attribute vec3 aVertexPosition;
attribute vec4 aVertexColor;

uniform mat4 uMVMatrix;
uniform mat4 uPMatrix;

varying vec4 vColor;
varying vec3 vPosition;

uniform float f; // this is incremented every frame
uniform float t; // this is time in milliseconds since epoch

void main(void) {
   gl_Position = vec4(aVertexPosition, 1.0);
   vColor = aVertexColor;
   vPosition = gl_Position.xyz;
}