From c5ba5b0456a711d157e317f220e9c739226e7f50 Mon Sep 17 00:00:00 2001 From: Joar Wandborg Date: Tue, 10 Jan 2012 01:54:37 +0100 Subject: Installed leaflet in extlib --- extlib/leaflet/src/geometry/PolyUtil.js | 55 +++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 extlib/leaflet/src/geometry/PolyUtil.js (limited to 'extlib/leaflet/src/geometry/PolyUtil.js') diff --git a/extlib/leaflet/src/geometry/PolyUtil.js b/extlib/leaflet/src/geometry/PolyUtil.js new file mode 100644 index 00000000..c5460709 --- /dev/null +++ b/extlib/leaflet/src/geometry/PolyUtil.js @@ -0,0 +1,55 @@ +/* + * L.PolyUtil contains utilify functions for polygons (clipping, etc.). + */ + +L.PolyUtil = {}; + +/* + * Sutherland-Hodgeman polygon clipping algorithm. + * Used to avoid rendering parts of a polygon that are not currently visible. + */ +L.PolyUtil.clipPolygon = function(points, bounds) { + var min = bounds.min, + max = bounds.max, + clippedPoints, + edges = [1, 4, 2, 8], + i, j, k, + a, b, + len, edge, p, + lu = L.LineUtil; + + for (i = 0, len = points.length; i < len; i++) { + points[i]._code = lu._getBitCode(points[i], bounds); + } + + // for each edge (left, bottom, right, top) + for (k = 0; k < 4; k++) { + edge = edges[k]; + clippedPoints = []; + + for (i = 0, len = points.length, j = len - 1; i < len; j = i++) { + a = points[i]; + b = points[j]; + + // if a is inside the clip window + if (!(a._code & edge)) { + // if b is outside the clip window (a->b goes out of screen) + if (b._code & edge) { + p = lu._getEdgeIntersection(b, a, edge, bounds); + p._code = lu._getBitCode(p, bounds); + clippedPoints.push(p); + } + clippedPoints.push(a); + + // else if b is inside the clip window (a->b enters the screen) + } else if (!(b._code & edge)) { + p = lu._getEdgeIntersection(b, a, edge, bounds); + p._code = lu._getBitCode(p, bounds); + clippedPoints.push(p); + } + } + points = clippedPoints; + } + + return points; +}; \ No newline at end of file -- cgit v1.2.3