From bc5ae2a41902bf0a672f415b7598d598b2059803 Mon Sep 17 00:00:00 2001
From: Brett Camper <bcamper@alum.mit.edu>
Date: Mon, 13 Jan 2014 22:48:04 -0500
Subject: [PATCH] add uniform for time to shaders (and some commented out test
 code for using it to alter vertices and pixels)

---
 fragment.glsl      |  5 +++--
 gl_renderer.js     |  2 ++
 vector_renderer.js |  6 +++---
 vertex.glsl        | 11 ++++++++++-
 4 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/fragment.glsl b/fragment.glsl
index f0e8acb33..bf62a7bba 100755
--- a/fragment.glsl
+++ b/fragment.glsl
@@ -1,5 +1,5 @@
 uniform vec2 resolution;
-// uniform vec2 map_center;
+uniform float time;
 
 varying vec3 fcolor;
 
@@ -17,8 +17,9 @@ void main (void) {
     // vec3 color = fcolor * max(1.0 - distance(position, vec2(0.0, 0.0)), 0.15);
     // vec3 color = fcolor * (1.0 - dot(normalize(vec3(rand(gl_FragCoord.xy * 0.01) * 10.0, 0.0, -1.0)), vec3(0, 0, 1.0)));
 
-    // Mutate colors by screen position
+    // Mutate colors by screen position or time
     // color += vec3(gl_FragCoord.x / resolution.x, 0.0, gl_FragCoord.y / resolution.y);
+    // color.r += sin(time);
 
     gl_FragColor = vec4(color, 1.0);
     // gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
diff --git a/gl_renderer.js b/gl_renderer.js
index 90c523585..712c4a342 100644
--- a/gl_renderer.js
+++ b/gl_renderer.js
@@ -41,6 +41,7 @@ GLRenderer.prototype.init = function GLRendererInit ()
     this.zoom_step = 0.02; // for fractional zoom user adjustment
     this.map_last_zoom = this.leaflet.map.getZoom();
     this.map_zooming = false;
+    this.start_time = +new Date();
 
     this.initMapHandlers();
     this.initInputHandlers();
@@ -815,6 +816,7 @@ GLRenderer.prototype.render = function GLRendererRender ()
 
     // Set values to this.program variables
     gl.uniform2f(gl.getUniformLocation(this.program, 'resolution'), gl.canvas.width, gl.canvas.height);
+    gl.uniform1f(gl.getUniformLocation(this.program, 'time'), ((+new Date()) - this.start_time) / 1000);
 
     var center = this.leaflet.map.getCenter(); // TODO: move map center tracking/projection to central class?
     center = Geo.latLngToMeters(Point(center.lng, center.lat));
diff --git a/vector_renderer.js b/vector_renderer.js
index daad160ef..5a1a12fda 100644
--- a/vector_renderer.js
+++ b/vector_renderer.js
@@ -8,7 +8,7 @@ function VectorRenderer (leaflet, layers, styles)
 
     this.tile_scale = 4096;
     this.tiles = {};
-    
+
     this.leaflet = leaflet;
 
     if (typeof(layers) == 'string') {
@@ -81,7 +81,7 @@ VectorRenderer.prototype.loadTile = function (coords, div)
         // Re-scale from meters to local tile coords
         renderer.scaleTile(tile, renderer.tile_scale);
 
-        tile.xhr = null;        
+        tile.xhr = null;
         tile.loading = false;
         tile.loaded = true;
 
@@ -166,7 +166,7 @@ VectorRenderer.prototype.scaleTile = function (tile, scale)
 VectorRenderer.prototype.printDebugForTile = function (tile)
 {
     console.log(
-        "debug for " + tile.key + ': [ ' + 
+        "debug for " + tile.key + ': [ ' +
         Object.keys(tile.debug).map(function (t) { return t + ': ' + tile.debug[t]; }).join(', ') + ' ]'
     );
 };
diff --git a/vertex.glsl b/vertex.glsl
index 83157db8b..ce87e658c 100644
--- a/vertex.glsl
+++ b/vertex.glsl
@@ -5,7 +5,7 @@ uniform vec2 meter_zoom;
 uniform vec2 tile_min;
 uniform vec2 tile_max;
 uniform float tile_scale; // geometries are scaled to this range within each tile
-// uniform float time;
+uniform float time;
 
 attribute vec3 position;
 attribute vec3 normal;
@@ -41,6 +41,14 @@ void main() {
     vposition.y *= -1.0; // adjust for flipped y-coords
     // vposition.y += tile_scale; // alternate, to also adjust for force-positive y coords in tile
     vposition.xy *= (tile_max - tile_min) / tile_scale; // adjust for vertex location within tile (scaled from local coords to meters)
+
+    // Vertex displacement tests
+    // if (vposition.z > 1.0) {
+    //     // vposition.x += sin(vposition.z + time) * 10.0 * sin(position.x); // swaying buildings
+    //     // vposition.y += cos(vposition.z + time) * 10.0;
+    //     vposition.z *= (sin(vposition.z / 25.0 * time) + 1.0) / 2.0 + 0.1; // evelator buildings
+    // }
+
     vposition.xy += tile_min.xy - map_center; // adjust for corner of tile relative to map center
 
     // Isometric-style projections
@@ -53,6 +61,7 @@ void main() {
 
     // Flat shading between surface normal and light
     fcolor = color;
+    // fcolor += vec3(sin(position.z + time), 0.0, 0.0); // color change on height + time
     light = vec3(-0.25, -0.25, 0.35); // vec3(0.1, 0.1, 0.35); // point light location
     light = normalize(vec3(vposition.x, vposition.y, -vposition.z) - light); // light angle from light point to vertex
     fcolor *= dot(vnormal, light * -1.0) + ambient + clamp(vposition.z * 2.0 / meter_zoom.x, 0.0, 0.25);