double SkDLine::nearPoint(const SkDPoint& xy) const { if (!AlmostBetweenUlps(fPts[0].fX, xy.fX, fPts[1].fX) || !AlmostBetweenUlps(fPts[0].fY, xy.fY, fPts[1].fY)) { return -1; } // project a perpendicular ray from the point to the line; find the T on the line SkDVector len = fPts[1] - fPts[0]; // the x/y magnitudes of the line double denom = len.fX * len.fX + len.fY * len.fY; // see DLine intersectRay SkDVector ab0 = xy - fPts[0]; double numer = len.fX * ab0.fX + ab0.fY * len.fY; if (!between(0, numer, denom)) { return -1; } double t = numer / denom; SkDPoint realPt = ptAtT(t); double dist = realPt.distance(xy); // OPTIMIZATION: can we compare against distSq instead ? // find the ordinal in the original line with the largest unsigned exponent double tiniest = SkTMin(SkTMin(SkTMin(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY); double largest = SkTMax(SkTMax(SkTMax(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY); largest = SkTMax(largest, -tiniest); if (!AlmostEqualUlps(largest, largest + dist)) { // is the dist within ULPS tolerance? return -1; } t = SkPinT(t); SkASSERT(between(0, t, 1)); return t; }
bool SkDLine::nearRay(const SkDPoint& xy) const { // project a perpendicular ray from the point to the line; find the T on the line SkDVector len = fPts[1] - fPts[0]; // the x/y magnitudes of the line double denom = len.fX * len.fX + len.fY * len.fY; // see DLine intersectRay SkDVector ab0 = xy - fPts[0]; double numer = len.fX * ab0.fX + ab0.fY * len.fY; double t = numer / denom; SkDPoint realPt = ptAtT(t); double dist = realPt.distance(xy); // OPTIMIZATION: can we compare against distSq instead ? // find the ordinal in the original line with the largest unsigned exponent double tiniest = SkTMin(SkTMin(SkTMin(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY); double largest = SkTMax(SkTMax(SkTMax(fPts[0].fX, fPts[0].fY), fPts[1].fX), fPts[1].fY); largest = SkTMax(largest, -tiniest); return RoughlyEqualUlps(largest, largest + dist); // is the dist within ULPS tolerance? }
static void pointFinder(const SkDQuad& q1, const SkDQuad& q2) { for (int index = 0; index < 3; ++index) { double t = q1.nearestT(q2[index]); SkDPoint onQuad = q1.ptAtT(t); SkDebugf("%s t=%1.9g (%1.9g,%1.9g) dist=%1.9g\n", __FUNCTION__, t, onQuad.fX, onQuad.fY, onQuad.distance(q2[index])); double left[3]; left[0] = ((const SkDLine&) q1[0]).isLeft(q2[index]); left[1] = ((const SkDLine&) q1[1]).isLeft(q2[index]); SkDLine diag = {{q1[0], q1[2]}}; left[2] = diag.isLeft(q2[index]); SkDebugf("%s left=(%d, %d, %d) inHull=%s\n", __FUNCTION__, floatSign(left[0]), floatSign(left[1]), floatSign(left[2]), q1.pointInHull(q2[index]) ? "true" : "false"); } SkDebugf("\n"); }