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1 /*
2  * Copyright 2014 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 "GrDashingEffect.h"
9 
10 #include "GrBatchFlushState.h"
11 #include "GrBatchTest.h"
12 #include "GrCaps.h"
13 #include "GrGeometryProcessor.h"
14 #include "GrContext.h"
15 #include "GrCoordTransform.h"
16 #include "GrDefaultGeoProcFactory.h"
17 #include "GrDrawTarget.h"
18 #include "GrInvariantOutput.h"
19 #include "GrProcessor.h"
20 #include "GrStrokeInfo.h"
21 #include "GrVertexBuffer.h"
22 #include "SkGr.h"
23 #include "batches/GrVertexBatch.h"
24 #include "glsl/GrGLSLFragmentShaderBuilder.h"
25 #include "glsl/GrGLSLGeometryProcessor.h"
26 #include "glsl/GrGLSLProgramDataManager.h"
27 #include "glsl/GrGLSLUniformHandler.h"
28 #include "glsl/GrGLSLVarying.h"
29 #include "glsl/GrGLSLVertexShaderBuilder.h"
30 
31 ///////////////////////////////////////////////////////////////////////////////
32 
33 // Returns whether or not the gpu can fast path the dash line effect.
CanDrawDashLine(const SkPoint pts[2],const GrStrokeInfo & strokeInfo,const SkMatrix & viewMatrix)34 bool GrDashingEffect::CanDrawDashLine(const SkPoint pts[2], const GrStrokeInfo& strokeInfo,
35                                       const SkMatrix& viewMatrix) {
36     // Pts must be either horizontal or vertical in src space
37     if (pts[0].fX != pts[1].fX && pts[0].fY != pts[1].fY) {
38         return false;
39     }
40 
41     // May be able to relax this to include skew. As of now cannot do perspective
42     // because of the non uniform scaling of bloating a rect
43     if (!viewMatrix.preservesRightAngles()) {
44         return false;
45     }
46 
47     if (!strokeInfo.isDashed() || 2 != strokeInfo.getDashCount()) {
48         return false;
49     }
50 
51     const SkScalar* intervals = strokeInfo.getDashIntervals();
52     if (0 == intervals[0] && 0 == intervals[1]) {
53         return false;
54     }
55 
56     SkPaint::Cap cap = strokeInfo.getCap();
57     // Current we do don't handle Round or Square cap dashes
58     if (SkPaint::kRound_Cap == cap && intervals[0] != 0.f) {
59         return false;
60     }
61 
62     return true;
63 }
64 
65 namespace {
66 struct DashLineVertex {
67     SkPoint fPos;
68     SkPoint fDashPos;
69     SkScalar fIntervalLength;
70     SkRect fRect;
71 };
72 struct DashCircleVertex {
73     SkPoint fPos;
74     SkPoint fDashPos;
75     SkScalar fIntervalLength;
76     SkScalar fRadius;
77     SkScalar fCenterX;
78 };
79 
80 enum DashAAMode {
81     kBW_DashAAMode,
82     kEdgeAA_DashAAMode,
83     kMSAA_DashAAMode,
84 
85     kDashAAModeCount,
86 };
87 };
88 
calc_dash_scaling(SkScalar * parallelScale,SkScalar * perpScale,const SkMatrix & viewMatrix,const SkPoint pts[2])89 static void calc_dash_scaling(SkScalar* parallelScale, SkScalar* perpScale,
90                             const SkMatrix& viewMatrix, const SkPoint pts[2]) {
91     SkVector vecSrc = pts[1] - pts[0];
92     SkScalar magSrc = vecSrc.length();
93     SkScalar invSrc = magSrc ? SkScalarInvert(magSrc) : 0;
94     vecSrc.scale(invSrc);
95 
96     SkVector vecSrcPerp;
97     vecSrc.rotateCW(&vecSrcPerp);
98     viewMatrix.mapVectors(&vecSrc, 1);
99     viewMatrix.mapVectors(&vecSrcPerp, 1);
100 
101     // parallelScale tells how much to scale along the line parallel to the dash line
102     // perpScale tells how much to scale in the direction perpendicular to the dash line
103     *parallelScale = vecSrc.length();
104     *perpScale = vecSrcPerp.length();
105 }
106 
107 // calculates the rotation needed to aligned pts to the x axis with pts[0] < pts[1]
108 // Stores the rotation matrix in rotMatrix, and the mapped points in ptsRot
align_to_x_axis(const SkPoint pts[2],SkMatrix * rotMatrix,SkPoint ptsRot[2]=nullptr)109 static void align_to_x_axis(const SkPoint pts[2], SkMatrix* rotMatrix, SkPoint ptsRot[2] = nullptr) {
110     SkVector vec = pts[1] - pts[0];
111     SkScalar mag = vec.length();
112     SkScalar inv = mag ? SkScalarInvert(mag) : 0;
113 
114     vec.scale(inv);
115     rotMatrix->setSinCos(-vec.fY, vec.fX, pts[0].fX, pts[0].fY);
116     if (ptsRot) {
117         rotMatrix->mapPoints(ptsRot, pts, 2);
118         // correction for numerical issues if map doesn't make ptsRot exactly horizontal
119         ptsRot[1].fY = pts[0].fY;
120     }
121 }
122 
123 // Assumes phase < sum of all intervals
calc_start_adjustment(const SkScalar intervals[2],SkScalar phase)124 static SkScalar calc_start_adjustment(const SkScalar intervals[2], SkScalar phase) {
125     SkASSERT(phase < intervals[0] + intervals[1]);
126     if (phase >= intervals[0] && phase != 0) {
127         SkScalar srcIntervalLen = intervals[0] + intervals[1];
128         return srcIntervalLen - phase;
129     }
130     return 0;
131 }
132 
calc_end_adjustment(const SkScalar intervals[2],const SkPoint pts[2],SkScalar phase,SkScalar * endingInt)133 static SkScalar calc_end_adjustment(const SkScalar intervals[2], const SkPoint pts[2],
134                                     SkScalar phase, SkScalar* endingInt) {
135     if (pts[1].fX <= pts[0].fX) {
136         return 0;
137     }
138     SkScalar srcIntervalLen = intervals[0] + intervals[1];
139     SkScalar totalLen = pts[1].fX - pts[0].fX;
140     SkScalar temp = totalLen / srcIntervalLen;
141     SkScalar numFullIntervals = SkScalarFloorToScalar(temp);
142     *endingInt = totalLen - numFullIntervals * srcIntervalLen + phase;
143     temp = *endingInt / srcIntervalLen;
144     *endingInt = *endingInt - SkScalarFloorToScalar(temp) * srcIntervalLen;
145     if (0 == *endingInt) {
146         *endingInt = srcIntervalLen;
147     }
148     if (*endingInt > intervals[0]) {
149         if (0 == intervals[0]) {
150             *endingInt -= 0.01f; // make sure we capture the last zero size pnt (used if has caps)
151         }
152         return *endingInt - intervals[0];
153     }
154     return 0;
155 }
156 
157 enum DashCap {
158     kRound_DashCap,
159     kNonRound_DashCap,
160 };
161 
162 static int kDashVertices = 4;
163 
164 template <typename T>
setup_dashed_rect_common(const SkRect & rect,const SkMatrix & matrix,T * vertices,int idx,SkScalar offset,SkScalar bloatX,SkScalar bloatY,SkScalar len,SkScalar stroke)165 void setup_dashed_rect_common(const SkRect& rect, const SkMatrix& matrix, T* vertices, int idx,
166                               SkScalar offset, SkScalar bloatX, SkScalar bloatY, SkScalar len,
167                               SkScalar stroke) {
168     SkScalar startDashX = offset - bloatX;
169     SkScalar endDashX = offset + len + bloatX;
170     SkScalar startDashY = -stroke - bloatY;
171     SkScalar endDashY = stroke + bloatY;
172     vertices[idx].fDashPos = SkPoint::Make(startDashX , startDashY);
173     vertices[idx + 1].fDashPos = SkPoint::Make(startDashX, endDashY);
174     vertices[idx + 2].fDashPos = SkPoint::Make(endDashX, endDashY);
175     vertices[idx + 3].fDashPos = SkPoint::Make(endDashX, startDashY);
176 
177     vertices[idx].fPos = SkPoint::Make(rect.fLeft, rect.fTop);
178     vertices[idx + 1].fPos = SkPoint::Make(rect.fLeft, rect.fBottom);
179     vertices[idx + 2].fPos = SkPoint::Make(rect.fRight, rect.fBottom);
180     vertices[idx + 3].fPos = SkPoint::Make(rect.fRight, rect.fTop);
181 
182     matrix.mapPointsWithStride(&vertices[idx].fPos, sizeof(T), 4);
183 }
184 
setup_dashed_rect(const SkRect & rect,void * vertices,int idx,const SkMatrix & matrix,SkScalar offset,SkScalar bloatX,SkScalar bloatY,SkScalar len,SkScalar stroke,SkScalar startInterval,SkScalar endInterval,SkScalar strokeWidth,DashCap cap,const size_t vertexStride)185 static void setup_dashed_rect(const SkRect& rect, void* vertices, int idx,
186                               const SkMatrix& matrix, SkScalar offset, SkScalar bloatX,
187                               SkScalar bloatY, SkScalar len, SkScalar stroke,
188                               SkScalar startInterval, SkScalar endInterval, SkScalar strokeWidth,
189                               DashCap cap, const size_t vertexStride) {
190     SkScalar intervalLength = startInterval + endInterval;
191 
192     if (kRound_DashCap == cap) {
193         SkASSERT(vertexStride == sizeof(DashCircleVertex));
194         DashCircleVertex* verts = reinterpret_cast<DashCircleVertex*>(vertices);
195 
196         setup_dashed_rect_common<DashCircleVertex>(rect, matrix, verts, idx, offset, bloatX,
197                                                    bloatY, len, stroke);
198 
199         SkScalar radius = SkScalarHalf(strokeWidth) - 0.5f;
200         SkScalar centerX = SkScalarHalf(endInterval);
201 
202         for (int i = 0; i < kDashVertices; i++) {
203             verts[idx + i].fIntervalLength = intervalLength;
204             verts[idx + i].fRadius = radius;
205             verts[idx + i].fCenterX = centerX;
206         }
207 
208     } else {
209         SkASSERT(kNonRound_DashCap == cap && vertexStride == sizeof(DashLineVertex));
210         DashLineVertex* verts = reinterpret_cast<DashLineVertex*>(vertices);
211 
212         setup_dashed_rect_common<DashLineVertex>(rect, matrix, verts, idx, offset, bloatX,
213                                                  bloatY, len, stroke);
214 
215         SkScalar halfOffLen = SkScalarHalf(endInterval);
216         SkScalar halfStroke = SkScalarHalf(strokeWidth);
217         SkRect rectParam;
218         rectParam.set(halfOffLen + 0.5f, -halfStroke + 0.5f,
219                       halfOffLen + startInterval - 0.5f, halfStroke - 0.5f);
220         for (int i = 0; i < kDashVertices; i++) {
221             verts[idx + i].fIntervalLength = intervalLength;
222             verts[idx + i].fRect = rectParam;
223         }
224     }
225 }
226 
setup_dashed_rect_pos(const SkRect & rect,int idx,const SkMatrix & matrix,SkPoint * verts)227 static void setup_dashed_rect_pos(const SkRect& rect, int idx, const SkMatrix& matrix,
228                                   SkPoint* verts) {
229     verts[idx] = SkPoint::Make(rect.fLeft, rect.fTop);
230     verts[idx + 1] = SkPoint::Make(rect.fLeft, rect.fBottom);
231     verts[idx + 2] = SkPoint::Make(rect.fRight, rect.fBottom);
232     verts[idx + 3] = SkPoint::Make(rect.fRight, rect.fTop);
233     matrix.mapPoints(&verts[idx], 4);
234 }
235 
236 
237 /**
238  * An GrGeometryProcessor that renders a dashed line.
239  * This GrGeometryProcessor is meant for dashed lines that only have a single on/off interval pair.
240  * Bounding geometry is rendered and the effect computes coverage based on the fragment's
241  * position relative to the dashed line.
242  */
243 static GrGeometryProcessor* create_dash_gp(GrColor,
244                                            DashAAMode aaMode,
245                                            DashCap cap,
246                                            const SkMatrix& localMatrix,
247                                            bool usesLocalCoords);
248 
249 class DashBatch : public GrVertexBatch {
250 public:
251     DEFINE_BATCH_CLASS_ID
252 
253     struct Geometry {
254         SkMatrix fViewMatrix;
255         SkMatrix fSrcRotInv;
256         SkPoint fPtsRot[2];
257         SkScalar fSrcStrokeWidth;
258         SkScalar fPhase;
259         SkScalar fIntervals[2];
260         SkScalar fParallelScale;
261         SkScalar fPerpendicularScale;
262         GrColor fColor;
263     };
264 
Create(const Geometry & geometry,SkPaint::Cap cap,DashAAMode aaMode,bool fullDash)265     static GrDrawBatch* Create(const Geometry& geometry, SkPaint::Cap cap, DashAAMode aaMode,
266                                bool fullDash) {
267         return new DashBatch(geometry, cap, aaMode, fullDash);
268     }
269 
name() const270     const char* name() const override { return "DashBatch"; }
271 
computePipelineOptimizations(GrInitInvariantOutput * color,GrInitInvariantOutput * coverage,GrBatchToXPOverrides * overrides) const272     void computePipelineOptimizations(GrInitInvariantOutput* color,
273                                       GrInitInvariantOutput* coverage,
274                                       GrBatchToXPOverrides* overrides) const override {
275         // When this is called on a batch, there is only one geometry bundle
276         color->setKnownFourComponents(fGeoData[0].fColor);
277         coverage->setUnknownSingleComponent();
278     }
279 
geoData()280     SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }
281 
282 private:
DashBatch(const Geometry & geometry,SkPaint::Cap cap,DashAAMode aaMode,bool fullDash)283     DashBatch(const Geometry& geometry, SkPaint::Cap cap, DashAAMode aaMode, bool fullDash)
284         : INHERITED(ClassID()) {
285         fGeoData.push_back(geometry);
286 
287         fBatch.fAAMode = aaMode;
288         fBatch.fCap = cap;
289         fBatch.fFullDash = fullDash;
290 
291         // compute bounds
292         SkScalar halfStrokeWidth = 0.5f * geometry.fSrcStrokeWidth;
293         SkScalar xBloat = SkPaint::kButt_Cap == cap ? 0 : halfStrokeWidth;
294         fBounds.set(geometry.fPtsRot[0], geometry.fPtsRot[1]);
295         fBounds.outset(xBloat, halfStrokeWidth);
296 
297         // Note, we actually create the combined matrix here, and save the work
298         SkMatrix& combinedMatrix = fGeoData[0].fSrcRotInv;
299         combinedMatrix.postConcat(geometry.fViewMatrix);
300         combinedMatrix.mapRect(&fBounds);
301     }
302 
initBatchTracker(const GrXPOverridesForBatch & overrides)303     void initBatchTracker(const GrXPOverridesForBatch& overrides) override {
304         // Handle any color overrides
305         if (!overrides.readsColor()) {
306             fGeoData[0].fColor = GrColor_ILLEGAL;
307         }
308         overrides.getOverrideColorIfSet(&fGeoData[0].fColor);
309 
310         // setup batch properties
311         fBatch.fColorIgnored = !overrides.readsColor();
312         fBatch.fColor = fGeoData[0].fColor;
313         fBatch.fUsesLocalCoords = overrides.readsLocalCoords();
314         fBatch.fCoverageIgnored = !overrides.readsCoverage();
315     }
316 
317     struct DashDraw {
DashDrawDashBatch::DashDraw318         DashDraw(const Geometry& geo) {
319             memcpy(fPtsRot, geo.fPtsRot, sizeof(geo.fPtsRot));
320             memcpy(fIntervals, geo.fIntervals, sizeof(geo.fIntervals));
321             fPhase = geo.fPhase;
322         }
323         SkPoint fPtsRot[2];
324         SkScalar fIntervals[2];
325         SkScalar fPhase;
326         SkScalar fStartOffset;
327         SkScalar fStrokeWidth;
328         SkScalar fLineLength;
329         SkScalar fHalfDevStroke;
330         SkScalar fDevBloatX;
331         SkScalar fDevBloatY;
332         bool fLineDone;
333         bool fHasStartRect;
334         bool fHasEndRect;
335     };
336 
onPrepareDraws(Target * target) const337     void onPrepareDraws(Target* target) const override {
338         int instanceCount = fGeoData.count();
339         SkPaint::Cap cap = this->cap();
340         bool isRoundCap = SkPaint::kRound_Cap == cap;
341         DashCap capType = isRoundCap ? kRound_DashCap : kNonRound_DashCap;
342 
343         SkAutoTUnref<const GrGeometryProcessor> gp;
344         if (this->fullDash()) {
345             gp.reset(create_dash_gp(this->color(), this->aaMode(), capType, this->viewMatrix(),
346                                     this->usesLocalCoords()));
347         } else {
348             // Set up the vertex data for the line and start/end dashes
349             using namespace GrDefaultGeoProcFactory;
350             Color color(this->color());
351             Coverage coverage(this->coverageIgnored() ? Coverage::kNone_Type :
352                                                         Coverage::kSolid_Type);
353             LocalCoords localCoords(this->usesLocalCoords() ? LocalCoords::kUsePosition_Type :
354                                                               LocalCoords::kUnused_Type);
355             gp.reset(CreateForDeviceSpace(color, coverage, localCoords, this->viewMatrix()));
356         }
357 
358         if (!gp) {
359             SkDebugf("Could not create GrGeometryProcessor\n");
360             return;
361         }
362 
363         target->initDraw(gp, this->pipeline());
364 
365         // useAA here means Edge AA or MSAA
366         bool useAA = this->aaMode() != kBW_DashAAMode;
367         bool fullDash = this->fullDash();
368 
369         // We do two passes over all of the dashes.  First we setup the start, end, and bounds,
370         // rectangles.  We preserve all of this work in the rects / draws arrays below.  Then we
371         // iterate again over these decomposed dashes to generate vertices
372         static const int kNumStackDashes = 128;
373         SkSTArray<kNumStackDashes, SkRect, true> rects;
374         SkSTArray<kNumStackDashes, DashDraw, true> draws;
375 
376         int totalRectCount = 0;
377         int rectOffset = 0;
378         rects.push_back_n(3 * instanceCount);
379         for (int i = 0; i < instanceCount; i++) {
380             const Geometry& args = fGeoData[i];
381 
382             DashDraw& draw = draws.push_back(args);
383 
384             bool hasCap = SkPaint::kButt_Cap != cap && 0 != args.fSrcStrokeWidth;
385 
386             // We always want to at least stroke out half a pixel on each side in device space
387             // so 0.5f / perpScale gives us this min in src space
388             SkScalar halfSrcStroke =
389                     SkMaxScalar(args.fSrcStrokeWidth * 0.5f, 0.5f / args.fPerpendicularScale);
390 
391             SkScalar strokeAdj;
392             if (!hasCap) {
393                 strokeAdj = 0.f;
394             } else {
395                 strokeAdj = halfSrcStroke;
396             }
397 
398             SkScalar startAdj = 0;
399 
400             bool lineDone = false;
401 
402             // Too simplify the algorithm, we always push back rects for start and end rect.
403             // Otherwise we'd have to track start / end rects for each individual geometry
404             SkRect& bounds = rects[rectOffset++];
405             SkRect& startRect = rects[rectOffset++];
406             SkRect& endRect = rects[rectOffset++];
407 
408             bool hasStartRect = false;
409             // If we are using AA, check to see if we are drawing a partial dash at the start. If so
410             // draw it separately here and adjust our start point accordingly
411             if (useAA) {
412                 if (draw.fPhase > 0 && draw.fPhase < draw.fIntervals[0]) {
413                     SkPoint startPts[2];
414                     startPts[0] = draw.fPtsRot[0];
415                     startPts[1].fY = startPts[0].fY;
416                     startPts[1].fX = SkMinScalar(startPts[0].fX + draw.fIntervals[0] - draw.fPhase,
417                                                  draw.fPtsRot[1].fX);
418                     startRect.set(startPts, 2);
419                     startRect.outset(strokeAdj, halfSrcStroke);
420 
421                     hasStartRect = true;
422                     startAdj = draw.fIntervals[0] + draw.fIntervals[1] - draw.fPhase;
423                 }
424             }
425 
426             // adjustments for start and end of bounding rect so we only draw dash intervals
427             // contained in the original line segment.
428             startAdj += calc_start_adjustment(draw.fIntervals, draw.fPhase);
429             if (startAdj != 0) {
430                 draw.fPtsRot[0].fX += startAdj;
431                 draw.fPhase = 0;
432             }
433             SkScalar endingInterval = 0;
434             SkScalar endAdj = calc_end_adjustment(draw.fIntervals, draw.fPtsRot, draw.fPhase,
435                                                   &endingInterval);
436             draw.fPtsRot[1].fX -= endAdj;
437             if (draw.fPtsRot[0].fX >= draw.fPtsRot[1].fX) {
438                 lineDone = true;
439             }
440 
441             bool hasEndRect = false;
442             // If we are using AA, check to see if we are drawing a partial dash at then end. If so
443             // draw it separately here and adjust our end point accordingly
444             if (useAA && !lineDone) {
445                 // If we adjusted the end then we will not be drawing a partial dash at the end.
446                 // If we didn't adjust the end point then we just need to make sure the ending
447                 // dash isn't a full dash
448                 if (0 == endAdj && endingInterval != draw.fIntervals[0]) {
449                     SkPoint endPts[2];
450                     endPts[1] = draw.fPtsRot[1];
451                     endPts[0].fY = endPts[1].fY;
452                     endPts[0].fX = endPts[1].fX - endingInterval;
453 
454                     endRect.set(endPts, 2);
455                     endRect.outset(strokeAdj, halfSrcStroke);
456 
457                     hasEndRect = true;
458                     endAdj = endingInterval + draw.fIntervals[1];
459 
460                     draw.fPtsRot[1].fX -= endAdj;
461                     if (draw.fPtsRot[0].fX >= draw.fPtsRot[1].fX) {
462                         lineDone = true;
463                     }
464                 }
465             }
466 
467             if (startAdj != 0) {
468                 draw.fPhase = 0;
469             }
470 
471             // Change the dashing info from src space into device space
472             SkScalar* devIntervals = draw.fIntervals;
473             devIntervals[0] = draw.fIntervals[0] * args.fParallelScale;
474             devIntervals[1] = draw.fIntervals[1] * args.fParallelScale;
475             SkScalar devPhase = draw.fPhase * args.fParallelScale;
476             SkScalar strokeWidth = args.fSrcStrokeWidth * args.fPerpendicularScale;
477 
478             if ((strokeWidth < 1.f && useAA) || 0.f == strokeWidth) {
479                 strokeWidth = 1.f;
480             }
481 
482             SkScalar halfDevStroke = strokeWidth * 0.5f;
483 
484             if (SkPaint::kSquare_Cap == cap && 0 != args.fSrcStrokeWidth) {
485                 // add cap to on interval and remove from off interval
486                 devIntervals[0] += strokeWidth;
487                 devIntervals[1] -= strokeWidth;
488             }
489             SkScalar startOffset = devIntervals[1] * 0.5f + devPhase;
490 
491             // For EdgeAA, we bloat in X & Y for both square and round caps.
492             // For MSAA, we don't bloat at all for square caps, and bloat in Y only for round caps.
493             SkScalar devBloatX = this->aaMode() == kEdgeAA_DashAAMode ? 0.5f : 0.0f;
494             SkScalar devBloatY = (SkPaint::kRound_Cap == cap && this->aaMode() == kMSAA_DashAAMode)
495                                  ? 0.5f : devBloatX;
496 
497             SkScalar bloatX = devBloatX / args.fParallelScale;
498             SkScalar bloatY = devBloatY / args.fPerpendicularScale;
499 
500             if (devIntervals[1] <= 0.f && useAA) {
501                 // Case when we end up drawing a solid AA rect
502                 // Reset the start rect to draw this single solid rect
503                 // but it requires to upload a new intervals uniform so we can mimic
504                 // one giant dash
505                 draw.fPtsRot[0].fX -= hasStartRect ? startAdj : 0;
506                 draw.fPtsRot[1].fX += hasEndRect ? endAdj : 0;
507                 startRect.set(draw.fPtsRot, 2);
508                 startRect.outset(strokeAdj, halfSrcStroke);
509                 hasStartRect = true;
510                 hasEndRect = false;
511                 lineDone = true;
512 
513                 SkPoint devicePts[2];
514                 args.fViewMatrix.mapPoints(devicePts, draw.fPtsRot, 2);
515                 SkScalar lineLength = SkPoint::Distance(devicePts[0], devicePts[1]);
516                 if (hasCap) {
517                     lineLength += 2.f * halfDevStroke;
518                 }
519                 devIntervals[0] = lineLength;
520             }
521 
522             totalRectCount += !lineDone ? 1 : 0;
523             totalRectCount += hasStartRect ? 1 : 0;
524             totalRectCount += hasEndRect ? 1 : 0;
525 
526             if (SkPaint::kRound_Cap == cap && 0 != args.fSrcStrokeWidth) {
527                 // need to adjust this for round caps to correctly set the dashPos attrib on
528                 // vertices
529                 startOffset -= halfDevStroke;
530             }
531 
532             if (!lineDone) {
533                 SkPoint devicePts[2];
534                 args.fViewMatrix.mapPoints(devicePts, draw.fPtsRot, 2);
535                 draw.fLineLength = SkPoint::Distance(devicePts[0], devicePts[1]);
536                 if (hasCap) {
537                     draw.fLineLength += 2.f * halfDevStroke;
538                 }
539 
540                 bounds.set(draw.fPtsRot[0].fX, draw.fPtsRot[0].fY,
541                            draw.fPtsRot[1].fX, draw.fPtsRot[1].fY);
542                 bounds.outset(bloatX + strokeAdj, bloatY + halfSrcStroke);
543             }
544 
545             if (hasStartRect) {
546                 SkASSERT(useAA);  // so that we know bloatX and bloatY have been set
547                 startRect.outset(bloatX, bloatY);
548             }
549 
550             if (hasEndRect) {
551                 SkASSERT(useAA);  // so that we know bloatX and bloatY have been set
552                 endRect.outset(bloatX, bloatY);
553             }
554 
555             draw.fStartOffset = startOffset;
556             draw.fDevBloatX = devBloatX;
557             draw.fDevBloatY = devBloatY;
558             draw.fHalfDevStroke = halfDevStroke;
559             draw.fStrokeWidth = strokeWidth;
560             draw.fHasStartRect = hasStartRect;
561             draw.fLineDone = lineDone;
562             draw.fHasEndRect = hasEndRect;
563         }
564 
565         if (!totalRectCount) {
566             return;
567         }
568 
569         QuadHelper helper;
570         void* vertices = helper.init(target, gp->getVertexStride(), totalRectCount);
571         if (!vertices) {
572             return;
573         }
574 
575         int curVIdx = 0;
576         int rectIndex = 0;
577         for (int i = 0; i < instanceCount; i++) {
578             const Geometry& geom = fGeoData[i];
579 
580             if (!draws[i].fLineDone) {
581                 if (fullDash) {
582                     setup_dashed_rect(rects[rectIndex], vertices, curVIdx, geom.fSrcRotInv,
583                                       draws[i].fStartOffset, draws[i].fDevBloatX,
584                                       draws[i].fDevBloatY, draws[i].fLineLength,
585                                       draws[i].fHalfDevStroke, draws[i].fIntervals[0],
586                                       draws[i].fIntervals[1], draws[i].fStrokeWidth,
587                                       capType, gp->getVertexStride());
588                 } else {
589                     SkPoint* verts = reinterpret_cast<SkPoint*>(vertices);
590                     SkASSERT(gp->getVertexStride() == sizeof(SkPoint));
591                     setup_dashed_rect_pos(rects[rectIndex], curVIdx, geom.fSrcRotInv, verts);
592                 }
593                 curVIdx += 4;
594             }
595             rectIndex++;
596 
597             if (draws[i].fHasStartRect) {
598                 if (fullDash) {
599                     setup_dashed_rect(rects[rectIndex], vertices, curVIdx, geom.fSrcRotInv,
600                                       draws[i].fStartOffset, draws[i].fDevBloatX,
601                                       draws[i].fDevBloatY, draws[i].fIntervals[0],
602                                       draws[i].fHalfDevStroke, draws[i].fIntervals[0],
603                                       draws[i].fIntervals[1], draws[i].fStrokeWidth, capType,
604                                       gp->getVertexStride());
605                 } else {
606                     SkPoint* verts = reinterpret_cast<SkPoint*>(vertices);
607                     SkASSERT(gp->getVertexStride() == sizeof(SkPoint));
608                     setup_dashed_rect_pos(rects[rectIndex], curVIdx, geom.fSrcRotInv, verts);
609                 }
610                 curVIdx += 4;
611             }
612             rectIndex++;
613 
614             if (draws[i].fHasEndRect) {
615                 if (fullDash) {
616                     setup_dashed_rect(rects[rectIndex], vertices, curVIdx, geom.fSrcRotInv,
617                                       draws[i].fStartOffset, draws[i].fDevBloatX,
618                                       draws[i].fDevBloatY, draws[i].fIntervals[0],
619                                       draws[i].fHalfDevStroke, draws[i].fIntervals[0],
620                                       draws[i].fIntervals[1], draws[i].fStrokeWidth, capType,
621                                       gp->getVertexStride());
622                 } else {
623                     SkPoint* verts = reinterpret_cast<SkPoint*>(vertices);
624                     SkASSERT(gp->getVertexStride() == sizeof(SkPoint));
625                     setup_dashed_rect_pos(rects[rectIndex], curVIdx, geom.fSrcRotInv, verts);
626                 }
627                 curVIdx += 4;
628             }
629             rectIndex++;
630         }
631         SkASSERT(0 == (curVIdx % 4) && (curVIdx / 4) == totalRectCount);
632         helper.recordDraw(target);
633     }
634 
onCombineIfPossible(GrBatch * t,const GrCaps & caps)635     bool onCombineIfPossible(GrBatch* t, const GrCaps& caps) override {
636         DashBatch* that = t->cast<DashBatch>();
637         if (!GrPipeline::CanCombine(*this->pipeline(), this->bounds(), *that->pipeline(),
638                                     that->bounds(), caps)) {
639             return false;
640         }
641 
642         if (this->aaMode() != that->aaMode()) {
643             return false;
644         }
645 
646         if (this->fullDash() != that->fullDash()) {
647             return false;
648         }
649 
650         if (this->cap() != that->cap()) {
651             return false;
652         }
653 
654         // TODO vertex color
655         if (this->color() != that->color()) {
656             return false;
657         }
658 
659         SkASSERT(this->usesLocalCoords() == that->usesLocalCoords());
660         if (this->usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
661             return false;
662         }
663 
664         fGeoData.push_back_n(that->geoData()->count(), that->geoData()->begin());
665         this->joinBounds(that->bounds());
666         return true;
667     }
668 
color() const669     GrColor color() const { return fBatch.fColor; }
usesLocalCoords() const670     bool usesLocalCoords() const { return fBatch.fUsesLocalCoords; }
viewMatrix() const671     const SkMatrix& viewMatrix() const { return fGeoData[0].fViewMatrix; }
aaMode() const672     DashAAMode aaMode() const { return fBatch.fAAMode; }
fullDash() const673     bool fullDash() const { return fBatch.fFullDash; }
cap() const674     SkPaint::Cap cap() const { return fBatch.fCap; }
coverageIgnored() const675     bool coverageIgnored() const { return fBatch.fCoverageIgnored; }
676 
677     struct BatchTracker {
678         GrColor fColor;
679         bool fUsesLocalCoords;
680         bool fColorIgnored;
681         bool fCoverageIgnored;
682         SkPaint::Cap fCap;
683         DashAAMode fAAMode;
684         bool fFullDash;
685     };
686 
687     static const int kVertsPerDash = 4;
688     static const int kIndicesPerDash = 6;
689 
690     BatchTracker fBatch;
691     SkSTArray<1, Geometry, true> fGeoData;
692 
693     typedef GrVertexBatch INHERITED;
694 };
695 
create_batch(GrColor color,const SkMatrix & viewMatrix,const SkPoint pts[2],bool useAA,const GrStrokeInfo & strokeInfo,bool msaaRT)696 static GrDrawBatch* create_batch(GrColor color, const SkMatrix& viewMatrix, const SkPoint pts[2],
697                                  bool useAA, const GrStrokeInfo& strokeInfo, bool msaaRT) {
698     const SkScalar* intervals = strokeInfo.getDashIntervals();
699     SkScalar phase = strokeInfo.getDashPhase();
700 
701     SkPaint::Cap cap = strokeInfo.getCap();
702 
703     DashBatch::Geometry geometry;
704     geometry.fSrcStrokeWidth = strokeInfo.getWidth();
705 
706     // the phase should be normalized to be [0, sum of all intervals)
707     SkASSERT(phase >= 0 && phase < intervals[0] + intervals[1]);
708 
709     // Rotate the src pts so they are aligned horizontally with pts[0].fX < pts[1].fX
710     if (pts[0].fY != pts[1].fY || pts[0].fX > pts[1].fX) {
711         SkMatrix rotMatrix;
712         align_to_x_axis(pts, &rotMatrix, geometry.fPtsRot);
713         if(!rotMatrix.invert(&geometry.fSrcRotInv)) {
714             SkDebugf("Failed to create invertible rotation matrix!\n");
715             return nullptr;
716         }
717     } else {
718         geometry.fSrcRotInv.reset();
719         memcpy(geometry.fPtsRot, pts, 2 * sizeof(SkPoint));
720     }
721 
722     // Scale corrections of intervals and stroke from view matrix
723     calc_dash_scaling(&geometry.fParallelScale, &geometry.fPerpendicularScale, viewMatrix,
724                       geometry.fPtsRot);
725 
726     SkScalar offInterval = intervals[1] * geometry.fParallelScale;
727     SkScalar strokeWidth = geometry.fSrcStrokeWidth * geometry.fPerpendicularScale;
728 
729     if (SkPaint::kSquare_Cap == cap && 0 != geometry.fSrcStrokeWidth) {
730         // add cap to on interveal and remove from off interval
731         offInterval -= strokeWidth;
732     }
733 
734     DashAAMode aaMode = msaaRT ? kMSAA_DashAAMode :
735                                  useAA ? kEdgeAA_DashAAMode : kBW_DashAAMode;
736 
737     // TODO we can do a real rect call if not using fulldash(ie no off interval, not using AA)
738     bool fullDash = offInterval > 0.f || aaMode != kBW_DashAAMode;
739 
740     geometry.fColor = color;
741     geometry.fViewMatrix = viewMatrix;
742     geometry.fPhase = phase;
743     geometry.fIntervals[0] = intervals[0];
744     geometry.fIntervals[1] = intervals[1];
745 
746     return DashBatch::Create(geometry, cap, aaMode, fullDash);
747 }
748 
DrawDashLine(GrDrawTarget * target,const GrPipelineBuilder & pipelineBuilder,GrColor color,const SkMatrix & viewMatrix,const SkPoint pts[2],bool useAA,const GrStrokeInfo & strokeInfo)749 bool GrDashingEffect::DrawDashLine(GrDrawTarget* target,
750                                    const GrPipelineBuilder& pipelineBuilder, GrColor color,
751                                    const SkMatrix& viewMatrix, const SkPoint pts[2],
752                                    bool useAA, const GrStrokeInfo& strokeInfo) {
753     SkAutoTUnref<GrDrawBatch> batch(
754             create_batch(color, viewMatrix, pts, useAA, strokeInfo,
755                          pipelineBuilder.getRenderTarget()->isUnifiedMultisampled()));
756     if (!batch) {
757         return false;
758     }
759 
760     target->drawBatch(pipelineBuilder, batch);
761     return true;
762 }
763 
764 //////////////////////////////////////////////////////////////////////////////
765 
766 class GLDashingCircleEffect;
767 
768 /*
769  * This effect will draw a dotted line (defined as a dashed lined with round caps and no on
770  * interval). The radius of the dots is given by the strokeWidth and the spacing by the DashInfo.
771  * Both of the previous two parameters are in device space. This effect also requires the setting of
772  * a vec2 vertex attribute for the the four corners of the bounding rect. This attribute is the
773  * "dash position" of each vertex. In other words it is the vertex coords (in device space) if we
774  * transform the line to be horizontal, with the start of line at the origin then shifted to the
775  * right by half the off interval. The line then goes in the positive x direction.
776  */
777 class DashingCircleEffect : public GrGeometryProcessor {
778 public:
779     typedef SkPathEffect::DashInfo DashInfo;
780 
781     static GrGeometryProcessor* Create(GrColor,
782                                        DashAAMode aaMode,
783                                        const SkMatrix& localMatrix,
784                                        bool usesLocalCoords);
785 
name() const786     const char* name() const override { return "DashingCircleEffect"; }
787 
inPosition() const788     const Attribute* inPosition() const { return fInPosition; }
789 
inDashParams() const790     const Attribute* inDashParams() const { return fInDashParams; }
791 
inCircleParams() const792     const Attribute* inCircleParams() const { return fInCircleParams; }
793 
aaMode() const794     DashAAMode aaMode() const { return fAAMode; }
795 
color() const796     GrColor color() const { return fColor; }
797 
colorIgnored() const798     bool colorIgnored() const { return GrColor_ILLEGAL == fColor; }
799 
localMatrix() const800     const SkMatrix& localMatrix() const { return fLocalMatrix; }
801 
usesLocalCoords() const802     bool usesLocalCoords() const { return fUsesLocalCoords; }
803 
804     void getGLSLProcessorKey(const GrGLSLCaps&, GrProcessorKeyBuilder* b) const override;
805 
806     GrGLSLPrimitiveProcessor* createGLSLInstance(const GrGLSLCaps&) const override;
807 
808 private:
809     DashingCircleEffect(GrColor, DashAAMode aaMode, const SkMatrix& localMatrix,
810                         bool usesLocalCoords);
811 
812     GrColor             fColor;
813     SkMatrix            fLocalMatrix;
814     bool                fUsesLocalCoords;
815     DashAAMode          fAAMode;
816     const Attribute*    fInPosition;
817     const Attribute*    fInDashParams;
818     const Attribute*    fInCircleParams;
819 
820     GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
821 
822     typedef GrGeometryProcessor INHERITED;
823 };
824 
825 //////////////////////////////////////////////////////////////////////////////
826 
827 class GLDashingCircleEffect : public GrGLSLGeometryProcessor {
828 public:
829     GLDashingCircleEffect();
830 
831     void onEmitCode(EmitArgs&, GrGPArgs*) override;
832 
833     static inline void GenKey(const GrGeometryProcessor&,
834                               const GrGLSLCaps&,
835                               GrProcessorKeyBuilder*);
836 
837     void setData(const GrGLSLProgramDataManager&, const GrPrimitiveProcessor&) override;
838 
setTransformData(const GrPrimitiveProcessor & primProc,const GrGLSLProgramDataManager & pdman,int index,const SkTArray<const GrCoordTransform *,true> & transforms)839     void setTransformData(const GrPrimitiveProcessor& primProc,
840                           const GrGLSLProgramDataManager& pdman,
841                           int index,
842                           const SkTArray<const GrCoordTransform*, true>& transforms) override {
843         this->setTransformDataHelper<DashingCircleEffect>(primProc, pdman, index, transforms);
844     }
845 
846 private:
847     UniformHandle fParamUniform;
848     UniformHandle fColorUniform;
849     GrColor       fColor;
850     SkScalar      fPrevRadius;
851     SkScalar      fPrevCenterX;
852     SkScalar      fPrevIntervalLength;
853     typedef GrGLSLGeometryProcessor INHERITED;
854 };
855 
GLDashingCircleEffect()856 GLDashingCircleEffect::GLDashingCircleEffect() {
857     fColor = GrColor_ILLEGAL;
858     fPrevRadius = SK_ScalarMin;
859     fPrevCenterX = SK_ScalarMin;
860     fPrevIntervalLength = SK_ScalarMax;
861 }
862 
onEmitCode(EmitArgs & args,GrGPArgs * gpArgs)863 void GLDashingCircleEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
864     const DashingCircleEffect& dce = args.fGP.cast<DashingCircleEffect>();
865     GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
866     GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
867     GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
868 
869     // emit attributes
870     varyingHandler->emitAttributes(dce);
871 
872     // XY are dashPos, Z is dashInterval
873     GrGLSLVertToFrag dashParams(kVec3f_GrSLType);
874     varyingHandler->addVarying("DashParam", &dashParams);
875     vertBuilder->codeAppendf("%s = %s;", dashParams.vsOut(), dce.inDashParams()->fName);
876 
877     // x refers to circle radius - 0.5, y refers to cicle's center x coord
878     GrGLSLVertToFrag circleParams(kVec2f_GrSLType);
879     varyingHandler->addVarying("CircleParams", &circleParams);
880     vertBuilder->codeAppendf("%s = %s;", circleParams.vsOut(), dce.inCircleParams()->fName);
881 
882     GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
883     // Setup pass through color
884     if (!dce.colorIgnored()) {
885         this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor, &fColorUniform);
886     }
887 
888     // Setup position
889     this->setupPosition(vertBuilder, gpArgs, dce.inPosition()->fName);
890 
891     // emit transforms
892     this->emitTransforms(vertBuilder,
893                          varyingHandler,
894                          uniformHandler,
895                          gpArgs->fPositionVar,
896                          dce.inPosition()->fName,
897                          dce.localMatrix(),
898                          args.fTransformsIn,
899                          args.fTransformsOut);
900 
901     // transforms all points so that we can compare them to our test circle
902     fragBuilder->codeAppendf("float xShifted = %s.x - floor(%s.x / %s.z) * %s.z;",
903                              dashParams.fsIn(), dashParams.fsIn(), dashParams.fsIn(),
904                              dashParams.fsIn());
905     fragBuilder->codeAppendf("vec2 fragPosShifted = vec2(xShifted, %s.y);", dashParams.fsIn());
906     fragBuilder->codeAppendf("vec2 center = vec2(%s.y, 0.0);", circleParams.fsIn());
907     fragBuilder->codeAppend("float dist = length(center - fragPosShifted);");
908     if (dce.aaMode() != kBW_DashAAMode) {
909         fragBuilder->codeAppendf("float diff = dist - %s.x;", circleParams.fsIn());
910         fragBuilder->codeAppend("diff = 1.0 - diff;");
911         fragBuilder->codeAppend("float alpha = clamp(diff, 0.0, 1.0);");
912     } else {
913         fragBuilder->codeAppendf("float alpha = 1.0;");
914         fragBuilder->codeAppendf("alpha *=  dist < %s.x + 0.5 ? 1.0 : 0.0;", circleParams.fsIn());
915     }
916     fragBuilder->codeAppendf("%s = vec4(alpha);", args.fOutputCoverage);
917 }
918 
setData(const GrGLSLProgramDataManager & pdman,const GrPrimitiveProcessor & processor)919 void GLDashingCircleEffect::setData(const GrGLSLProgramDataManager& pdman,
920                                     const GrPrimitiveProcessor& processor) {
921     const DashingCircleEffect& dce = processor.cast<DashingCircleEffect>();
922     if (dce.color() != fColor) {
923         float c[4];
924         GrColorToRGBAFloat(dce.color(), c);
925         pdman.set4fv(fColorUniform, 1, c);
926         fColor = dce.color();
927     }
928 }
929 
GenKey(const GrGeometryProcessor & gp,const GrGLSLCaps &,GrProcessorKeyBuilder * b)930 void GLDashingCircleEffect::GenKey(const GrGeometryProcessor& gp,
931                                    const GrGLSLCaps&,
932                                    GrProcessorKeyBuilder* b) {
933     const DashingCircleEffect& dce = gp.cast<DashingCircleEffect>();
934     uint32_t key = 0;
935     key |= dce.usesLocalCoords() && dce.localMatrix().hasPerspective() ? 0x1 : 0x0;
936     key |= dce.colorIgnored() ? 0x2 : 0x0;
937     key |= dce.aaMode() << 8;
938     b->add32(key);
939 }
940 
941 //////////////////////////////////////////////////////////////////////////////
942 
Create(GrColor color,DashAAMode aaMode,const SkMatrix & localMatrix,bool usesLocalCoords)943 GrGeometryProcessor* DashingCircleEffect::Create(GrColor color,
944                                                  DashAAMode aaMode,
945                                                  const SkMatrix& localMatrix,
946                                                  bool usesLocalCoords) {
947     return new DashingCircleEffect(color, aaMode, localMatrix, usesLocalCoords);
948 }
949 
getGLSLProcessorKey(const GrGLSLCaps & caps,GrProcessorKeyBuilder * b) const950 void DashingCircleEffect::getGLSLProcessorKey(const GrGLSLCaps& caps,
951                                               GrProcessorKeyBuilder* b) const {
952     GLDashingCircleEffect::GenKey(*this, caps, b);
953 }
954 
createGLSLInstance(const GrGLSLCaps &) const955 GrGLSLPrimitiveProcessor* DashingCircleEffect::createGLSLInstance(const GrGLSLCaps&) const {
956     return new GLDashingCircleEffect();
957 }
958 
DashingCircleEffect(GrColor color,DashAAMode aaMode,const SkMatrix & localMatrix,bool usesLocalCoords)959 DashingCircleEffect::DashingCircleEffect(GrColor color,
960                                          DashAAMode aaMode,
961                                          const SkMatrix& localMatrix,
962                                          bool usesLocalCoords)
963     : fColor(color)
964     , fLocalMatrix(localMatrix)
965     , fUsesLocalCoords(usesLocalCoords)
966     , fAAMode(aaMode) {
967     this->initClassID<DashingCircleEffect>();
968     fInPosition = &this->addVertexAttrib(Attribute("inPosition", kVec2f_GrVertexAttribType));
969     fInDashParams = &this->addVertexAttrib(Attribute("inDashParams", kVec3f_GrVertexAttribType));
970     fInCircleParams = &this->addVertexAttrib(Attribute("inCircleParams",
971                                                        kVec2f_GrVertexAttribType));
972 }
973 
974 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(DashingCircleEffect);
975 
TestCreate(GrProcessorTestData * d)976 const GrGeometryProcessor* DashingCircleEffect::TestCreate(GrProcessorTestData* d) {
977     DashAAMode aaMode = static_cast<DashAAMode>(d->fRandom->nextULessThan(kDashAAModeCount));
978     return DashingCircleEffect::Create(GrRandomColor(d->fRandom),
979                                       aaMode, GrTest::TestMatrix(d->fRandom),
980                                       d->fRandom->nextBool());
981 }
982 
983 //////////////////////////////////////////////////////////////////////////////
984 
985 class GLDashingLineEffect;
986 
987 /*
988  * This effect will draw a dashed line. The width of the dash is given by the strokeWidth and the
989  * length and spacing by the DashInfo. Both of the previous two parameters are in device space.
990  * This effect also requires the setting of a vec2 vertex attribute for the the four corners of the
991  * bounding rect. This attribute is the "dash position" of each vertex. In other words it is the
992  * vertex coords (in device space) if we transform the line to be horizontal, with the start of
993  * line at the origin then shifted to the right by half the off interval. The line then goes in the
994  * positive x direction.
995  */
996 class DashingLineEffect : public GrGeometryProcessor {
997 public:
998     typedef SkPathEffect::DashInfo DashInfo;
999 
1000     static GrGeometryProcessor* Create(GrColor,
1001                                        DashAAMode aaMode,
1002                                        const SkMatrix& localMatrix,
1003                                        bool usesLocalCoords);
1004 
name() const1005     const char* name() const override { return "DashingEffect"; }
1006 
inPosition() const1007     const Attribute* inPosition() const { return fInPosition; }
1008 
inDashParams() const1009     const Attribute* inDashParams() const { return fInDashParams; }
1010 
inRectParams() const1011     const Attribute* inRectParams() const { return fInRectParams; }
1012 
aaMode() const1013     DashAAMode aaMode() const { return fAAMode; }
1014 
color() const1015     GrColor color() const { return fColor; }
1016 
colorIgnored() const1017     bool colorIgnored() const { return GrColor_ILLEGAL == fColor; }
1018 
localMatrix() const1019     const SkMatrix& localMatrix() const { return fLocalMatrix; }
1020 
usesLocalCoords() const1021     bool usesLocalCoords() const { return fUsesLocalCoords; }
1022 
1023     void getGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override;
1024 
1025     GrGLSLPrimitiveProcessor* createGLSLInstance(const GrGLSLCaps&) const override;
1026 
1027 private:
1028     DashingLineEffect(GrColor, DashAAMode aaMode, const SkMatrix& localMatrix,
1029                       bool usesLocalCoords);
1030 
1031     GrColor             fColor;
1032     SkMatrix            fLocalMatrix;
1033     bool                fUsesLocalCoords;
1034     DashAAMode          fAAMode;
1035     const Attribute*    fInPosition;
1036     const Attribute*    fInDashParams;
1037     const Attribute*    fInRectParams;
1038 
1039     GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
1040 
1041     typedef GrGeometryProcessor INHERITED;
1042 };
1043 
1044 //////////////////////////////////////////////////////////////////////////////
1045 
1046 class GLDashingLineEffect : public GrGLSLGeometryProcessor {
1047 public:
1048     GLDashingLineEffect();
1049 
1050     void onEmitCode(EmitArgs&, GrGPArgs*) override;
1051 
1052     static inline void GenKey(const GrGeometryProcessor&,
1053                               const GrGLSLCaps&,
1054                               GrProcessorKeyBuilder*);
1055 
1056     void setData(const GrGLSLProgramDataManager&, const GrPrimitiveProcessor&) override;
1057 
setTransformData(const GrPrimitiveProcessor & primProc,const GrGLSLProgramDataManager & pdman,int index,const SkTArray<const GrCoordTransform *,true> & transforms)1058     void setTransformData(const GrPrimitiveProcessor& primProc,
1059                           const GrGLSLProgramDataManager& pdman,
1060                           int index,
1061                           const SkTArray<const GrCoordTransform*, true>& transforms) override {
1062         this->setTransformDataHelper<DashingLineEffect>(primProc, pdman, index, transforms);
1063     }
1064 
1065 private:
1066     GrColor       fColor;
1067     UniformHandle fColorUniform;
1068     typedef GrGLSLGeometryProcessor INHERITED;
1069 };
1070 
GLDashingLineEffect()1071 GLDashingLineEffect::GLDashingLineEffect() {
1072     fColor = GrColor_ILLEGAL;
1073 }
1074 
onEmitCode(EmitArgs & args,GrGPArgs * gpArgs)1075 void GLDashingLineEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
1076     const DashingLineEffect& de = args.fGP.cast<DashingLineEffect>();
1077 
1078     GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
1079     GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
1080     GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
1081 
1082     // emit attributes
1083     varyingHandler->emitAttributes(de);
1084 
1085     // XY refers to dashPos, Z is the dash interval length
1086     GrGLSLVertToFrag inDashParams(kVec3f_GrSLType);
1087     varyingHandler->addVarying("DashParams", &inDashParams, GrSLPrecision::kHigh_GrSLPrecision);
1088     vertBuilder->codeAppendf("%s = %s;", inDashParams.vsOut(), de.inDashParams()->fName);
1089 
1090     // The rect uniform's xyzw refer to (left + 0.5, top + 0.5, right - 0.5, bottom - 0.5),
1091     // respectively.
1092     GrGLSLVertToFrag inRectParams(kVec4f_GrSLType);
1093     varyingHandler->addVarying("RectParams", &inRectParams, GrSLPrecision::kHigh_GrSLPrecision);
1094     vertBuilder->codeAppendf("%s = %s;", inRectParams.vsOut(), de.inRectParams()->fName);
1095 
1096     GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
1097     // Setup pass through color
1098     if (!de.colorIgnored()) {
1099         this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor, &fColorUniform);
1100     }
1101 
1102     // Setup position
1103     this->setupPosition(vertBuilder, gpArgs, de.inPosition()->fName);
1104 
1105     // emit transforms
1106     this->emitTransforms(vertBuilder,
1107                          varyingHandler,
1108                          uniformHandler,
1109                          gpArgs->fPositionVar,
1110                          de.inPosition()->fName,
1111                          de.localMatrix(),
1112                          args.fTransformsIn,
1113                          args.fTransformsOut);
1114 
1115     // transforms all points so that we can compare them to our test rect
1116     fragBuilder->codeAppendf("float xShifted = %s.x - floor(%s.x / %s.z) * %s.z;",
1117                              inDashParams.fsIn(), inDashParams.fsIn(), inDashParams.fsIn(),
1118                              inDashParams.fsIn());
1119     fragBuilder->codeAppendf("vec2 fragPosShifted = vec2(xShifted, %s.y);", inDashParams.fsIn());
1120     if (de.aaMode() == kEdgeAA_DashAAMode) {
1121         // The amount of coverage removed in x and y by the edges is computed as a pair of negative
1122         // numbers, xSub and ySub.
1123         fragBuilder->codeAppend("float xSub, ySub;");
1124         fragBuilder->codeAppendf("xSub = min(fragPosShifted.x - %s.x, 0.0);", inRectParams.fsIn());
1125         fragBuilder->codeAppendf("xSub += min(%s.z - fragPosShifted.x, 0.0);", inRectParams.fsIn());
1126         fragBuilder->codeAppendf("ySub = min(fragPosShifted.y - %s.y, 0.0);", inRectParams.fsIn());
1127         fragBuilder->codeAppendf("ySub += min(%s.w - fragPosShifted.y, 0.0);", inRectParams.fsIn());
1128         // Now compute coverage in x and y and multiply them to get the fraction of the pixel
1129         // covered.
1130         fragBuilder->codeAppendf(
1131             "float alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));");
1132     } else if (de.aaMode() == kMSAA_DashAAMode) {
1133         // For MSAA, we don't modulate the alpha by the Y distance, since MSAA coverage will handle
1134         // AA on the the top and bottom edges. The shader is only responsible for intra-dash alpha.
1135         fragBuilder->codeAppend("float xSub;");
1136         fragBuilder->codeAppendf("xSub = min(fragPosShifted.x - %s.x, 0.0);", inRectParams.fsIn());
1137         fragBuilder->codeAppendf("xSub += min(%s.z - fragPosShifted.x, 0.0);", inRectParams.fsIn());
1138         // Now compute coverage in x to get the fraction of the pixel covered.
1139         fragBuilder->codeAppendf("float alpha = (1.0 + max(xSub, -1.0));");
1140     } else {
1141         // Assuming the bounding geometry is tight so no need to check y values
1142         fragBuilder->codeAppendf("float alpha = 1.0;");
1143         fragBuilder->codeAppendf("alpha *= (fragPosShifted.x - %s.x) > -0.5 ? 1.0 : 0.0;",
1144                                  inRectParams.fsIn());
1145         fragBuilder->codeAppendf("alpha *= (%s.z - fragPosShifted.x) >= -0.5 ? 1.0 : 0.0;",
1146                                  inRectParams.fsIn());
1147     }
1148     fragBuilder->codeAppendf("%s = vec4(alpha);", args.fOutputCoverage);
1149 }
1150 
setData(const GrGLSLProgramDataManager & pdman,const GrPrimitiveProcessor & processor)1151 void GLDashingLineEffect::setData(const GrGLSLProgramDataManager& pdman,
1152                                   const GrPrimitiveProcessor& processor) {
1153     const DashingLineEffect& de = processor.cast<DashingLineEffect>();
1154     if (de.color() != fColor) {
1155         float c[4];
1156         GrColorToRGBAFloat(de.color(), c);
1157         pdman.set4fv(fColorUniform, 1, c);
1158         fColor = de.color();
1159     }
1160 }
1161 
GenKey(const GrGeometryProcessor & gp,const GrGLSLCaps &,GrProcessorKeyBuilder * b)1162 void GLDashingLineEffect::GenKey(const GrGeometryProcessor& gp,
1163                                  const GrGLSLCaps&,
1164                                  GrProcessorKeyBuilder* b) {
1165     const DashingLineEffect& de = gp.cast<DashingLineEffect>();
1166     uint32_t key = 0;
1167     key |= de.usesLocalCoords() && de.localMatrix().hasPerspective() ? 0x1 : 0x0;
1168     key |= de.colorIgnored() ? 0x2 : 0x0;
1169     key |= de.aaMode() << 8;
1170     b->add32(key);
1171 }
1172 
1173 //////////////////////////////////////////////////////////////////////////////
1174 
Create(GrColor color,DashAAMode aaMode,const SkMatrix & localMatrix,bool usesLocalCoords)1175 GrGeometryProcessor* DashingLineEffect::Create(GrColor color,
1176                                                DashAAMode aaMode,
1177                                                const SkMatrix& localMatrix,
1178                                                bool usesLocalCoords) {
1179     return new DashingLineEffect(color, aaMode, localMatrix, usesLocalCoords);
1180 }
1181 
getGLSLProcessorKey(const GrGLSLCaps & caps,GrProcessorKeyBuilder * b) const1182 void DashingLineEffect::getGLSLProcessorKey(const GrGLSLCaps& caps,
1183                                             GrProcessorKeyBuilder* b) const {
1184     GLDashingLineEffect::GenKey(*this, caps, b);
1185 }
1186 
createGLSLInstance(const GrGLSLCaps &) const1187 GrGLSLPrimitiveProcessor* DashingLineEffect::createGLSLInstance(const GrGLSLCaps&) const {
1188     return new GLDashingLineEffect();
1189 }
1190 
DashingLineEffect(GrColor color,DashAAMode aaMode,const SkMatrix & localMatrix,bool usesLocalCoords)1191 DashingLineEffect::DashingLineEffect(GrColor color,
1192                                      DashAAMode aaMode,
1193                                      const SkMatrix& localMatrix,
1194                                      bool usesLocalCoords)
1195     : fColor(color)
1196     , fLocalMatrix(localMatrix)
1197     , fUsesLocalCoords(usesLocalCoords)
1198     , fAAMode(aaMode) {
1199     this->initClassID<DashingLineEffect>();
1200     fInPosition = &this->addVertexAttrib(Attribute("inPosition", kVec2f_GrVertexAttribType));
1201     fInDashParams = &this->addVertexAttrib(Attribute("inDashParams", kVec3f_GrVertexAttribType));
1202     fInRectParams = &this->addVertexAttrib(Attribute("inRect", kVec4f_GrVertexAttribType));
1203 }
1204 
1205 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(DashingLineEffect);
1206 
TestCreate(GrProcessorTestData * d)1207 const GrGeometryProcessor* DashingLineEffect::TestCreate(GrProcessorTestData* d) {
1208     DashAAMode aaMode = static_cast<DashAAMode>(d->fRandom->nextULessThan(kDashAAModeCount));
1209     return DashingLineEffect::Create(GrRandomColor(d->fRandom),
1210                                      aaMode, GrTest::TestMatrix(d->fRandom),
1211                                      d->fRandom->nextBool());
1212 }
1213 
1214 //////////////////////////////////////////////////////////////////////////////
1215 
create_dash_gp(GrColor color,DashAAMode dashAAMode,DashCap cap,const SkMatrix & viewMatrix,bool usesLocalCoords)1216 static GrGeometryProcessor* create_dash_gp(GrColor color,
1217                                            DashAAMode dashAAMode,
1218                                            DashCap cap,
1219                                            const SkMatrix& viewMatrix,
1220                                            bool usesLocalCoords) {
1221     SkMatrix invert;
1222     if (usesLocalCoords && !viewMatrix.invert(&invert)) {
1223         SkDebugf("Failed to invert\n");
1224         return nullptr;
1225     }
1226 
1227     switch (cap) {
1228         case kRound_DashCap:
1229             return DashingCircleEffect::Create(color, dashAAMode, invert, usesLocalCoords);
1230         case kNonRound_DashCap:
1231             return DashingLineEffect::Create(color, dashAAMode, invert, usesLocalCoords);
1232     }
1233     return nullptr;
1234 }
1235 
1236 /////////////////////////////////////////////////////////////////////////////////////////////////
1237 
1238 #ifdef GR_TEST_UTILS
1239 
DRAW_BATCH_TEST_DEFINE(DashBatch)1240 DRAW_BATCH_TEST_DEFINE(DashBatch) {
1241     GrColor color = GrRandomColor(random);
1242     SkMatrix viewMatrix = GrTest::TestMatrixPreservesRightAngles(random);
1243     bool useAA = random->nextBool();
1244     bool msaaRT = random->nextBool();
1245 
1246     // We can only dash either horizontal or vertical lines
1247     SkPoint pts[2];
1248     if (random->nextBool()) {
1249         // vertical
1250         pts[0].fX = 1.f;
1251         pts[0].fY = random->nextF() * 10.f;
1252         pts[1].fX = 1.f;
1253         pts[1].fY = random->nextF() * 10.f;
1254     } else {
1255         // horizontal
1256         pts[0].fX = random->nextF() * 10.f;
1257         pts[0].fY = 1.f;
1258         pts[1].fX = random->nextF() * 10.f;
1259         pts[1].fY = 1.f;
1260     }
1261 
1262     // pick random cap
1263     SkPaint::Cap cap = SkPaint::Cap(random->nextULessThan(SkPaint::Cap::kCapCount));
1264 
1265     SkScalar intervals[2];
1266 
1267     // We can only dash with the following intervals
1268     enum Intervals {
1269         kOpenOpen_Intervals ,
1270         kOpenClose_Intervals,
1271         kCloseOpen_Intervals,
1272     };
1273 
1274     Intervals intervalType = SkPaint::kRound_Cap ?
1275                              kOpenClose_Intervals :
1276                              Intervals(random->nextULessThan(kCloseOpen_Intervals + 1));
1277     static const SkScalar kIntervalMin = 0.1f;
1278     static const SkScalar kIntervalMax = 10.f;
1279     switch (intervalType) {
1280         case kOpenOpen_Intervals:
1281             intervals[0] = random->nextRangeScalar(kIntervalMin, kIntervalMax);
1282             intervals[1] = random->nextRangeScalar(kIntervalMin, kIntervalMax);
1283             break;
1284         case kOpenClose_Intervals:
1285             intervals[0] = 0.f;
1286             intervals[1] = random->nextRangeScalar(kIntervalMin, kIntervalMax);
1287             break;
1288         case kCloseOpen_Intervals:
1289             intervals[0] = random->nextRangeScalar(kIntervalMin, kIntervalMax);
1290             intervals[1] = 0.f;
1291             break;
1292 
1293     }
1294 
1295     // phase is 0 < sum (i0, i1)
1296     SkScalar phase = random->nextRangeScalar(0, intervals[0] + intervals[1]);
1297 
1298     SkPaint p;
1299     p.setStyle(SkPaint::kStroke_Style);
1300     p.setStrokeWidth(SkIntToScalar(1));
1301     p.setStrokeCap(cap);
1302 
1303     GrStrokeInfo strokeInfo(p);
1304 
1305     SkPathEffect::DashInfo info;
1306     info.fIntervals = intervals;
1307     info.fCount = 2;
1308     info.fPhase = phase;
1309     SkDEBUGCODE(bool success = ) strokeInfo.setDashInfo(info);
1310     SkASSERT(success);
1311 
1312     return create_batch(color, viewMatrix, pts, useAA, strokeInfo, msaaRT);
1313 }
1314 
1315 #endif
1316