mirror of
https://github.com/scratchfoundation/paper.js.git
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Speed up Line class by removing internal dependance on Point.
This commit is contained in:
Jürg Lehni
parent
c9a669ae37
commit
f771233d37
1 changed files with 81 additions and 49 deletions
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@ -24,11 +24,25 @@ var Line = this.Line = Base.extend(/** @lends Line# */{
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* @param {Point} point2
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* @param {Boolean} [asVector=false]
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*/
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initialize: function(point1, point2, asVector) {
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this.point = Point.read(arguments);
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this.vector = Point.read(arguments);
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if (!Base.read(arguments))
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this.vector = this.vector.subtract(this.point);
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initialize: function(arg0, arg1, arg2, arg3, arg4) {
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var asVector = false;
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if (arguments.length >= 4) {
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this._px = arg0;
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this._py = arg1;
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this._vx = arg2;
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this._vy = arg3;
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asVector = arg4;
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} else {
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this._px = arg0.x;
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this._py = arg0.y;
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this._vx = arg1.x;
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this._vy = arg1.y;
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asVector = arg2;
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}
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if (!asVector) {
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this._vx -= this._px;
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this._vy -= this._py;
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}
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},
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/**
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@ -37,6 +51,9 @@ var Line = this.Line = Base.extend(/** @lends Line# */{
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* @name Line#point
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* @type Point
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*/
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getPoint: function() {
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return Point.create(this._px, this._py);
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},
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/**
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* The vector of the line
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@ -44,6 +61,9 @@ var Line = this.Line = Base.extend(/** @lends Line# */{
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* @name Line#vector
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* @type Point
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*/
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getVector: function() {
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return Point.create(this._vx, this._vy);
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},
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/**
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* @param {Line} line
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@ -52,11 +72,9 @@ var Line = this.Line = Base.extend(/** @lends Line# */{
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* if the two lines are colinear, or {@code null} if they don't intersect.
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*/
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intersect: function(line, isInfinite) {
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var p1 = this.point,
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v1 = this.vector,
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p2 = line.point,
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v2 = line.vector;
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return Line.intersect(p1.x, p1.y, v1.x, v1.y, p2.x, p2.y, v2.x, v2.y,
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return Line.intersect(
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this._px, this._py, this._vx, this._vy,
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line._px, line._py, line._vx, line._vy,
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true, isInfinite);
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},
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@ -66,31 +84,9 @@ var Line = this.Line = Base.extend(/** @lends Line# */{
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* @return {Number}
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*/
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getSide: function(point) {
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point = Point.read(arguments);
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var v1 = this.vector,
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v2 = point.subtract(this.point),
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ccw = v2.cross(v1);
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if (ccw === 0) {
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ccw = v2.dot(v1);
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if (ccw > 0) {
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ccw = v2.subtract(v1).dot(v1);
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if (ccw < 0)
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ccw = 0;
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}
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}
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return ccw < 0 ? -1 : ccw > 0 ? 1 : 0;
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},
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// DOCS: document Line#getSignedDistance(point)
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/**
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* @param {Point} point
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* @return {Number}
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*/
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getSignedDistance: function(point) {
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var m = this.vector.y / this.vector.x, // slope
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b = this.point.y - (m * this.point.x); // y offset
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// Distance to the linear equation
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return (point.y - (m * point.x) - b) / Math.sqrt(m * m + 1);
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return Line.getSide(
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this._px, this._py, this._vx, this._vy,
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point.x, point.y, true);
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},
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// DOCS: document Line#getDistance(point)
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@ -99,34 +95,70 @@ var Line = this.Line = Base.extend(/** @lends Line# */{
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* @return {Number}
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*/
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getDistance: function(point) {
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return Math.abs(this.getSignedDistance(point));
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return Math.abs(Line.getSignedDistance(
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this._px, this._py, this._vx, this._vy,
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point.x, point.y, true));
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},
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statics: /** @lends Line */{
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intersect: function(ax1, ay1, ax2, ay2, bx1, by1, bx2, by2, asVectors,
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intersect: function(apx, apy, avx, avy, bpx, bpy, bvx, bvy, asVector,
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isInfinite) {
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// Convert 2nd points to vectors if they are not specified as such.
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if (!asVectors) {
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ax2 -= ax1;
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ay2 -= ay1;
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bx2 -= bx1;
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by2 -= by1;
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if (!asVector) {
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avx -= apx;
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avy -= apy;
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bvx -= bpx;
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bvy -= bpy;
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}
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var cross = by2 * ax2 - bx2 * ay2;
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var cross = bvy * avx - bvx * avy;
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// Avoid divisions by 0, and errors when getting too close to 0
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if (!Numerical.isZero(cross)) {
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var dx = ax1 - bx1,
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dy = ay1 - by1,
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ta = (bx2 * dy - by2 * dx) / cross,
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tb = (ax2 * dy - ay2 * dx) / cross;
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var dx = apx - bpx,
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dy = apy - bpy,
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ta = (bvx * dy - bvy * dx) / cross,
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tb = (avx * dy - avy * dx) / cross;
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// Check the ranges of t parameters if the line is not allowed
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// to extend beyond the definition points.
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if ((isInfinite || 0 <= ta && ta <= 1)
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&& (isInfinite || 0 <= tb && tb <= 1))
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return Point.create(
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ax1 + ta * ax2,
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ay1 + ta * ay2);
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apx + ta * avx,
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apy + ta * avy);
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}
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},
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getSide: function(px, py, vx, vy, x, y, asVector) {
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if (!asVector) {
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vx -= px;
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vy -= py;
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}
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var vx = x - px,
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vy = y - py,
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ccw = vx * vy - vy * vx; // ccw = v2.cross(v1);
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if (ccw === 0) {
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ccw = vx * vx + vy * vy; // ccw = v2.dot(v1);
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if (ccw > 0) {
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// ccw = v2.subtract(v1).dot(v1);
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vx -= vx;
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vy -= vy;
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ccw = vx * vx + vy * vy;
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if (ccw < 0)
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ccw = 0;
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}
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}
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return ccw < 0 ? -1 : ccw > 0 ? 1 : 0;
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},
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getSignedDistance: function(px, py, vx, vy, x, y, asVector) {
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if (!asVector) {
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vx -= px;
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vy -= py;
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}
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// Cache these values since they're used heavily in fatline code
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var m = vy / vx, // slope
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b = py - m * px; // y offset
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// Distance to the linear equation
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return (y - (m * x) - b) / Math.sqrt(m * m + 1);
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}
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}
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});
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