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));
}
LineSegment PolygonShape::getExcludedInterval(LayoutUnit logicalTop, LayoutUnit logicalHeight) const
{
float y1 = logicalTop.toFloat();
float y2 = logicalTop.toFloat() + logicalHeight.toFloat();
if (m_polygon.isEmpty() || !overlapsYRange(m_polygon.boundingBox(), y1 - shapeMargin(), y2 + shapeMargin()))
return LineSegment();
Vector<const FloatPolygonEdge*> 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));
}
}
if (excludedInterval.isEmpty())
return LineSegment();
return LineSegment(excludedInterval.x1(), excludedInterval.x2());
}
