scratchfoundation/paper.js
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Winding: Some improvements to comments and documentation.

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This commit is contained in:
Jürg Lehni 2016-07-16 20:17:20 +02:00
parent 8513144ae1
commit 91e67887da
1 changed files with 30 additions and 11 deletions
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41
src/path/PathItem.Boolean.js
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@ -217,7 +217,11 @@ PathItem.inject(new function() {
* Divides the path-items at the given locations. * Divides the path-items at the given locations.
* *
* @param {CurveLocation[]} locations an array of the locations to split the * @param {CurveLocation[]} locations an array of the locations to split the
* path-item at. * path-item at.
* @param {Function} [include] a function that determines if dividing should
* happen at a given location.
* @return {CurveLocation[]} the locations at which the involved path-items
* were divided
* @private * @private
*/ */
function divideLocations(locations, include) { function divideLocations(locations, include) {
@ -295,6 +299,21 @@ PathItem.inject(new function() {
return results || locations; return results || locations;
} }
/**
* Returns the winding contribution number of the given point in respect
* to the shapes described by the passed curves.
*
* @param {Point} point the location for which to determine the winding
* contribution
* @param {Curve[]} curves the curves that describe the shape against which
* to check, as returned by {@link Path#getCurves()} or
* {@link CompoundPath#getCurves()}
* @param {Number} [dir=0] the direction in which to determine the
* winding contribution, `0`: in x-direction, `1`: in y-direction
* @return {Object} an object containing the calculated winding number, as
* well as an indication whether the point was situated on the contour
* @private
*/
function getWinding(point, curves, dir) { function getWinding(point, curves, dir) {
var epsilon = /*#=*/Numerical.WINDING_EPSILON, var epsilon = /*#=*/Numerical.WINDING_EPSILON,
abs = Math.abs, abs = Math.abs,
@ -415,7 +434,7 @@ PathItem.inject(new function() {
( a0 > aAfter && a1 > aAfter && ( a0 > aAfter && a1 > aAfter &&
a2 > aAfter && a3 > aAfter) a2 > aAfter && a3 > aAfter)
? [v] : Curve.getMonoCurves(v, dir); ? [v] : Curve.getMonoCurves(v, dir);
for (var i = 0; i < monoCurves.length; i++) { for (var i = 0, l = monoCurves.length; i < l; i++) {
prevV = addWinding(monoCurves[i]); prevV = addWinding(monoCurves[i]);
} }
} }
@ -437,7 +456,7 @@ PathItem.inject(new function() {
x1 = p1._x, y1 = p1._y, x1 = p1._x, y1 = p1._y,
x2 = p2._x, y2 = p2._y; x2 = p2._x, y2 = p2._y;
closeV = [x1, y1, x1, y1, x2, y2, x2, y2]; closeV = [x1, y1, x1, y1, x2, y2, x2, y2];
// The closing curve is a potential candidate for the last // This closing curve is a potential candidate for the last
// non-horizontal curve. // non-horizontal curve.
if (closeV[io] !== closeV[io + 6]) { if (closeV[io] !== closeV[io + 6]) {
prevV = closeV; prevV = closeV;
@ -528,9 +547,9 @@ PathItem.inject(new function() {
parent = path._parent, parent = path._parent,
t = curve.getTimeAt(length), t = curve.getTimeAt(length),
pt = curve.getPointAtTime(t), pt = curve.getPointAtTime(t),
// Determine whether to check winding in horizontal or // Determine the direction in which to check the winding
// vertical direction from the point based on the curve's // from the point (horizontal or vertical), based on the
// direction at the given point. // curve's direction at that point.
dir = Math.abs(curve.getTangentAtTime(t).normalize().y) dir = Math.abs(curve.getTangentAtTime(t).normalize().y)
< 0.5 ? 1 : 0; < 0.5 ? 1 : 0;
if (parent instanceof CompoundPath) if (parent instanceof CompoundPath)
@ -750,13 +769,13 @@ PathItem.inject(new function() {
return /** @lends PathItem# */{ return /** @lends PathItem# */{
/** /**
* Returns the winding contribution of the given point with respect to * Returns the winding contribution number of the given point in respect
* this PathItem. * to this PathItem.
* *
* @param {Point} point the location for which to determine the winding * @param {Point} point the location for which to determine the winding
* direction * contribution
* @param {Boolean} horizontal whether we need to consider this point as * @param {Number} [dir=0] the direction in which to determine the
* part of a horizontal curve * winding contribution, `0`: in x-direction, `1`: in y-direction
* @return {Number} the winding number * @return {Number} the winding number
*/ */
_getWinding: function(point, dir) { _getWinding: function(point, dir) {