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@@ -0,0 +1,494 @@
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+package hxd.earcut;
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+
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+class EarNode {
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+ public var next : EarNode;
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+ public var prev : EarNode;
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+ public var nextZ : EarNode;
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+ public var prevZ : EarNode;
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+ public var allocNext : EarNode;
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+ public var x : Float;
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+ public var y : Float;
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+ public var i : Int;
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+ public var z : Int;
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+ public var steiner : Bool;
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+ public function new() {
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+ }
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+}
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+
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+/**
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+ Ported from https://github.com/mapbox/earcut by @ncannasse
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+**/
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+class Earcut {
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+
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+ var triangles : Array<Int>;
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+ var cache : EarNode;
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+ var allocated : EarNode;
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+ var minX : Float;
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+ var minY : Float;
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+ var size : Float;
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+ var hasSize : Bool;
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+
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+ public function new() {
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+ }
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+
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+ @:generic public function triangulate<T:{x:Float,y:Float}>( points : Array<T> ) : Array<Int> {
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+ var outerLen = points.length;
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+
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+ if( outerLen < 3 )
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+ return [];
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+
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+ var root : EarNode = allocNode( -1, 0, 0, null);
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+ var first = root;
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+
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+ // check polygon winding
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+ var sum = 0.;
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+ var p = points[points.length - 1];
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+ for( p2 in points ) {
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+ sum += (p.x - p2.x) * (p.y + p2.y);
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+ p = p2;
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+ }
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+ if( sum > 0 ) {
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+ // clockwise
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+ for( i in 0...points.length ) {
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+ var p = points[i];
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+ root = allocNode(i, p.x, p.y, root);
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+ }
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+ } else {
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+ var last = points.length - 1;
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+ for( i in 0...points.length ) {
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+ var p = points[last - i];
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+ root = allocNode(last - i, p.x, p.y, root);
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+ }
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+ }
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+
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+ // close loop
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+ root.next = first.next;
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+ root.next.prev = root;
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+ return triangulateNode(root, points.length > 80);
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+ }
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+
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+ public function triangulateNode( root : EarNode, useZOrder ) {
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+ triangles = [];
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+ root = filterPoints(root);
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+ if( useZOrder && root != null ) {
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+ var maxX, maxY;
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+ minX = maxX = root.x;
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+ minY = maxY = root.y;
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+ var p = root.next;
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+ while( p != root ) {
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+ var x = p.x;
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+ var y = p.y;
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+ if (x < minX) minX = x;
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+ if (y < minY) minY = y;
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+ if (x > maxX) maxX = x;
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+ if (y > maxY) maxY = y;
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+ p = p.next;
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+ }
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+ // minX, minY and size are later used to transform coords into integers for z-order calculation
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+ size = Math.max(maxX - minX, maxY - minY);
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+ hasSize = true;
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+ } else
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+ hasSize = false;
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+ earcutLinked(root);
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+ var result = triangles;
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+ triangles = null;
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+
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+ // recycle allocated into cache
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+ var n = allocated;
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+ if( cache != null ) {
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+ while( n != cache )
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+ n = n.allocNext;
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+ n = n.allocNext;
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+ }
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+ while( n != null ) {
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+ n.next = cache;
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+ cache = n;
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+ n = n.allocNext;
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+ }
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+
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+ return result;
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+ }
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+
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+ inline function equals(p1:EarNode, p2:EarNode) {
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+ return p1.x == p2.x && p1.y == p2.y;
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+ }
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+
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+ inline function area(p:EarNode, q:EarNode, r:EarNode) {
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+ return (q.y - p.y) * (r.x - q.x) - (q.x - p.x) * (r.y - q.y);
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+ }
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+
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+ inline function intersects(p1, q1, p2, q2) {
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+ return (area(p1, q1, p2) > 0) != (area(p1, q1, q2) > 0) && (area(p2, q2, p1) > 0) != (area(p2, q2, q1) > 0);
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+ }
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+
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+ // check if a polygon diagonal is locally inside the polygon
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+ inline function locallyInside(a:EarNode, b:EarNode) {
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+ return area(a.prev, a, a.next) < 0 ?
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+ area(a, b, a.next) >= 0 && area(a, a.prev, b) >= 0 :
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+ area(a, b, a.prev) < 0 || area(a, a.next, b) < 0;
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+ }
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+
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+ function filterPoints(start:EarNode, end:EarNode=null) {
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+ if( start == null ) return start;
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+ if( end == null ) end = start;
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+ var p = start, again;
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+ do {
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+ again = false;
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+ if( !p.steiner && (equals(p, p.next) || area(p.prev, p, p.next) == 0) ) {
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+ removeNode(p);
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+ p = end = p.prev;
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+ if (p == p.next) return null;
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+ again = true;
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+ } else {
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+ p = p.next;
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+ }
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+ } while (again || p != end);
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+ return end;
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+ }
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+
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+ inline function removeNode(p:EarNode) {
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+ p.next.prev = p.prev;
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+ p.prev.next = p.next;
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+ if (p.prevZ != null) p.prevZ.nextZ = p.nextZ;
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+ if (p.nextZ != null) p.nextZ.prevZ = p.prevZ;
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+ }
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+
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+ inline function allocNode(i, x, y, last=null) {
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+ var n = cache;
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+ if( n == null ) {
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+ n = new EarNode();
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+ n.allocNext = allocated;
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+ allocated = n;
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+ } else
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+ cache = n.next;
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+ n.i = i;
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+ n.z = -1;
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+ n.x = x;
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+ n.y = y;
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+ n.next = null;
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+ n.prev = last;
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+ n.steiner = false;
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+ n.prevZ = null;
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+ n.nextZ = null;
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+ if( last != null )
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+ last.next = n;
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+ return n;
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+ }
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+
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+ function earcutLinked(ear:EarNode, pass = 0) {
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+ if ( ear == null ) return;
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+
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+ // interlink polygon nodes in z-order
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+ if( pass == 0 && hasSize ) indexCurve(ear);
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+
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+ var stop = ear,
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+ prev, next;
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+
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+ // iterate through ears, slicing them one by one
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+ while (ear.prev != ear.next) {
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+ prev = ear.prev;
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+ next = ear.next;
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+
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+ if ( hasSize ? isEarHashed(ear) : isEar(ear)) {
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+ // cut off the triangle
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+ triangles.push(prev.i);
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+ triangles.push(ear.i);
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+ triangles.push(next.i);
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+
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+ removeNode(ear);
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+
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+ // skipping the next vertice leads to less sliver triangles
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+ ear = next.next;
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+ stop = next.next;
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+
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+ continue;
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+ }
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+
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+ ear = next;
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+
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+ // if we looped through the whole remaining polygon and can't find any more ears
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+ if (ear == stop) {
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+ // try filtering points and slicing again
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+ switch( pass ) {
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+ case 0:
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+ earcutLinked(filterPoints(ear), 1);
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+ // if this didn't work, try curing all small self-intersections locally
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+ case 1:
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+ ear = cureLocalIntersections(ear);
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+ earcutLinked(ear, 2);
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+ // as a last resort, try splitting the remaining polygon into two
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+ case 2:
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+ splitEarcut(ear);
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+ }
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+ break;
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+ }
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+ }
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+ }
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+
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+ // check whether a polygon node forms a valid ear with adjacent nodes
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+ function isEar(ear:EarNode) {
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+ var a = ear.prev,
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+ b = ear,
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+ c = ear.next;
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+
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+ if (area(a, b, c) >= 0) return false; // reflex, can't be an ear
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+
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+ // now make sure we don't have other points inside the potential ear
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+ var p = ear.next.next;
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+
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+ while (p != ear.prev) {
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+ if (pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) &&
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+ area(p.prev, p, p.next) >= 0) return false;
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+ p = p.next;
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+ }
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+
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+ return true;
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+ }
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+
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+ function isEarHashed(ear:EarNode) {
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+ var a = ear.prev,
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+ b = ear,
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+ c = ear.next;
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+
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+ if (area(a, b, c) >= 0) return false; // reflex, can't be an ear
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+
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+ // triangle bbox; min & max are calculated like this for speed
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+ var minTX = a.x < b.x ? (a.x < c.x ? a.x : c.x) : (b.x < c.x ? b.x : c.x),
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+ minTY = a.y < b.y ? (a.y < c.y ? a.y : c.y) : (b.y < c.y ? b.y : c.y),
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+ maxTX = a.x > b.x ? (a.x > c.x ? a.x : c.x) : (b.x > c.x ? b.x : c.x),
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+ maxTY = a.y > b.y ? (a.y > c.y ? a.y : c.y) : (b.y > c.y ? b.y : c.y);
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+
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+ // z-order range for the current triangle bbox;
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+ var minZ = zOrder(minTX, minTY),
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+ maxZ = zOrder(maxTX, maxTY);
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+
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+ // first look for points inside the triangle in increasing z-order
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+ var p = ear.nextZ;
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+
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+ while (p != null && p.z <= maxZ) {
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+ if (p != ear.prev && p != ear.next &&
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+ pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) &&
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+ area(p.prev, p, p.next) >= 0) return false;
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+ p = p.nextZ;
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+ }
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+
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+ // then look for points in decreasing z-order
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+ p = ear.prevZ;
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+
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+ while (p != null && p.z >= minZ) {
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+ if (p != ear.prev && p != ear.next &&
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+ pointInTriangle(a.x, a.y, b.x, b.y, c.x, c.y, p.x, p.y) &&
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+ area(p.prev, p, p.next) >= 0) return false;
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+ p = p.prevZ;
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+ }
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+
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+ return true;
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+ }
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+
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+ // go through all polygon nodes and cure small local self-intersections
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+ function cureLocalIntersections(start:EarNode) {
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+ var p = start;
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+ do {
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+ var a = p.prev,
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+ b = p.next.next;
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+
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+ // a self-intersection where edge (v[i-1],v[i]) intersects (v[i+1],v[i+2])
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+ if (intersects(a, p, p.next, b) && locallyInside(a, b) && locallyInside(b, a)) {
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+
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+ triangles.push(a.i);
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+ triangles.push(p.i);
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+ triangles.push(b.i);
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+
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+ // remove two nodes involved
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+ removeNode(p);
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+ removeNode(p.next);
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+
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+ p = start = b;
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+ }
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+ p = p.next;
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+ } while (p != start);
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+
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+ return p;
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+ }
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+
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+ // try splitting polygon into two and triangulate them independently
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+ function splitEarcut(start:EarNode) {
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+ // look for a valid diagonal that divides the polygon into two
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+ var a = start;
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+ do {
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+ var b = a.next.next;
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+ while (b != a.prev) {
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+ if (a.i != b.i && isValidDiagonal(a, b)) {
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+ // split the polygon in two by the diagonal
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+ var c = splitPolygon(a, b);
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+
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+ // filter colinear points around the cuts
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+ a = filterPoints(a, a.next);
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+ c = filterPoints(c, c.next);
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+
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+ // run earcut on each half
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+ earcutLinked(a);
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+ earcutLinked(c);
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+ return;
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+ }
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+ b = b.next;
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+ }
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+ a = a.next;
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+ } while (a != start);
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+ }
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+
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+ // link two polygon vertices with a bridge; if the vertices belong to the same ring, it splits polygon into two;
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+ // if one belongs to the outer ring and another to a hole, it merges it into a single ring
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+ function splitPolygon(a : EarNode, b : EarNode) {
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+ var a2 = allocNode(a.i, a.x, a.y),
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+ b2 = allocNode(b.i, b.x, b.y),
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+ an = a.next,
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+ bp = b.prev;
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+
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+ a.next = b;
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+ b.prev = a;
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+
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+ a2.next = an;
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+ an.prev = a2;
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+
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+ b2.next = a2;
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+ a2.prev = b2;
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+
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+ bp.next = b2;
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+ b2.prev = bp;
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+
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+ return b2;
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+ }
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+
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+ inline function pointInTriangle(ax:Float, ay:Float, bx:Float, by:Float, cx:Float, cy:Float, px:Float, py:Float) {
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+ return (cx - px) * (ay - py) - (ax - px) * (cy - py) >= 0 &&
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+ (ax - px) * (by - py) - (bx - px) * (ay - py) >= 0 &&
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+ (bx - px) * (cy - py) - (cx - px) * (by - py) >= 0;
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+ }
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+
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+ // check if a diagonal between two polygon nodes is valid (lies in polygon interior)
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+ function isValidDiagonal(a:EarNode, b:EarNode) {
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+ return equals(a, b) || a.next.i != b.i && a.prev.i != b.i && !intersectsPolygon(a, b) &&
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+ locallyInside(a, b) && locallyInside(b, a) && middleInside(a, b);
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+ }
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+
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+ // check if the middle point of a polygon diagonal is inside the polygon
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+ function middleInside(a:EarNode, b:EarNode) {
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+ var p = a,
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+ inside = false,
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+ px = (a.x + b.x) / 2,
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+ py = (a.y + b.y) / 2;
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+ do {
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+ if (((p.y > py) != (p.next.y > py)) && (px < (p.next.x - p.x) * (py - p.y) / (p.next.y - p.y) + p.x))
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+ inside = !inside;
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+ p = p.next;
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+ } while (p != a);
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+
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+ return inside;
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+ }
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+
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+ // check if a polygon diagonal intersects any polygon segments
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+ function intersectsPolygon(a:EarNode, b:EarNode) {
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+ var p = a;
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+ do {
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+ if (p.i != a.i && p.next.i != a.i && p.i != b.i && p.next.i != b.i &&
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+ intersects(p, p.next, a, b)) return true;
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+ p = p.next;
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+ } while (p != a);
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+ return false;
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+ }
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+
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+ inline function zOrder(px:Float, py:Float) {
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+ // coords are transformed into non-negative 15-bit integer range
|
|
|
+ var x = Std.int(32767 * (px - minX) / size);
|
|
|
+ var y = Std.int(32767 * (py - minY) / size);
|
|
|
+
|
|
|
+ x = (x | (x << 8)) & 0x00FF00FF;
|
|
|
+ x = (x | (x << 4)) & 0x0F0F0F0F;
|
|
|
+ x = (x | (x << 2)) & 0x33333333;
|
|
|
+ x = (x | (x << 1)) & 0x55555555;
|
|
|
+
|
|
|
+ y = (y | (y << 8)) & 0x00FF00FF;
|
|
|
+ y = (y | (y << 4)) & 0x0F0F0F0F;
|
|
|
+ y = (y | (y << 2)) & 0x33333333;
|
|
|
+ y = (y | (y << 1)) & 0x55555555;
|
|
|
+
|
|
|
+ return x | (y << 1);
|
|
|
+ }
|
|
|
+
|
|
|
+ function indexCurve( start : EarNode ) {
|
|
|
+ var p = start;
|
|
|
+ do {
|
|
|
+ if( p.z < 0 ) p.z = zOrder(p.x, p.y);
|
|
|
+ p.prevZ = p.prev;
|
|
|
+ p.nextZ = p.next;
|
|
|
+ p = p.next;
|
|
|
+ } while (p != start);
|
|
|
+
|
|
|
+ p.prevZ.nextZ = null;
|
|
|
+ p.prevZ = null;
|
|
|
+
|
|
|
+ sortLinked(p);
|
|
|
+ }
|
|
|
+
|
|
|
+ function sortLinked(list:EarNode) {
|
|
|
+ var p : EarNode, q : EarNode, e : EarNode, tail : EarNode, numMerges, pSize, qSize,
|
|
|
+ inSize = 1;
|
|
|
+
|
|
|
+ do {
|
|
|
+ p = list;
|
|
|
+ list = null;
|
|
|
+ tail = null;
|
|
|
+ numMerges = 0;
|
|
|
+
|
|
|
+ while (p != null) {
|
|
|
+ numMerges++;
|
|
|
+ q = p;
|
|
|
+ pSize = 0;
|
|
|
+ for( i in 0...inSize ) {
|
|
|
+ pSize++;
|
|
|
+ q = q.nextZ;
|
|
|
+ if (q == null) break;
|
|
|
+ }
|
|
|
+
|
|
|
+ qSize = inSize;
|
|
|
+
|
|
|
+ while (pSize > 0 || (qSize > 0 && q != null)) {
|
|
|
+
|
|
|
+ if (pSize == 0) {
|
|
|
+ e = q;
|
|
|
+ q = q.nextZ;
|
|
|
+ qSize--;
|
|
|
+ } else if (qSize == 0 || q == null) {
|
|
|
+ e = p;
|
|
|
+ p = p.nextZ;
|
|
|
+ pSize--;
|
|
|
+ } else if (p.z <= q.z) {
|
|
|
+ e = p;
|
|
|
+ p = p.nextZ;
|
|
|
+ pSize--;
|
|
|
+ } else {
|
|
|
+ e = q;
|
|
|
+ q = q.nextZ;
|
|
|
+ qSize--;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (tail != null) tail.nextZ = e;
|
|
|
+ else list = e;
|
|
|
+
|
|
|
+ e.prevZ = tail;
|
|
|
+ tail = e;
|
|
|
+ }
|
|
|
+
|
|
|
+ p = q;
|
|
|
+ }
|
|
|
+
|
|
|
+ tail.nextZ = null;
|
|
|
+ inSize *= 2;
|
|
|
+
|
|
|
+ } while (numMerges > 1);
|
|
|
+
|
|
|
+ return list;
|
|
|
+ }
|
|
|
+
|
|
|
+}
|
Nicolas Cannasse