Increase floating point precision

Author: flekschas

src/point.vs

@@ -1,5 +1,5 @@
 const VERTEX_SHADER = `
-precision mediump float;
+precision highp float;
 
 uniform sampler2D colorTex;
 uniform float colorTexRes;
@@ -47,7 +47,7 @@ void main() {
   eps = 0.5 / colorTexRes;
   float colorLinearIndex = colorIndex + globalState;
   // Need to add cEps here to avoid floating point issue that can lead to
-  // dramatic changes in which color is loaded as floor(3/2.9) = 1 but
+  // dramatic changes in which color is loaded as floor(3/2.9999) = 1 but
   // floor(3/3.0001) = 0!
   float colorRowIndex = floor((colorLinearIndex + eps) / colorTexRes);