/** * @params:{ * checkPoint:已知点 * polygonPoints:不规则多边形所有定点坐标 * } */ function isInPolygon(checkPoint, polygonPoints) { var counter = 0; var i; var xinters; var p1, p2; var pointCount = polygonPoints.length; p1 = polygonPoints[0]; for (i = 1; i <= pointCount; i++) { p2 = polygonPoints[i % pointCount]; if ( checkPoint[0] > Math.min(p1[0], p2[0]) && checkPoint[0] <= Math.max(p1[0], p2[0]) ) { if (checkPoint[1] <= Math.max(p1[1], p2[1])) { if (p1[0] != p2[0]) { xinters = (checkPoint[0] - p1[0]) * (p2[1] - p1[1]) / (p2[0] - p1[0]) + p1[1]; if (p1[1] == p2[1] || checkPoint[1] <= xinters) { counter++; } } } } p1 = p2; } if (counter % 2 == 0) { return false; } else { return true; } }