// 2D overlay (overlay.ludic): pixels with the origin top-left, straight to clip space
layout(location = 0) in vec2 a_pos;
layout(location = 1) in vec2 a_uv;
layout(location = 2) in vec4 a_col;
uniform vec2 u_screen;
out vec2 v_uv;
out vec4 v_col;
void main() {
  vec2 p = a_pos / u_screen * 2.0 - 1.0;
  gl_Position = vec4(p.x, -p.y, 0.0, 1.0);
  v_uv = a_uv;
  v_col = a_col;
}