| /* |
| * Copyright (C) 2012 Adobe Systems Incorporated. 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 THE COPYRIGHT HOLDERS AND 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 THE |
| * COPYRIGHT HOLDER OR 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. |
| */ |
| |
| #include "config.h" |
| #include "ExclusionRectangle.h" |
| |
| #include <wtf/MathExtras.h> |
| |
| namespace WebCore { |
| |
| static inline float ellipseXIntercept(float y, float rx, float ry) |
| { |
| ASSERT(ry > 0); |
| return rx * sqrt(1 - (y * y) / (ry * ry)); |
| } |
| |
| static inline float ellipseYIntercept(float x, float rx, float ry) |
| { |
| ASSERT(rx > 0); |
| return ry * sqrt(1 - (x * x) / (rx * rx)); |
| } |
| |
| void ExclusionRectangle::getExcludedIntervals(float logicalTop, float logicalHeight, SegmentList& result) const |
| { |
| if (isEmpty()) |
| return; |
| |
| float y1 = logicalTop; |
| float y2 = y1 + logicalHeight; |
| |
| if (y2 < m_y || y1 >= m_y + m_height) |
| return; |
| |
| float x1 = m_x; |
| float x2 = m_x + m_width; |
| |
| if (m_ry > 0) { |
| if (y2 < m_y + m_ry) { |
| float yi = y2 - m_y - m_ry; |
| float xi = ellipseXIntercept(yi, m_rx, m_ry); |
| x1 = m_x + m_rx - xi; |
| x2 = m_x + m_width - m_rx + xi; |
| } else if (y1 > m_y + m_height - m_ry) { |
| float yi = y1 - (m_y + m_height - m_ry); |
| float xi = ellipseXIntercept(yi, m_rx, m_ry); |
| x1 = m_x + m_rx - xi; |
| x2 = m_x + m_width - m_rx + xi; |
| } |
| } |
| |
| result.append(LineSegment(x1, x2)); |
| } |
| |
| void ExclusionRectangle::getIncludedIntervals(float logicalTop, float logicalHeight, SegmentList& result) const |
| { |
| if (isEmpty()) |
| return; |
| |
| float y1 = logicalTop; |
| float y2 = y1 + logicalHeight; |
| |
| if (y1 < m_y || y2 > m_y + m_height) |
| return; |
| |
| float x1 = m_x; |
| float x2 = m_x + m_width; |
| |
| if (m_ry > 0) { |
| bool y1InterceptsCorner = y1 < m_y + m_ry; |
| bool y2InterceptsCorner = y2 > m_y + m_height - m_ry; |
| float xi = 0; |
| |
| if (y1InterceptsCorner && y2InterceptsCorner) { |
| if (y1 < m_height + 2*m_y - y2) { |
| float yi = y1 - m_y - m_ry; |
| xi = ellipseXIntercept(yi, m_rx, m_ry); |
| } else { |
| float yi = y2 - (m_y + m_height - m_ry); |
| xi = ellipseXIntercept(yi, m_rx, m_ry); |
| } |
| } else if (y1InterceptsCorner) { |
| float yi = y1 - m_y - m_ry; |
| xi = ellipseXIntercept(yi, m_rx, m_ry); |
| } else if (y2InterceptsCorner) { |
| float yi = y2 - (m_y + m_height - m_ry); |
| xi = ellipseXIntercept(yi, m_rx, m_ry); |
| } |
| |
| if (y1InterceptsCorner || y2InterceptsCorner) { |
| x1 = m_x + m_rx - xi; |
| x2 = m_x + m_width - m_rx + xi; |
| } |
| } |
| |
| result.append(LineSegment(x1, x2)); |
| } |
| |
| FloatPoint ExclusionRectangle::cornerInterceptForWidth(float width) const |
| { |
| float xi = (m_width - width) / 2; |
| float yi = m_ry - ellipseYIntercept(m_rx - xi, m_rx, m_ry); |
| return FloatPoint(xi, yi); |
| } |
| |
| bool ExclusionRectangle::firstIncludedIntervalLogicalTop(float minLogicalIntervalTop, const FloatSize& minLogicalIntervalSize, float& result) const |
| { |
| if (minLogicalIntervalSize.width() > m_width) |
| return false; |
| |
| float minY = std::max(m_y, minLogicalIntervalTop); |
| float maxY = minY + minLogicalIntervalSize.height(); |
| |
| if (maxY > m_y + m_height) |
| return false; |
| |
| bool intervalOverlapsMinCorner = minY < m_y + m_ry; |
| bool intervalOverlapsMaxCorner = maxY > m_y + m_height - m_ry; |
| |
| if (!intervalOverlapsMinCorner && !intervalOverlapsMaxCorner) { |
| result = minY; |
| return true; |
| } |
| |
| float centerY = m_y + m_height / 2; |
| bool minCornerDefinesX = fabs(centerY - minY) > fabs(centerY - maxY); |
| bool intervalFitsWithinCorners = minLogicalIntervalSize.width() + 2 * m_rx <= m_width; |
| FloatPoint cornerIntercept = cornerInterceptForWidth(minLogicalIntervalSize.width()); |
| |
| if (intervalOverlapsMinCorner && (!intervalOverlapsMaxCorner || minCornerDefinesX)) { |
| if (intervalFitsWithinCorners || m_y + cornerIntercept.y() < minY) { |
| result = minY; |
| return true; |
| } |
| if (minLogicalIntervalSize.height() < m_height - (2 * cornerIntercept.y())) { |
| result = m_y + cornerIntercept.y(); |
| return true; |
| } |
| } |
| |
| if (intervalOverlapsMaxCorner && (!intervalOverlapsMinCorner || !minCornerDefinesX)) { |
| if (intervalFitsWithinCorners || minY <= m_y + m_height - cornerIntercept.y() - minLogicalIntervalSize.height()) { |
| result = minY; |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| } // namespace WebCore |