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| author | Aditi <aditi.iitr@gmail.com> | 2013-06-21 23:09:22 +0530 |
|---|---|---|
| committer | Aditi <aditi.iitr@gmail.com> | 2013-06-21 23:09:22 +0530 |
| commit | 2719d546a57c2332e36cc056ac80ec5d79672c1a (patch) | |
| tree | 1f62ab8f761026d4faa5442032df133fc90d47f2 /extlib/leaflet/src/geometry/PolyUtil.js | |
| parent | 1a6f065419290b3f4234ce4a89bb2c46b13e8a12 (diff) | |
| parent | 92b22e7deac547835f69168f97012b52e87b6de4 (diff) | |
| download | mediagoblin-2719d546a57c2332e36cc056ac80ec5d79672c1a.tar.lz mediagoblin-2719d546a57c2332e36cc056ac80ec5d79672c1a.tar.xz mediagoblin-2719d546a57c2332e36cc056ac80ec5d79672c1a.zip | |
Merge remote-tracking branch 'cweb/master'
Diffstat (limited to 'extlib/leaflet/src/geometry/PolyUtil.js')
| -rw-r--r-- | extlib/leaflet/src/geometry/PolyUtil.js | 55 |
1 files changed, 55 insertions, 0 deletions
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 |