/* * 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 "PolygonShape.h" #include namespace WebCore { static inline FloatSize inwardEdgeNormal(const FloatPolygonEdge& edge) { FloatSize edgeDelta = edge.vertex2() - edge.vertex1(); if (!edgeDelta.width()) return FloatSize((edgeDelta.height() > 0 ? -1 : 1), 0); if (!edgeDelta.height()) return FloatSize(0, (edgeDelta.width() > 0 ? 1 : -1)); float edgeLength = edgeDelta.diagonalLength(); return FloatSize(-edgeDelta.height() / edgeLength, edgeDelta.width() / edgeLength); } static inline FloatSize outwardEdgeNormal(const FloatPolygonEdge& edge) { return -inwardEdgeNormal(edge); } float OffsetPolygonEdge::xIntercept(float y) const { ASSERT(y >= minY() && y <= maxY()); if (vertex1().y() == vertex2().y() || vertex1().x() == vertex2().x()) return minX(); if (y == minY()) return vertex1().y() < vertex2().y() ? vertex1().x() : vertex2().x(); if (y == maxY()) return vertex1().y() > vertex2().y() ? vertex1().x() : vertex2().x(); return vertex1().x() + ((y - vertex1().y()) * (vertex2().x() - vertex1().x()) / (vertex2().y() - vertex1().y())); } FloatShapeInterval OffsetPolygonEdge::clippedEdgeXRange(float y1, float y2) const { if (!overlapsYRange(y1, y2) || (y1 == maxY() && minY() <= y1) || (y2 == minY() && maxY() >= y2)) return FloatShapeInterval(); if (isWithinYRange(y1, y2)) return FloatShapeInterval(minX(), maxX()); // Clip the edge line segment to the vertical range y1,y2 and then return // the clipped line segment's horizontal range. FloatPoint minYVertex; FloatPoint maxYVertex; if (vertex1().y() < vertex2().y()) { minYVertex = vertex1(); maxYVertex = vertex2(); } else { minYVertex = vertex2(); maxYVertex = vertex1(); } float xForY1 = (minYVertex.y() < y1) ? xIntercept(y1) : minYVertex.x(); float xForY2 = (maxYVertex.y() > y2) ? xIntercept(y2) : maxYVertex.x(); return FloatShapeInterval(std::min(xForY1, xForY2), std::max(xForY1, xForY2)); } static float circleXIntercept(float y, float radius) { ASSERT(radius > 0); return radius * sqrt(1 - (y * y) / (radius * radius)); } static FloatShapeInterval clippedCircleXRange(const FloatPoint& center, float radius, float y1, float y2) { if (y1 >= center.y() + radius || y2 <= center.y() - radius) return FloatShapeInterval(); if (center.y() >= y1 && center.y() <= y2) return FloatShapeInterval(center.x() - radius, center.x() + radius); // Clip the circle to the vertical range y1,y2 and return the extent of the clipped circle's // projection on the X axis float xi = circleXIntercept((y2 < center.y() ? y2 : y1) - center.y(), radius); return FloatShapeInterval(center.x() - xi, center.x() + xi); } LayoutRect PolygonShape::shapeMarginLogicalBoundingBox() const { FloatRect box = m_polygon.boundingBox(); box.inflate(shapeMargin()); return LayoutRect(box); } LineSegment PolygonShape::getExcludedInterval(LayoutUnit logicalTop, LayoutUnit logicalHeight) const { float y1 = logicalTop; float y2 = logicalTop + logicalHeight; if (m_polygon.isEmpty() || !m_polygon.boundingBox().overlapsYRange(y1 - shapeMargin(), y2 + shapeMargin())) return LineSegment(); Vector overlappingEdges; if (!m_polygon.overlappingEdges(y1 - shapeMargin(), y2 + shapeMargin(), overlappingEdges)) return LineSegment(); FloatShapeInterval excludedInterval; for (unsigned i = 0; i < overlappingEdges.size(); i++) { const FloatPolygonEdge& edge = *(overlappingEdges[i]); if (edge.maxY() == edge.minY()) continue; if (!shapeMargin()) excludedInterval.unite(OffsetPolygonEdge(edge, FloatSize()).clippedEdgeXRange(y1, y2)); else { excludedInterval.unite(OffsetPolygonEdge(edge, outwardEdgeNormal(edge) * shapeMargin()).clippedEdgeXRange(y1, y2)); excludedInterval.unite(OffsetPolygonEdge(edge, inwardEdgeNormal(edge) * shapeMargin()).clippedEdgeXRange(y1, y2)); excludedInterval.unite(clippedCircleXRange(edge.vertex1(), shapeMargin(), y1, y2)); excludedInterval.unite(clippedCircleXRange(edge.vertex2(), shapeMargin(), y1, y2)); } } if (excludedInterval.isEmpty()) return LineSegment(); return LineSegment(excludedInterval.x1(), excludedInterval.x2()); } void PolygonShape::buildDisplayPaths(DisplayPaths& paths) const { if (m_polygon.isEmpty()) return; paths.shape.moveTo(m_polygon.vertexAt(0)); for (unsigned i = 1; i < m_polygon.numberOfVertices(); i++) paths.shape.addLineTo(m_polygon.vertexAt(i)); paths.shape.closeSubpath(); } } // namespace WebCore