attribute vec3 a_Position;
attribute vec2 a_TexCoords;

uniform float u_OffsetX;
uniform float u_OffsetY;
uniform vec2 u_RenderSize;

varying vec2 v_TexCoords;
varying vec2 v_Offset;

void main() {
  v_Offset = vec2(u_OffsetX, u_OffsetY) * 1.0/u_RenderSize;
  gl_Position = vec4(a_Position, 1.0);
  v_TexCoords = a_TexCoords;
}