1/*
2 * Copyright (C) 2013 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#include "config.h"
31#include "platform/geometry/FloatRoundedRect.h"
32
33#include <algorithm>
34
35namespace blink {
36
37FloatRoundedRect::FloatRoundedRect(float x, float y, float width, float height)
38    : m_rect(x, y, width, height)
39{
40}
41
42FloatRoundedRect::FloatRoundedRect(const FloatRect& rect, const Radii& radii)
43    : m_rect(rect)
44    , m_radii(radii)
45{
46}
47
48FloatRoundedRect::FloatRoundedRect(const FloatRect& rect, const FloatSize& topLeft, const FloatSize& topRight, const FloatSize& bottomLeft, const FloatSize& bottomRight)
49    : m_rect(rect)
50    , m_radii(topLeft, topRight, bottomLeft, bottomRight)
51{
52}
53
54bool FloatRoundedRect::Radii::isZero() const
55{
56    return m_topLeft.isZero() && m_topRight.isZero() && m_bottomLeft.isZero() && m_bottomRight.isZero();
57}
58
59void FloatRoundedRect::Radii::scale(float factor)
60{
61    if (factor == 1)
62        return;
63
64    // If either radius on a corner becomes zero, reset both radii on that corner.
65    m_topLeft.scale(factor);
66    if (!m_topLeft.width() || !m_topLeft.height())
67        m_topLeft = FloatSize();
68    m_topRight.scale(factor);
69    if (!m_topRight.width() || !m_topRight.height())
70        m_topRight = FloatSize();
71    m_bottomLeft.scale(factor);
72    if (!m_bottomLeft.width() || !m_bottomLeft.height())
73        m_bottomLeft = FloatSize();
74    m_bottomRight.scale(factor);
75    if (!m_bottomRight.width() || !m_bottomRight.height())
76        m_bottomRight = FloatSize();
77
78}
79
80void FloatRoundedRect::Radii::expand(float topWidth, float bottomWidth, float leftWidth, float rightWidth)
81{
82    if (m_topLeft.width() > 0 && m_topLeft.height() > 0) {
83        m_topLeft.setWidth(std::max<float>(0, m_topLeft.width() + leftWidth));
84        m_topLeft.setHeight(std::max<float>(0, m_topLeft.height() + topWidth));
85    }
86    if (m_topRight.width() > 0 && m_topRight.height() > 0) {
87        m_topRight.setWidth(std::max<float>(0, m_topRight.width() + rightWidth));
88        m_topRight.setHeight(std::max<float>(0, m_topRight.height() + topWidth));
89    }
90    if (m_bottomLeft.width() > 0 && m_bottomLeft.height() > 0) {
91        m_bottomLeft.setWidth(std::max<float>(0, m_bottomLeft.width() + leftWidth));
92        m_bottomLeft.setHeight(std::max<float>(0, m_bottomLeft.height() + bottomWidth));
93    }
94    if (m_bottomRight.width() > 0 && m_bottomRight.height() > 0) {
95        m_bottomRight.setWidth(std::max<float>(0, m_bottomRight.width() + rightWidth));
96        m_bottomRight.setHeight(std::max<float>(0, m_bottomRight.height() + bottomWidth));
97    }
98}
99
100static inline float cornerRectIntercept(float y, const FloatRect& cornerRect)
101{
102    ASSERT(cornerRect.height() > 0);
103    return cornerRect.width() * sqrt(1 - (y * y) / (cornerRect.height() * cornerRect.height()));
104}
105
106bool FloatRoundedRect::xInterceptsAtY(float y, float& minXIntercept, float& maxXIntercept) const
107{
108    if (y < rect().y() || y >  rect().maxY())
109        return false;
110
111    if (!isRounded()) {
112        minXIntercept = rect().x();
113        maxXIntercept = rect().maxX();
114        return true;
115    }
116
117    const FloatRect& topLeftRect = topLeftCorner();
118    const FloatRect& bottomLeftRect = bottomLeftCorner();
119
120    if (!topLeftRect.isEmpty() && y >= topLeftRect.y() && y < topLeftRect.maxY())
121        minXIntercept = topLeftRect.maxX() - cornerRectIntercept(topLeftRect.maxY() - y, topLeftRect);
122    else if (!bottomLeftRect.isEmpty() && y >= bottomLeftRect.y() && y <= bottomLeftRect.maxY())
123        minXIntercept =  bottomLeftRect.maxX() - cornerRectIntercept(y - bottomLeftRect.y(), bottomLeftRect);
124    else
125        minXIntercept = m_rect.x();
126
127    const FloatRect& topRightRect = topRightCorner();
128    const FloatRect& bottomRightRect = bottomRightCorner();
129
130    if (!topRightRect.isEmpty() && y >= topRightRect.y() && y <= topRightRect.maxY())
131        maxXIntercept = topRightRect.x() + cornerRectIntercept(topRightRect.maxY() - y, topRightRect);
132    else if (!bottomRightRect.isEmpty() && y >= bottomRightRect.y() && y <= bottomRightRect.maxY())
133        maxXIntercept = bottomRightRect.x() + cornerRectIntercept(y - bottomRightRect.y(), bottomRightRect);
134    else
135        maxXIntercept = m_rect.maxX();
136
137    return true;
138}
139
140} // namespace blink
141