Add support for non-square tiles

src/ol/size.js

@@ -2,6 +2,9 @@ goog.provide('ol.Size');
 goog.provide('ol.size');
 
 
+goog.require('goog.asserts');
+
+
 /**
  * An array of numbers representing a size: `[width, height]`.
  * @typedef {Array.<number>}
@@ -10,6 +13,23 @@ goog.provide('ol.size');
 ol.Size;
 
 
+/**
+ * Returns a buffered size.
+ * @param {ol.Size} size Size.
+ * @param {number} buffer Buffer.
+ * @param {ol.Size=} opt_size Optional reusable size array.
+ * @return {ol.Size}
+ */
+ol.size.buffer = function(size, buffer, opt_size) {
+  if (!goog.isDef(opt_size)) {
+    opt_size = [0, 0];
+  }
+  opt_size[0] = size[0] + 2 * buffer;
+  opt_size[1] = size[1] + 2 * buffer;
+  return opt_size;
+};
+
+
 /**
  * Compares sizes for equality.
  * @param {ol.Size} a Size.
@@ -19,3 +39,40 @@ ol.Size;
 ol.size.equals = function(a, b) {
   return a[0] == b[0] && a[1] == b[1];
 };
+
+
+/**
+ * Returns a size scaled by a ratio. The result will be an array of integers.
+ * @param {ol.Size} size Size.
+ * @param {number} ratio Ratio.
+ * @param {ol.Size=} opt_size Optional reusable size array.
+ * @return {ol.Size}
+ */
+ol.size.scale = function(size, ratio, opt_size) {
+  if (!goog.isDef(opt_size)) {
+    opt_size = [0, 0];
+  }
+  opt_size[0] = (size[0] * ratio + 0.5) | 0;
+  opt_size[1] = (size[1] * ratio + 0.5) | 0;
+  return opt_size;
+};
+
+
+/**
+ * @param {number|ol.Size} size Width and height.
+ * @param {ol.Size=} opt_size Optional reusable size array.
+ * @return {ol.Size} Size.
+ */
+ol.size.toSize = function(size, opt_size) {
+  if (goog.isArray(size)) {
+    return size;
+  } else {
+    if (!goog.isDef(opt_size)) {
+      opt_size = [0, 0];
+    }
+    goog.asserts.assert(goog.isNumber(size));
+    opt_size[0] = size;
+    opt_size[1] = size;
+    return opt_size;
+  }
+};