使用PathIterator返回约束区域的所有线段？

在Java中，如何使用PathIterator迭代约束Area线段？ Area仅由线条约束（但曲线支撑不会受到伤害）。

该方法应返回所有线段的集合。

Answer 1

这有效（在所有情况下，我相信），但它可能需要更彻底的测试：

 Area area; // The value is set elsewhere in the code ArrayList areaPoints = new ArrayList(); ArrayList areaSegments = new ArrayList(); double[] coords = new double[6]; for (PathIterator pi = area.getPathIterator(null); !pi.isDone(); pi.next()) { // The type will be SEG_LINETO, SEG_MOVETO, or SEG_CLOSE // Because the Area is composed of straight lines int type = pi.currentSegment(coords); // We record a double array of {segment type, x coord, y coord} double[] pathIteratorCoords = {type, coords[0], coords[1]}; areaPoints.add(pathIteratorCoords); } double[] start = new double[3]; // To record where each polygon starts for (int i = 0; i < areaPoints.size(); i++) { // If we're not on the last point, return a line from this point to the next double[] currentElement = areaPoints.get(i); // We need a default value in case we've reached the end of the ArrayList double[] nextElement = {-1, -1, -1}; if (i < areaPoints.size() - 1) { nextElement = areaPoints.get(i + 1); } // Make the lines if (currentElement[0] == PathIterator.SEG_MOVETO) { start = currentElement; // Record where the polygon started to close it later } if (nextElement[0] == PathIterator.SEG_LINETO) { areaSegments.add( new Line2D.Double( currentElement[1], currentElement[2], nextElement[1], nextElement[2] ) ); } else if (nextElement[0] == PathIterator.SEG_CLOSE) { areaSegments.add( new Line2D.Double( currentElement[1], currentElement[2], start[1], start[2] ) ); } } // areaSegments now contains all the line segments