uniform vec2 u_patternscale_a;
uniform vec2 u_patternscale_b;
uniform vec2 u_offset_a;
uniform vec2 u_offset_b;

attribute vec2 a_pos;

uniform mat4 u_matrix;
uniform vec2 u_world;

varying vec2 v_pos_a;
varying vec2 v_pos_b;
varying vec2 v_pos;


void main() {
    gl_Position = u_matrix * vec4(a_pos, 0, 1);
    v_pos_a = u_patternscale_a * a_pos + u_offset_a;
    v_pos_b = u_patternscale_b * a_pos + u_offset_b;
    v_pos = (gl_Position.xy/gl_Position.w + 1.0) / 2.0 * u_world;
}