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
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/*
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// Cubic curve classification algorithm from "Rendering Vector Art on
// the GPU" by Loop and Blinn, GPU Gems 3, Chapter 25:
// http://http.developer.nvidia.com/GPUGems3/gpugems3_ch25.html .
#ifndef LoopBlinnClassifier_h
#define LoopBlinnClassifier_h
#include <wtf/Noncopyable.h>
namespace WebCore {
class FloatPoint;
// Classifies cubic curves into specific types.
class LoopBlinnClassifier {
WTF_MAKE_NONCOPYABLE(LoopBlinnClassifier);
public:
// The types of cubic curves.
enum CurveType {
kSerpentine,
kCusp,
kLoop,
kQuadratic,
kLine,
kPoint
};
// The result of the classifier.
struct Result {
public:
Result(CurveType inputCurveType, float inputD1, float inputD2, float inputD3)
: curveType(inputCurveType)
, d1(inputD1)
, d2(inputD2)
, d3(inputD3) { }
CurveType curveType;
// These are coefficients used later in the computation of
// texture coordinates per vertex.
float d1;
float d2;
float d3;
};
// Classifies the given cubic bezier curve starting at c0, ending
// at c3, and affected by control points c1 and c2.
static Result classify(const FloatPoint& c0,
const FloatPoint& c1,
const FloatPoint& c2,
const FloatPoint& c3);
private:
// This class does not need to be instantiated.
LoopBlinnClassifier() { }
};
} // namespace WebCore
#endif // LoopBlinnClassifier_h
|