// determine that slop required after quad/quad finds a candidate intersection // use the cross of the tangents plus the distance from 1 or 0 as knobs DEF_TEST(PathOpsCubicQuadSlop, reporter) { // create a random non-selfintersecting cubic // break it into quadratics // offset the quadratic, measuring the slop required to find the intersection if (!gPathOpCubicQuadSlopVerbose) { // takes a while to run -- so exclude it by default return; } int results[101]; sk_bzero(results, sizeof(results)); double minCross[101]; sk_bzero(minCross, sizeof(minCross)); double maxCross[101]; sk_bzero(maxCross, sizeof(maxCross)); double sumCross[101]; sk_bzero(sumCross, sizeof(sumCross)); int foundOne = 0; int slopCount = 1; SkRandom ran; for (int index = 0; index < 10000000; ++index) { if (index % 1000 == 999) SkDebugf("."); SkDCubic cubic = {{ {ran.nextRangeF(-1000, 1000), ran.nextRangeF(-1000, 1000)}, {ran.nextRangeF(-1000, 1000), ran.nextRangeF(-1000, 1000)}, {ran.nextRangeF(-1000, 1000), ran.nextRangeF(-1000, 1000)}, {ran.nextRangeF(-1000, 1000), ran.nextRangeF(-1000, 1000)} }}; SkIntersections i; if (i.intersect(cubic)) { continue; } SkSTArray<kCubicToQuadSubdivisionDepth, double, true> ts; cubic.toQuadraticTs(cubic.calcPrecision(), &ts); double tStart = 0; int tsCount = ts.count(); for (int i1 = 0; i1 <= tsCount; ++i1) { const double tEnd = i1 < tsCount ? ts[i1] : 1; SkDCubic part = cubic.subDivide(tStart, tEnd); SkDQuad quad = part.toQuad(); SkReduceOrder reducer; int order = reducer.reduce(quad); if (order != 3) { continue; } for (int i2 = 0; i2 < 100; ++i2) { SkDPoint endDisplacement = {ran.nextRangeF(-100, 100), ran.nextRangeF(-100, 100)}; SkDQuad nearby = {{ {quad[0].fX + endDisplacement.fX, quad[0].fY + endDisplacement.fY}, {quad[1].fX + ran.nextRangeF(-100, 100), quad[1].fY + ran.nextRangeF(-100, 100)}, {quad[2].fX - endDisplacement.fX, quad[2].fY - endDisplacement.fY} }}; order = reducer.reduce(nearby); if (order != 3) { continue; } SkIntersections locals; locals.allowNear(false); locals.intersect(quad, nearby); if (locals.used() != 1) { continue; } // brute force find actual intersection SkDLine cubicLine = {{ {0, 0}, {cubic[0].fX, cubic[0].fY } }}; SkIntersections liner; int i3; int found = -1; int foundErr = true; for (i3 = 1; i3 <= 1000; ++i3) { cubicLine[0] = cubicLine[1]; cubicLine[1] = cubic.ptAtT(i3 / 1000.); liner.reset(); liner.allowNear(false); liner.intersect(nearby, cubicLine); if (liner.used() == 0) { continue; } if (liner.used() > 1) { foundErr = true; break; } if (found > 0) { foundErr = true; break; } foundErr = false; found = i3; } if (foundErr) { continue; } SkDVector dist = liner.pt(0) - locals.pt(0); SkDVector qV = nearby.dxdyAtT(locals[0][0]); double cubicT = (found - 1 + liner[1][0]) / 1000.; SkDVector cV = cubic.dxdyAtT(cubicT); double qxc = qV.crossCheck(cV); double qvLen = qV.length(); double cvLen = cV.length(); double maxLen = SkTMax(qvLen, cvLen); qxc /= maxLen; double quadT = tStart + (tEnd - tStart) * locals[0][0]; double diffT = fabs(cubicT - quadT); int diffIdx = (int) (diffT * 100); results[diffIdx]++; double absQxc = fabs(qxc); if (sumCross[diffIdx] == 0) { minCross[diffIdx] = maxCross[diffIdx] = sumCross[diffIdx] = absQxc; } else { minCross[diffIdx] = SkTMin(minCross[diffIdx], absQxc); maxCross[diffIdx] = SkTMax(maxCross[diffIdx], absQxc); sumCross[diffIdx] += absQxc; } if (diffIdx >= 20) { #if 01 SkDebugf("cubic={{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}}}" " quad={{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}}}" " {{{%1.9g,%1.9g}, {%1.9g,%1.9g}}}" " qT=%1.9g cT=%1.9g dist=%1.9g cross=%1.9g\n", cubic[0].fX, cubic[0].fY, cubic[1].fX, cubic[1].fY, cubic[2].fX, cubic[2].fY, cubic[3].fX, cubic[3].fY, nearby[0].fX, nearby[0].fY, nearby[1].fX, nearby[1].fY, nearby[2].fX, nearby[2].fY, liner.pt(0).fX, liner.pt(0).fY, locals.pt(0).fX, locals.pt(0).fY, quadT, cubicT, dist.length(), qxc); #else SkDebugf("qT=%1.9g cT=%1.9g dist=%1.9g cross=%1.9g\n", quadT, cubicT, dist.length(), qxc); SkDebugf("<div id=\"slop%d\">\n", ++slopCount); SkDebugf("{{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}}}\n" "{{{%1.9g,%1.9g}, {%1.9g,%1.9g}, {%1.9g,%1.9g}}}\n" "{{{%1.9g,%1.9g}, {%1.9g,%1.9g}}}\n", cubic[0].fX, cubic[0].fY, cubic[1].fX, cubic[1].fY, cubic[2].fX, cubic[2].fY, cubic[3].fX, cubic[3].fY, nearby[0].fX, nearby[0].fY, nearby[1].fX, nearby[1].fY, nearby[2].fX, nearby[2].fY, liner.pt(0).fX, liner.pt(0).fY, locals.pt(0).fX, locals.pt(0).fY); SkDebugf("</div>\n\n"); #endif } ++foundOne; } tStart = tEnd; } if (++foundOne >= 100000) { break; } } #if 01 SkDebugf("slopCount=%d\n", slopCount); int max = 100; while (results[max] == 0) { --max; } for (int i = 0; i <= max; ++i) { if (i > 0 && i % 10 == 0) { SkDebugf("\n"); } SkDebugf("%d ", results[i]); } SkDebugf("min\n"); for (int i = 0; i <= max; ++i) { if (i > 0 && i % 10 == 0) { SkDebugf("\n"); } SkDebugf("%1.9g ", minCross[i]); } SkDebugf("max\n"); for (int i = 0; i <= max; ++i) { if (i > 0 && i % 10 == 0) { SkDebugf("\n"); } SkDebugf("%1.9g ", maxCross[i]); } SkDebugf("avg\n"); for (int i = 0; i <= max; ++i) { if (i > 0 && i % 10 == 0) { SkDebugf("\n"); } SkDebugf("%1.9g ", sumCross[i] / results[i]); } #else for (int i = 1; i < slopCount; ++i) { SkDebugf(" slop%d,\n", i); } #endif SkDebugf("\n"); }
bool SkOpAngle::endsIntersect(const SkOpAngle& rh) const { SkPath::Verb lVerb = fSegment->verb(); SkPath::Verb rVerb = rh.fSegment->verb(); int lPts = SkPathOpsVerbToPoints(lVerb); int rPts = SkPathOpsVerbToPoints(rVerb); SkDLine rays[] = {{{fCurvePart[0], rh.fCurvePart[rPts]}}, {{fCurvePart[0], fCurvePart[lPts]}}}; if (rays[0][1] == rays[1][1]) { return checkParallel(rh); } double smallTs[2] = {-1, -1}; bool limited[2] = {false, false}; for (int index = 0; index < 2; ++index) { const SkOpSegment& segment = index ? *rh.fSegment : *fSegment; SkIntersections i; (*CurveIntersectRay[index ? rPts : lPts])(segment.pts(), rays[index], &i); // SkASSERT(i.used() >= 1); // if (i.used() <= 1) { // continue; // } double tStart = segment.t(index ? rh.fStart : fStart); double tEnd = segment.t(index ? rh.fComputedEnd : fComputedEnd); bool testAscends = index ? rh.fStart < rh.fComputedEnd : fStart < fComputedEnd; double t = testAscends ? 0 : 1; for (int idx2 = 0; idx2 < i.used(); ++idx2) { double testT = i[0][idx2]; if (!approximately_between_orderable(tStart, testT, tEnd)) { continue; } if (approximately_equal_orderable(tStart, testT)) { continue; } smallTs[index] = t = testAscends ? SkTMax(t, testT) : SkTMin(t, testT); limited[index] = approximately_equal_orderable(t, tEnd); } } #if 0 if (smallTs[0] < 0 && smallTs[1] < 0) { // if neither ray intersects, do endpoint sort double m0xm1 = 0; if (lVerb == SkPath::kLine_Verb) { SkASSERT(rVerb != SkPath::kLine_Verb); SkDVector m0 = rays[1][1] - fCurvePart[0]; SkDPoint endPt; endPt.set(rh.fSegment->pts()[rh.fStart < rh.fEnd ? rPts : 0]); SkDVector m1 = endPt - fCurvePart[0]; m0xm1 = m0.crossCheck(m1); } if (rVerb == SkPath::kLine_Verb) { SkDPoint endPt; endPt.set(fSegment->pts()[fStart < fEnd ? lPts : 0]); SkDVector m0 = endPt - fCurvePart[0]; SkDVector m1 = rays[0][1] - fCurvePart[0]; m0xm1 = m0.crossCheck(m1); } if (m0xm1 != 0) { return m0xm1 < 0; } } #endif bool sRayLonger = false; SkDVector sCept = {0, 0}; double sCeptT = -1; int sIndex = -1; bool useIntersect = false; for (int index = 0; index < 2; ++index) { if (smallTs[index] < 0) { continue; } const SkOpSegment& segment = index ? *rh.fSegment : *fSegment; const SkDPoint& dPt = segment.dPtAtT(smallTs[index]); SkDVector cept = dPt - rays[index][0]; // If this point is on the curve, it should have been detected earlier by ordinary // curve intersection. This may be hard to determine in general, but for lines, // the point could be close to or equal to its end, but shouldn't be near the start. if ((index ? lPts : rPts) == 1) { SkDVector total = rays[index][1] - rays[index][0]; if (cept.lengthSquared() * 2 < total.lengthSquared()) { continue; } } SkDVector end = rays[index][1] - rays[index][0]; if (cept.fX * end.fX < 0 || cept.fY * end.fY < 0) { continue; } double rayDist = cept.length(); double endDist = end.length(); bool rayLonger = rayDist > endDist; if (limited[0] && limited[1] && rayLonger) { useIntersect = true; sRayLonger = rayLonger; sCept = cept; sCeptT = smallTs[index]; sIndex = index; break; } double delta = fabs(rayDist - endDist); double minX, minY, maxX, maxY; minX = minY = SK_ScalarInfinity; maxX = maxY = -SK_ScalarInfinity; const SkDCubic& curve = index ? rh.fCurvePart : fCurvePart; int ptCount = index ? rPts : lPts; for (int idx2 = 0; idx2 <= ptCount; ++idx2) { minX = SkTMin(minX, curve[idx2].fX); minY = SkTMin(minY, curve[idx2].fY); maxX = SkTMax(maxX, curve[idx2].fX); maxY = SkTMax(maxY, curve[idx2].fY); } double maxWidth = SkTMax(maxX - minX, maxY - minY); delta /= maxWidth; if (delta > 1e-4 && (useIntersect ^= true)) { // FIXME: move this magic number sRayLonger = rayLonger; sCept = cept; sCeptT = smallTs[index]; sIndex = index; } } if (useIntersect) { const SkDCubic& curve = sIndex ? rh.fCurvePart : fCurvePart; const SkOpSegment& segment = sIndex ? *rh.fSegment : *fSegment; double tStart = segment.t(sIndex ? rh.fStart : fStart); SkDVector mid = segment.dPtAtT(tStart + (sCeptT - tStart) / 2) - curve[0]; double septDir = mid.crossCheck(sCept); if (!septDir) { return checkParallel(rh); } return sRayLonger ^ (sIndex == 0) ^ (septDir < 0); } else { return checkParallel(rh); } }
static void testQuadAngles(skiatest::Reporter* reporter, const SkDQuad& quad1, const SkDQuad& quad2, int testNo, SkChunkAlloc* allocator) { SkPoint shortQuads[2][3]; SkOpContour contour; SkOpGlobalState state(NULL PATH_OPS_DEBUG_PARAMS(&contour)); contour.init(&state, false, false); makeSegment(&contour, quad1, shortQuads[0], allocator); makeSegment(&contour, quad1, shortQuads[1], allocator); SkOpSegment* seg1 = contour.first(); seg1->debugAddAngle(0, 1, allocator); SkOpSegment* seg2 = seg1->next(); seg2->debugAddAngle(0, 1, allocator); int realOverlap = PathOpsAngleTester::ConvexHullOverlaps(*seg1->debugLastAngle(), *seg2->debugLastAngle()); const SkDPoint& origin = quad1[0]; REPORTER_ASSERT(reporter, origin == quad2[0]); double a1s = atan2(origin.fY - quad1[1].fY, quad1[1].fX - origin.fX); double a1e = atan2(origin.fY - quad1[2].fY, quad1[2].fX - origin.fX); double a2s = atan2(origin.fY - quad2[1].fY, quad2[1].fX - origin.fX); double a2e = atan2(origin.fY - quad2[2].fY, quad2[2].fX - origin.fX); bool oldSchoolOverlap = radianBetween(a1s, a2s, a1e) || radianBetween(a1s, a2e, a1e) || radianBetween(a2s, a1s, a2e) || radianBetween(a2s, a1e, a2e); int overlap = quadHullsOverlap(reporter, quad1, quad2); bool realMatchesOverlap = realOverlap == overlap || SK_ScalarPI - fabs(a2s - a1s) < 0.002; if (realOverlap != overlap) { SkDebugf("\nSK_ScalarPI - fabs(a2s - a1s) = %1.9g\n", SK_ScalarPI - fabs(a2s - a1s)); } if (!realMatchesOverlap) { DumpQ(quad1, quad2, testNo); } REPORTER_ASSERT(reporter, realMatchesOverlap); if (oldSchoolOverlap != (overlap < 0)) { overlap = quadHullsOverlap(reporter, quad1, quad2); // set a breakpoint and debug if assert fires REPORTER_ASSERT(reporter, oldSchoolOverlap == (overlap < 0)); } SkDVector v1s = quad1[1] - quad1[0]; SkDVector v1e = quad1[2] - quad1[0]; SkDVector v2s = quad2[1] - quad2[0]; SkDVector v2e = quad2[2] - quad2[0]; double vDir[2] = { v1s.cross(v1e), v2s.cross(v2e) }; bool ray1In2 = v1s.cross(v2s) * vDir[1] <= 0 && v1s.cross(v2e) * vDir[1] >= 0; bool ray2In1 = v2s.cross(v1s) * vDir[0] <= 0 && v2s.cross(v1e) * vDir[0] >= 0; if (overlap >= 0) { // verify that hulls really don't overlap REPORTER_ASSERT(reporter, !ray1In2); REPORTER_ASSERT(reporter, !ray2In1); bool ctrl1In2 = v1e.cross(v2s) * vDir[1] <= 0 && v1e.cross(v2e) * vDir[1] >= 0; REPORTER_ASSERT(reporter, !ctrl1In2); bool ctrl2In1 = v2e.cross(v1s) * vDir[0] <= 0 && v2e.cross(v1e) * vDir[0] >= 0; REPORTER_ASSERT(reporter, !ctrl2In1); // check answer against reference bruteForce(reporter, quad1, quad2, overlap > 0); } // continue end point rays and see if they intersect the opposite curve SkDLine rays[] = {{{origin, quad2[2]}}, {{origin, quad1[2]}}}; const SkDQuad* quads[] = {&quad1, &quad2}; SkDVector midSpokes[2]; SkIntersections intersect[2]; double minX, minY, maxX, maxY; minX = minY = SK_ScalarInfinity; maxX = maxY = -SK_ScalarInfinity; double maxWidth = 0; bool useIntersect = false; double smallestTs[] = {1, 1}; for (unsigned index = 0; index < SK_ARRAY_COUNT(quads); ++index) { const SkDQuad& q = *quads[index]; midSpokes[index] = q.ptAtT(0.5) - origin; minX = SkTMin(SkTMin(SkTMin(minX, origin.fX), q[1].fX), q[2].fX); minY = SkTMin(SkTMin(SkTMin(minY, origin.fY), q[1].fY), q[2].fY); maxX = SkTMax(SkTMax(SkTMax(maxX, origin.fX), q[1].fX), q[2].fX); maxY = SkTMax(SkTMax(SkTMax(maxY, origin.fY), q[1].fY), q[2].fY); maxWidth = SkTMax(maxWidth, SkTMax(maxX - minX, maxY - minY)); intersect[index].intersectRay(q, rays[index]); const SkIntersections& i = intersect[index]; REPORTER_ASSERT(reporter, i.used() >= 1); bool foundZero = false; double smallT = 1; for (int idx2 = 0; idx2 < i.used(); ++idx2) { double t = i[0][idx2]; if (t == 0) { foundZero = true; continue; } if (smallT > t) { smallT = t; } } REPORTER_ASSERT(reporter, foundZero == true); if (smallT == 1) { continue; } SkDVector ray = q.ptAtT(smallT) - origin; SkDVector end = rays[index][1] - origin; if (ray.fX * end.fX < 0 || ray.fY * end.fY < 0) { continue; } double rayDist = ray.length(); double endDist = end.length(); double delta = fabs(rayDist - endDist) / maxWidth; if (delta > 1e-4) { useIntersect ^= true; } smallestTs[index] = smallT; } bool firstInside; if (useIntersect) { int sIndex = (int) (smallestTs[1] < 1); REPORTER_ASSERT(reporter, smallestTs[sIndex ^ 1] == 1); double t = smallestTs[sIndex]; const SkDQuad& q = *quads[sIndex]; SkDVector ray = q.ptAtT(t) - origin; SkDVector end = rays[sIndex][1] - origin; double rayDist = ray.length(); double endDist = end.length(); SkDVector mid = q.ptAtT(t / 2) - origin; double midXray = mid.crossCheck(ray); if (gPathOpsAngleIdeasVerbose) { SkDebugf("rayDist>endDist:%d sIndex==0:%d vDir[sIndex]<0:%d midXray<0:%d\n", rayDist > endDist, sIndex == 0, vDir[sIndex] < 0, midXray < 0); } SkASSERT(SkScalarSignAsInt(SkDoubleToScalar(midXray)) == SkScalarSignAsInt(SkDoubleToScalar(vDir[sIndex]))); firstInside = (rayDist > endDist) ^ (sIndex == 0) ^ (vDir[sIndex] < 0); } else if (overlap >= 0) { return; // answer has already been determined } else { firstInside = checkParallel(reporter, quad1, quad2); } if (overlap < 0) { SkDEBUGCODE(int realEnds =) PathOpsAngleTester::EndsIntersect(*seg1->debugLastAngle(), *seg2->debugLastAngle()); SkASSERT(realEnds == (firstInside ? 1 : 0)); }
static double flat_measure(const SkDQuad& q) { SkDVector mid = q[1] - q[0]; SkDVector dxy = q[2] - q[0]; double length = dxy.length(); // OPTIMIZE: get rid of sqrt return fabs(mid.cross(dxy) / length); }
int SkDCubic::ComplexBreak(const SkPoint pointsPtr[4], SkScalar* t) { SkDCubic cubic; cubic.set(pointsPtr); if (cubic.monotonicInX() && cubic.monotonicInY()) { return 0; } SkScalar d[3]; SkCubicType cubicType = SkClassifyCubic(pointsPtr, d); switch (cubicType) { case kLoop_SkCubicType: { // crib code from gpu path utils that finds t values where loop self-intersects // use it to find mid of t values which should be a friendly place to chop SkScalar tempSqrt = SkScalarSqrt(4.f * d[0] * d[2] - 3.f * d[1] * d[1]); SkScalar ls = d[1] - tempSqrt; SkScalar lt = 2.f * d[0]; SkScalar ms = d[1] + tempSqrt; SkScalar mt = 2.f * d[0]; if (roughly_between(0, ls, lt) && roughly_between(0, ms, mt)) { ls = ls / lt; ms = ms / mt; SkASSERT(roughly_between(0, ls, 1) && roughly_between(0, ms, 1)); t[0] = (ls + ms) / 2; SkASSERT(roughly_between(0, *t, 1)); return (int) (t[0] > 0 && t[0] < 1); } } // fall through if no t value found case kSerpentine_SkCubicType: case kCusp_SkCubicType: { double inflectionTs[2]; int infTCount = cubic.findInflections(inflectionTs); double maxCurvature[3]; int roots = cubic.findMaxCurvature(maxCurvature); #if DEBUG_CUBIC_SPLIT SkDebugf("%s\n", __FUNCTION__); cubic.dump(); for (int index = 0; index < infTCount; ++index) { SkDebugf("inflectionsTs[%d]=%1.9g ", index, inflectionTs[index]); SkDPoint pt = cubic.ptAtT(inflectionTs[index]); SkDVector dPt = cubic.dxdyAtT(inflectionTs[index]); SkDLine perp = {{pt - dPt, pt + dPt}}; perp.dump(); } for (int index = 0; index < roots; ++index) { SkDebugf("maxCurvature[%d]=%1.9g ", index, maxCurvature[index]); SkDPoint pt = cubic.ptAtT(maxCurvature[index]); SkDVector dPt = cubic.dxdyAtT(maxCurvature[index]); SkDLine perp = {{pt - dPt, pt + dPt}}; perp.dump(); } #endif if (infTCount == 2) { for (int index = 0; index < roots; ++index) { if (between(inflectionTs[0], maxCurvature[index], inflectionTs[1])) { t[0] = maxCurvature[index]; return (int) (t[0] > 0 && t[0] < 1); } } } else { int resultCount = 0; // FIXME: constant found through experimentation -- maybe there's a better way.... double precision = cubic.calcPrecision() * 2; for (int index = 0; index < roots; ++index) { double testT = maxCurvature[index]; if (0 >= testT || testT >= 1) { continue; } // don't call dxdyAtT since we want (0,0) results SkDVector dPt = { derivative_at_t(&cubic.fPts[0].fX, testT), derivative_at_t(&cubic.fPts[0].fY, testT) }; double dPtLen = dPt.length(); if (dPtLen < precision) { t[resultCount++] = testT; } } if (!resultCount && infTCount == 1) { t[0] = inflectionTs[0]; resultCount = (int) (t[0] > 0 && t[0] < 1); } return resultCount; } } default: ; } return 0; }