blob: 3ae10d216a2b3cf0b97800efe34a408ad4af579a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "CubicUtilities.h"
#include "CurveIntersection.h"
#include "TestUtilities.h"
void quad_to_cubic(const Quadratic& quad, Cubic& cubic) {
cubic[0] = quad[0];
cubic[1].x = quad[0].x / 3 + quad[1].x * 2 / 3;
cubic[1].y = quad[0].y / 3 + quad[1].y * 2 / 3;
cubic[2].x = quad[2].x / 3 + quad[1].x * 2 / 3;
cubic[2].y = quad[2].y / 3 + quad[1].y * 2 / 3;
cubic[3] = quad[2];
}
static bool tiny(const Cubic& cubic) {
int index, minX, maxX, minY, maxY;
minX = maxX = minY = maxY = 0;
for (index = 1; index < 4; ++index) {
if (cubic[minX].x > cubic[index].x) {
minX = index;
}
if (cubic[minY].y > cubic[index].y) {
minY = index;
}
if (cubic[maxX].x < cubic[index].x) {
maxX = index;
}
if (cubic[maxY].y < cubic[index].y) {
maxY = index;
}
}
return approximately_equal(cubic[maxX].x, cubic[minX].x)
&& approximately_equal(cubic[maxY].y, cubic[minY].y);
}
void find_tight_bounds(const Cubic& cubic, _Rect& bounds) {
CubicPair cubicPair;
chop_at(cubic, cubicPair, 0.5);
if (!tiny(cubicPair.first()) && !controls_inside(cubicPair.first())) {
find_tight_bounds(cubicPair.first(), bounds);
} else {
bounds.add(cubicPair.first()[0]);
bounds.add(cubicPair.first()[3]);
}
if (!tiny(cubicPair.second()) && !controls_inside(cubicPair.second())) {
find_tight_bounds(cubicPair.second(), bounds);
} else {
bounds.add(cubicPair.second()[0]);
bounds.add(cubicPair.second()[3]);
}
}
bool controls_inside(const Cubic& cubic) {
return
((cubic[0].x <= cubic[1].x && cubic[0].x <= cubic[2].x && cubic[1].x <= cubic[3].x && cubic[2].x <= cubic[3].x)
|| (cubic[0].x >= cubic[1].x && cubic[0].x >= cubic[2].x && cubic[1].x >= cubic[3].x && cubic[2].x >= cubic[3].x))
&& ((cubic[0].y <= cubic[1].y && cubic[0].y <= cubic[2].y && cubic[1].y <= cubic[3].y && cubic[2].y <= cubic[3].y)
|| (cubic[0].y >= cubic[1].y && cubic[0].y >= cubic[2].y && cubic[1].y >= cubic[3].y && cubic[2].x >= cubic[3].y));
}
|
