#[compute]
#version 450
#VERSION_DEFINES
layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
#define NO_CHILDREN 0xFFFFFFFF
struct CellChildren {
uint children[8];
};
layout(set = 0, binding = 1, std430) buffer CellChildrenBuffer {
CellChildren data[];
}
cell_children;
struct CellData {
uint position; // xyz 10 bits
uint albedo; //rgb albedo
uint emission; //rgb normalized with e as multiplier
uint normal; //RGB normal encoded
};
layout(set = 0, binding = 2, std430) buffer CellDataBuffer {
CellData data[];
}
cell_data;
#define LIGHT_TYPE_DIRECTIONAL 0
#define LIGHT_TYPE_OMNI 1
#define LIGHT_TYPE_SPOT 2
#ifdef MODE_COMPUTE_LIGHT
struct Light {
uint type;
float energy;
float radius;
float attenuation;
vec3 color;
float cos_spot_angle;
vec3 position;
float inv_spot_attenuation;
vec3 direction;
bool has_shadow;
};
layout(set = 0, binding = 3, std140) uniform Lights {
Light data[MAX_LIGHTS];
}
lights;
#endif
layout(push_constant, std430) uniform Params {
ivec3 limits;
uint stack_size;
float emission_scale;
float propagation;
float dynamic_range;
uint light_count;
uint cell_offset;
uint cell_count;
uint pad[2];
}
params;
layout(set = 0, binding = 4, std140) uniform Outputs {
vec4 data[];
}
output;
#ifdef MODE_COMPUTE_LIGHT
uint raymarch(float distance, float distance_adv, vec3 from, vec3 direction) {
uint result = NO_CHILDREN;
ivec3 size = ivec3(max(max(params.limits.x, params.limits.y), params.limits.z));
while (distance > -distance_adv) { //use this to avoid precision errors
uint cell = 0;
ivec3 pos = ivec3(from);
if (all(greaterThanEqual(pos, ivec3(0))) && all(lessThan(pos, size))) {
ivec3 ofs = ivec3(0);
ivec3 half_size = size / 2;
for (int i = 0; i < params.stack_size - 1; i++) {
bvec3 greater = greaterThanEqual(pos, ofs + half_size);
ofs += mix(ivec3(0), half_size, greater);
uint child = 0; //wonder if this can be done faster
if (greater.x) {
child |= 1;
}
if (greater.y) {
child |= 2;
}
if (greater.z) {
child |= 4;
}
cell = cell_children.data[cell].children[child];
if (cell == NO_CHILDREN) {
break;
}
half_size >>= ivec3(1);
}
if (cell != NO_CHILDREN) {
return cell; //found cell!
}
}
from += direction * distance_adv;
distance -= distance_adv;
}
return NO_CHILDREN;
}
bool compute_light_vector(uint light, uint cell, vec3 pos, out float attenuation, out vec3 light_pos) {
if (lights.data[light].type == LIGHT_TYPE_DIRECTIONAL) {
light_pos = pos - lights.data[light].direction * length(vec3(params.limits));
attenuation = 1.0;
} else {
light_pos = lights.data[light].position;
float distance = length(pos - light_pos);
if (distance >= lights.data[light].radius) {
return false;
}
attenuation = pow(clamp(1.0 - distance / lights.data[light].radius, 0.0001, 1.0), lights.data[light].attenuation);
if (lights.data[light].type == LIGHT_TYPE_SPOT) {
vec3 rel = normalize(pos - light_pos);
float cos_spot_angle = lights.data[light].cos_spot_angle;
float cos_angle = dot(rel, lights.data[light].direction);
if (cos_angle < cos_spot_angle) {
return false;
}
float scos = max(cos_angle, cos_spot_angle);
float spot_rim = max(0.0001, (1.0 - scos) / (1.0 - cos_spot_angle));
attenuation *= 1.0 - pow(spot_rim, lights.data[light].inv_spot_attenuation);
}
}
return true;
}
float get_normal_advance(vec3 p_normal) {
vec3 normal = p_normal;
vec3 unorm = abs(normal);
if ((unorm.x >= unorm.y) && (unorm.x >= unorm.z)) {
// x code
unorm = normal.x > 0.0 ? vec3(1.0, 0.0, 0.0) : vec3(-1.0, 0.0, 0.0);
} else if ((unorm.y > unorm.x) && (unorm.y >= unorm.z)) {
// y code
unorm = normal.y > 0.0 ? vec3(0.0, 1.0, 0.0) : vec3(0.0, -1.0, 0.0);
} else if ((unorm.z > unorm.x) && (unorm.z > unorm.y)) {
// z code
unorm = normal.z > 0.0 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 0.0, -1.0);
} else {
// oh-no we messed up code
// has to be
unorm = vec3(1.0, 0.0, 0.0);
}
return 1.0 / dot(normal, unorm);
}
#endif
void main() {
uint cell_index = gl_GlobalInvocationID.x;
if (cell_index >= params.cell_count) {
return;
}
cell_index += params.cell_offset;
uvec3 posu = uvec3(cell_data.data[cell_index].position & 0x7FF, (cell_data.data[cell_index].position >> 11) & 0x3FF, cell_data.data[cell_index].position >> 21);
vec4 albedo = unpackUnorm4x8(cell_data.data[cell_index].albedo);
#ifdef MODE_COMPUTE_LIGHT
vec3 pos = vec3(posu) + vec3(0.5);
vec3 emission = vec3(ivec3(cell_data.data[cell_index].emission & 0x3FF, (cell_data.data[cell_index].emission >> 10) & 0x7FF, cell_data.data[cell_index].emission >> 21)) * params.emission_scale;
vec4 normal = unpackSnorm4x8(cell_data.data[cell_index].normal);
vec3 accum = vec3(0.0);
for (uint i = 0; i < params.light_count; i++) {
float attenuation;
vec3 light_pos;
if (!compute_light_vector(i, cell_index, pos, attenuation, light_pos)) {
continue;
}
vec3 light_dir = pos - light_pos;
float distance = length(light_dir);
light_dir = normalize(light_dir);
if (length(normal.xyz) > 0.2 && dot(normal.xyz, light_dir) >= 0) {
continue; //not facing the light
}
if (lights.data[i].has_shadow) {
float distance_adv = get_normal_advance(light_dir);
distance += distance_adv - mod(distance, distance_adv); //make it reach the center of the box always
vec3 from = pos - light_dir * distance; //approximate
from -= sign(light_dir) * 0.45; //go near the edge towards the light direction to avoid self occlusion
uint result = raymarch(distance, distance_adv, from, light_dir);
if (result != cell_index) {
continue; //was occluded
}
}
vec3 light = lights.data[i].color * albedo.rgb * attenuation * lights.data[i].energy;
if (length(normal.xyz) > 0.2) {
accum += max(0.0, dot(normal.xyz, -light_dir)) * light + emission;
} else {
//all directions
accum += light + emission;
}
}
output.data[cell_index] = vec4(accum, 0.0);
#endif //MODE_COMPUTE_LIGHT
#ifdef MODE_UPDATE_MIPMAPS
{
vec3 light_accum = vec3(0.0);
float count = 0.0;
for (uint i = 0; i < 8; i++) {
uint child_index = cell_children.data[cell_index].children[i];
if (child_index == NO_CHILDREN) {
continue;
}
light_accum += output.data[child_index].rgb;
count += 1.0;
}
float divisor = mix(8.0, count, params.propagation);
output.data[cell_index] = vec4(light_accum / divisor, 0.0);
}
#endif
#ifdef MODE_WRITE_TEXTURE
{
}
#endif
}
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