ol.vec.Mat4 improvements

* Rename ol.vec.Mat4.fromMatrix to ol.vec.Mat4.fromTransform
* Make result from ol.vec.Mat4.fromTransform immutable by adding result
  matrix as argument.

src/ol/dom/dom.js

@@ -6,6 +6,13 @@ goog.require('ol');
 goog.require('ol.vec.Mat4');
 
 
+/**
+ * @type {Array.<number>}
+ * @private
+ */
+ol.dom.tmpMat4_ = ol.vec.Mat4.create();
+
+
 /**
  * Create an html canvas element and returns its 2d context.
  * @param {number=} opt_width Canvas width.
@@ -136,7 +143,7 @@ ol.dom.transformElement2D = function(element, transform, opt_precision) {
   var i;
   if (ol.dom.canUseCssTransform3D()) {
     var value3D;
-    var transform3D = ol.vec.Mat4.fromMatrix(transform);
+    var transform3D = ol.vec.Mat4.fromTransform(ol.dom.tmpMat4_, transform);
     if (opt_precision !== undefined) {
       /** @type {Array.<string>} */
       var strings3D = new Array(16);

src/ol/render/webgl/webglreplay.js

@@ -145,6 +145,12 @@ ol.render.webgl.ImageReplay = function(tolerance, maxExtent) {
    */
   this.projectionMatrix_ = ol.transform.create();
 
+  /**
+   * @type {Array.<number>}
+   * @private
+   */
+  this.tmpMat4_ = ol.vec.Mat4.create();
+
   /**
    * @private
    * @type {boolean|undefined}
@@ -565,9 +571,12 @@ ol.render.webgl.ImageReplay.prototype.replay = function(context,
     ol.transform.rotate(offsetRotateMatrix, -rotation);
   }
 
-  gl.uniformMatrix4fv(locations.u_projectionMatrix, false, ol.vec.Mat4.fromMatrix(projectionMatrix));
+  gl.uniformMatrix4fv(locations.u_projectionMatrix, false,
-  gl.uniformMatrix4fv(locations.u_offsetScaleMatrix, false, ol.vec.Mat4.fromMatrix(offsetScaleMatrix));
+      ol.vec.Mat4.fromTransform(this.tmpMat4_, projectionMatrix));
-  gl.uniformMatrix4fv(locations.u_offsetRotateMatrix, false, ol.vec.Mat4.fromMatrix(offsetRotateMatrix));
+  gl.uniformMatrix4fv(locations.u_offsetScaleMatrix, false,
+      ol.vec.Mat4.fromTransform(this.tmpMat4_, offsetScaleMatrix));
+  gl.uniformMatrix4fv(locations.u_offsetRotateMatrix, false,
+      ol.vec.Mat4.fromTransform(this.tmpMat4_, offsetRotateMatrix));
   gl.uniform1f(locations.u_opacity, opacity);
 
   // draw!

src/ol/renderer/webgl/webgllayerrenderer.js

@@ -73,6 +73,12 @@ ol.renderer.webgl.Layer = function(mapRenderer, layer) {
    */
   this.projectionMatrix = ol.transform.create();
 
+  /**
+   * @type {Array.<number>}
+   * @private
+   */
+  this.tmpMat4_ = ol.vec.Mat4.create();
+
   /**
    * @private
    * @type {ol.renderer.webgl.map.shader.Default.Locations}
@@ -169,9 +175,9 @@ ol.renderer.webgl.Layer.prototype.composeFrame = function(frameState, layerState
   }
 
   gl.uniformMatrix4fv(locations.u_texCoordMatrix, false,
-      ol.vec.Mat4.fromMatrix(this.getTexCoordMatrix()));
+      ol.vec.Mat4.fromTransform(this.tmpMat4_, this.getTexCoordMatrix()));
   gl.uniformMatrix4fv(locations.u_projectionMatrix, false,
-      ol.vec.Mat4.fromMatrix(this.getProjectionMatrix()));
+      ol.vec.Mat4.fromTransform(this.tmpMat4_, this.getProjectionMatrix()));
   gl.uniform1f(locations.u_opacity, layerState.opacity);
   gl.bindTexture(goog.webgl.TEXTURE_2D, this.getTexture());
   gl.drawArrays(goog.webgl.TRIANGLE_STRIP, 0, 4);

src/ol/vec/mat4.js

@@ -2,22 +2,24 @@ goog.provide('ol.vec.Mat4');
 
 
 /**
- * @type {Array.<number>}
+ * @return {Array.<number>} 4x4 matrix representing a 3D identity transform.
  */
-ol.vec.Mat4.tmpMatrix_ = [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
+ol.vec.Mat4.create = function() {
+  return [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
+};
 
 
 /**
- * @param {ol.Transform} mat Transformation matrix.
+ * @param {Array.<number>} mat4 Flattened 4x4 matrix receiving the result.
+ * @param {ol.Transform} transform Transformation matrix.
  * @return {Array.<number>} 2D transformation matrix as flattened 4x4 matrix.
  */
-ol.vec.Mat4.fromMatrix = function(mat) {
+ol.vec.Mat4.fromTransform = function(mat4, transform) {
-  var mat4 = ol.vec.Mat4.tmpMatrix_;
+  mat4[0] = transform[0];
-  mat4[0] = mat[0];
+  mat4[1] = transform[1];
-  mat4[1] = mat[1];
+  mat4[4] = transform[2];
-  mat4[4] = mat[2];
+  mat4[5] = transform[3];
-  mat4[5] = mat[3];
+  mat4[12] = transform[4];
-  mat4[12] = mat[4];
+  mat4[13] = transform[5];
-  mat4[13] = mat[5];
   return mat4;
 };