Factor out ol.geom.flat.contains and interiorpoint

src/ol/geom/flat/containsflatgeom.js

@@ -0,0 +1,92 @@
+goog.provide('ol.geom.flat.contains');
+
+goog.require('goog.asserts');
+goog.require('ol.geom.flat');
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {number} end End.
+ * @param {number} stride Stride.
+ * @param {number} x X.
+ * @param {number} y Y.
+ * @return {boolean} Contains (x, y).
+ */
+ol.geom.flat.contains.linearRingContainsXY =
+    function(flatCoordinates, offset, end, stride, x, y) {
+  // http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html
+  var contains = false;
+  var x1 = flatCoordinates[end - stride];
+  var y1 = flatCoordinates[end - stride + 1];
+  for (; offset < end; offset += stride) {
+    var x2 = flatCoordinates[offset];
+    var y2 = flatCoordinates[offset + 1];
+    var intersect = ((y1 > y) != (y2 > y)) &&
+        (x < (x2 - x1) * (y - y1) / (y2 - y1) + x1);
+    if (intersect) {
+      contains = !contains;
+    }
+    x1 = x2;
+    y1 = y2;
+  }
+  return contains;
+};
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<number>} ends Ends.
+ * @param {number} stride Stride.
+ * @param {number} x X.
+ * @param {number} y Y.
+ * @return {boolean} Contains (x, y).
+ */
+ol.geom.flat.contains.linearRingsContainsXY =
+    function(flatCoordinates, offset, ends, stride, x, y) {
+  goog.asserts.assert(ends.length > 0);
+  if (ends.length === 0) {
+    return false;
+  }
+  if (!ol.geom.flat.contains.linearRingContainsXY(
+      flatCoordinates, offset, ends[0], stride, x, y)) {
+    return false;
+  }
+  var i, ii;
+  for (i = 1, ii = ends.length; i < ii; ++i) {
+    if (ol.geom.flat.contains.linearRingContainsXY(
+        flatCoordinates, ends[i - 1], ends[i], stride, x, y)) {
+      return false;
+    }
+  }
+  return true;
+};
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<Array.<number>>} endss Endss.
+ * @param {number} stride Stride.
+ * @param {number} x X.
+ * @param {number} y Y.
+ * @return {boolean} Contains (x, y).
+ */
+ol.geom.flat.contains.linearRingssContainsXY =
+    function(flatCoordinates, offset, endss, stride, x, y) {
+  goog.asserts.assert(endss.length > 0);
+  if (endss.length === 0) {
+    return false;
+  }
+  var i, ii;
+  for (i = 0, ii = endss.length; i < ii; ++i) {
+    var ends = endss[i];
+    if (ol.geom.flat.contains.linearRingsContainsXY(
+        flatCoordinates, offset, ends, stride, x, y)) {
+      return true;
+    }
+    offset = ends[ends.length - 1];
+  }
+  return false;
+};