Factor out ol.geom.flat.orient

src/ol/geom/flat/orientflatgeom.js

@@ -0,0 +1,115 @@
+goog.provide('ol.geom.flat.orient');
+
+goog.require('ol.geom.flat');
+
+
+/**
+ * @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;
+};
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<number>} ends Ends.
+ * @param {number} stride Stride.
+ * @return {boolean} `true` if all rings are correctly oriented, `false`
+ *     otherwise.
+ */
+ol.geom.flat.orient.linearRingsAreOriented =
+    function(flatCoordinates, offset, ends, stride) {
+  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 ? !isClockwise : isClockwise) {
+      return false;
+    }
+    offset = end;
+  }
+  return true;
+};
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<Array.<number>>} endss Endss.
+ * @param {number} stride Stride.
+ * @return {boolean} `true` if all rings are correctly oriented, `false`
+ *     otherwise.
+ */
+ol.geom.flat.linearRingssAreOriented =
+    function(flatCoordinates, offset, endss, stride) {
+  var i, ii;
+  for (i = 0, ii = endss.length; i < ii; ++i) {
+    if (!ol.geom.flat.orient.linearRingsAreOriented(
+        flatCoordinates, offset, endss[i], stride)) {
+      return false;
+    }
+  }
+  return true;
+};
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<number>} ends Ends.
+ * @param {number} stride Stride.
+ * @return {number} End.
+ */
+ol.geom.flat.orient.orientLinearRings =
+    function(flatCoordinates, offset, ends, stride) {
+  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 ? !isClockwise : isClockwise;
+    if (reverse) {
+      ol.geom.flat.reverseCoordinates(flatCoordinates, offset, end, stride);
+    }
+    offset = end;
+  }
+  return offset;
+};
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<Array.<number>>} endss Endss.
+ * @param {number} stride Stride.
+ * @return {number} End.
+ */
+ol.geom.flat.orient.orientLinearRingss =
+    function(flatCoordinates, offset, endss, stride) {
+  var i, ii;
+  for (i = 0, ii = endss.length; i < ii; ++i) {
+    offset = ol.geom.flat.orient.orientLinearRings(
+        flatCoordinates, offset, endss[i], stride);
+  }
+  return offset;
+};

src/ol/geom/flatgeom.js

@@ -228,31 +228,6 @@ ol.geom.flat.linearRingContainsXY =
 };
 
 
-/**
- * @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.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;
-};
-
-
 /**
  * @param {Array.<number>} flatCoordinates Flat coordinates.
  * @param {number} offset Offset.
@@ -348,51 +323,6 @@ ol.geom.flat.linearRingsGetInteriorPoint = function(flatCoordinates, offset,
 };
 
 
-/**
- * @param {Array.<number>} flatCoordinates Flat coordinates.
- * @param {number} offset Offset.
- * @param {Array.<number>} ends Ends.
- * @param {number} stride Stride.
- * @return {boolean} `true` if all rings are correctly oriented, `false`
- *     otherwise.
- */
-ol.geom.flat.linearRingsAreOriented =
-    function(flatCoordinates, offset, ends, stride) {
-  var i, ii;
-  for (i = 0, ii = ends.length; i < ii; ++i) {
-    var end = ends[i];
-    var isClockwise = ol.geom.flat.linearRingIsClockwise(
-        flatCoordinates, offset, end, stride);
-    if (i === 0 ? !isClockwise : isClockwise) {
-      return false;
-    }
-    offset = end;
-  }
-  return true;
-};
-
-
-/**
- * @param {Array.<number>} flatCoordinates Flat coordinates.
- * @param {number} offset Offset.
- * @param {Array.<Array.<number>>} endss Endss.
- * @param {number} stride Stride.
- * @return {boolean} `true` if all rings are correctly oriented, `false`
- *     otherwise.
- */
-ol.geom.flat.linearRingssAreOriented =
-    function(flatCoordinates, offset, endss, stride) {
-  var i, ii;
-  for (i = 0, ii = endss.length; i < ii; ++i) {
-    if (!ol.geom.flat.linearRingsAreOriented(
-        flatCoordinates, offset, endss[i], stride)) {
-      return false;
-    }
-  }
-  return true;
-};
-
-
 /**
  * @param {Array.<number>} flatCoordinates Flat coordinates.
  * @param {number} offset Offset.
@@ -467,48 +397,6 @@ ol.geom.flat.linearRingssGetFlatCenters =
 };
 
 
-/**
- * @param {Array.<number>} flatCoordinates Flat coordinates.
- * @param {number} offset Offset.
- * @param {Array.<number>} ends Ends.
- * @param {number} stride Stride.
- * @return {number} End.
- */
-ol.geom.flat.orientLinearRings =
-    function(flatCoordinates, offset, ends, stride) {
-  var i, ii;
-  for (i = 0, ii = ends.length; i < ii; ++i) {
-    var end = ends[i];
-    var isClockwise = ol.geom.flat.linearRingIsClockwise(
-        flatCoordinates, offset, end, stride);
-    var reverse = i === 0 ? !isClockwise : isClockwise;
-    if (reverse) {
-      ol.geom.flat.reverseCoordinates(flatCoordinates, offset, end, stride);
-    }
-    offset = end;
-  }
-  return offset;
-};
-
-
-/**
- * @param {Array.<number>} flatCoordinates Flat coordinates.
- * @param {number} offset Offset.
- * @param {Array.<Array.<number>>} endss Endss.
- * @param {number} stride Stride.
- * @return {number} End.
- */
-ol.geom.flat.orientLinearRingss =
-    function(flatCoordinates, offset, endss, stride) {
-  var i, ii;
-  for (i = 0, ii = endss.length; i < ii; ++i) {
-    offset = ol.geom.flat.orientLinearRings(
-        flatCoordinates, offset, endss[i], stride);
-  }
-  return offset;
-};
-
-
 /**
  * @param {Array.<number>} flatCoordinates Flat coordinates.
  * @param {number} offset Offset.

src/ol/geom/multipolygon.js

@@ -10,6 +10,7 @@ goog.require('ol.geom.SimpleGeometry');
 goog.require('ol.geom.flat');
 goog.require('ol.geom.flat.area');
 goog.require('ol.geom.flat.closest');
+goog.require('ol.geom.flat.orient');
 goog.require('ol.geom.flat.simplify');
 
 
@@ -204,7 +205,8 @@ ol.geom.MultiPolygon.prototype.getOrientedFlatCoordinates = function() {
       this.orientedFlatCoordinates_ = flatCoordinates;
     } else {
       this.orientedFlatCoordinates_ = flatCoordinates.slice();
-      this.orientedFlatCoordinates_.length = ol.geom.flat.orientLinearRingss(
+      this.orientedFlatCoordinates_.length =
+          ol.geom.flat.orient.orientLinearRingss(
               this.orientedFlatCoordinates_, 0, this.endss_, this.stride);
     }
     this.orientedRevision_ = this.getRevision();

src/ol/geom/polygon.js

@@ -10,6 +10,7 @@ goog.require('ol.geom.SimpleGeometry');
 goog.require('ol.geom.flat');
 goog.require('ol.geom.flat.area');
 goog.require('ol.geom.flat.closest');
+goog.require('ol.geom.flat.orient');
 goog.require('ol.geom.flat.simplify');
 
 
@@ -223,12 +224,13 @@ ol.geom.Polygon.prototype.getLinearRings = function() {
 ol.geom.Polygon.prototype.getOrientedFlatCoordinates = function() {
   if (this.orientedRevision_ != this.getRevision()) {
     var flatCoordinates = this.flatCoordinates;
-    if (ol.geom.flat.linearRingsAreOriented(
+    if (ol.geom.flat.orient.linearRingsAreOriented(
         flatCoordinates, 0, this.ends_, this.stride)) {
       this.orientedFlatCoordinates_ = flatCoordinates;
     } else {
       this.orientedFlatCoordinates_ = flatCoordinates.slice();
-      this.orientedFlatCoordinates_.length = ol.geom.flat.orientLinearRings(
+      this.orientedFlatCoordinates_.length =
+          ol.geom.flat.orient.orientLinearRings(
               this.orientedFlatCoordinates_, 0, this.ends_, this.stride);
     }
     this.orientedRevision_ = this.getRevision();

test/spec/ol/geom/flat/orientflatgeom.test.js

@@ -0,0 +1,26 @@
+goog.provide('ol.test.geom.flat.orient');
+
+describe('ol.geom.flat.orient', function() {
+
+  describe('ol.geom.flat.orient.linearRingIsClockwise', function() {
+
+    it('identifies clockwise rings', function() {
+      var flatCoordinates = [0, 1, 1, 4, 4, 3, 3, 0];
+      var isClockwise = ol.geom.flat.orient.linearRingIsClockwise(
+          flatCoordinates, 0, flatCoordinates.length, 2);
+      expect(isClockwise).to.be(true);
+    });
+
+    it('identifies anti-clockwise rings', function() {
+      var flatCoordinates = [2, 2, 3, 2, 3, 3, 2, 3];
+      var isClockwise = ol.geom.flat.orient.linearRingIsClockwise(
+          flatCoordinates, 0, flatCoordinates.length, 2);
+      expect(isClockwise).to.be(false);
+    });
+
+  });
+
+});
+
+goog.require('ol.geom.flat');
+goog.require('ol.geom.flat.orient');

test/spec/ol/geom/flatgeom.test.js

@@ -85,24 +85,6 @@ describe('ol.geom.flat', function() {
 
   });
 
-  describe('ol.geom.flat.linearRingIsClockwise', function() {
-
-    it('identifies clockwise rings', function() {
-      var flatCoordinates = [0, 1, 1, 4, 4, 3, 3, 0];
-      var isClockwise = ol.geom.flat.linearRingIsClockwise(
-          flatCoordinates, 0, flatCoordinates.length, 2);
-      expect(isClockwise).to.be(true);
-    });
-
-    it('identifies anti-clockwise rings', function() {
-      var flatCoordinates = [2, 2, 3, 2, 3, 3, 2, 3];
-      var isClockwise = ol.geom.flat.linearRingIsClockwise(
-          flatCoordinates, 0, flatCoordinates.length, 2);
-      expect(isClockwise).to.be(false);
-    });
-
-  });
-
   describe('ol.geom.flat.reverseCoordinates', function() {
 
     describe('with a stride of 2', function() {