[require]
shader model >= 4.0
geometry-shader

[vertex shader]
struct vs_data
{
    float4 pos : SV_Position;
    float4 color : COLOR;
};

void main(out struct vs_data vs_output)
{
    vs_output.pos = float4(0.0, 0.0, 1.0, 1.0);
    vs_output.color = float4(0.0, 0.0, 1.0, 1.0);
}

[geometry shader]
struct gs_data
{
    float4 pos : SV_Position;
    float4 color : COLOR;
};

struct gs_out
{
    float4 pos : SV_Position;
    float4 color : COLOR;
    uint prim_id : SV_PrimitiveId;
};

    [maxvertexcount(4)]
void main(point struct gs_data vin[1], in uint prim_id : SV_PrimitiveId, inout TriangleStream<gs_out> vout)
{
    float offset = 0.2 * vin[0].pos.w;
    gs_out v;

    v.color = vin[0].color;
    /* This only confirms that prim_id is zero. */
    v.color.x = prim_id * 0.25f;

    v.pos = float4(vin[0].pos.x - offset, vin[0].pos.y - offset, vin[0].pos.z, 1.0);
    v.prim_id = 0;
    vout.Append(v);
    v.pos = float4(vin[0].pos.x - offset, vin[0].pos.y + offset, vin[0].pos.z, 1.0);
    v.prim_id = 1;
    vout.Append(v);
    v.pos = float4(vin[0].pos.x + offset, vin[0].pos.y - offset, vin[0].pos.z, 1.0);
    vout.Append(v);
    v.pos = float4(vin[0].pos.x + offset, vin[0].pos.y + offset, vin[0].pos.z, 1.0);
    vout.Append(v);
}

[pixel shader]
struct ps_data
{
    float4 pos : SV_Position;
    float4 color : COLOR;
    uint prim_id : SV_PrimitiveId;
};

float4 main(struct ps_data ps_input) : SV_Target
{
    float4 color = ps_input.color;
    color.y = ps_input.prim_id * 0.25f;
    return color;
}

[test]
todo(glsl) draw point list 1
probe rtv 0 (320, 190) f32(0.0, 0.0, 0.0, 0.0)
probe rtv 0 (255, 240) f32(0.0, 0.0, 0.0, 0.0)
probe rtv 0 (319, 241) f32(0.0, 0.0, 1.0, 1.0)
probe rtv 0 (321, 239) f32(0.0, 0.25, 1.0, 1.0)
probe rtv 0 (385, 240) f32(0.0, 0.0, 0.0, 0.0)
probe rtv 0 (320, 290) f32(0.0, 0.0, 0.0, 0.0)