1/*
2 * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above
9 *    copyright notice, this list of conditions and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above
12 *    copyright notice, this list of conditions and the following
13 *    disclaimer in the documentation and/or other materials
14 *    provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
19 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
20 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
21 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27 * OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#ifndef ShapeInterval_h
31#define ShapeInterval_h
32
33#include <wtf/Vector.h>
34
35namespace WebCore {
36
37template <typename T>
38class ShapeInterval {
39    WTF_MAKE_FAST_ALLOCATED;
40public:
41    ShapeInterval()
42        : m_x1(-1)
43        , m_x2(-2)
44    {
45        // The initial values of m_x1,x2 don't matter (unless you're looking
46        // at them in the debugger) so long as isUndefined() is true.
47        ASSERT(isUndefined());
48    }
49
50    ShapeInterval(T x1, T x2)
51        : m_x1(x1)
52        , m_x2(x2)
53    {
54        ASSERT(x2 >= x1);
55    }
56
57    bool isUndefined() const { return m_x2 < m_x1; }
58    T x1() const { return isUndefined() ? 0 : m_x1; }
59    T x2() const { return isUndefined() ? 0 : m_x2; }
60    T width() const { return isUndefined() ? 0 : m_x2 - m_x1; }
61    bool isEmpty() const { return isUndefined() ? true : m_x1 == m_x2; }
62
63    void set(T x1, T x2)
64    {
65        ASSERT(x2 >= x1);
66        m_x1 = x1;
67        m_x2 = x2;
68    }
69
70    bool overlaps(const ShapeInterval<T>& interval) const
71    {
72        if (isUndefined() || interval.isUndefined())
73            return false;
74        return x2() >= interval.x1() && x1() <= interval.x2();
75    }
76
77    bool contains(const ShapeInterval<T>& interval) const
78    {
79        if (isUndefined() || interval.isUndefined())
80            return false;
81        return x1() <= interval.x1() && x2() >= interval.x2();
82    }
83
84    void unite(const ShapeInterval<T>& interval)
85    {
86        if (interval.isUndefined())
87            return;
88        if (isUndefined())
89            set(interval.x1(), interval.x2());
90        else
91            set(std::min<T>(x1(), interval.x1()), std::max<T>(x2(), interval.x2()));
92    }
93
94    bool operator==(const ShapeInterval<T>& other) const { return x1() == other.x1() && x2() == other.x2(); }
95    bool operator!=(const ShapeInterval<T>& other) const { return !operator==(other); }
96
97private:
98    T m_x1;
99    T m_x2;
100};
101
102typedef ShapeInterval<int> IntShapeInterval;
103typedef ShapeInterval<float> FloatShapeInterval;
104
105typedef Vector<IntShapeInterval> IntShapeIntervals;
106typedef Vector<FloatShapeInterval> FloatShapeIntervals;
107
108} // namespace WebCore
109
110#endif // ShapeInterval_h
111