vkd3d/tests/hlsl/alpha-test.shader_test

% Testing equality comparison is a bit tricky here. The alpha test ref is
% fed through a UNORM in d3d, so we can only pass a value that's a multiple of
% 1/255 from 0 to 1. While we can quantize to an integer from 0-255, dividing
% back down by 255 yields slightly inconsistent results. Fortunately, testing
% 1.0 works and is a lot more reliable.

[require]
shader model < 4.0

[vertex shader]
void main(inout float4 pos : position, out float alpha : texcoord)
{
    alpha = pos.x;
}

[pixel shader]
float4 main(float alpha : texcoord) : sv_target
{
    return float4(0, 1, 0, floor((alpha + 1) * 2 + 0.5) / 2);
}

[test]

alpha test always
clear rtv 0  1 0 0 1
draw quad
probe (160, 0) rgba (0, 1, 0, 0.5)
probe (320, 0) rgba (0, 1, 0, 1.0)
probe (480, 0) rgba (0, 1, 0, 1.5)

alpha test equal 1.0
clear rtv 0  1 0 0 1
draw quad
probe (160, 0) rgba (1, 0, 0, 1)
probe (320, 0) rgba (0, 1, 0, 1.0)
probe (480, 0) rgba (1, 0, 0, 1)

alpha test not equal 1.0
clear rtv 0  1 0 0 1
draw quad
probe (160, 0) rgba (0, 1, 0, 0.5)
probe (320, 0) rgba (1, 0, 0, 1)
probe (480, 0) rgba (0, 1, 0, 1.5)

alpha test greater 1.0
clear rtv 0  1 0 0 1
draw quad
probe (160, 0) rgba (1, 0, 0, 1)
probe (320, 0) rgba (1, 0, 0, 1)
probe (480, 0) rgba (0, 1, 0, 1.5)

alpha test greater equal 1.0
clear rtv 0  1 0 0 1
draw quad
probe (160, 0) rgba (1, 0, 0, 1)
probe (320, 0) rgba (0, 1, 0, 1.0)
probe (480, 0) rgba (0, 1, 0, 1.5)

alpha test less equal 1.0
clear rtv 0  1 0 0 1
draw quad
probe (160, 0) rgba (0, 1, 0, 0.5)
probe (320, 0) rgba (0, 1, 0, 1.0)
probe (480, 0) rgba (1, 0, 0, 1)

alpha test less 1.0
clear rtv 0  1 0 0 1
draw quad
probe (160, 0) rgba (0, 1, 0, 0.5)
probe (320, 0) rgba (1, 0, 0, 1)
probe (480, 0) rgba (1, 0, 0, 1)

alpha test never
clear rtv 0  1 0 0 1
draw quad
probe (160, 0) rgba (1, 0, 0, 1)
probe (320, 0) rgba (1, 0, 0, 1)
probe (480, 0) rgba (1, 0, 0, 1)