heroes-of-nerevelon/assets/shaders/alpha_mask.glsl

vec4 effect(vec4 color, Image tex, vec2 texCoord, vec2 screenCoord)
{
    vec4 px = Texel(tex, texCoord);
    if (px.a == 0.0) {
        discard;
    }
    return vec4(1.0);
}