50 lines
1.4 KiB
JavaScript
50 lines
1.4 KiB
JavaScript
|
var Class = require('../core/class');
|
||
|
|
var Path = require('../core/path');
|
||
|
|
var Transform = require('../core/transform');
|
||
|
|
|
||
|
|
module.exports = Class(Path, {
|
||
|
|
|
||
|
|
onReset: function(){
|
||
|
|
this.points = [];
|
||
|
|
this.left = this.top = Infinity;
|
||
|
|
this.right = this.bottom = -Infinity;
|
||
|
|
this.width = this.height = 0;
|
||
|
|
this.length = 0;
|
||
|
|
},
|
||
|
|
|
||
|
|
onMove: function(sx, sy, ex, ey){
|
||
|
|
this.points.push(this.length, ex, ey);
|
||
|
|
},
|
||
|
|
|
||
|
|
onLine: function(sx, sy, ex, ey){
|
||
|
|
var x = ex - sx, y = ey - sy;
|
||
|
|
this.points.push((this.length += Math.sqrt(x * x + y * y)), ex, ey);
|
||
|
|
this.left = Math.min(this.left, sx, x);
|
||
|
|
this.right = Math.max(this.right, sx, x);
|
||
|
|
this.top = Math.min(this.top, sy, y);
|
||
|
|
this.bottom = Math.max(this.bottom, sy, y);
|
||
|
|
this.width = this.right - this.left;
|
||
|
|
this.height = this.bottom - this.top;
|
||
|
|
},
|
||
|
|
|
||
|
|
point: function(lengthToPoint){
|
||
|
|
// TODO: Binary search, store last distance-and-index to make second look ups faster
|
||
|
|
var points = this.points, last = points.length - 3, next;
|
||
|
|
if (last < 3) return null;
|
||
|
|
for (var i = 3; i < last; i+=3)
|
||
|
|
if (points[i] >= lengthToPoint)
|
||
|
|
break;
|
||
|
|
|
||
|
|
var l = points[i],
|
||
|
|
x = points[i+1], y = points[i+2],
|
||
|
|
|
||
|
|
dl = l - points[i-3],
|
||
|
|
dx = x - points[i-2], dy = y - points[i-1];
|
||
|
|
|
||
|
|
var offset = (l - lengthToPoint) / dl,
|
||
|
|
cos = dx / dl, sin = dy / dl;
|
||
|
|
x -= dx * offset; y -= dy * offset;
|
||
|
|
return new Transform(cos, sin, -sin, cos, x, y);
|
||
|
|
}
|
||
|
|
|
||
|
|
});
|