scratchfoundation/paper.js
1
0
Fork 0
mirror of https://github.com/scratchfoundation/paper.js.git synced 2025-01-19 14:10:14 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

More work on Path#getStrokeBounds(), unfinished.

Browse source
This commit is contained in:
Jürg Lehni 2011-03-06 11:42:33 +00:00
parent 0a690788ef
commit fd0d409d9e
1 changed files with 61 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

67
src/path/Path.js
View file

@ -419,6 +419,15 @@ var Path = this.Path = PathItem.extend({
}
}, new function() { // Inject methods that require scoped privates
// Add some tolerance for good roots, as t = 0 / 1 are added seperately
// anyhow, and we don't want joins to be added with radiuses in
// calculateBounds
// TODO: Find out about the maximum precision of these calculations.
// -32 was chosen arbitrarily.
var epsilon = Math.pow(2, -32),
tMin = epsilon,
tMax = 1 - epsilon;
function calculateBounds(that, strokeRadius) {
// Code ported and further optimised from:
// http://blog.hackers-cafe.net/2009/06/how-to-calculate-bezier-curves-bounding.html
@ -475,7 +484,7 @@ var Path = this.Path = PathItem.extend({
continue;
var t = -c / b;
// Test for good root and add to bounds if good (same below)
if (0 < t && t < 1)
if (tMin < t && t < tMax)
add(null, t);
continue;
}
@ -487,9 +496,9 @@ var Path = this.Path = PathItem.extend({
f = 1 / (a * -2),
t1 = (b - sqrt) * f,
t2 = (b + sqrt) * f;
if (0 < t1 && t1 < 1)
if (tMin < t1 && t1 < tMax)
add(null, t1);
if (0 < t2 && t2 < 1)
if (tMin < t2 && t2 < tMax)
add(null, t2);
}
prev = segment;
@ -552,9 +561,55 @@ var Path = this.Path = PathItem.extend({
radius = width / 2,
join = this.getStrokeJoin(),
cap = this.getStrokeCap(),
miter = this.getMiterLimit();
var bounds = calculateBounds(this, radius);
// TODO: Handle cap and join
miter = this.getMiterLimit(),
segments = this._segments,
length = segments.length,
closed= this.closed,
bounds = calculateBounds(this, radius);
function addJoin(segment, join) {
var joinBounds,
handleIn = segment.getHandleInIfSet(),
handleOut = segment.getHandleOutIfSet();
if (join == 'round' || handleIn && handleOut) {
joinBounds = new Rectangle(new Size(width, width))
.setCenter(segment._point)
} else {
switch (join) {
case 'bevel':
break;
case 'miter':
break;
}
}
if (joinBounds)
bounds = bounds.unite(joinBounds);
}
function addCap(segment, cap) {
var capBounds;
switch (cap) {
case 'round':
return addJoin(segment, cap);
case 'square':
break;
case 'butt':
break;
}
if (capBounds)
bounds = bounds.unite(capBounds);
}
for (var i = 1, l = length - (closed ? 0 : 1); i < l; i++) {
addJoin(segments[i], join);
}
if (closed) {
addJoin(segments[0], join);
} else {
addCap(segments[0], cap);
addCap(segments[length - 1], cap);
}
return bounds;
},