| /* | |
| * Copyright 2011 Google Inc. | |
| * | |
| * Use of this source code is governed by a BSD-style license that can be | |
| * found in the LICENSE file. | |
| */ | |
| #include "GrAAHairLinePathRenderer.h" | |
| #include "GrBuffer.h" | |
| #include "GrCaps.h" | |
| #include "GrClip.h" | |
| #include "GrDefaultGeoProcFactory.h" | |
| #include "GrDrawOpTest.h" | |
| #include "GrOpFlushState.h" | |
| #include "GrPathUtils.h" | |
| #include "GrProcessor.h" | |
| #include "GrResourceProvider.h" | |
| #include "GrShape.h" | |
| #include "GrSimpleMeshDrawOpHelper.h" | |
| #include "GrStyle.h" | |
| #include "SkGeometry.h" | |
| #include "SkMatrixPriv.h" | |
| #include "SkPoint3.h" | |
| #include "SkPointPriv.h" | |
| #include "SkRectPriv.h" | |
| #include "SkStroke.h" | |
| #include "SkTemplates.h" | |
| #include "effects/GrBezierEffect.h" | |
| #include "ops/GrMeshDrawOp.h" | |
| #define PREALLOC_PTARRAY(N) SkSTArray<(N),SkPoint, true> | |
| // quadratics are rendered as 5-sided polys in order to bound the | |
| // AA stroke around the center-curve. See comments in push_quad_index_buffer and | |
| // bloat_quad. Quadratics and conics share an index buffer | |
| // lines are rendered as: | |
| // *______________* | |
| // |\ -_______ /| | |
| // | \ \ / | | |
| // | *--------* | | |
| // | / ______/ \ | | |
| // */_-__________\* | |
| // For: 6 vertices and 18 indices (for 6 triangles) | |
| // Each quadratic is rendered as a five sided polygon. This poly bounds | |
| // the quadratic's bounding triangle but has been expanded so that the | |
| // 1-pixel wide area around the curve is inside the poly. | |
| // If a,b,c are the original control points then the poly a0,b0,c0,c1,a1 | |
| // that is rendered would look like this: | |
| // b0 | |
| // b | |
| // | |
| // a0 c0 | |
| // a c | |
| // a1 c1 | |
| // Each is drawn as three triangles ((a0,a1,b0), (b0,c1,c0), (a1,c1,b0)) | |
| // specified by these 9 indices: | |
| static const uint16_t kQuadIdxBufPattern[] = { | |
| 0, 1, 2, | |
| 2, 4, 3, | |
| 1, 4, 2 | |
| }; | |
| static const int kIdxsPerQuad = SK_ARRAY_COUNT(kQuadIdxBufPattern); | |
| static const int kQuadNumVertices = 5; | |
| static const int kQuadsNumInIdxBuffer = 256; | |
| GR_DECLARE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey); | |
| static sk_sp<const GrBuffer> get_quads_index_buffer(GrResourceProvider* resourceProvider) { | |
| GR_DEFINE_STATIC_UNIQUE_KEY(gQuadsIndexBufferKey); | |
| return resourceProvider->findOrCreatePatternedIndexBuffer( | |
| kQuadIdxBufPattern, kIdxsPerQuad, kQuadsNumInIdxBuffer, kQuadNumVertices, | |
| gQuadsIndexBufferKey); | |
| } | |
| // Each line segment is rendered as two quads and two triangles. | |
| // p0 and p1 have alpha = 1 while all other points have alpha = 0. | |
| // The four external points are offset 1 pixel perpendicular to the | |
| // line and half a pixel parallel to the line. | |
| // | |
| // p4 p5 | |
| // p0 p1 | |
| // p2 p3 | |
| // | |
| // Each is drawn as six triangles specified by these 18 indices: | |
| static const uint16_t kLineSegIdxBufPattern[] = { | |
| 0, 1, 3, | |
| 0, 3, 2, | |
| 0, 4, 5, | |
| 0, 5, 1, | |
| 0, 2, 4, | |
| 1, 5, 3 | |
| }; | |
| static const int kIdxsPerLineSeg = SK_ARRAY_COUNT(kLineSegIdxBufPattern); | |
| static const int kLineSegNumVertices = 6; | |
| static const int kLineSegsNumInIdxBuffer = 256; | |
| GR_DECLARE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey); | |
| static sk_sp<const GrBuffer> get_lines_index_buffer(GrResourceProvider* resourceProvider) { | |
| GR_DEFINE_STATIC_UNIQUE_KEY(gLinesIndexBufferKey); | |
| return resourceProvider->findOrCreatePatternedIndexBuffer( | |
| kLineSegIdxBufPattern, kIdxsPerLineSeg, kLineSegsNumInIdxBuffer, kLineSegNumVertices, | |
| gLinesIndexBufferKey); | |
| } | |
| // Takes 178th time of logf on Z600 / VC2010 | |
| static int get_float_exp(float x) { | |
| GR_STATIC_ASSERT(sizeof(int) == sizeof(float)); | |
| #ifdef SK_DEBUG | |
| static bool tested; | |
| if (!tested) { | |
| tested = true; | |
| SkASSERT(get_float_exp(0.25f) == -2); | |
| SkASSERT(get_float_exp(0.3f) == -2); | |
| SkASSERT(get_float_exp(0.5f) == -1); | |
| SkASSERT(get_float_exp(1.f) == 0); | |
| SkASSERT(get_float_exp(2.f) == 1); | |
| SkASSERT(get_float_exp(2.5f) == 1); | |
| SkASSERT(get_float_exp(8.f) == 3); | |
| SkASSERT(get_float_exp(100.f) == 6); | |
| SkASSERT(get_float_exp(1000.f) == 9); | |
| SkASSERT(get_float_exp(1024.f) == 10); | |
| SkASSERT(get_float_exp(3000000.f) == 21); | |
| } | |
| #endif | |
| const int* iptr = (const int*)&x; | |
| return (((*iptr) & 0x7f800000) >> 23) - 127; | |
| } | |
| // Uses the max curvature function for quads to estimate | |
| // where to chop the conic. If the max curvature is not | |
| // found along the curve segment it will return 1 and | |
| // dst[0] is the original conic. If it returns 2 the dst[0] | |
| // and dst[1] are the two new conics. | |
| static int split_conic(const SkPoint src[3], SkConic dst[2], const SkScalar weight) { | |
| SkScalar t = SkFindQuadMaxCurvature(src); | |
| if (t == 0 || t == 1) { | |
| if (dst) { | |
| dst[0].set(src, weight); | |
| } | |
| return 1; | |
| } else { | |
| if (dst) { | |
| SkConic conic; | |
| conic.set(src, weight); | |
| if (!conic.chopAt(t, dst)) { | |
| dst[0].set(src, weight); | |
| return 1; | |
| } | |
| } | |
| return 2; | |
| } | |
| } | |
| // Calls split_conic on the entire conic and then once more on each subsection. | |
| // Most cases will result in either 1 conic (chop point is not within t range) | |
| // or 3 points (split once and then one subsection is split again). | |
| static int chop_conic(const SkPoint src[3], SkConic dst[4], const SkScalar weight) { | |
| SkConic dstTemp[2]; | |
| int conicCnt = split_conic(src, dstTemp, weight); | |
| if (2 == conicCnt) { | |
| int conicCnt2 = split_conic(dstTemp[0].fPts, dst, dstTemp[0].fW); | |
| conicCnt = conicCnt2 + split_conic(dstTemp[1].fPts, &dst[conicCnt2], dstTemp[1].fW); | |
| } else { | |
| dst[0] = dstTemp[0]; | |
| } | |
| return conicCnt; | |
| } | |
| // returns 0 if quad/conic is degen or close to it | |
| // in this case approx the path with lines | |
| // otherwise returns 1 | |
| static int is_degen_quad_or_conic(const SkPoint p[3], SkScalar* dsqd) { | |
| static const SkScalar gDegenerateToLineTol = GrPathUtils::kDefaultTolerance; | |
| static const SkScalar gDegenerateToLineTolSqd = | |
| gDegenerateToLineTol * gDegenerateToLineTol; | |
| if (SkPointPriv::DistanceToSqd(p[0], p[1]) < gDegenerateToLineTolSqd || | |
| SkPointPriv::DistanceToSqd(p[1], p[2]) < gDegenerateToLineTolSqd) { | |
| return 1; | |
| } | |
| *dsqd = SkPointPriv::DistanceToLineBetweenSqd(p[1], p[0], p[2]); | |
| if (*dsqd < gDegenerateToLineTolSqd) { | |
| return 1; | |
| } | |
| if (SkPointPriv::DistanceToLineBetweenSqd(p[2], p[1], p[0]) < gDegenerateToLineTolSqd) { | |
| return 1; | |
| } | |
| return 0; | |
| } | |
| static int is_degen_quad_or_conic(const SkPoint p[3]) { | |
| SkScalar dsqd; | |
| return is_degen_quad_or_conic(p, &dsqd); | |
| } | |
| // we subdivide the quads to avoid huge overfill | |
| // if it returns -1 then should be drawn as lines | |
| static int num_quad_subdivs(const SkPoint p[3]) { | |
| SkScalar dsqd; | |
| if (is_degen_quad_or_conic(p, &dsqd)) { | |
| return -1; | |
| } | |
| // tolerance of triangle height in pixels | |
| // tuned on windows Quadro FX 380 / Z600 | |
| // trade off of fill vs cpu time on verts | |
| // maybe different when do this using gpu (geo or tess shaders) | |
| static const SkScalar gSubdivTol = 175 * SK_Scalar1; | |
| if (dsqd <= gSubdivTol * gSubdivTol) { | |
| return 0; | |
| } else { | |
| static const int kMaxSub = 4; | |
| // subdividing the quad reduces d by 4. so we want x = log4(d/tol) | |
| // = log4(d*d/tol*tol)/2 | |
| // = log2(d*d/tol*tol) | |
| // +1 since we're ignoring the mantissa contribution. | |
| int log = get_float_exp(dsqd/(gSubdivTol*gSubdivTol)) + 1; | |
| log = SkTMin(SkTMax(0, log), kMaxSub); | |
| return log; | |
| } | |
| } | |
| /** | |
| * Generates the lines and quads to be rendered. Lines are always recorded in | |
| * device space. We will do a device space bloat to account for the 1pixel | |
| * thickness. | |
| * Quads are recorded in device space unless m contains | |
| * perspective, then in they are in src space. We do this because we will | |
| * subdivide large quads to reduce over-fill. This subdivision has to be | |
| * performed before applying the perspective matrix. | |
| */ | |
| static int gather_lines_and_quads(const SkPath& path, | |
| const SkMatrix& m, | |
| const SkIRect& devClipBounds, | |
| SkScalar capLength, | |
| bool convertConicsToQuads, | |
| GrAAHairLinePathRenderer::PtArray* lines, | |
| GrAAHairLinePathRenderer::PtArray* quads, | |
| GrAAHairLinePathRenderer::PtArray* conics, | |
| GrAAHairLinePathRenderer::IntArray* quadSubdivCnts, | |
| GrAAHairLinePathRenderer::FloatArray* conicWeights) { | |
| SkPath::Iter iter(path, false); | |
| int totalQuadCount = 0; | |
| SkRect bounds; | |
| SkIRect ibounds; | |
| bool persp = m.hasPerspective(); | |
| // Whenever a degenerate, zero-length contour is encountered, this code will insert a | |
| // 'capLength' x-aligned line segment. Since this is rendering hairlines it is hoped this will | |
| // suffice for AA square & circle capping. | |
| int verbsInContour = 0; // Does not count moves | |
| bool seenZeroLengthVerb = false; | |
| SkPoint zeroVerbPt; | |
| // Adds a quad that has already been chopped to the list and checks for quads that are close to | |
| // lines. Also does a bounding box check. It takes points that are in src space and device | |
| // space. The src points are only required if the view matrix has perspective. | |
| auto addChoppedQuad = [&](const SkPoint srcPts[3], const SkPoint devPts[4], | |
| bool isContourStart) { | |
| SkRect bounds; | |
| SkIRect ibounds; | |
| bounds.setBounds(devPts, 3); | |
| bounds.outset(SK_Scalar1, SK_Scalar1); | |
| bounds.roundOut(&ibounds); | |
| // We only need the src space space pts when not in perspective. | |
| SkASSERT(srcPts || !persp); | |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { | |
| int subdiv = num_quad_subdivs(devPts); | |
| SkASSERT(subdiv >= -1); | |
| if (-1 == subdiv) { | |
| SkPoint* pts = lines->push_back_n(4); | |
| pts[0] = devPts[0]; | |
| pts[1] = devPts[1]; | |
| pts[2] = devPts[1]; | |
| pts[3] = devPts[2]; | |
| if (isContourStart && pts[0] == pts[1] && pts[2] == pts[3]) { | |
| seenZeroLengthVerb = true; | |
| zeroVerbPt = pts[0]; | |
| } | |
| } else { | |
| // when in perspective keep quads in src space | |
| const SkPoint* qPts = persp ? srcPts : devPts; | |
| SkPoint* pts = quads->push_back_n(3); | |
| pts[0] = qPts[0]; | |
| pts[1] = qPts[1]; | |
| pts[2] = qPts[2]; | |
| quadSubdivCnts->push_back() = subdiv; | |
| totalQuadCount += 1 << subdiv; | |
| } | |
| } | |
| }; | |
| // Applies the view matrix to quad src points and calls the above helper. | |
| auto addSrcChoppedQuad = [&](const SkPoint srcSpaceQuadPts[3], bool isContourStart) { | |
| SkPoint devPts[3]; | |
| m.mapPoints(devPts, srcSpaceQuadPts, 3); | |
| addChoppedQuad(srcSpaceQuadPts, devPts, isContourStart); | |
| }; | |
| for (;;) { | |
| SkPoint pathPts[4]; | |
| SkPath::Verb verb = iter.next(pathPts, false); | |
| switch (verb) { | |
| case SkPath::kConic_Verb: | |
| if (convertConicsToQuads) { | |
| SkScalar weight = iter.conicWeight(); | |
| SkAutoConicToQuads converter; | |
| const SkPoint* quadPts = converter.computeQuads(pathPts, weight, 0.25f); | |
| for (int i = 0; i < converter.countQuads(); ++i) { | |
| addSrcChoppedQuad(quadPts + 2 * i, !verbsInContour && 0 == i); | |
| } | |
| } else { | |
| SkConic dst[4]; | |
| // We chop the conics to create tighter clipping to hide error | |
| // that appears near max curvature of very thin conics. Thin | |
| // hyperbolas with high weight still show error. | |
| int conicCnt = chop_conic(pathPts, dst, iter.conicWeight()); | |
| for (int i = 0; i < conicCnt; ++i) { | |
| SkPoint devPts[4]; | |
| SkPoint* chopPnts = dst[i].fPts; | |
| m.mapPoints(devPts, chopPnts, 3); | |
| bounds.setBounds(devPts, 3); | |
| bounds.outset(SK_Scalar1, SK_Scalar1); | |
| bounds.roundOut(&ibounds); | |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { | |
| if (is_degen_quad_or_conic(devPts)) { | |
| SkPoint* pts = lines->push_back_n(4); | |
| pts[0] = devPts[0]; | |
| pts[1] = devPts[1]; | |
| pts[2] = devPts[1]; | |
| pts[3] = devPts[2]; | |
| if (verbsInContour == 0 && i == 0 && pts[0] == pts[1] && | |
| pts[2] == pts[3]) { | |
| seenZeroLengthVerb = true; | |
| zeroVerbPt = pts[0]; | |
| } | |
| } else { | |
| // when in perspective keep conics in src space | |
| SkPoint* cPts = persp ? chopPnts : devPts; | |
| SkPoint* pts = conics->push_back_n(3); | |
| pts[0] = cPts[0]; | |
| pts[1] = cPts[1]; | |
| pts[2] = cPts[2]; | |
| conicWeights->push_back() = dst[i].fW; | |
| } | |
| } | |
| } | |
| } | |
| verbsInContour++; | |
| break; | |
| case SkPath::kMove_Verb: | |
| // New contour (and last one was unclosed). If it was just a zero length drawing | |
| // operation, and we're supposed to draw caps, then add a tiny line. | |
| if (seenZeroLengthVerb && verbsInContour == 1 && capLength > 0) { | |
| SkPoint* pts = lines->push_back_n(2); | |
| pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY); | |
| pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY); | |
| } | |
| verbsInContour = 0; | |
| seenZeroLengthVerb = false; | |
| break; | |
| case SkPath::kLine_Verb: { | |
| SkPoint devPts[2]; | |
| m.mapPoints(devPts, pathPts, 2); | |
| bounds.setBounds(devPts, 2); | |
| bounds.outset(SK_Scalar1, SK_Scalar1); | |
| bounds.roundOut(&ibounds); | |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { | |
| SkPoint* pts = lines->push_back_n(2); | |
| pts[0] = devPts[0]; | |
| pts[1] = devPts[1]; | |
| if (verbsInContour == 0 && pts[0] == pts[1]) { | |
| seenZeroLengthVerb = true; | |
| zeroVerbPt = pts[0]; | |
| } | |
| } | |
| verbsInContour++; | |
| break; | |
| } | |
| case SkPath::kQuad_Verb: { | |
| SkPoint choppedPts[5]; | |
| // Chopping the quad helps when the quad is either degenerate or nearly degenerate. | |
| // When it is degenerate it allows the approximation with lines to work since the | |
| // chop point (if there is one) will be at the parabola's vertex. In the nearly | |
| // degenerate the QuadUVMatrix computed for the points is almost singular which | |
| // can cause rendering artifacts. | |
| int n = SkChopQuadAtMaxCurvature(pathPts, choppedPts); | |
| for (int i = 0; i < n; ++i) { | |
| addSrcChoppedQuad(choppedPts + i * 2, !verbsInContour && 0 == i); | |
| } | |
| verbsInContour++; | |
| break; | |
| } | |
| case SkPath::kCubic_Verb: { | |
| SkPoint devPts[4]; | |
| m.mapPoints(devPts, pathPts, 4); | |
| bounds.setBounds(devPts, 4); | |
| bounds.outset(SK_Scalar1, SK_Scalar1); | |
| bounds.roundOut(&ibounds); | |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { | |
| PREALLOC_PTARRAY(32) q; | |
| // We convert cubics to quadratics (for now). | |
| // In perspective have to do conversion in src space. | |
| if (persp) { | |
| SkScalar tolScale = | |
| GrPathUtils::scaleToleranceToSrc(SK_Scalar1, m, path.getBounds()); | |
| GrPathUtils::convertCubicToQuads(pathPts, tolScale, &q); | |
| } else { | |
| GrPathUtils::convertCubicToQuads(devPts, SK_Scalar1, &q); | |
| } | |
| for (int i = 0; i < q.count(); i += 3) { | |
| if (persp) { | |
| addSrcChoppedQuad(&q[i], !verbsInContour && 0 == i); | |
| } else { | |
| addChoppedQuad(nullptr, &q[i], !verbsInContour && 0 == i); | |
| } | |
| } | |
| } | |
| verbsInContour++; | |
| break; | |
| } | |
| case SkPath::kClose_Verb: | |
| // Contour is closed, so we don't need to grow the starting line, unless it's | |
| // *just* a zero length subpath. (SVG Spec 11.4, 'stroke'). | |
| if (capLength > 0) { | |
| if (seenZeroLengthVerb && verbsInContour == 1) { | |
| SkPoint* pts = lines->push_back_n(2); | |
| pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY); | |
| pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY); | |
| } else if (verbsInContour == 0) { | |
| // Contour was (moveTo, close). Add a line. | |
| SkPoint devPts[2]; | |
| m.mapPoints(devPts, pathPts, 1); | |
| devPts[1] = devPts[0]; | |
| bounds.setBounds(devPts, 2); | |
| bounds.outset(SK_Scalar1, SK_Scalar1); | |
| bounds.roundOut(&ibounds); | |
| if (SkIRect::Intersects(devClipBounds, ibounds)) { | |
| SkPoint* pts = lines->push_back_n(2); | |
| pts[0] = SkPoint::Make(devPts[0].fX - capLength, devPts[0].fY); | |
| pts[1] = SkPoint::Make(devPts[1].fX + capLength, devPts[1].fY); | |
| } | |
| } | |
| } | |
| break; | |
| case SkPath::kDone_Verb: | |
| if (seenZeroLengthVerb && verbsInContour == 1 && capLength > 0) { | |
| // Path ended with a dangling (moveTo, line|quad|etc). If the final verb is | |
| // degenerate, we need to draw a line. | |
| SkPoint* pts = lines->push_back_n(2); | |
| pts[0] = SkPoint::Make(zeroVerbPt.fX - capLength, zeroVerbPt.fY); | |
| pts[1] = SkPoint::Make(zeroVerbPt.fX + capLength, zeroVerbPt.fY); | |
| } | |
| return totalQuadCount; | |
| } | |
| } | |
| } | |
| struct LineVertex { | |
| SkPoint fPos; | |
| float fCoverage; | |
| }; | |
| struct BezierVertex { | |
| SkPoint fPos; | |
| union { | |
| struct { | |
| SkScalar fKLM[3]; | |
| } fConic; | |
| SkVector fQuadCoord; | |
| struct { | |
| SkScalar fBogus[4]; | |
| }; | |
| }; | |
| }; | |
| GR_STATIC_ASSERT(sizeof(BezierVertex) == 3 * sizeof(SkPoint)); | |
| static void intersect_lines(const SkPoint& ptA, const SkVector& normA, | |
| const SkPoint& ptB, const SkVector& normB, | |
| SkPoint* result) { | |
| SkScalar lineAW = -normA.dot(ptA); | |
| SkScalar lineBW = -normB.dot(ptB); | |
| SkScalar wInv = normA.fX * normB.fY - normA.fY * normB.fX; | |
| wInv = SkScalarInvert(wInv); | |
| if (!SkScalarIsFinite(wInv)) { | |
| // lines are parallel, pick the point in between | |
| *result = (ptA + ptB)*SK_ScalarHalf; | |
| *result += normA; | |
| } else { | |
| result->fX = normA.fY * lineBW - lineAW * normB.fY; | |
| result->fX *= wInv; | |
| result->fY = lineAW * normB.fX - normA.fX * lineBW; | |
| result->fY *= wInv; | |
| } | |
| } | |
| static void set_uv_quad(const SkPoint qpts[3], BezierVertex verts[kQuadNumVertices]) { | |
| // this should be in the src space, not dev coords, when we have perspective | |
| GrPathUtils::QuadUVMatrix DevToUV(qpts); | |
| DevToUV.apply(verts, kQuadNumVertices, sizeof(BezierVertex), sizeof(SkPoint)); | |
| } | |
| static void bloat_quad(const SkPoint qpts[3], const SkMatrix* toDevice, | |
| const SkMatrix* toSrc, BezierVertex verts[kQuadNumVertices]) { | |
| SkASSERT(!toDevice == !toSrc); | |
| // original quad is specified by tri a,b,c | |
| SkPoint a = qpts[0]; | |
| SkPoint b = qpts[1]; | |
| SkPoint c = qpts[2]; | |
| if (toDevice) { | |
| toDevice->mapPoints(&a, 1); | |
| toDevice->mapPoints(&b, 1); | |
| toDevice->mapPoints(&c, 1); | |
| } | |
| // make a new poly where we replace a and c by a 1-pixel wide edges orthog | |
| // to edges ab and bc: | |
| // | |
| // before | after | |
| // | b0 | |
| // b | | |
| // | | |
| // | a0 c0 | |
| // a c | a1 c1 | |
| // | |
| // edges a0->b0 and b0->c0 are parallel to original edges a->b and b->c, | |
| // respectively. | |
| BezierVertex& a0 = verts[0]; | |
| BezierVertex& a1 = verts[1]; | |
| BezierVertex& b0 = verts[2]; | |
| BezierVertex& c0 = verts[3]; | |
| BezierVertex& c1 = verts[4]; | |
| SkVector ab = b; | |
| ab -= a; | |
| SkVector ac = c; | |
| ac -= a; | |
| SkVector cb = b; | |
| cb -= c; | |
| // After the transform we might have a line, try to do something reasonable | |
| if (toDevice && SkPointPriv::LengthSqd(ab) <= SK_ScalarNearlyZero*SK_ScalarNearlyZero) { | |
| ab = cb; | |
| } | |
| if (toDevice && SkPointPriv::LengthSqd(cb) <= SK_ScalarNearlyZero*SK_ScalarNearlyZero) { | |
| cb = ab; | |
| } | |
| // We should have already handled degenerates | |
| SkASSERT(toDevice || (ab.length() > 0 && cb.length() > 0)); | |
| ab.normalize(); | |
| SkVector abN = SkPointPriv::MakeOrthog(ab, SkPointPriv::kLeft_Side); | |
| if (abN.dot(ac) > 0) { | |
| abN.negate(); | |
| } | |
| cb.normalize(); | |
| SkVector cbN = SkPointPriv::MakeOrthog(cb, SkPointPriv::kLeft_Side); | |
| if (cbN.dot(ac) < 0) { | |
| cbN.negate(); | |
| } | |
| a0.fPos = a; | |
| a0.fPos += abN; | |
| a1.fPos = a; | |
| a1.fPos -= abN; | |
| if (toDevice && SkPointPriv::LengthSqd(ac) <= SK_ScalarNearlyZero*SK_ScalarNearlyZero) { | |
| c = b; | |
| } | |
| c0.fPos = c; | |
| c0.fPos += cbN; | |
| c1.fPos = c; | |
| c1.fPos -= cbN; | |
| intersect_lines(a0.fPos, abN, c0.fPos, cbN, &b0.fPos); | |
| if (toSrc) { | |
| SkMatrixPriv::MapPointsWithStride(*toSrc, &verts[0].fPos, sizeof(BezierVertex), | |
| kQuadNumVertices); | |
| } | |
| } | |
| // Equations based off of Loop-Blinn Quadratic GPU Rendering | |
| // Input Parametric: | |
| // 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) | |
| // Output Implicit: | |
| // f(x, y, w) = f(P) = K^2 - LM | |
| // K = dot(k, P), L = dot(l, P), M = dot(m, P) | |
| // k, l, m are calculated in function GrPathUtils::getConicKLM | |
| static void set_conic_coeffs(const SkPoint p[3], BezierVertex verts[kQuadNumVertices], | |
| const SkScalar weight) { | |
| SkMatrix klm; | |
| GrPathUtils::getConicKLM(p, weight, &klm); | |
| for (int i = 0; i < kQuadNumVertices; ++i) { | |
| const SkPoint3 pt3 = {verts[i].fPos.x(), verts[i].fPos.y(), 1.f}; | |
| klm.mapHomogeneousPoints((SkPoint3* ) verts[i].fConic.fKLM, &pt3, 1); | |
| } | |
| } | |
| static void add_conics(const SkPoint p[3], | |
| const SkScalar weight, | |
| const SkMatrix* toDevice, | |
| const SkMatrix* toSrc, | |
| BezierVertex** vert) { | |
| bloat_quad(p, toDevice, toSrc, *vert); | |
| set_conic_coeffs(p, *vert, weight); | |
| *vert += kQuadNumVertices; | |
| } | |
| static void add_quads(const SkPoint p[3], | |
| int subdiv, | |
| const SkMatrix* toDevice, | |
| const SkMatrix* toSrc, | |
| BezierVertex** vert) { | |
| SkASSERT(subdiv >= 0); | |
| if (subdiv) { | |
| SkPoint newP[5]; | |
| SkChopQuadAtHalf(p, newP); | |
| add_quads(newP + 0, subdiv-1, toDevice, toSrc, vert); | |
| add_quads(newP + 2, subdiv-1, toDevice, toSrc, vert); | |
| } else { | |
| bloat_quad(p, toDevice, toSrc, *vert); | |
| set_uv_quad(p, *vert); | |
| *vert += kQuadNumVertices; | |
| } | |
| } | |
| static void add_line(const SkPoint p[2], | |
| const SkMatrix* toSrc, | |
| uint8_t coverage, | |
| LineVertex** vert) { | |
| const SkPoint& a = p[0]; | |
| const SkPoint& b = p[1]; | |
| SkVector ortho, vec = b; | |
| vec -= a; | |
| SkScalar lengthSqd = SkPointPriv::LengthSqd(vec); | |
| if (vec.setLength(SK_ScalarHalf)) { | |
| // Create a vector orthogonal to 'vec' and of unit length | |
| ortho.fX = 2.0f * vec.fY; | |
| ortho.fY = -2.0f * vec.fX; | |
| float floatCoverage = GrNormalizeByteToFloat(coverage); | |
| if (lengthSqd >= 1.0f) { | |
| // Relative to points a and b: | |
| // The inner vertices are inset half a pixel along the line a,b | |
| (*vert)[0].fPos = a + vec; | |
| (*vert)[0].fCoverage = floatCoverage; | |
| (*vert)[1].fPos = b - vec; | |
| (*vert)[1].fCoverage = floatCoverage; | |
| } else { | |
| // The inner vertices are inset a distance of length(a,b) from the outer edge of | |
| // geometry. For the "a" inset this is the same as insetting from b by half a pixel. | |
| // The coverage is then modulated by the length. This gives us the correct | |
| // coverage for rects shorter than a pixel as they get translated subpixel amounts | |
| // inside of a pixel. | |
| SkScalar length = SkScalarSqrt(lengthSqd); | |
| (*vert)[0].fPos = b - vec; | |
| (*vert)[0].fCoverage = floatCoverage * length; | |
| (*vert)[1].fPos = a + vec; | |
| (*vert)[1].fCoverage = floatCoverage * length; | |
| } | |
| // Relative to points a and b: | |
| // The outer vertices are outset half a pixel along the line a,b and then a whole pixel | |
| // orthogonally. | |
| (*vert)[2].fPos = a - vec + ortho; | |
| (*vert)[2].fCoverage = 0; | |
| (*vert)[3].fPos = b + vec + ortho; | |
| (*vert)[3].fCoverage = 0; | |
| (*vert)[4].fPos = a - vec - ortho; | |
| (*vert)[4].fCoverage = 0; | |
| (*vert)[5].fPos = b + vec - ortho; | |
| (*vert)[5].fCoverage = 0; | |
| if (toSrc) { | |
| SkMatrixPriv::MapPointsWithStride(*toSrc, &(*vert)->fPos, sizeof(LineVertex), | |
| kLineSegNumVertices); | |
| } | |
| } else { | |
| // just make it degenerate and likely offscreen | |
| for (int i = 0; i < kLineSegNumVertices; ++i) { | |
| (*vert)[i].fPos.set(SK_ScalarMax, SK_ScalarMax); | |
| } | |
| } | |
| *vert += kLineSegNumVertices; | |
| } | |
| /////////////////////////////////////////////////////////////////////////////// | |
| GrPathRenderer::CanDrawPath | |
| GrAAHairLinePathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const { | |
| if (!(AATypeFlags::kCoverage & args.fAATypeFlags)) { | |
| return CanDrawPath::kNo; | |
| } | |
| if (!IsStrokeHairlineOrEquivalent(args.fShape->style(), *args.fViewMatrix, nullptr)) { | |
| return CanDrawPath::kNo; | |
| } | |
| // We don't currently handle dashing in this class though perhaps we should. | |
| if (args.fShape->style().pathEffect()) { | |
| return CanDrawPath::kNo; | |
| } | |
| if (SkPath::kLine_SegmentMask == args.fShape->segmentMask() || | |
| args.fCaps->shaderCaps()->shaderDerivativeSupport()) { | |
| return CanDrawPath::kYes; | |
| } | |
| return CanDrawPath::kNo; | |
| } | |
| template <class VertexType> | |
| bool check_bounds(const SkMatrix& viewMatrix, const SkRect& devBounds, void* vertices, int vCount) | |
| { | |
| SkRect tolDevBounds = devBounds; | |
| // The bounds ought to be tight, but in perspective the below code runs the verts | |
| // through the view matrix to get back to dev coords, which can introduce imprecision. | |
| if (viewMatrix.hasPerspective()) { | |
| tolDevBounds.outset(SK_Scalar1 / 1000, SK_Scalar1 / 1000); | |
| } else { | |
| // Non-persp matrices cause this path renderer to draw in device space. | |
| SkASSERT(viewMatrix.isIdentity()); | |
| } | |
| SkRect actualBounds; | |
| VertexType* verts = reinterpret_cast<VertexType*>(vertices); | |
| bool first = true; | |
| for (int i = 0; i < vCount; ++i) { | |
| SkPoint pos = verts[i].fPos; | |
| // This is a hack to workaround the fact that we move some degenerate segments offscreen. | |
| if (SK_ScalarMax == pos.fX) { | |
| continue; | |
| } | |
| viewMatrix.mapPoints(&pos, 1); | |
| if (first) { | |
| actualBounds.set(pos.fX, pos.fY, pos.fX, pos.fY); | |
| first = false; | |
| } else { | |
| SkRectPriv::GrowToInclude(&actualBounds, pos); | |
| } | |
| } | |
| if (!first) { | |
| return tolDevBounds.contains(actualBounds); | |
| } | |
| return true; | |
| } | |
| namespace { | |
| class AAHairlineOp final : public GrMeshDrawOp { | |
| private: | |
| using Helper = GrSimpleMeshDrawOpHelperWithStencil; | |
| public: | |
| DEFINE_OP_CLASS_ID | |
| static std::unique_ptr<GrDrawOp> Make(GrRecordingContext* context, | |
| GrPaint&& paint, | |
| const SkMatrix& viewMatrix, | |
| const SkPath& path, | |
| const GrStyle& style, | |
| const SkIRect& devClipBounds, | |
| const GrUserStencilSettings* stencilSettings) { | |
| SkScalar hairlineCoverage; | |
| uint8_t newCoverage = 0xff; | |
| if (GrPathRenderer::IsStrokeHairlineOrEquivalent(style, viewMatrix, &hairlineCoverage)) { | |
| newCoverage = SkScalarRoundToInt(hairlineCoverage * 0xff); | |
| } | |
| const SkStrokeRec& stroke = style.strokeRec(); | |
| SkScalar capLength = SkPaint::kButt_Cap != stroke.getCap() ? hairlineCoverage * 0.5f : 0.0f; | |
| return Helper::FactoryHelper<AAHairlineOp>(context, std::move(paint), newCoverage, | |
| viewMatrix, path, | |
| devClipBounds, capLength, stencilSettings); | |
| } | |
| AAHairlineOp(const Helper::MakeArgs& helperArgs, | |
| const SkPMColor4f& color, | |
| uint8_t coverage, | |
| const SkMatrix& viewMatrix, | |
| const SkPath& path, | |
| SkIRect devClipBounds, | |
| SkScalar capLength, | |
| const GrUserStencilSettings* stencilSettings) | |
| : INHERITED(ClassID()) | |
| , fHelper(helperArgs, GrAAType::kCoverage, stencilSettings) | |
| , fColor(color) | |
| , fCoverage(coverage) { | |
| fPaths.emplace_back(PathData{viewMatrix, path, devClipBounds, capLength}); | |
| this->setTransformedBounds(path.getBounds(), viewMatrix, HasAABloat::kYes, | |
| IsZeroArea::kYes); | |
| } | |
| const char* name() const override { return "AAHairlineOp"; } | |
| void visitProxies(const VisitProxyFunc& func, VisitorType) const override { | |
| fHelper.visitProxies(func); | |
| } | |
| #ifdef SK_DEBUG | |
| SkString dumpInfo() const override { | |
| SkString string; | |
| string.appendf("Color: 0x%08x Coverage: 0x%02x, Count: %d\n", fColor.toBytes_RGBA(), | |
| fCoverage, fPaths.count()); | |
| string += INHERITED::dumpInfo(); | |
| string += fHelper.dumpInfo(); | |
| return string; | |
| } | |
| #endif | |
| FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); } | |
| GrProcessorSet::Analysis finalize(const GrCaps& caps, const GrAppliedClip* clip, | |
| GrFSAAType fsaaType, GrClampType clampType) override { | |
| // This Op uses uniform (not vertex) color, so doesn't need to track wide color. | |
| return fHelper.finalizeProcessors(caps, clip, fsaaType, clampType, | |
| GrProcessorAnalysisCoverage::kSingleChannel, &fColor, | |
| nullptr); | |
| } | |
| private: | |
| void onPrepareDraws(Target*) override; | |
| void onExecute(GrOpFlushState*, const SkRect& chainBounds) override; | |
| typedef SkTArray<SkPoint, true> PtArray; | |
| typedef SkTArray<int, true> IntArray; | |
| typedef SkTArray<float, true> FloatArray; | |
| CombineResult onCombineIfPossible(GrOp* t, const GrCaps& caps) override { | |
| AAHairlineOp* that = t->cast<AAHairlineOp>(); | |
| if (!fHelper.isCompatible(that->fHelper, caps, this->bounds(), that->bounds())) { | |
| return CombineResult::kCannotCombine; | |
| } | |
| if (this->viewMatrix().hasPerspective() != that->viewMatrix().hasPerspective()) { | |
| return CombineResult::kCannotCombine; | |
| } | |
| // We go to identity if we don't have perspective | |
| if (this->viewMatrix().hasPerspective() && | |
| !this->viewMatrix().cheapEqualTo(that->viewMatrix())) { | |
| return CombineResult::kCannotCombine; | |
| } | |
| // TODO we can actually combine hairlines if they are the same color in a kind of bulk | |
| // method but we haven't implemented this yet | |
| // TODO investigate going to vertex color and coverage? | |
| if (this->coverage() != that->coverage()) { | |
| return CombineResult::kCannotCombine; | |
| } | |
| if (this->color() != that->color()) { | |
| return CombineResult::kCannotCombine; | |
| } | |
| if (fHelper.usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) { | |
| return CombineResult::kCannotCombine; | |
| } | |
| fPaths.push_back_n(that->fPaths.count(), that->fPaths.begin()); | |
| return CombineResult::kMerged; | |
| } | |
| const SkPMColor4f& color() const { return fColor; } | |
| uint8_t coverage() const { return fCoverage; } | |
| const SkMatrix& viewMatrix() const { return fPaths[0].fViewMatrix; } | |
| struct PathData { | |
| SkMatrix fViewMatrix; | |
| SkPath fPath; | |
| SkIRect fDevClipBounds; | |
| SkScalar fCapLength; | |
| }; | |
| SkSTArray<1, PathData, true> fPaths; | |
| Helper fHelper; | |
| SkPMColor4f fColor; | |
| uint8_t fCoverage; | |
| typedef GrMeshDrawOp INHERITED; | |
| }; | |
| } // anonymous namespace | |
| void AAHairlineOp::onPrepareDraws(Target* target) { | |
| // Setup the viewmatrix and localmatrix for the GrGeometryProcessor. | |
| SkMatrix invert; | |
| if (!this->viewMatrix().invert(&invert)) { | |
| return; | |
| } | |
| // we will transform to identity space if the viewmatrix does not have perspective | |
| bool hasPerspective = this->viewMatrix().hasPerspective(); | |
| const SkMatrix* geometryProcessorViewM = &SkMatrix::I(); | |
| const SkMatrix* geometryProcessorLocalM = &invert; | |
| const SkMatrix* toDevice = nullptr; | |
| const SkMatrix* toSrc = nullptr; | |
| if (hasPerspective) { | |
| geometryProcessorViewM = &this->viewMatrix(); | |
| geometryProcessorLocalM = &SkMatrix::I(); | |
| toDevice = &this->viewMatrix(); | |
| toSrc = &invert; | |
| } | |
| // This is hand inlined for maximum performance. | |
| PREALLOC_PTARRAY(128) lines; | |
| PREALLOC_PTARRAY(128) quads; | |
| PREALLOC_PTARRAY(128) conics; | |
| IntArray qSubdivs; | |
| FloatArray cWeights; | |
| int quadCount = 0; | |
| int instanceCount = fPaths.count(); | |
| bool convertConicsToQuads = !target->caps().shaderCaps()->floatIs32Bits(); | |
| for (int i = 0; i < instanceCount; i++) { | |
| const PathData& args = fPaths[i]; | |
| quadCount += gather_lines_and_quads(args.fPath, args.fViewMatrix, args.fDevClipBounds, | |
| args.fCapLength, convertConicsToQuads, &lines, &quads, | |
| &conics, &qSubdivs, &cWeights); | |
| } | |
| int lineCount = lines.count() / 2; | |
| int conicCount = conics.count() / 3; | |
| int quadAndConicCount = conicCount + quadCount; | |
| static constexpr int kMaxLines = SK_MaxS32 / kLineSegNumVertices; | |
| static constexpr int kMaxQuadsAndConics = SK_MaxS32 / kQuadNumVertices; | |
| if (lineCount > kMaxLines || quadAndConicCount > kMaxQuadsAndConics) { | |
| return; | |
| } | |
| // do lines first | |
| if (lineCount) { | |
| sk_sp<GrGeometryProcessor> lineGP; | |
| { | |
| using namespace GrDefaultGeoProcFactory; | |
| Color color(this->color()); | |
| LocalCoords localCoords(fHelper.usesLocalCoords() ? LocalCoords::kUsePosition_Type | |
| : LocalCoords::kUnused_Type); | |
| localCoords.fMatrix = geometryProcessorLocalM; | |
| lineGP = GrDefaultGeoProcFactory::Make(target->caps().shaderCaps(), | |
| color, Coverage::kAttribute_Type, localCoords, | |
| *geometryProcessorViewM); | |
| } | |
| sk_sp<const GrBuffer> linesIndexBuffer = get_lines_index_buffer(target->resourceProvider()); | |
| sk_sp<const GrBuffer> vertexBuffer; | |
| int firstVertex; | |
| SkASSERT(sizeof(LineVertex) == lineGP->vertexStride()); | |
| int vertexCount = kLineSegNumVertices * lineCount; | |
| LineVertex* verts = reinterpret_cast<LineVertex*>(target->makeVertexSpace( | |
| sizeof(LineVertex), vertexCount, &vertexBuffer, &firstVertex)); | |
| if (!verts|| !linesIndexBuffer) { | |
| SkDebugf("Could not allocate vertices\n"); | |
| return; | |
| } | |
| for (int i = 0; i < lineCount; ++i) { | |
| add_line(&lines[2*i], toSrc, this->coverage(), &verts); | |
| } | |
| GrMesh* mesh = target->allocMesh(GrPrimitiveType::kTriangles); | |
| mesh->setIndexedPatterned(std::move(linesIndexBuffer), kIdxsPerLineSeg, kLineSegNumVertices, | |
| lineCount, kLineSegsNumInIdxBuffer); | |
| mesh->setVertexData(std::move(vertexBuffer), firstVertex); | |
| target->recordDraw(std::move(lineGP), mesh); | |
| } | |
| if (quadCount || conicCount) { | |
| sk_sp<GrGeometryProcessor> quadGP(GrQuadEffect::Make(this->color(), | |
| *geometryProcessorViewM, | |
| GrClipEdgeType::kHairlineAA, | |
| target->caps(), | |
| *geometryProcessorLocalM, | |
| fHelper.usesLocalCoords(), | |
| this->coverage())); | |
| sk_sp<GrGeometryProcessor> conicGP(GrConicEffect::Make(this->color(), | |
| *geometryProcessorViewM, | |
| GrClipEdgeType::kHairlineAA, | |
| target->caps(), | |
| *geometryProcessorLocalM, | |
| fHelper.usesLocalCoords(), | |
| this->coverage())); | |
| sk_sp<const GrBuffer> vertexBuffer; | |
| int firstVertex; | |
| sk_sp<const GrBuffer> quadsIndexBuffer = get_quads_index_buffer(target->resourceProvider()); | |
| SkASSERT(sizeof(BezierVertex) == quadGP->vertexStride()); | |
| SkASSERT(sizeof(BezierVertex) == conicGP->vertexStride()); | |
| int vertexCount = kQuadNumVertices * quadAndConicCount; | |
| void* vertices = target->makeVertexSpace(sizeof(BezierVertex), vertexCount, &vertexBuffer, | |
| &firstVertex); | |
| if (!vertices || !quadsIndexBuffer) { | |
| SkDebugf("Could not allocate vertices\n"); | |
| return; | |
| } | |
| // Setup vertices | |
| BezierVertex* bezVerts = reinterpret_cast<BezierVertex*>(vertices); | |
| int unsubdivQuadCnt = quads.count() / 3; | |
| for (int i = 0; i < unsubdivQuadCnt; ++i) { | |
| SkASSERT(qSubdivs[i] >= 0); | |
| add_quads(&quads[3*i], qSubdivs[i], toDevice, toSrc, &bezVerts); | |
| } | |
| // Start Conics | |
| for (int i = 0; i < conicCount; ++i) { | |
| add_conics(&conics[3*i], cWeights[i], toDevice, toSrc, &bezVerts); | |
| } | |
| if (quadCount > 0) { | |
| GrMesh* mesh = target->allocMesh(GrPrimitiveType::kTriangles); | |
| mesh->setIndexedPatterned(quadsIndexBuffer, kIdxsPerQuad, kQuadNumVertices, quadCount, | |
| kQuadsNumInIdxBuffer); | |
| mesh->setVertexData(vertexBuffer, firstVertex); | |
| target->recordDraw(std::move(quadGP), mesh); | |
| firstVertex += quadCount * kQuadNumVertices; | |
| } | |
| if (conicCount > 0) { | |
| GrMesh* mesh = target->allocMesh(GrPrimitiveType::kTriangles); | |
| mesh->setIndexedPatterned(std::move(quadsIndexBuffer), kIdxsPerQuad, kQuadNumVertices, | |
| conicCount, kQuadsNumInIdxBuffer); | |
| mesh->setVertexData(std::move(vertexBuffer), firstVertex); | |
| target->recordDraw(std::move(conicGP), mesh); | |
| } | |
| } | |
| } | |
| void AAHairlineOp::onExecute(GrOpFlushState* flushState, const SkRect& chainBounds) { | |
| fHelper.executeDrawsAndUploads(this, flushState, chainBounds); | |
| } | |
| bool GrAAHairLinePathRenderer::onDrawPath(const DrawPathArgs& args) { | |
| GR_AUDIT_TRAIL_AUTO_FRAME(args.fRenderTargetContext->auditTrail(), | |
| "GrAAHairlinePathRenderer::onDrawPath"); | |
| SkASSERT(GrFSAAType::kUnifiedMSAA != args.fRenderTargetContext->fsaaType()); | |
| SkIRect devClipBounds; | |
| args.fClip->getConservativeBounds(args.fRenderTargetContext->width(), | |
| args.fRenderTargetContext->height(), | |
| &devClipBounds); | |
| SkPath path; | |
| args.fShape->asPath(&path); | |
| std::unique_ptr<GrDrawOp> op = | |
| AAHairlineOp::Make(args.fContext, std::move(args.fPaint), *args.fViewMatrix, path, | |
| args.fShape->style(), devClipBounds, args.fUserStencilSettings); | |
| args.fRenderTargetContext->addDrawOp(*args.fClip, std::move(op)); | |
| return true; | |
| } | |
| /////////////////////////////////////////////////////////////////////////////////////////////////// | |
| #if GR_TEST_UTILS | |
| GR_DRAW_OP_TEST_DEFINE(AAHairlineOp) { | |
| SkMatrix viewMatrix = GrTest::TestMatrix(random); | |
| SkPath path = GrTest::TestPath(random); | |
| SkIRect devClipBounds; | |
| devClipBounds.setEmpty(); | |
| return AAHairlineOp::Make(context, std::move(paint), viewMatrix, path, | |
| GrStyle::SimpleHairline(), devClipBounds, | |
| GrGetRandomStencil(random, context)); | |
| } | |
| #endif |