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@@ -1,9 +1,5 @@
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-/**
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- * An implementation of the earcut polygon triangulation algorithm. The code
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- * is a port of [mapbox/earcut]{@link https://github.com/mapbox/earcut mapbox/earcut} (v2.2.4).
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- *
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- * @hideconstructor
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- */
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+import earcut from 'earcut';
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+
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class Earcut {
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/**
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@@ -17,784 +13,10 @@ class Earcut {
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*/
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static triangulate( data, holeIndices, dim = 2 ) {
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- const hasHoles = holeIndices && holeIndices.length;
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- const outerLen = hasHoles ? holeIndices[ 0 ] * dim : data.length;
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- let outerNode = linkedList( data, 0, outerLen, dim, true );
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- const triangles = [];
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-
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- if ( ! outerNode || outerNode.next === outerNode.prev ) return triangles;
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-
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- let minX, minY, maxX, maxY, x, y, invSize;
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-
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- if ( hasHoles ) outerNode = eliminateHoles( data, holeIndices, outerNode, dim );
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-
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- // if the shape is not too simple, we'll use z-order curve hash later; calculate polygon bbox
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- if ( data.length > 80 * dim ) {
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-
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- minX = maxX = data[ 0 ];
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- minY = maxY = data[ 1 ];
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-
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- for ( let i = dim; i < outerLen; i += dim ) {
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-
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- x = data[ i ];
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- y = data[ i + 1 ];
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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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-
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- }
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-
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- // minX, minY and invSize are later used to transform coords into integers for z-order calculation
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- invSize = Math.max( maxX - minX, maxY - minY );
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- invSize = invSize !== 0 ? 32767 / invSize : 0;
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-
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- }
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-
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- earcutLinked( outerNode, triangles, dim, minX, minY, invSize, 0 );
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-
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- return triangles;
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-
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- }
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-
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-}
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-
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-// create a circular doubly linked list from polygon points in the specified winding order
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-function linkedList( data, start, end, dim, clockwise ) {
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-
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- let i, last;
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-
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- if ( clockwise === ( signedArea( data, start, end, dim ) > 0 ) ) {
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-
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- for ( i = start; i < end; i += dim ) last = insertNode( i, data[ i ], data[ i + 1 ], last );
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-
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- } else {
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-
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- for ( i = end - dim; i >= start; i -= dim ) last = insertNode( i, data[ i ], data[ i + 1 ], last );
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-
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- }
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-
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- if ( last && equals( last, last.next ) ) {
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-
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- removeNode( last );
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- last = last.next;
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-
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- }
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-
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- return last;
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-
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-}
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-
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-// eliminate colinear or duplicate points
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-function filterPoints( start, end ) {
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-
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- if ( ! start ) return start;
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- if ( ! end ) end = start;
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-
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- let p = start,
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- again;
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- do {
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-
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- again = false;
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-
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- if ( ! p.steiner && ( equals( p, p.next ) || area( p.prev, p, p.next ) === 0 ) ) {
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-
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- removeNode( p );
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- p = end = p.prev;
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- if ( p === p.next ) break;
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- again = true;
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-
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- } else {
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-
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- p = p.next;
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-
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- }
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-
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- } while ( again || p !== end );
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-
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- return end;
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-
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-}
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-
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-// main ear slicing loop which triangulates a polygon (given as a linked list)
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-function earcutLinked( ear, triangles, dim, minX, minY, invSize, pass ) {
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-
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- if ( ! ear ) return;
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-
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- // interlink polygon nodes in z-order
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- if ( ! pass && invSize ) indexCurve( ear, minX, minY, invSize );
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-
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- let 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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-
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- prev = ear.prev;
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- next = ear.next;
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-
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- if ( invSize ? isEarHashed( ear, minX, minY, invSize ) : isEar( ear ) ) {
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-
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- // cut off the triangle
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- triangles.push( prev.i / dim | 0 );
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- triangles.push( ear.i / dim | 0 );
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- triangles.push( next.i / dim | 0 );
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-
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- removeNode( ear );
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-
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- // skipping the next vertex 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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-
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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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-
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- // try filtering points and slicing again
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- if ( ! pass ) {
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-
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- earcutLinked( filterPoints( ear ), triangles, dim, minX, minY, invSize, 1 );
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-
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- // if this didn't work, try curing all small self-intersections locally
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-
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- } else if ( pass === 1 ) {
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-
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- ear = cureLocalIntersections( filterPoints( ear ), triangles, dim );
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- earcutLinked( ear, triangles, dim, minX, minY, invSize, 2 );
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-
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- // as a last resort, try splitting the remaining polygon into two
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-
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- } else if ( pass === 2 ) {
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-
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- splitEarcut( ear, triangles, dim, minX, minY, invSize );
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-
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- }
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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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-
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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 ) {
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-
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- const 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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- const ax = a.x, bx = b.x, cx = c.x, ay = a.y, by = b.y, cy = c.y;
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-
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- // triangle bbox; min & max are calculated like this for speed
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- const x0 = ax < bx ? ( ax < cx ? ax : cx ) : ( bx < cx ? bx : cx ),
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- y0 = ay < by ? ( ay < cy ? ay : cy ) : ( by < cy ? by : cy ),
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- x1 = ax > bx ? ( ax > cx ? ax : cx ) : ( bx > cx ? bx : cx ),
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- y1 = ay > by ? ( ay > cy ? ay : cy ) : ( by > cy ? by : cy );
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-
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- let p = c.next;
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- while ( p !== a ) {
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-
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- if ( p.x >= x0 && p.x <= x1 && p.y >= y0 && p.y <= y1 &&
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- pointInTriangle( ax, ay, bx, by, cx, cy, 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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-
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- return true;
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-
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-}
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-
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-function isEarHashed( ear, minX, minY, invSize ) {
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-
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- const 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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- const ax = a.x, bx = b.x, cx = c.x, ay = a.y, by = b.y, cy = c.y;
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-
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- // triangle bbox; min & max are calculated like this for speed
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- const x0 = ax < bx ? ( ax < cx ? ax : cx ) : ( bx < cx ? bx : cx ),
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- y0 = ay < by ? ( ay < cy ? ay : cy ) : ( by < cy ? by : cy ),
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- x1 = ax > bx ? ( ax > cx ? ax : cx ) : ( bx > cx ? bx : cx ),
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- y1 = ay > by ? ( ay > cy ? ay : cy ) : ( by > cy ? by : cy );
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-
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- // z-order range for the current triangle bbox;
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- const minZ = zOrder( x0, y0, minX, minY, invSize ),
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- maxZ = zOrder( x1, y1, minX, minY, invSize );
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-
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- let p = ear.prevZ,
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- n = ear.nextZ;
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-
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- // look for points inside the triangle in both directions
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- while ( p && p.z >= minZ && n && n.z <= maxZ ) {
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-
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- if ( p.x >= x0 && p.x <= x1 && p.y >= y0 && p.y <= y1 && p !== a && p !== c &&
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- pointInTriangle( ax, ay, bx, by, cx, cy, p.x, p.y ) && area( p.prev, p, p.next ) >= 0 ) return false;
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- p = p.prevZ;
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-
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- if ( n.x >= x0 && n.x <= x1 && n.y >= y0 && n.y <= y1 && n !== a && n !== c &&
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- pointInTriangle( ax, ay, bx, by, cx, cy, n.x, n.y ) && area( n.prev, n, n.next ) >= 0 ) return false;
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- n = n.nextZ;
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-
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- }
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-
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- // look for remaining points in decreasing z-order
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- while ( p && p.z >= minZ ) {
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-
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- if ( p.x >= x0 && p.x <= x1 && p.y >= y0 && p.y <= y1 && p !== a && p !== c &&
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- pointInTriangle( ax, ay, bx, by, cx, cy, p.x, p.y ) && 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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-
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- // look for remaining points in increasing z-order
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- while ( n && n.z <= maxZ ) {
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-
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- if ( n.x >= x0 && n.x <= x1 && n.y >= y0 && n.y <= y1 && n !== a && n !== c &&
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- pointInTriangle( ax, ay, bx, by, cx, cy, n.x, n.y ) && area( n.prev, n, n.next ) >= 0 ) return false;
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- n = n.nextZ;
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-
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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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-
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-// go through all polygon nodes and cure small local self-intersections
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-function cureLocalIntersections( start, triangles, dim ) {
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-
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- let p = start;
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- do {
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-
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- const a = p.prev,
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- b = p.next.next;
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-
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- if ( ! equals( a, b ) && intersects( a, p, p.next, b ) && locallyInside( a, b ) && locallyInside( b, a ) ) {
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-
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- triangles.push( a.i / dim | 0 );
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- triangles.push( p.i / dim | 0 );
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- triangles.push( b.i / dim | 0 );
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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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- }
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-
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- p = p.next;
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-
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- } while ( p !== start );
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-
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- return filterPoints( p );
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-
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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, triangles, dim, minX, minY, invSize ) {
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-
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- // look for a valid diagonal that divides the polygon into two
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- let a = start;
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- do {
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-
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- let b = a.next.next;
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- while ( b !== a.prev ) {
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-
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- if ( a.i !== b.i && isValidDiagonal( a, b ) ) {
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-
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- // split the polygon in two by the diagonal
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- let 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, triangles, dim, minX, minY, invSize, 0 );
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- earcutLinked( c, triangles, dim, minX, minY, invSize, 0 );
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- return;
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-
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- }
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-
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- b = b.next;
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-
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- }
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-
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- a = a.next;
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-
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- } while ( a !== start );
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-
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-}
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-
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-// link every hole into the outer loop, producing a single-ring polygon without holes
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-function eliminateHoles( data, holeIndices, outerNode, dim ) {
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-
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- const queue = [];
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- let i, len, start, end, list;
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-
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- for ( i = 0, len = holeIndices.length; i < len; i ++ ) {
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-
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- start = holeIndices[ i ] * dim;
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- end = i < len - 1 ? holeIndices[ i + 1 ] * dim : data.length;
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- list = linkedList( data, start, end, dim, false );
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- if ( list === list.next ) list.steiner = true;
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- queue.push( getLeftmost( list ) );
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-
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- }
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-
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- queue.sort( compareX );
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-
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- // process holes from left to right
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- for ( i = 0; i < queue.length; i ++ ) {
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-
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- outerNode = eliminateHole( queue[ i ], outerNode );
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-
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- }
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-
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- return outerNode;
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-
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-}
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-
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-function compareX( a, b ) {
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-
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- return a.x - b.x;
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-
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-}
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-
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-// find a bridge between vertices that connects hole with an outer ring and link it
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-function eliminateHole( hole, outerNode ) {
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-
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- const bridge = findHoleBridge( hole, outerNode );
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- if ( ! bridge ) {
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-
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- return outerNode;
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-
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- }
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-
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- const bridgeReverse = splitPolygon( bridge, hole );
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-
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- // filter collinear points around the cuts
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- filterPoints( bridgeReverse, bridgeReverse.next );
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- return filterPoints( bridge, bridge.next );
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-
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-}
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-
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-// David Eberly's algorithm for finding a bridge between hole and outer polygon
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-function findHoleBridge( hole, outerNode ) {
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-
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- let p = outerNode,
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- qx = - Infinity,
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- m;
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-
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- const hx = hole.x, hy = hole.y;
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-
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- // find a segment intersected by a ray from the hole's leftmost point to the left;
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- // segment's endpoint with lesser x will be potential connection point
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- do {
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-
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- if ( hy <= p.y && hy >= p.next.y && p.next.y !== p.y ) {
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-
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- const x = p.x + ( hy - p.y ) * ( p.next.x - p.x ) / ( p.next.y - p.y );
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- if ( x <= hx && x > qx ) {
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-
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- qx = x;
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- m = p.x < p.next.x ? p : p.next;
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- if ( x === hx ) return m; // hole touches outer segment; pick leftmost endpoint
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-
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- }
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-
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- }
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-
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- p = p.next;
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-
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- } while ( p !== outerNode );
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|
|
-
|
|
|
- if ( ! m ) return null;
|
|
|
-
|
|
|
- // look for points inside the triangle of hole point, segment intersection and endpoint;
|
|
|
- // if there are no points found, we have a valid connection;
|
|
|
- // otherwise choose the point of the minimum angle with the ray as connection point
|
|
|
-
|
|
|
- const stop = m,
|
|
|
- mx = m.x,
|
|
|
- my = m.y;
|
|
|
- let tanMin = Infinity, tan;
|
|
|
-
|
|
|
- p = m;
|
|
|
-
|
|
|
- do {
|
|
|
-
|
|
|
- if ( hx >= p.x && p.x >= mx && hx !== p.x &&
|
|
|
- pointInTriangle( hy < my ? hx : qx, hy, mx, my, hy < my ? qx : hx, hy, p.x, p.y ) ) {
|
|
|
-
|
|
|
- tan = Math.abs( hy - p.y ) / ( hx - p.x ); // tangential
|
|
|
-
|
|
|
- if ( locallyInside( p, hole ) && ( tan < tanMin || ( tan === tanMin && ( p.x > m.x || ( p.x === m.x && sectorContainsSector( m, p ) ) ) ) ) ) {
|
|
|
-
|
|
|
- m = p;
|
|
|
- tanMin = tan;
|
|
|
-
|
|
|
- }
|
|
|
-
|
|
|
- }
|
|
|
-
|
|
|
- p = p.next;
|
|
|
-
|
|
|
- } while ( p !== stop );
|
|
|
-
|
|
|
- return m;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// whether sector in vertex m contains sector in vertex p in the same coordinates
|
|
|
-function sectorContainsSector( m, p ) {
|
|
|
-
|
|
|
- return area( m.prev, m, p.prev ) < 0 && area( p.next, m, m.next ) < 0;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// interlink polygon nodes in z-order
|
|
|
-function indexCurve( start, minX, minY, invSize ) {
|
|
|
-
|
|
|
- let p = start;
|
|
|
- do {
|
|
|
-
|
|
|
- if ( p.z === 0 ) p.z = zOrder( p.x, p.y, minX, minY, invSize );
|
|
|
- p.prevZ = p.prev;
|
|
|
- p.nextZ = p.next;
|
|
|
- p = p.next;
|
|
|
-
|
|
|
- } while ( p !== start );
|
|
|
-
|
|
|
- p.prevZ.nextZ = null;
|
|
|
- p.prevZ = null;
|
|
|
-
|
|
|
- sortLinked( p );
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// Simon Tatham's linked list merge sort algorithm
|
|
|
-// http://www.chiark.greenend.org.uk/~sgtatham/algorithms/listsort.html
|
|
|
-function sortLinked( list ) {
|
|
|
-
|
|
|
- let i, p, q, e, tail, numMerges, pSize, qSize,
|
|
|
- inSize = 1;
|
|
|
-
|
|
|
- do {
|
|
|
-
|
|
|
- p = list;
|
|
|
- list = null;
|
|
|
- tail = null;
|
|
|
- numMerges = 0;
|
|
|
-
|
|
|
- while ( p ) {
|
|
|
-
|
|
|
- numMerges ++;
|
|
|
- q = p;
|
|
|
- pSize = 0;
|
|
|
- for ( i = 0; i < inSize; i ++ ) {
|
|
|
-
|
|
|
- pSize ++;
|
|
|
- q = q.nextZ;
|
|
|
- if ( ! q ) break;
|
|
|
-
|
|
|
- }
|
|
|
-
|
|
|
- qSize = inSize;
|
|
|
-
|
|
|
- while ( pSize > 0 || ( qSize > 0 && q ) ) {
|
|
|
-
|
|
|
- if ( pSize !== 0 && ( qSize === 0 || ! q || p.z <= q.z ) ) {
|
|
|
-
|
|
|
- e = p;
|
|
|
- p = p.nextZ;
|
|
|
- pSize --;
|
|
|
-
|
|
|
- } else {
|
|
|
-
|
|
|
- e = q;
|
|
|
- q = q.nextZ;
|
|
|
- qSize --;
|
|
|
-
|
|
|
- }
|
|
|
-
|
|
|
- if ( tail ) tail.nextZ = e;
|
|
|
- else list = e;
|
|
|
-
|
|
|
- e.prevZ = tail;
|
|
|
- tail = e;
|
|
|
-
|
|
|
- }
|
|
|
-
|
|
|
- p = q;
|
|
|
-
|
|
|
- }
|
|
|
-
|
|
|
- tail.nextZ = null;
|
|
|
- inSize *= 2;
|
|
|
-
|
|
|
- } while ( numMerges > 1 );
|
|
|
-
|
|
|
- return list;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// z-order of a point given coords and inverse of the longer side of data bbox
|
|
|
-function zOrder( x, y, minX, minY, invSize ) {
|
|
|
-
|
|
|
- // coords are transformed into non-negative 15-bit integer range
|
|
|
- x = ( x - minX ) * invSize | 0;
|
|
|
- y = ( y - minY ) * invSize | 0;
|
|
|
-
|
|
|
- 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 );
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// find the leftmost node of a polygon ring
|
|
|
-function getLeftmost( start ) {
|
|
|
-
|
|
|
- let p = start,
|
|
|
- leftmost = start;
|
|
|
- do {
|
|
|
-
|
|
|
- if ( p.x < leftmost.x || ( p.x === leftmost.x && p.y < leftmost.y ) ) leftmost = p;
|
|
|
- p = p.next;
|
|
|
-
|
|
|
- } while ( p !== start );
|
|
|
-
|
|
|
- return leftmost;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// check if a point lies within a convex triangle
|
|
|
-function pointInTriangle( ax, ay, bx, by, cx, cy, px, py ) {
|
|
|
-
|
|
|
- return ( cx - px ) * ( ay - py ) >= ( ax - px ) * ( cy - py ) &&
|
|
|
- ( ax - px ) * ( by - py ) >= ( bx - px ) * ( ay - py ) &&
|
|
|
- ( bx - px ) * ( cy - py ) >= ( cx - px ) * ( by - py );
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// check if a diagonal between two polygon nodes is valid (lies in polygon interior)
|
|
|
-function isValidDiagonal( a, b ) {
|
|
|
-
|
|
|
- return a.next.i !== b.i && a.prev.i !== b.i && ! intersectsPolygon( a, b ) && // doesn't intersect other edges
|
|
|
- ( locallyInside( a, b ) && locallyInside( b, a ) && middleInside( a, b ) && // locally visible
|
|
|
- ( area( a.prev, a, b.prev ) || area( a, b.prev, b ) ) || // does not create opposite-facing sectors
|
|
|
- equals( a, b ) && area( a.prev, a, a.next ) > 0 && area( b.prev, b, b.next ) > 0 ); // special zero-length case
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// signed area of a triangle
|
|
|
-function area( p, q, r ) {
|
|
|
-
|
|
|
- return ( q.y - p.y ) * ( r.x - q.x ) - ( q.x - p.x ) * ( r.y - q.y );
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// check if two points are equal
|
|
|
-function equals( p1, p2 ) {
|
|
|
-
|
|
|
- return p1.x === p2.x && p1.y === p2.y;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// check if two segments intersect
|
|
|
-function intersects( p1, q1, p2, q2 ) {
|
|
|
-
|
|
|
- const o1 = sign( area( p1, q1, p2 ) );
|
|
|
- const o2 = sign( area( p1, q1, q2 ) );
|
|
|
- const o3 = sign( area( p2, q2, p1 ) );
|
|
|
- const o4 = sign( area( p2, q2, q1 ) );
|
|
|
-
|
|
|
- if ( o1 !== o2 && o3 !== o4 ) return true; // general case
|
|
|
-
|
|
|
- if ( o1 === 0 && onSegment( p1, p2, q1 ) ) return true; // p1, q1 and p2 are collinear and p2 lies on p1q1
|
|
|
- if ( o2 === 0 && onSegment( p1, q2, q1 ) ) return true; // p1, q1 and q2 are collinear and q2 lies on p1q1
|
|
|
- if ( o3 === 0 && onSegment( p2, p1, q2 ) ) return true; // p2, q2 and p1 are collinear and p1 lies on p2q2
|
|
|
- if ( o4 === 0 && onSegment( p2, q1, q2 ) ) return true; // p2, q2 and q1 are collinear and q1 lies on p2q2
|
|
|
-
|
|
|
- return false;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// for collinear points p, q, r, check if point q lies on segment pr
|
|
|
-function onSegment( p, q, r ) {
|
|
|
-
|
|
|
- return q.x <= Math.max( p.x, r.x ) && q.x >= Math.min( p.x, r.x ) && q.y <= Math.max( p.y, r.y ) && q.y >= Math.min( p.y, r.y );
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-function sign( num ) {
|
|
|
-
|
|
|
- return num > 0 ? 1 : num < 0 ? - 1 : 0;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// check if a polygon diagonal intersects any polygon segments
|
|
|
-function intersectsPolygon( a, b ) {
|
|
|
-
|
|
|
- let p = a;
|
|
|
- do {
|
|
|
-
|
|
|
- if ( p.i !== a.i && p.next.i !== a.i && p.i !== b.i && p.next.i !== b.i &&
|
|
|
- intersects( p, p.next, a, b ) ) return true;
|
|
|
- p = p.next;
|
|
|
-
|
|
|
- } while ( p !== a );
|
|
|
-
|
|
|
- return false;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// check if a polygon diagonal is locally inside the polygon
|
|
|
-function locallyInside( a, b ) {
|
|
|
-
|
|
|
- return area( a.prev, a, a.next ) < 0 ?
|
|
|
- area( a, b, a.next ) >= 0 && area( a, a.prev, b ) >= 0 :
|
|
|
- area( a, b, a.prev ) < 0 || area( a, a.next, b ) < 0;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// check if the middle point of a polygon diagonal is inside the polygon
|
|
|
-function middleInside( a, b ) {
|
|
|
-
|
|
|
- let p = a,
|
|
|
- inside = false;
|
|
|
- const px = ( a.x + b.x ) / 2,
|
|
|
- py = ( a.y + b.y ) / 2;
|
|
|
- do {
|
|
|
-
|
|
|
- if ( ( ( p.y > py ) !== ( p.next.y > py ) ) && p.next.y !== p.y &&
|
|
|
- ( px < ( p.next.x - p.x ) * ( py - p.y ) / ( p.next.y - p.y ) + p.x ) )
|
|
|
- inside = ! inside;
|
|
|
- p = p.next;
|
|
|
-
|
|
|
- } while ( p !== a );
|
|
|
-
|
|
|
- return inside;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// link two polygon vertices with a bridge; if the vertices belong to the same ring, it splits polygon into two;
|
|
|
-// if one belongs to the outer ring and another to a hole, it merges it into a single ring
|
|
|
-function splitPolygon( a, b ) {
|
|
|
-
|
|
|
- const a2 = new Node( a.i, a.x, a.y ),
|
|
|
- b2 = new Node( b.i, b.x, b.y ),
|
|
|
- an = a.next,
|
|
|
- bp = b.prev;
|
|
|
-
|
|
|
- a.next = b;
|
|
|
- b.prev = a;
|
|
|
-
|
|
|
- a2.next = an;
|
|
|
- an.prev = a2;
|
|
|
-
|
|
|
- b2.next = a2;
|
|
|
- a2.prev = b2;
|
|
|
-
|
|
|
- bp.next = b2;
|
|
|
- b2.prev = bp;
|
|
|
-
|
|
|
- return b2;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-// create a node and optionally link it with previous one (in a circular doubly linked list)
|
|
|
-function insertNode( i, x, y, last ) {
|
|
|
-
|
|
|
- const p = new Node( i, x, y );
|
|
|
-
|
|
|
- if ( ! last ) {
|
|
|
-
|
|
|
- p.prev = p;
|
|
|
- p.next = p;
|
|
|
-
|
|
|
- } else {
|
|
|
-
|
|
|
- p.next = last.next;
|
|
|
- p.prev = last;
|
|
|
- last.next.prev = p;
|
|
|
- last.next = p;
|
|
|
+ return earcut( data, holeIndices, dim );
|
|
|
|
|
|
}
|
|
|
|
|
|
- return p;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-function removeNode( p ) {
|
|
|
-
|
|
|
- p.next.prev = p.prev;
|
|
|
- p.prev.next = p.next;
|
|
|
-
|
|
|
- if ( p.prevZ ) p.prevZ.nextZ = p.nextZ;
|
|
|
- if ( p.nextZ ) p.nextZ.prevZ = p.prevZ;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-function Node( i, x, y ) {
|
|
|
-
|
|
|
- // vertex index in coordinates array
|
|
|
- this.i = i;
|
|
|
-
|
|
|
- // vertex coordinates
|
|
|
- this.x = x;
|
|
|
- this.y = y;
|
|
|
-
|
|
|
- // previous and next vertex nodes in a polygon ring
|
|
|
- this.prev = null;
|
|
|
- this.next = null;
|
|
|
-
|
|
|
- // z-order curve value
|
|
|
- this.z = 0;
|
|
|
-
|
|
|
- // previous and next nodes in z-order
|
|
|
- this.prevZ = null;
|
|
|
- this.nextZ = null;
|
|
|
-
|
|
|
- // indicates whether this is a steiner point
|
|
|
- this.steiner = false;
|
|
|
-
|
|
|
-}
|
|
|
-
|
|
|
-function signedArea( data, start, end, dim ) {
|
|
|
-
|
|
|
- let sum = 0;
|
|
|
- for ( let i = start, j = end - dim; i < end; i += dim ) {
|
|
|
-
|
|
|
- sum += ( data[ j ] - data[ i ] ) * ( data[ i + 1 ] + data[ j + 1 ] );
|
|
|
- j = i;
|
|
|
-
|
|
|
- }
|
|
|
-
|
|
|
- return sum;
|
|
|
-
|
|
|
}
|
|
|
|
|
|
export { Earcut };
|
Garrett Johnson