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Always use parameter in getCurveLineIntersection() by flipping curve1 / 2 values as well.

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This commit is contained in:
Jürg Lehni 2013-05-24 19:53:30 -07:00
parent d964ca3496
commit 26d79e6c16
1 changed files with 31 additions and 31 deletions
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62
fatline/Intersect.js
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@ -386,38 +386,37 @@ function getSignedDistance(a1x, a1y, a2x, a2y, bx, by) {
* because of Numerical class. We can rotate the curve and line so that the line
* is on X axis, and solve the implicit equations for X axis and the curve
*/
function _getCurveLineIntersection(v1, v2, curve1, curve2, locations, _other) {
var vc = v1,
vl = v2;
if (_other === undefined)
_other = Curve.isLinear(v1);
if (_other) {
vl = v1;
vc = v2;
}
var l1x = vl[0], l1y = vl[1],
l2x = vl[6], l2y = vl[7];
// rotate both the curve and line around l1 so that line is on x axis
var lvx = l2x - l1x,
lvy = l2y - l1y;
// Angle with x axis (1, 0)
var angle = Math.atan2(-lvy, lvx),
sina = Math.sin(angle),
cosa = Math.cos(angle);
// Rotated line and curve values
// (rl1x, rl1y) = (0, 0)
var rl2x = lvx * cosa - lvy * sina,
rl2y = lvy * cosa + lvx * sina;
// Rotate the curve so the line is horizontal
var vcr = [];
function _getCurveLineIntersection(v1, v2, curve1, curve2, locations, _flip) {
if (_flip === undefined)
_flip = Curve.isLinear(v1);
var vc = _flip ? v2 : v1,
vl = _flip ? v1 : v2,
l1x = vl[0], l1y = vl[1],
l2x = vl[6], l2y = vl[7],
// Rotate both the curve and line around l1 so that line is on x axis
lvx = l2x - l1x,
lvy = l2y - l1y,
// Angle with x axis (1, 0)
angle = Math.atan2(-lvy, lvx),
sin = Math.sin(angle),
cos = Math.cos(angle),
// (rl1x, rl1y) = (0, 0)
rl2x = lvx * cos - lvy * sin,
rl2y = lvy * cos + lvx * sin,
vcr = [];
for(var i = 0; i < 8; i += 2) {
var x = vc[i] - l1x,
y = vc[i + 1] - l1y;
vcr.push(x * cosa - y * sina, y * cosa + x * sina);
vcr.push(
x * cos - y * sin,
y * cos + x * sin);
}
var rootsvcr = [];
var i = Curve.solveCubic(vcr, 1, 0, roots);
while (i--) {
var roots = [],
count = Curve.solveCubic(vcr, 1, 0, roots);
// NOTE: i could theoretically be -1 for inifnite solutions, although that
// should only happen with lines, in which case we should not be here.
for (var i = 0; i < count; i++) {
var t = roots[i];
if (t >= 0 && t <= 1) {
var point = Curve.evaluate(vcr, t, true, 0);
@ -426,13 +425,14 @@ function _getCurveLineIntersection(v1, v2, curve1, curve2, locations, _other) {
if (point.x >= 0 && point.x <= rl2x) {
// The actual intersection point
point = Curve.evaluate(vc, t, true, 0);
if (_other)
t = null;
var first = locations[0],
last = locations[locations.length - 1];
if ((!first || !point.equals(first._point))
&& (!last || !point.equals(last._point)))
locations.push(new CurveLocation(curve1, t, point, curve2));
locations.push(new CurveLocation(
_flip ? curve2 : curve1,
t, point,
_flip ? curve1 : curve2));
}
}
}