in vec2 a_pos;
out vec2 v_uv;

uniform float u_overlay_scale;

void main() {
    // This vertex shader expects a EXTENT x EXTENT quad,
    // The UV coordinates for the overlay texture can be calculated using that knowledge
    v_uv = a_pos / 8192.0;
    gl_Position = projectTileWithElevation(a_pos * u_overlay_scale, get_elevation(a_pos));
}