#version 300 es

precision mediump float;

layout(location = 0) in vec4 a_rect;
layout(location = 1) in vec4 a_uv_rect;
layout(location = 2) in vec3 a_fg;
layout(location = 3) in vec3 a_bg;

out vec2 v_uv;
out vec3 v_fg;
out vec3 v_bg;

void main() {
    vec2 pos;
    vec2 uv;
    int corner = gl_VertexID % 6;
    if (corner == 0) {
        pos = vec2(a_rect.x, a_rect.y);
        uv = vec2(a_uv_rect.x, a_uv_rect.y);
    } else if (corner == 1) {
        pos = vec2(a_rect.z, a_rect.y);
        uv = vec2(a_uv_rect.z, a_uv_rect.y);
    } else if (corner == 2) {
        pos = vec2(a_rect.z, a_rect.w);
        uv = vec2(a_uv_rect.z, a_uv_rect.w);
    } else if (corner == 3) {
        pos = vec2(a_rect.x, a_rect.y);
        uv = vec2(a_uv_rect.x, a_uv_rect.y);
    } else if (corner == 4) {
        pos = vec2(a_rect.z, a_rect.w);
        uv = vec2(a_uv_rect.z, a_uv_rect.w);
    } else {
        pos = vec2(a_rect.x, a_rect.w);
        uv = vec2(a_uv_rect.x, a_uv_rect.w);
    }
    v_uv = uv;
    v_fg = a_fg;
    v_bg = a_bg;
    gl_Position = vec4(pos, 0.0, 1.0);
}