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#include "config.h"
31#include "core/rendering/shapes/RectangleShape.h"
32
33#include "wtf/MathExtras.h"
34
35namespace blink {
36
37static inline float ellipseXIntercept(float y, float rx, float ry)
38{
39    ASSERT(ry > 0);
40    return rx * sqrt(1 - (y * y) / (ry * ry));
41}
42
43FloatRect RectangleShape::shapeMarginBounds() const
44{
45    ASSERT(shapeMargin() >= 0);
46    if (!shapeMargin())
47        return m_bounds;
48
49    float boundsX = x() - shapeMargin();
50    float boundsY = y() - shapeMargin();
51    float boundsWidth = width() + shapeMargin() * 2;
52    float boundsHeight = height() + shapeMargin() * 2;
53    return FloatRect(boundsX, boundsY, boundsWidth, boundsHeight);
54}
55
56LineSegment RectangleShape::getExcludedInterval(LayoutUnit logicalTop, LayoutUnit logicalHeight) const
57{
58    const FloatRect& bounds = shapeMarginBounds();
59    if (bounds.isEmpty())
60        return LineSegment();
61
62    float y1 = logicalTop.toFloat();
63    float y2 = (logicalTop + logicalHeight).toFloat();
64
65    if (y2 < bounds.y() || y1 >= bounds.maxY())
66        return LineSegment();
67
68    float x1 = bounds.x();
69    float x2 = bounds.maxX();
70
71    float marginRadiusX = rx() + shapeMargin();
72    float marginRadiusY = ry() + shapeMargin();
73
74    if (marginRadiusY > 0) {
75        if (y2 < bounds.y() + marginRadiusY) {
76            float yi = y2 - bounds.y() - marginRadiusY;
77            float xi = ellipseXIntercept(yi, marginRadiusX, marginRadiusY);
78            x1 = bounds.x() + marginRadiusX - xi;
79            x2 = bounds.maxX() - marginRadiusX + xi;
80        } else if (y1 > bounds.maxY() - marginRadiusY) {
81            float yi =  y1 - (bounds.maxY() - marginRadiusY);
82            float xi = ellipseXIntercept(yi, marginRadiusX, marginRadiusY);
83            x1 = bounds.x() + marginRadiusX - xi;
84            x2 = bounds.maxX() - marginRadiusX + xi;
85        }
86    }
87
88    return LineSegment(x1, x2);
89}
90
91void RectangleShape::buildDisplayPaths(DisplayPaths& paths) const
92{
93    paths.shape.addRoundedRect(m_bounds, m_radii);
94    if (shapeMargin())
95        paths.marginShape.addRoundedRect(shapeMarginBounds(), FloatSize(m_radii.width() + shapeMargin(), m_radii.height() + shapeMargin()));
96}
97
98} // namespace blink
99