WIP

js/data/bucket.js

@@ -4,6 +4,7 @@ var featureFilter = require('feature-filter');
 var Buffer = require('./buffer');
 var StyleLayer = require('../style/style_layer');
 var util = require('../util/util');
+var assert = require('assert');
 
 module.exports = Bucket;
 
@@ -232,7 +233,12 @@ Bucket.prototype.setAttribPointers = function(shaderName, gl, shader, offset, ar
     }
 
     // Set enabled attributes
-    this.buffers[this.getBufferName(shaderName, 'vertex')].setAttribPointers(gl, shader, offset);
+    var enabledAttributes = this.getAttributes(shaderName, {isEnabled: true});
+    var vertexBuffer = this.buffers[this.getBufferName(shaderName, 'vertex')];
+    assert(enabledAttributes.length === vertexBuffer.attributes.length);
+    vertexBuffer.setAttribPointers(gl, shader, offset, util.mapObjectKV(enabledAttributes, function(attribute) {
+        return [attribute.name, 'a_' + attribute.name];
+    }));
 };
 
 /**

js/data/buffer.js

@@ -123,13 +123,21 @@ Buffer.prototype.destroy = function(gl) {
  * @param shader The active WebGL shader
  * @param {number} offset The offset of the attribute data in the currently bound GL buffer.
  */
-Buffer.prototype.setAttribPointers = function(gl, shader, offset) {
-    for (var i = 0; i < this.attributes.length; i++) {
-        var attrib = this.attributes[i];
+Buffer.prototype.setAttribPointers = function(gl, shader, offset, attribs) {
+    for (var bufferAttribName in attribs) {
+        var shaderAttribName = attribs[bufferAttribName];
+        var attrib = this.attributes.find(function(attribute) {
+            return attribute.name === bufferAttribName;
+        });
 
         gl.vertexAttribPointer(
-            shader['a_' + attrib.name], attrib.components, gl[attrib.type.name],
-            false, this.itemSize, offset + attrib.offset);
+            shader[shaderName],
+            attrib.components,
+            gl[attrib.type.name],
+            false,
+            this.itemSize,
+            offset + attrib.offset
+        );
     }
 };
 

js/render/draw_fill.js

@@ -105,13 +105,15 @@ function drawFill(painter, source, layer, coord) {
     for (var i = 0; i < elementGroups.length; i++) {
         var group = elementGroups[i];
         var offset = group.vertexStartIndex * vertex.itemSize;
-        vertex.setAttribPointers(gl, painter.fillShader, offset);
+        bucket.setAttribPointers('fill', gl, shader, offset, [{$zoom: painter.transform.zoom}]);
 
         var count = group.elementLength * 3;
         var elementOffset = group.elementStartIndex * elements.itemSize;
         gl.drawElements(gl.TRIANGLES, count, gl.UNSIGNED_SHORT, elementOffset);
     }
 
+    bucket.unsetAttribPointers('fill', gl, shader);
+
     // Now that we have the stencil mask in the stencil buffer, we can start
     // writing to the color buffer.
     gl.colorMask(true, true, true, true);

js/render/draw_symbol.js

@@ -99,7 +99,7 @@ function drawSymbol(painter, layer, posMatrix, tile, bucket, elementGroups, pref
     var extra = (topedgelength + x) / topedgelength - 1;
 
     var text = prefix === 'text';
-    var shader, vertex, elements, texsize;
+    var shader, shaderName, vertex, elements, texsize;
 
     if (!text && !painter.style.sprite.loaded())
         return;
@@ -190,7 +190,7 @@ function drawSymbol(painter, layer, posMatrix, tile, bucket, elementGroups, pref
             group = elementGroups[i];
             offset = group.vertexStartIndex * vertex.itemSize;
             vertex.bind(gl);
-            vertex.setAttribPointers(gl, shader, offset);
+            bucket.setAttribPointers('symbol', gl, shader, offset);
 
             count = group.elementLength * 3;
             elementOffset = group.elementStartIndex * elements.itemSize;
@@ -203,7 +203,7 @@ function drawSymbol(painter, layer, posMatrix, tile, bucket, elementGroups, pref
             group = elementGroups[k];
             offset = group.vertexStartIndex * vertex.itemSize;
             vertex.bind(gl);
-            vertex.setAttribPointers(gl, shader, offset);
+            bucket.setAttribPointers('symbol', gl, shader, offset);
 
             count = group.elementLength * 3;
             elementOffset = group.elementStartIndex * elements.itemSize;

js/util/util.js

@@ -430,6 +430,15 @@ exports.mapObject = function(input, iterator, context) {
     return output;
 };
 
+exports.mapObjectKV = function(input, iterator, context) {
+    var output = {};
+    for (var key in input) {
+        var pair = iterator.call(context || this, input[key], key, input);
+        output[pair[0]] = pair[1]; 
+    }
+    return output;
+};
+
 /**
  * Create an object by filtering out values of an existing object
  * @param {Object} input