From 1b2bd0a7b2c512e05a477b957c3ee7dfb60fac75 Mon Sep 17 00:00:00 2001
From: Robin Hawkes <rob@rawkes.com>
Date: Sat, 15 Feb 2014 00:57:05 +0000
Subject: [PATCH] - Refined batching for Web Workers - Fixed grid movement bug

---
 examples/index.html                 |  2 +-
 src/client/Grid.js                  |  8 +++-----
 src/client/objects/ObjectManager.js | 32 ++++++++++++++++-------------
 3 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/examples/index.html b/examples/index.html
index bb3603f..4092ed4 100644
--- a/examples/index.html
+++ b/examples/index.html
@@ -31,7 +31,7 @@
 		city.init({
 			coords: [-0.01924, 51.50358] // Canary Wharf
 			// coords: [-0.1159894466, 51.5045487479] // London Eye
-			// coords: [-73.984762, 40.7516199] // Empire State
+			// coords: [-73.984762, 40.7516199] // NYC
 		});
 	</script>
 
diff --git a/src/client/Grid.js b/src/client/Grid.js
index 354b232..4f50cf2 100644
--- a/src/client/Grid.js
+++ b/src/client/Grid.js
@@ -82,7 +82,6 @@
 					tile.position.z = position[1] + this.tileSize / 2;
 					tile.rotation.x = - 90 * Math.PI / 180;
 
-					// this.publish("addToScene", tile);
 					this.gridModel.add(tile);
 				}
 			}
@@ -147,7 +146,7 @@
 			];
 
 			if (Math.abs(gridDiff[0]) > 0 || Math.abs(gridDiff[1]) > 0) {
-				//VIZI.Log("Update grid", gridDiff);
+				VIZI.Log("Update grid", gridDiff);
 
 				this.pos2d.x = centerPixels[0];
 				this.pos2d.y = centerPixels[1];
@@ -160,9 +159,8 @@
 				this.boundsHighLonLat = this.getBoundsLonLat(this.boundsHigh);
 				this.boundsLowLonLat = this.getBoundsLonLat(this.boundsLow);
 
-				var position = this.geo.projection(this.tile2lonlat(Math.floor(this.centerTile[0]), Math.floor(this.centerTile[1]), this.geo.tileZoom));
-				this.gridModel.position.x = position[0] + this.tileSize / 2;
-				this.gridModel.position.z = position[1] + this.tileSize / 2;
+				this.gridModel.position.x += this.tileSize * gridDiff[0];
+				this.gridModel.position.z += this.tileSize * gridDiff[1];
 
 				this.publish("gridUpdated");
 			}
diff --git a/src/client/objects/ObjectManager.js b/src/client/objects/ObjectManager.js
index 3f4417f..210fdaf 100644
--- a/src/client/objects/ObjectManager.js
+++ b/src/client/objects/ObjectManager.js
@@ -191,30 +191,34 @@
 		// Solution: https://speakerdeck.com/mourner/high-performance-data-visualizations?slide=51
 		// TODO: See if simply batching objects and creating them in the browser is less sluggish for the browser
 		// TODO: Work out why not every feature is being returned in the promises (about 10–20 less than expected)
+		// TODO: Come up with a method of chosing enough batches to avoid call stack exceeded errors (too many things to render)
+		//       while not using too many batches to cause problems with small numbers of features (eg. a single feature)
+		//  - Manhattan is a good test for this
 
 		// Batch features
 		// 4 batches or below seems to stop the model.faces typed array from converting to a normal array
 		// Ideal 8 batches, if odd then subtract difference to make featuresPerBatch division clean
-		// var batches = 8 - (features.length % 8);
-		var batches = 1;
+		var batchCount = (features.length < 100) ? 6 : 12;
+		var batchDiff = features.length % batchCount;
+		var batches = (features.length < batchCount) ? features.length : batchCount;
 
-		// Use all features while testing tile-loading
-		// var featuresPerBatch = Math.ceil(features.length / batches);
+		var featuresPerBatch = Math.floor(features.length / batches);
 
 		var batchPromises = [];
 
-		// var i = batches;
-		// while (i--) {
-		// var startIndex = i * featuresPerBatch;
-		// startIndex = (startIndex < 0) ? 0 : startIndex;
+		for (var i = 0; i < batches; i++) {
+			var startIndex = i * featuresPerBatch;
+			var endIndex = startIndex + featuresPerBatch;
+			
+			// Add diff if at end of batch
+			if (i === batches - 1) {
+				endIndex += batchDiff;
+			}
 
-		// var featuresBatch = features.splice(startIndex, featuresPerBatch-1);
+			var featuresBatch = features.slice(startIndex, endIndex);
 
-		// batchPromises.push(this.workerPromise(worker, featuresBatch));
-		// }
-
-		// Process all features in one go while testing tile-loading
-		batchPromises.push(this.workerPromise(worker, features));
+			batchPromises.push(this.workerPromise(worker, featuresBatch));
+		}
 
 		var loader = new THREE.JSONLoader();
 		var material = new THREE.MeshLambertMaterial({vertexColors: THREE.VertexColors});