static bool is_linear_inner(const SkDQuad& q1, double t1s, double t1e, const SkDQuad& q2, double t2s, double t2e, SkIntersections* i, bool* subDivide) { SkDQuad hull = q1.subDivide(t1s, t1e); SkDLine line = {{hull[2], hull[0]}}; const SkDLine* testLines[] = { &line, (const SkDLine*) &hull[0], (const SkDLine*) &hull[1] }; const size_t kTestCount = SK_ARRAY_COUNT(testLines); SkSTArray<kTestCount * 2, double, true> tsFound; for (size_t index = 0; index < kTestCount; ++index) { SkIntersections rootTs; rootTs.allowNear(false); int roots = rootTs.intersect(q2, *testLines[index]); for (int idx2 = 0; idx2 < roots; ++idx2) { double t = rootTs[0][idx2]; #if 0 // def SK_DEBUG // FIXME : accurate for error = 16, error of 17.5 seen // {{{136.08723965397621, 1648.2814535211637}, {593.49031197259478, 1190.8784277439891}, {593.49031197259478, 544.0128173828125}}} // {{{-968.181396484375, 544.0128173828125}, {592.2825927734375, 870.552490234375}, {593.435302734375, 557.8828125}}} SkDPoint qPt = q2.ptAtT(t); SkDPoint lPt = testLines[index]->ptAtT(rootTs[1][idx2]); SkASSERT(qPt.approximatelyDEqual(lPt)); #endif if (approximately_negative(t - t2s) || approximately_positive(t - t2e)) { continue; } tsFound.push_back(rootTs[0][idx2]); } } int tCount = tsFound.count(); if (tCount <= 0) { return true; } double tMin, tMax; if (tCount == 1) { tMin = tMax = tsFound[0]; } else { SkASSERT(tCount > 1); SkTQSort<double>(tsFound.begin(), tsFound.end() - 1); tMin = tsFound[0]; tMax = tsFound[tsFound.count() - 1]; } SkDPoint end = q2.ptAtT(t2s); bool startInTriangle = hull.pointInHull(end); if (startInTriangle) { tMin = t2s; } end = q2.ptAtT(t2e); bool endInTriangle = hull.pointInHull(end); if (endInTriangle) { tMax = t2e; } int split = 0; SkDVector dxy1, dxy2; if (tMin != tMax || tCount > 2) { dxy2 = q2.dxdyAtT(tMin); for (int index = 1; index < tCount; ++index) { dxy1 = dxy2; dxy2 = q2.dxdyAtT(tsFound[index]); double dot = dxy1.dot(dxy2); if (dot < 0) { split = index - 1; break; } } } if (split == 0) { // there's one point if (add_intercept(q1, q2, tMin, tMax, i, subDivide)) { return true; } i->swap(); return is_linear_inner(q2, tMin, tMax, q1, t1s, t1e, i, subDivide); } // At this point, we have two ranges of t values -- treat each separately at the split bool result; if (add_intercept(q1, q2, tMin, tsFound[split - 1], i, subDivide)) { result = true; } else { i->swap(); result = is_linear_inner(q2, tMin, tsFound[split - 1], q1, t1s, t1e, i, subDivide); } if (add_intercept(q1, q2, tsFound[split], tMax, i, subDivide)) { result = true; } else { i->swap(); result |= is_linear_inner(q2, tsFound[split], tMax, q1, t1s, t1e, i, subDivide); } return result; }