Generated shader for Cornell box with spheres

cornell_spheres.glsl

bool trace(inout uint seed, inout vec3 pos, inout vec3 dir, inout vec4 color)
{
    float best_dist = 1e8;
    uint best_hit = 0;
    float dist;
    dist = hit_sphere(pos, dir, vec3(0.0e+00, 6.05000019e+00, 0.0e+00), 5.01999998e+00);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 1;
    }
    dist = hit_plane(pos, dir,  vec3(0.0e+00, 0.0e+00, 1.0e+00), -1.0e+00);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 2;
    }
    dist = hit_plane(pos, dir,  vec3(1.0e+00, 0.0e+00, 0.0e+00), -1.0e+00);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 3;
    }
    dist = hit_plane(pos, dir,  vec3(-1.0e+00, 0.0e+00, 0.0e+00), -1.0e+00);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 4;
    }
    dist = hit_plane(pos, dir,  vec3(0.0e+00, -1.0e+00, 0.0e+00), -1.04999995e+00);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 5;
    }
    dist = hit_plane(pos, dir,  vec3(0.0e+00, 1.0e+00, 0.0e+00), -1.0e+00);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 6;
    }
    dist = hit_plane(pos, dir,  vec3(0.0e+00, 0.0e+00, -1.0e+00), -1.0e+00);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 7;
    }
    dist = hit_sphere(pos, dir, vec3(-3.00000011e-01, -6.00000023e-01, -2.00000002e-01), 4.00000005e-01);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 8;
    }
    dist = hit_sphere(pos, dir, vec3(5.0e-01, -6.99999988e-01, 3.00000011e-01), 3.00000011e-01);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 9;
    }
    dist = hit_sphere(pos, dir, vec3(1.00000001e-01, -8.00000011e-01, 5.0e-01), 2.00000002e-01);
    if (dist > SURFACE_EPSILON && dist < best_dist) {
        best_dist = dist;
        best_hit = 10;
    }

    // If we missed all objects, terminate immediately with blackness
    if (best_hit == 0) {
        color = vec4(0);
        return true;
    }
    pos = pos + dir*best_dist;

    const uvec4 key_arr[] = {
        uvec4(0), // Dummy
        uvec4(1, 1, 2, 1),
        uvec4(2, 1, 1, 1),
        uvec4(2, 2, 1, 2),
        uvec4(2, 3, 1, 4),
        uvec4(2, 4, 1, 1),
        uvec4(2, 5, 1, 1),
        uvec4(2, 6, 1, 1),
        uvec4(1, 2, 1, 3),
        uvec4(1, 3, 3, 1),
        uvec4(1, 4, 4, 1),
    };
    uvec4 key = key_arr[best_hit];

    // Calculate normal based on shape type and sub-index
    vec3 norm = vec3(0);
    switch (key.x) {
        case SHAPE_SPHERE: {
            // Sphere centers
            const vec3 data[] = {
                vec3(0), // Dummy
                vec3(0.0e+00, 6.05000019e+00, 0.0e+00),
                vec3(-3.00000011e-01, -6.00000023e-01, -2.00000002e-01),
                vec3(5.0e-01, -6.99999988e-01, 3.00000011e-01),
                vec3(1.00000001e-01, -8.00000011e-01, 5.0e-01),
            };
            norm = norm_sphere(pos, data[key.y]);
            break;
        }
        case SHAPE_INFINITE_PLANE: {
            // Plane normals
            const vec3 data[] = {
                vec3(0), // Dummy
                vec3(0.0e+00, 0.0e+00, 1.0e+00),
                vec3(1.0e+00, 0.0e+00, 0.0e+00),
                vec3(-1.0e+00, 0.0e+00, 0.0e+00),
                vec3(0.0e+00, -1.0e+00, 0.0e+00),
                vec3(0.0e+00, 1.0e+00, 0.0e+00),
                vec3(0.0e+00, 0.0e+00, -1.0e+00),
            };
            norm = norm_plane(data[key.y]);
            break;
        }
        case SHAPE_FINITE_PLANE: {
            // Plane normals
            const vec3 data[] = {
                vec3(0), // Dummy
            };
            norm = norm_plane(data[key.y]);
            break;
        }
    }

    // Calculate material behavior based on mat type and sub-index
    switch (key.z) {
        case MAT_DIFFUSE: {
            const vec3 data[] = {
                vec3(0), // Dummy
                vec3(1.0e+00, 1.0e+00, 1.0e+00),
                vec3(1.0e+00, 1.00000001e-01, 1.00000001e-01),
                vec3(1.00000001e-01, 1.00000001e-01, 1.0e+00),
                vec3(1.00000001e-01, 1.0e+00, 1.00000001e-01),
            };
            return mat_diffuse(seed, color, dir, norm, data[key.w]);
        }
        case MAT_LIGHT: {
            const vec3 data[] = {
                vec3(0), // Dummy
                vec3(4.0e+00, 4.0e+00, 4.0e+00),
            };
            return mat_light(color, data[key.w]);
        }
        case MAT_METAL: {
            // R, G, B, fuzz
            const vec4 data[] = {
                vec4(0), // Dummy
                vec4(1.0e+00, 1.0e+00, 5.0e-01, 1.00000001e-01),
            };
            vec4 m = data[key.w];
            return mat_metal(seed, color, dir, norm, m.xyz, m.w);
        }
        case MAT_GLASS: {
            // R, G, B, eta
            const vec2 data[] = {
                vec2(0), // Dummy
                vec2(1.29999995e+00, 1.30000000e-03),
            };
            vec2 m = data[key.w];
            return mat_glass(seed, color, dir, norm, m.x, m.y);
        }
        case MAT_LASER: {
            // R, G, B, focus
            const vec4 data[] = {
                vec4(0), // Dummy
            };
            vec4 m = data[key.w];
            return mat_laser(color, dir, norm, m.xyz, m.w);
        }
    }

    // Reaching here is an error, so set the color to green and terminate
    color = vec4(0, 1, 0, 0);
    return true;
}