Standardizing color ranges (see #129)

src/ol/color.js

@@ -1,6 +1,7 @@
 goog.provide('ol.Color');
 
 goog.require('goog.color');
+goog.require('goog.math');
 
 
 
@@ -9,29 +10,29 @@ goog.require('goog.color');
  * @param {number} r Red, 0 to 255.
  * @param {number} g Green, 0 to 255.
  * @param {number} b Blue, 0 to 255.
- * @param {number} a Alpha, 0 (fully transparent) to 255 (fully opaque).
+ * @param {number} a Alpha, 0 (fully transparent) to 1 (fully opaque).
  */
 ol.Color = function(r, g, b, a) {
 
   /**
    * @type {number}
    */
-  this.r = r;
+  this.r = goog.math.clamp(r, 0, 255);
 
   /**
    * @type {number}
    */
-  this.g = g;
+  this.g = goog.math.clamp(g, 0, 255);
 
   /**
    * @type {number}
    */
-  this.b = b;
+  this.b = goog.math.clamp(b, 0, 255);
 
   /**
    * @type {number}
    */
-  this.a = a;
+  this.a = goog.math.clamp(a, 0, 1);
 
 };
 

src/ol/map.js

@@ -618,7 +618,7 @@ ol.Map.prototype.renderFrame_ = function(time) {
     frameState = {
       animate: false,
       backgroundColor: goog.isDef(backgroundColor) ?
-          backgroundColor : new ol.Color(1, 1, 1, 1),
+          backgroundColor : new ol.Color(255, 255, 255, 1),
       coordinateToPixelMatrix: this.coordinateToPixelMatrix_,
       extent: null,
       layersArray: layersArray,

src/ol/renderer/canvas/canvasmaprenderer.js

@@ -138,7 +138,7 @@ ol.renderer.canvas.Map.prototype.renderFrame = function(frameState) {
       backgroundColor.r.toFixed(0) + ',' +
       backgroundColor.g.toFixed(0) + ',' +
       backgroundColor.b.toFixed(0) + ')';
-  context.globalAlpha = 1;
+  context.globalAlpha = backgroundColor.a;
   context.fillRect(0, 0, size.width, size.height);
 
   goog.array.forEach(frameState.layersArray, function(layer) {

src/ol/renderer/webgl/webglmaprenderer.js

@@ -490,7 +490,8 @@ ol.renderer.webgl.Map.prototype.renderFrame = function(frameState) {
   gl.bindFramebuffer(goog.webgl.FRAMEBUFFER, null);
 
   var clearColor = frameState.backgroundColor;
-  gl.clearColor(clearColor.r, clearColor.g, clearColor.b, clearColor.a);
+  gl.clearColor(clearColor.r / 255, clearColor.g / 255,
+      clearColor.b / 255, clearColor.a);
   gl.clear(goog.webgl.COLOR_BUFFER_BIT);
   gl.enable(goog.webgl.BLEND);
   gl.viewport(0, 0, size.width, size.height);