
1080     if (hasPerspective) {
1081         geometryProcessorViewM = &this->viewMatrix();
1082         geometryProcessorLocalM = &SkMatrix::I();
1083     }
1084 
1085     auto pipeline = fHelper.createPipeline(caps, arena, writeView.swizzle(),
1086                                            std::move(appliedClip), dstProxyView);
1087 
1088     if (fCharacterization & Program::kLine) {
1089         this->makeLineProgramInfo(*caps, arena, pipeline, writeView, usesMSAASurface,
1090                                   geometryProcessorViewM, geometryProcessorLocalM,
1091                                   renderPassXferBarriers, colorLoadOp);
1092     }
1093     if (fCharacterization & Program::kQuad) {
1094         this->makeQuadProgramInfo(*caps, arena, pipeline, writeView, usesMSAASurface,
1095                                   geometryProcessorViewM, geometryProcessorLocalM,
1096                                   renderPassXferBarriers, colorLoadOp);
1097     }
1098     if (fCharacterization & Program::kConic) {
1099         this->makeConicProgramInfo(*caps, arena, pipeline, writeView, usesMSAASurface,
1100                                    geometryProcessorViewM, geometryProcessorLocalM,
1101                                    renderPassXferBarriers, colorLoadOp);
1102 
1103     }
1104 }
1105 
onPrePrepareDraws(GrRecordingContext* context, const GrSurfaceProxyView& writeView, GrAppliedClip* clip, const GrDstProxyView& dstProxyView, GrXferBarrierFlags renderPassXferBarriers, GrLoadOp colorLoadOp)1106 void AAHairlineOp::onPrePrepareDraws(GrRecordingContext* context,
1107                                      const GrSurfaceProxyView& writeView,
1108                                      GrAppliedClip* clip,
1109                                      const GrDstProxyView& dstProxyView,
1110                                      GrXferBarrierFlags renderPassXferBarriers,
1111                                      GrLoadOp colorLoadOp) {
1112     SkArenaAlloc* arena = context->priv().recordTimeAllocator();
1113     const GrCaps* caps = context->priv().caps();
1114 
1115     // http://skbug.com/12201 -- DDL does not yet support DMSAA.
1116     bool usesMSAASurface = writeView.asRenderTargetProxy()->numSamples() > 1;
1117 
1118     // This is equivalent to a GrOpFlushState::detachAppliedClip
1119     GrAppliedClip appliedClip = clip ? std::move(*clip) : GrAppliedClip::Disabled();
1120 
1121     // Conservatively predict which programs will be required
1122     fCharacterization = this->predictPrograms(caps);
1123 
1124     this->createProgramInfo(caps, arena, writeView, usesMSAASurface, std::move(appliedClip),
1125                             dstProxyView, renderPassXferBarriers, colorLoadOp);
1126 
1127     context->priv().recordProgramInfo(fProgramInfos[0]);
1128     context->priv().recordProgramInfo(fProgramInfos[1]);
1129     context->priv().recordProgramInfo(fProgramInfos[2]);
1130 }
1131 
onPrepareDraws(GrMeshDrawTarget* target)1132 void AAHairlineOp::onPrepareDraws(GrMeshDrawTarget* target) {
1133     // Setup the viewmatrix and localmatrix for the GrGeometryProcessor.
1134     SkMatrix invert;
1135     if (!this->viewMatrix().invert(&invert)) {
1136         return;
1137     }
1138 
1139     // we will transform to identity space if the viewmatrix does not have perspective
1140     const SkMatrix* toDevice = nullptr;
1141     const SkMatrix* toSrc = nullptr;
1142     if (this->viewMatrix().hasPerspective()) {
1143         toDevice = &this->viewMatrix();
1144         toSrc = &invert;
1145     }
1146 
1147     SkDEBUGCODE(Program predictedPrograms = this->predictPrograms(&target->caps()));
1148     Program actualPrograms = Program::kNone;
1149 
1150     // This is hand inlined for maximum performance.
1151     PREALLOC_PTARRAY(128) lines;
1152     PREALLOC_PTARRAY(128) quads;
1153     PREALLOC_PTARRAY(128) conics;
1154     IntArray qSubdivs;
1155     FloatArray cWeights;
1156     int quadCount = 0;
1157 
1158     int instanceCount = fPaths.count();
1159     bool convertConicsToQuads = !target->caps().shaderCaps()->floatIs32Bits();
1160     for (int i = 0; i < instanceCount; i++) {
1161         const PathData& args = fPaths[i];
1162         quadCount += gather_lines_and_quads(args.fPath, args.fViewMatrix, args.fDevClipBounds,
1163                                             args.fCapLength, convertConicsToQuads, &lines, &quads,
1164                                             &conics, &qSubdivs, &cWeights);
1165     }
1166 
1167     int lineCount = lines.count() / 2;
1168     int conicCount = conics.count() / 3;
1169     int quadAndConicCount = conicCount + quadCount;
1170 
1171     static constexpr int kMaxLines = SK_MaxS32 / kLineSegNumVertices;
1172     static constexpr int kMaxQuadsAndConics = SK_MaxS32 / kQuadNumVertices;
1173     if (lineCount > kMaxLines || quadAndConicCount > kMaxQuadsAndConics) {
1174         return;
1175     }
1176 
1177     // do lines first
1178     if (lineCount) {
1179         SkASSERT(predictedPrograms & Program::kLine);
1180         actualPrograms |= Program::kLine;
1181 
1182         sk_sp<const GrBuffer> linesIndexBuffer = get_lines_index_buffer(target->resourceProvider());
1183 
1184         GrMeshDrawOp::PatternHelper helper(target, GrPrimitiveType::kTriangles, sizeof(LineVertex),
1185                                            std::move(linesIndexBuffer), kLineSegNumVertices,
1186                                            kIdxsPerLineSeg, lineCount, kLineSegsNumInIdxBuffer);
1187 
1188         LineVertex* verts = reinterpret_cast<LineVertex*>(helper.vertices());
1189         if (!verts) {
1190             SkDebugf("Could not allocate vertices\n");
1191             return;
1192         }
1193 
1194         for (int i = 0; i < lineCount; ++i) {
1195             add_line(&lines[2*i], toSrc, this->coverage(), &verts);
1196         }
1197 
1198         fMeshes[0] = helper.mesh();
1199     }
1200 
1201     if (quadCount || conicCount) {
1202         sk_sp<const GrBuffer> vertexBuffer;
1203         int firstVertex;
1204 
1205         sk_sp<const GrBuffer> quadsIndexBuffer = get_quads_index_buffer(target->resourceProvider());
1206 
1207         int vertexCount = kQuadNumVertices * quadAndConicCount;
1208         void* vertices = target->makeVertexSpace(sizeof(BezierVertex), vertexCount, &vertexBuffer,
1209                                                  &firstVertex);
1210 
1211         if (!vertices || !quadsIndexBuffer) {
1212             SkDebugf("Could not allocate vertices\n");
1213             return;
1214         }
1215 
1216         // Setup vertices
1217         BezierVertex* bezVerts = reinterpret_cast<BezierVertex*>(vertices);
1218 
1219         int unsubdivQuadCnt = quads.count() / 3;
1220         for (int i = 0; i < unsubdivQuadCnt; ++i) {
1221             SkASSERT(qSubdivs[i] >= 0);
1222             if (!quads[3*i].isFinite() || !quads[3*i+1].isFinite() || !quads[3*i+2].isFinite()) {
1223                 return;
1224             }
1225             add_quads(&quads[3*i], qSubdivs[i], toDevice, toSrc, &bezVerts);
1226         }
1227 
1228         // Start Conics
1229         for (int i = 0; i < conicCount; ++i) {
1230             add_conics(&conics[3*i], cWeights[i], toDevice, toSrc, &bezVerts);
1231         }
1232 
1233         if (quadCount > 0) {
1234             SkASSERT(predictedPrograms & Program::kQuad);
1235             actualPrograms |= Program::kQuad;
1236 
1237             fMeshes[1] = target->allocMesh();
1238             fMeshes[1]->setIndexedPatterned(quadsIndexBuffer, kIdxsPerQuad, quadCount,
1239                                             kQuadsNumInIdxBuffer, vertexBuffer, kQuadNumVertices,
1240                                             firstVertex);
1241             firstVertex += quadCount * kQuadNumVertices;
1242         }
1243 
1244         if (conicCount > 0) {
1245             SkASSERT(predictedPrograms & Program::kConic);
1246             actualPrograms |= Program::kConic;
1247 
1248             fMeshes[2] = target->allocMesh();
1249             fMeshes[2]->setIndexedPatterned(std::move(quadsIndexBuffer), kIdxsPerQuad, conicCount,
1250                                             kQuadsNumInIdxBuffer, std::move(vertexBuffer),
1251                                             kQuadNumVertices, firstVertex);
1252         }
1253     }
1254 
1255     // In DDL mode this will replace the predicted program requirements with the actual ones.
1256     // However, we will already have surfaced the predicted programs to the DDL.
1257     fCharacterization = actualPrograms;
1258 }
1259 
onExecute(GrOpFlushState* flushState, const SkRect& chainBounds)1260 void AAHairlineOp::onExecute(GrOpFlushState* flushState, const SkRect& chainBounds) {
1261     this->createProgramInfo(flushState);
1262 
1263     for (int i = 0; i < 3; ++i) {
1264         if (fProgramInfos[i] && fMeshes[i]) {
1265             flushState->bindPipelineAndScissorClip(*fProgramInfos[i], chainBounds);
1266             flushState->bindTextures(fProgramInfos[i]->geomProc(), nullptr,
1267                                      fProgramInfos[i]->pipeline());
1268             flushState->drawMesh(*fMeshes[i]);
1269         }
1270     }
1271 }
1272 
1273 } // anonymous namespace
1274 
1275 ///////////////////////////////////////////////////////////////////////////////////////////////////
1276 
1277 #if GR_TEST_UTILS
1278 
GR_DRAW_OP_TEST_DEFINE(AAHairlineOp)1279 GR_DRAW_OP_TEST_DEFINE(AAHairlineOp) {
1280     SkMatrix viewMatrix = GrTest::TestMatrix(random);
1281     const SkPath& path = GrTest::TestPath(random);
1282     SkIRect devClipBounds;
1283     devClipBounds.setEmpty();
1284     return AAHairlineOp::Make(context, std::move(paint), viewMatrix, path,
1285                               GrStyle::SimpleHairline(), devClipBounds,
1286                               GrGetRandomStencil(random, context));
1287 }
1288 
1289 #endif
1290 
1291 ///////////////////////////////////////////////////////////////////////////////////////////////////
1292 
1293 namespace skgpu::v1 {
1294 
onCanDrawPath(const CanDrawPathArgs& args) const1295 PathRenderer::CanDrawPath AAHairLinePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
1296     if (GrAAType::kCoverage != args.fAAType) {
1297         return CanDrawPath::kNo;
1298     }
1299 
1300     if (!GrIsStrokeHairlineOrEquivalent(args.fShape->style(), *args.fViewMatrix, nullptr)) {
1301         return CanDrawPath::kNo;
1302     }
1303 
1304     // We don't currently handle dashing in this class though perhaps we should.
1305     if (args.fShape->style().pathEffect()) {
1306         return CanDrawPath::kNo;
1307     }
1308 
1309     if (SkPath::kLine_SegmentMask == args.fShape->segmentMask() ||
1310         args.fCaps->shaderCaps()->shaderDerivativeSupport()) {
1311         return CanDrawPath::kYes;
1312     }
1313 
1314     return CanDrawPath::kNo;
1315 }
1316 
1317 
onDrawPath(const DrawPathArgs& args)1318 bool AAHairLinePathRenderer::onDrawPath(const DrawPathArgs& args) {
1319     GR_AUDIT_TRAIL_AUTO_FRAME(args.fContext->priv().auditTrail(),
1320                               "AAHairlinePathRenderer::onDrawPath");
1321     SkASSERT(args.fSurfaceDrawContext->numSamples() <= 1);
1322 
1323     SkPath path;
1324     args.fShape->asPath(&path);
1325     GrOp::Owner op =
1326             AAHairlineOp::Make(args.fContext, std::move(args.fPaint), *args.fViewMatrix, path,
1327                                args.fShape->style(), *args.fClipConservativeBounds,
1328                                args.fUserStencilSettings);
1329     args.fSurfaceDrawContext->addDrawOp(args.fClip, std::move(op));
1330     return true;
1331 }
1332 
1333 } // namespace skgpu::v1
1334 
1335