Move flat geom files so they are named like their provides

src/ol/geom/flat/orient.js

@@ -0,0 +1,143 @@
+goog.provide('ol.geom.flat.orient');
+
+goog.require('ol');
+goog.require('ol.geom.flat.reverse');
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {number} end End.
+ * @param {number} stride Stride.
+ * @return {boolean} Is clockwise.
+ */
+ol.geom.flat.orient.linearRingIsClockwise = function(flatCoordinates, offset, end, stride) {
+  // http://tinyurl.com/clockwise-method
+  // https://github.com/OSGeo/gdal/blob/trunk/gdal/ogr/ogrlinearring.cpp
+  var edge = 0;
+  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];
+    edge += (x2 - x1) * (y2 + y1);
+    x1 = x2;
+    y1 = y2;
+  }
+  return edge > 0;
+};
+
+
+/**
+ * Determines if linear rings are oriented.  By default, left-hand orientation
+ * is tested (first ring must be clockwise, remaining rings counter-clockwise).
+ * To test for right-hand orientation, use the `opt_right` argument.
+ *
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<number>} ends Array of end indexes.
+ * @param {number} stride Stride.
+ * @param {boolean=} opt_right Test for right-hand orientation
+ *     (counter-clockwise exterior ring and clockwise interior rings).
+ * @return {boolean} Rings are correctly oriented.
+ */
+ol.geom.flat.orient.linearRingsAreOriented = function(flatCoordinates, offset, ends, stride, opt_right) {
+  var right = opt_right !== undefined ? opt_right : false;
+  var i, ii;
+  for (i = 0, ii = ends.length; i < ii; ++i) {
+    var end = ends[i];
+    var isClockwise = ol.geom.flat.orient.linearRingIsClockwise(
+        flatCoordinates, offset, end, stride);
+    if (i === 0) {
+      if ((right && isClockwise) || (!right && !isClockwise)) {
+        return false;
+      }
+    } else {
+      if ((right && !isClockwise) || (!right && isClockwise)) {
+        return false;
+      }
+    }
+    offset = end;
+  }
+  return true;
+};
+
+
+/**
+ * Determines if linear rings are oriented.  By default, left-hand orientation
+ * is tested (first ring must be clockwise, remaining rings counter-clockwise).
+ * To test for right-hand orientation, use the `opt_right` argument.
+ *
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<Array.<number>>} endss Array of array of end indexes.
+ * @param {number} stride Stride.
+ * @param {boolean=} opt_right Test for right-hand orientation
+ *     (counter-clockwise exterior ring and clockwise interior rings).
+ * @return {boolean} Rings are correctly oriented.
+ */
+ol.geom.flat.orient.linearRingssAreOriented = function(flatCoordinates, offset, endss, stride, opt_right) {
+  var i, ii;
+  for (i = 0, ii = endss.length; i < ii; ++i) {
+    if (!ol.geom.flat.orient.linearRingsAreOriented(
+        flatCoordinates, offset, endss[i], stride, opt_right)) {
+      return false;
+    }
+  }
+  return true;
+};
+
+
+/**
+ * Orient coordinates in a flat array of linear rings.  By default, rings
+ * are oriented following the left-hand rule (clockwise for exterior and
+ * counter-clockwise for interior rings).  To orient according to the
+ * right-hand rule, use the `opt_right` argument.
+ *
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<number>} ends Ends.
+ * @param {number} stride Stride.
+ * @param {boolean=} opt_right Follow the right-hand rule for orientation.
+ * @return {number} End.
+ */
+ol.geom.flat.orient.orientLinearRings = function(flatCoordinates, offset, ends, stride, opt_right) {
+  var right = opt_right !== undefined ? opt_right : false;
+  var i, ii;
+  for (i = 0, ii = ends.length; i < ii; ++i) {
+    var end = ends[i];
+    var isClockwise = ol.geom.flat.orient.linearRingIsClockwise(
+        flatCoordinates, offset, end, stride);
+    var reverse = i === 0 ?
+        (right && isClockwise) || (!right && !isClockwise) :
+        (right && !isClockwise) || (!right && isClockwise);
+    if (reverse) {
+      ol.geom.flat.reverse.coordinates(flatCoordinates, offset, end, stride);
+    }
+    offset = end;
+  }
+  return offset;
+};
+
+
+/**
+ * Orient coordinates in a flat array of linear rings.  By default, rings
+ * are oriented following the left-hand rule (clockwise for exterior and
+ * counter-clockwise for interior rings).  To orient according to the
+ * right-hand rule, use the `opt_right` argument.
+ *
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<Array.<number>>} endss Array of array of end indexes.
+ * @param {number} stride Stride.
+ * @param {boolean=} opt_right Follow the right-hand rule for orientation.
+ * @return {number} End.
+ */
+ol.geom.flat.orient.orientLinearRingss = function(flatCoordinates, offset, endss, stride, opt_right) {
+  var i, ii;
+  for (i = 0, ii = endss.length; i < ii; ++i) {
+    offset = ol.geom.flat.orient.orientLinearRings(
+        flatCoordinates, offset, endss[i], stride, opt_right);
+  }
+  return offset;
+};