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Fatline clipping: remove old fatline code. This is handled by the CurveIntersections method now

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hkrish 2013-12-09 19:30:03 +01:00
parent 6041b2b09d
commit 35acebb91d
1 changed files with 24 additions and 91 deletions
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115
src/path/Curve.js
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@ -1311,108 +1311,41 @@ new function() { // Scope for methods that require numerical integration
tmaxNew = tmax * clip_tmax + tmin * (1 - clip_tmax); tmaxNew = tmax * clip_tmax + tmin * (1 - clip_tmax);
// Check if we need to subdivide the curves // Check if we need to subdivide the curves
if (oldTdiff > 0.8 && tDiff > 0.8) if (oldTdiff > 0.8 && tDiff > 0.8)
if (tmaxNew - tminNew > umax - umin) { // Subdivide the curve which has converged the least.
if (tmaxNew-tminNew > umax-umin) {
var parts = Curve.subdivide(v1New, 0.5), t = tminNew+(tmaxNew-tminNew)/2;
addCurveIntersections(v2, parts[0], curve2, curve1, locations,
umin, umax, tminNew, t, tDiff, !reverse, recursion+1);
addCurveIntersections(v2, parts[1], curve2, curve1, locations,
umin, umax, t, tmaxNew, tDiff, !reverse, recursion+1);
} else { } else {
var parts = Curve.subdivide(v2, 0.5), t = umin+(umax-umin)/2;
addCurveIntersections(parts[0], v1New, curve2, curve1, locations,
umin, t, tminNew, tmaxNew, tDiff, !reverse, recursion+1);
addCurveIntersections(parts[1], v1New, curve2, curve1, locations,
t, umax, tminNew, tmaxNew, tDiff, !reverse, recursion+1);
} }
else if (Math.max(umax - umin, tmaxNew - tminNew) < Numerical.TOLERANCE) else if (Math.max(umax-umin, tmaxNew-tminNew) < Numerical.TOLERANCE)
// We have isolated the intersection with sufficient precision // We have isolated the intersection with sufficient precision
if (reverse){ if (reverse){
var t1 = umin+(umax-umin)/2,
t2 = tminNew+(tmaxNew-tminNew)/2;
addLocation(locations,
curve2, t1, Curve.evaluate(v2, t1, 0),
curve1, t2, Curve.evaluate(v1, t2, 0));
} else { } else {
var t1 = tminNew+(tmaxNew-tminNew)/2,
t2 = umin+(umax-umin)/2;
addLocation(locations,
curve1, t1, Curve.evaluate(v1, t1, 0),
curve2, t2, Curve.evaluate(v2, t2, 0));
} }
else // Iterate else // Iterate
addCurveIntersections(v2, v1, curve2, curve1, locations, addCurveIntersections(v2, v1New, curve2, curve1, locations,
umin, umax, tminNew, tmaxNew, tDiff, !reverse, recursion); umin, umax, tminNew, tmaxNew, tDiff, !reverse, recursion);
} }
/*#*/ if (__options.fatline) { /*#*/ if (__options.fatline) {
/**
* Clip curve V2 with fat-line of v1
* @param {Array} v1 section of the first curve, for which we will make a
* fat-line
* @param {Array} v2 section of the second curve; we will clip this curve
* with the fat-line of v1
* @param {Array} range2 the parameter range of v2
* @return {Number} 0: no Intersection, 1: one or more intersection
*/
function clipFatLine(v1, v2, tRangeV2) {
function clipCHull(hull_top, hull_bottom, dmin, dmax) {
var tProxy, tVal = null, i, li, px, py, qx, qy;
for (i = 0, li = hull_bottom.length-1; i < li; i++) {
py = hull_bottom[i][1];
qy = hull_bottom[i+1][1];
if (py < qy)
tProxy = null;
else if (qy <= dmax) {
px = hull_bottom[i][0];
qx = hull_bottom[i+1][0];
tProxy = px + (dmax - py) * (qx - px) / (qy - py);
} else
// Try the next chain
continue;
// We got a proxy-t;
break;
}
if (hull_top[0][1] <= dmax)
tProxy = hull_top[0][0];
for (i = 0, li = hull_top.length-1; i < li; i++) {
py = hull_top[i][1];
qy = hull_top[i+1][1];
if (py >= dmin)
tVal = tProxy;
else if (py > qy)
tVal = null;
else if (qy >= dmin) {
px = hull_top[i][0];
qx = hull_top[i+1][0];
tVal = px + (dmin - py) * (qx - px) / (qy - py);
} else
continue;
break;
}
return tVal;
}
// Let P be the first curve and Q be the second
var p0x = v1[0], p0y = v1[1], p3x = v1[6], p3y = v1[7],
getSignedDistance = Line.getSignedDistance,
// Calculate the fat-line L for P is the baseline l and two
// offsets which completely encloses the curve P.
d1 = getSignedDistance(p0x, p0y, p3x, p3y, v1[2], v1[3]) || 0,
d2 = getSignedDistance(p0x, p0y, p3x, p3y, v1[4], v1[5]) || 0,
factor = d1 * d2 > 0 ? 3 / 4 : 4 / 9,
dmin = factor * Math.min(0, d1, d2),
dmax = factor * Math.max(0, d1, d2),
// Calculate non-parametric bezier curve D(ti, di(t)) - di(t) is the
// distance of Q from the baseline l of the fat-line, ti is equally
// spaced in [0, 1]
dq0 = getSignedDistance(p0x, p0y, p3x, p3y, v2[0], v2[1]),
dq1 = getSignedDistance(p0x, p0y, p3x, p3y, v2[2], v2[3]),
dq2 = getSignedDistance(p0x, p0y, p3x, p3y, v2[4], v2[5]),
dq3 = getSignedDistance(p0x, p0y, p3x, p3y, v2[6], v2[7]);
// Get the top and bottom parts of the convex-hull
var hull = getConvexHull(dq0, dq1, dq2, dq3),
top = hull[0], bottom = hull[1], tmin, tmax;
tmin = clipCHull(top, bottom, dmin, dmax);
top.reverse();
bottom.reverse();
tmax = clipCHull(top, bottom, dmin, dmax);
// No intersections if one of the tvalues are null
if(tmin == null || tmax == null)
return 0;
// tmin and tmax are within the range (0, 1). We need to project it
// to the original parameter range for v2.
var v2tmin = tRangeV2[0],
tdiff = tRangeV2[1] - v2tmin;
tRangeV2[0] = v2tmin + tmin * tdiff;
tRangeV2[1] = v2tmin + tmax * tdiff;
return 1;
}
/** /**
* Calculate the convex hull for the non-paramertic bezier curve D(ti, di(t)) * Calculate the convex hull for the non-paramertic bezier curve D(ti, di(t))
* The ti is equally spaced across [0..1] — [0, 1/3, 2/3, 1] for * The ti is equally spaced across [0..1] — [0, 1/3, 2/3, 1] for