[require]
GLSL >= 1.10

[vertex shader]
uniform int index;
varying vec4 m[2];
varying vec4 pos;

void main()
{
    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;

    m[0].xy = vec2(1.0, 1.1);
    m[1].xy = vec2(2.0, 2.1);
    m[0].zw = vec2(5.0, 5.1);
    m[1].zw = vec2(6.0, 6.1);

    if (index >= 2)
        m[index-2].zw = vec2(0.0, 0.1);
    else
        m[index].xy = vec2(0.0, 0.1);

    pos = gl_Position;
}

[fragment shader]
uniform int index;
varying vec4 m[2];
varying vec4 pos;

void main()
{
    /* Correct the fragment coordinate to window size. */
    vec2 p_gl = gl_FragCoord.xy / 125.0 - 1.0;
    vec2 err = abs(p_gl - pos.xy);

    bool pass = (length(err) < 0.001);

    if (!pass) {
         normalize(err);
    } else {
        err = vec2(1.0, 0.0);
    }

    for (int i = 0; i < 2; i++)
        pass = pass && m[i].xy == (index == i ? vec2(0.0, 0.1) : vec2(1.0, 1.1) + vec2(i));

    for (int i = 0; i < 2; i++)
        pass = pass && m[i].zw == (index == 2+i ? vec2(0.0, 0.1) : vec2(5.0, 5.1) + vec2(i));

    gl_FragColor = pass ? vec4(0.0, 1.0, 0.0, 1.0) : vec4(err.x, 0.0, err.y, 1.0);
}

[test]
clear color 0.5 0.5 0.5 0.5
clear
ortho

uniform int index 0
draw rect 5 5 10 10
probe rgb 10 25 0.0 1.0 0.0

uniform int index 1
draw rect 185 5 10 10
probe rgb 190 10 0.0 1.0 0.0

uniform int index 2
draw rect 5 185 10 10
probe rgb 10 190 0.0 1.0 0.0

uniform int index 3
draw rect 185 185 10 10
probe rgb 190 190 0.0 1.0 0.0

uniform int index 1
draw rect 5 20 10 10
probe rgb 10 25 0.0 1.0 0.0