SPIRV-Cross/reference/shaders/comp/generate_height.comp

#version 310 es
layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;

layout(binding = 0, std430) buffer Distribution
{
    vec2 distribution[];
} _190;

layout(binding = 2, std140) uniform UBO
{
    vec4 uModTime;
} _218;

layout(binding = 1, std430) buffer HeightmapFFT
{
    uint heights[];
} _276;

uvec2 workaround_mix(uvec2 a, uvec2 b, bvec2 sel)
{
    uint _137;
    uint _148;
    if (sel.x)
    {
        _137 = b.x;
    }
    else
    {
        _137 = a.x;
    }
    uint _147 = _137;
    if (sel.y)
    {
        _148 = b.y;
    }
    else
    {
        _148 = a.y;
    }
    return uvec2(_147, _148);
}

vec2 alias(vec2 i, vec2 N)
{
    return mix(i, (i - N), greaterThan(i, (N * 0.5)));
}

vec2 cmul(vec2 a, vec2 b)
{
    vec2 r3 = a.yx;
    vec2 r1 = b.xx;
    vec2 R0 = (a * r1);
    vec2 r2 = b.yy;
    vec2 R1 = (r2 * r3);
    return (R0 + vec2((-R1.x), R1.y));
}

uint pack2(vec2 v)
{
    return packHalf2x16(v);
}

void generate_heightmap()
{
    uvec2 N = (uvec2(64u, 1u) * gl_NumWorkGroups.xy);
    uvec2 i = gl_GlobalInvocationID.xy;
    uvec2 param = (N - i);
    uvec2 param_1 = uvec2(0u);
    bvec2 param_2 = equal(i, uvec2(0u));
    uvec2 wi = workaround_mix(param, param_1, param_2);
    vec2 a = _190.distribution[((i.y * N.x) + i.x)];
    vec2 b = _190.distribution[((wi.y * N.x) + wi.x)];
    vec2 param_3 = vec2(i);
    vec2 param_4 = vec2(N);
    vec2 k = (_218.uModTime.xy * alias(param_3, param_4));
    float k_len = length(k);
    float w = (sqrt((9.81000041961669921875 * k_len)) * _218.uModTime.z);
    float cw = cos(w);
    float sw = sin(w);
    vec2 param_5 = a;
    vec2 param_6 = vec2(cw, sw);
    a = cmul(param_5, param_6);
    vec2 param_7 = b;
    vec2 param_8 = vec2(cw, sw);
    b = cmul(param_7, param_8);
    b = vec2(b.x, (-b.y));
    vec2 res = (a + b);
    vec2 param_9 = res;
    _276.heights[((i.y * N.x) + i.x)] = pack2(param_9);
}

void main()
{
    generate_heightmap();
}