godot/modules/lightmapper_rd/lm_compute.glsl
reduz d3b49c416a Refactor GLSL shader compilation
-Used a more consistent set of keywords for the shader
-Remove all harcoded entry points
-Re-wrote the GLSL shader parser, new system is more flexible. Allows any entry point organization.
-Entry point for sky shaders is now sky().
-Entry point for particle shaders is now process().
2021-04-14 11:37:52 -03:00

657 lines
21 KiB
GLSL

#[versions]
primary = "#define MODE_DIRECT_LIGHT";
secondary = "#define MODE_BOUNCE_LIGHT";
dilate = "#define MODE_DILATE";
unocclude = "#define MODE_UNOCCLUDE";
light_probes = "#define MODE_LIGHT_PROBES";
#[compute]
#version 450
#VERSION_DEFINES
// One 2D local group focusing in one layer at a time, though all
// in parallel (no barriers) makes more sense than a 3D local group
// as this can take more advantage of the cache for each group.
#ifdef MODE_LIGHT_PROBES
layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
#else
layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
#endif
#include "lm_common_inc.glsl"
#ifdef MODE_LIGHT_PROBES
layout(set = 1, binding = 0, std430) restrict buffer LightProbeData {
vec4 data[];
}
light_probes;
layout(set = 1, binding = 1) uniform texture2DArray source_light;
layout(set = 1, binding = 2) uniform texture2DArray source_direct_light; //also need the direct light, which was omitted
layout(set = 1, binding = 3) uniform texture2D environment;
#endif
#ifdef MODE_UNOCCLUDE
layout(rgba32f, set = 1, binding = 0) uniform restrict image2DArray position;
layout(rgba32f, set = 1, binding = 1) uniform restrict readonly image2DArray unocclude;
#endif
#if defined(MODE_DIRECT_LIGHT) || defined(MODE_BOUNCE_LIGHT)
layout(rgba16f, set = 1, binding = 0) uniform restrict writeonly image2DArray dest_light;
layout(set = 1, binding = 1) uniform texture2DArray source_light;
layout(set = 1, binding = 2) uniform texture2DArray source_position;
layout(set = 1, binding = 3) uniform texture2DArray source_normal;
layout(rgba16f, set = 1, binding = 4) uniform restrict image2DArray accum_light;
#endif
#ifdef MODE_BOUNCE_LIGHT
layout(rgba32f, set = 1, binding = 5) uniform restrict image2DArray bounce_accum;
layout(set = 1, binding = 6) uniform texture2D environment;
#endif
#ifdef MODE_DIRECT_LIGHT
layout(rgba32f, set = 1, binding = 5) uniform restrict writeonly image2DArray primary_dynamic;
#endif
#ifdef MODE_DILATE
layout(rgba16f, set = 1, binding = 0) uniform restrict writeonly image2DArray dest_light;
layout(set = 1, binding = 1) uniform texture2DArray source_light;
#endif
layout(push_constant, binding = 0, std430) uniform Params {
ivec2 atlas_size; // x used for light probe mode total probes
uint ray_count;
uint ray_to;
vec3 world_size;
float bias;
vec3 to_cell_offset;
uint ray_from;
vec3 to_cell_size;
uint light_count;
int grid_size;
int atlas_slice;
ivec2 region_ofs;
mat3x4 env_transform;
}
params;
//check it, but also return distance and barycentric coords (for uv lookup)
bool ray_hits_triangle(vec3 from, vec3 dir, float max_dist, vec3 p0, vec3 p1, vec3 p2, out float r_distance, out vec3 r_barycentric) {
const vec3 e0 = p1 - p0;
const vec3 e1 = p0 - p2;
vec3 triangleNormal = cross(e1, e0);
const vec3 e2 = (1.0 / dot(triangleNormal, dir)) * (p0 - from);
const vec3 i = cross(dir, e2);
r_barycentric.y = dot(i, e1);
r_barycentric.z = dot(i, e0);
r_barycentric.x = 1.0 - (r_barycentric.z + r_barycentric.y);
r_distance = dot(triangleNormal, e2);
return (r_distance > params.bias) && (r_distance < max_dist) && all(greaterThanEqual(r_barycentric, vec3(0.0)));
}
bool trace_ray(vec3 p_from, vec3 p_to
#if defined(MODE_BOUNCE_LIGHT) || defined(MODE_LIGHT_PROBES)
,
out uint r_triangle, out vec3 r_barycentric
#endif
#if defined(MODE_UNOCCLUDE)
,
out float r_distance, out vec3 r_normal
#endif
) {
/* world coords */
vec3 rel = p_to - p_from;
float rel_len = length(rel);
vec3 dir = normalize(rel);
vec3 inv_dir = 1.0 / dir;
/* cell coords */
vec3 from_cell = (p_from - params.to_cell_offset) * params.to_cell_size;
vec3 to_cell = (p_to - params.to_cell_offset) * params.to_cell_size;
//prepare DDA
vec3 rel_cell = to_cell - from_cell;
ivec3 icell = ivec3(from_cell);
ivec3 iendcell = ivec3(to_cell);
vec3 dir_cell = normalize(rel_cell);
vec3 delta = abs(1.0 / dir_cell); //vec3(length(rel_cell)) / rel_cell);
ivec3 step = ivec3(sign(rel_cell));
vec3 side = (sign(rel_cell) * (vec3(icell) - from_cell) + (sign(rel_cell) * 0.5) + 0.5) * delta;
uint iters = 0;
while (all(greaterThanEqual(icell, ivec3(0))) && all(lessThan(icell, ivec3(params.grid_size))) && iters < 1000) {
uvec2 cell_data = texelFetch(usampler3D(grid, linear_sampler), icell, 0).xy;
if (cell_data.x > 0) { //triangles here
bool hit = false;
#if defined(MODE_UNOCCLUDE)
bool hit_backface = false;
#endif
float best_distance = 1e20;
for (uint i = 0; i < cell_data.x; i++) {
uint tidx = grid_indices.data[cell_data.y + i];
//Ray-Box test
vec3 t0 = (boxes.data[tidx].min_bounds - p_from) * inv_dir;
vec3 t1 = (boxes.data[tidx].max_bounds - p_from) * inv_dir;
vec3 tmin = min(t0, t1), tmax = max(t0, t1);
if (max(tmin.x, max(tmin.y, tmin.z)) <= min(tmax.x, min(tmax.y, tmax.z))) {
continue; //ray box failed
}
//prepare triangle vertices
vec3 vtx0 = vertices.data[triangles.data[tidx].indices.x].position;
vec3 vtx1 = vertices.data[triangles.data[tidx].indices.y].position;
vec3 vtx2 = vertices.data[triangles.data[tidx].indices.z].position;
#if defined(MODE_UNOCCLUDE)
vec3 normal = -normalize(cross((vtx0 - vtx1), (vtx0 - vtx2)));
bool backface = dot(normal, dir) >= 0.0;
#endif
float distance;
vec3 barycentric;
if (ray_hits_triangle(p_from, dir, rel_len, vtx0, vtx1, vtx2, distance, barycentric)) {
#ifdef MODE_DIRECT_LIGHT
return true; //any hit good
#endif
#if defined(MODE_UNOCCLUDE)
if (!backface) {
// the case of meshes having both a front and back face in the same plane is more common than
// expected, so if this is a front-face, bias it closer to the ray origin, so it always wins over the back-face
distance = max(params.bias, distance - params.bias);
}
hit = true;
if (distance < best_distance) {
hit_backface = backface;
best_distance = distance;
r_distance = distance;
r_normal = normal;
}
#endif
#if defined(MODE_BOUNCE_LIGHT) || defined(MODE_LIGHT_PROBES)
hit = true;
if (distance < best_distance) {
best_distance = distance;
r_triangle = tidx;
r_barycentric = barycentric;
}
#endif
}
}
#if defined(MODE_UNOCCLUDE)
if (hit) {
return hit_backface;
}
#endif
#if defined(MODE_BOUNCE_LIGHT) || defined(MODE_LIGHT_PROBES)
if (hit) {
return true;
}
#endif
}
if (icell == iendcell) {
break;
}
bvec3 mask = lessThanEqual(side.xyz, min(side.yzx, side.zxy));
side += vec3(mask) * delta;
icell += ivec3(vec3(mask)) * step;
iters++;
}
return false;
}
const float PI = 3.14159265f;
const float GOLDEN_ANGLE = PI * (3.0 - sqrt(5.0));
vec3 vogel_hemisphere(uint p_index, uint p_count, float p_offset) {
float r = sqrt(float(p_index) + 0.5f) / sqrt(float(p_count));
float theta = float(p_index) * GOLDEN_ANGLE + p_offset;
float y = cos(r * PI * 0.5);
float l = sin(r * PI * 0.5);
return vec3(l * cos(theta), l * sin(theta), y);
}
float quick_hash(vec2 pos) {
return fract(sin(dot(pos * 19.19, vec2(49.5791, 97.413))) * 49831.189237);
}
float get_omni_attenuation(float distance, float inv_range, float decay) {
float nd = distance * inv_range;
nd *= nd;
nd *= nd; // nd^4
nd = max(1.0 - nd, 0.0);
nd *= nd; // nd^2
return nd * pow(max(distance, 0.0001), -decay);
}
void main() {
#ifdef MODE_LIGHT_PROBES
int probe_index = int(gl_GlobalInvocationID.x);
if (probe_index >= params.atlas_size.x) { //too large, do nothing
return;
}
#else
ivec2 atlas_pos = ivec2(gl_GlobalInvocationID.xy) + params.region_ofs;
if (any(greaterThanEqual(atlas_pos, params.atlas_size))) { //too large, do nothing
return;
}
#endif
#ifdef MODE_DIRECT_LIGHT
vec3 normal = texelFetch(sampler2DArray(source_normal, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
if (length(normal) < 0.5) {
return; //empty texel, no process
}
vec3 position = texelFetch(sampler2DArray(source_position, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
//go through all lights
//start by own light (emissive)
vec3 static_light = vec3(0.0);
vec3 dynamic_light = vec3(0.0);
#ifdef USE_SH_LIGHTMAPS
vec4 sh_accum[4] = vec4[](
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0));
#endif
for (uint i = 0; i < params.light_count; i++) {
vec3 light_pos;
float attenuation;
if (lights.data[i].type == LIGHT_TYPE_DIRECTIONAL) {
vec3 light_vec = lights.data[i].direction;
light_pos = position - light_vec * length(params.world_size);
attenuation = 1.0;
} else {
light_pos = lights.data[i].position;
float d = distance(position, light_pos);
if (d > lights.data[i].range) {
continue;
}
d /= lights.data[i].range;
attenuation = get_omni_attenuation(d, 1.0 / lights.data[i].range, lights.data[i].attenuation);
if (lights.data[i].type == LIGHT_TYPE_SPOT) {
vec3 rel = normalize(position - light_pos);
float cos_spot_angle = lights.data[i].cos_spot_angle;
float cos_angle = dot(rel, lights.data[i].direction);
if (cos_angle < cos_spot_angle) {
continue; //invisible, dont try
}
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[i].inv_spot_attenuation);
}
}
vec3 light_dir = normalize(light_pos - position);
attenuation *= max(0.0, dot(normal, light_dir));
if (attenuation <= 0.0001) {
continue; //no need to do anything
}
if (!trace_ray(position + light_dir * params.bias, light_pos)) {
vec3 light = lights.data[i].color * lights.data[i].energy * attenuation;
if (lights.data[i].static_bake) {
static_light += light;
#ifdef USE_SH_LIGHTMAPS
float c[4] = float[](
0.282095, //l0
0.488603 * light_dir.y, //l1n1
0.488603 * light_dir.z, //l1n0
0.488603 * light_dir.x //l1p1
);
for (uint j = 0; j < 4; j++) {
sh_accum[j].rgb += light * c[j] * (1.0 / 3.0);
}
#endif
} else {
dynamic_light += light;
}
}
}
vec3 albedo = texelFetch(sampler2DArray(albedo_tex, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).rgb;
vec3 emissive = texelFetch(sampler2DArray(emission_tex, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).rgb;
dynamic_light *= albedo; //if it will bounce, must multiply by albedo
dynamic_light += emissive;
//keep for lightprobes
imageStore(primary_dynamic, ivec3(atlas_pos, params.atlas_slice), vec4(dynamic_light, 1.0));
dynamic_light += static_light * albedo; //send for bounces
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice), vec4(dynamic_light, 1.0));
#ifdef USE_SH_LIGHTMAPS
//keep for adding at the end
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + 0), sh_accum[0]);
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + 1), sh_accum[1]);
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + 2), sh_accum[2]);
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + 3), sh_accum[3]);
#else
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice), vec4(static_light, 1.0));
#endif
#endif
#ifdef MODE_BOUNCE_LIGHT
vec3 normal = texelFetch(sampler2DArray(source_normal, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
if (length(normal) < 0.5) {
return; //empty texel, no process
}
vec3 position = texelFetch(sampler2DArray(source_position, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
vec3 v0 = abs(normal.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 1.0, 0.0);
vec3 tangent = normalize(cross(v0, normal));
vec3 bitangent = normalize(cross(tangent, normal));
mat3 normal_mat = mat3(tangent, bitangent, normal);
#ifdef USE_SH_LIGHTMAPS
vec4 sh_accum[4] = vec4[](
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0));
#endif
vec3 light_average = vec3(0.0);
for (uint i = params.ray_from; i < params.ray_to; i++) {
vec3 ray_dir = normal_mat * vogel_hemisphere(i, params.ray_count, quick_hash(vec2(atlas_pos)));
uint tidx;
vec3 barycentric;
vec3 light;
if (trace_ray(position + ray_dir * params.bias, position + ray_dir * length(params.world_size), tidx, barycentric)) {
//hit a triangle
vec2 uv0 = vertices.data[triangles.data[tidx].indices.x].uv;
vec2 uv1 = vertices.data[triangles.data[tidx].indices.y].uv;
vec2 uv2 = vertices.data[triangles.data[tidx].indices.z].uv;
vec3 uvw = vec3(barycentric.x * uv0 + barycentric.y * uv1 + barycentric.z * uv2, float(triangles.data[tidx].slice));
light = textureLod(sampler2DArray(source_light, linear_sampler), uvw, 0.0).rgb;
} else {
//did not hit a triangle, reach out for the sky
vec3 sky_dir = normalize(mat3(params.env_transform) * ray_dir);
vec2 st = vec2(
atan(sky_dir.x, sky_dir.z),
acos(sky_dir.y));
if (st.x < 0.0)
st.x += PI * 2.0;
st /= vec2(PI * 2.0, PI);
light = textureLod(sampler2D(environment, linear_sampler), st, 0.0).rgb;
}
light_average += light;
#ifdef USE_SH_LIGHTMAPS
float c[4] = float[](
0.282095, //l0
0.488603 * ray_dir.y, //l1n1
0.488603 * ray_dir.z, //l1n0
0.488603 * ray_dir.x //l1p1
);
for (uint j = 0; j < 4; j++) {
sh_accum[j].rgb += light * c[j] * (8.0 / float(params.ray_count));
}
#endif
}
vec3 light_total;
if (params.ray_from == 0) {
light_total = vec3(0.0);
} else {
light_total = imageLoad(bounce_accum, ivec3(atlas_pos, params.atlas_slice)).rgb;
}
light_total += light_average;
#ifdef USE_SH_LIGHTMAPS
for (int i = 0; i < 4; i++) {
vec4 accum = imageLoad(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + i));
accum.rgb += sh_accum[i].rgb;
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + i), accum);
}
#endif
if (params.ray_to == params.ray_count) {
light_total /= float(params.ray_count);
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice), vec4(light_total, 1.0));
#ifndef USE_SH_LIGHTMAPS
vec4 accum = imageLoad(accum_light, ivec3(atlas_pos, params.atlas_slice));
accum.rgb += light_total;
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice), accum);
#endif
} else {
imageStore(bounce_accum, ivec3(atlas_pos, params.atlas_slice), vec4(light_total, 1.0));
}
#endif
#ifdef MODE_UNOCCLUDE
//texel_size = 0.5;
//compute tangents
vec4 position_alpha = imageLoad(position, ivec3(atlas_pos, params.atlas_slice));
if (position_alpha.a < 0.5) {
return;
}
vec3 vertex_pos = position_alpha.xyz;
vec4 normal_tsize = imageLoad(unocclude, ivec3(atlas_pos, params.atlas_slice));
vec3 face_normal = normal_tsize.xyz;
float texel_size = normal_tsize.w;
vec3 v0 = abs(face_normal.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 1.0, 0.0);
vec3 tangent = normalize(cross(v0, face_normal));
vec3 bitangent = normalize(cross(tangent, face_normal));
vec3 base_pos = vertex_pos + face_normal * params.bias; //raise a bit
vec3 rays[4] = vec3[](tangent, bitangent, -tangent, -bitangent);
float min_d = 1e20;
for (int i = 0; i < 4; i++) {
vec3 ray_to = base_pos + rays[i] * texel_size;
float d;
vec3 norm;
if (trace_ray(base_pos, ray_to, d, norm)) {
if (d < min_d) {
vertex_pos = base_pos + rays[i] * d + norm * params.bias * 10.0; //this bias needs to be greater than the regular bias, because otherwise later, rays will go the other side when pointing back.
min_d = d;
}
}
}
position_alpha.xyz = vertex_pos;
imageStore(position, ivec3(atlas_pos, params.atlas_slice), position_alpha);
#endif
#ifdef MODE_LIGHT_PROBES
vec3 position = probe_positions.data[probe_index].xyz;
vec4 probe_sh_accum[9] = vec4[](
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0));
for (uint i = params.ray_from; i < params.ray_to; i++) {
vec3 ray_dir = vogel_hemisphere(i, params.ray_count, quick_hash(vec2(float(probe_index), 0.0)));
if (bool(i & 1)) {
//throw to both sides, so alternate them
ray_dir.z *= -1.0;
}
uint tidx;
vec3 barycentric;
vec3 light;
if (trace_ray(position + ray_dir * params.bias, position + ray_dir * length(params.world_size), tidx, barycentric)) {
vec2 uv0 = vertices.data[triangles.data[tidx].indices.x].uv;
vec2 uv1 = vertices.data[triangles.data[tidx].indices.y].uv;
vec2 uv2 = vertices.data[triangles.data[tidx].indices.z].uv;
vec3 uvw = vec3(barycentric.x * uv0 + barycentric.y * uv1 + barycentric.z * uv2, float(triangles.data[tidx].slice));
light = textureLod(sampler2DArray(source_light, linear_sampler), uvw, 0.0).rgb;
light += textureLod(sampler2DArray(source_direct_light, linear_sampler), uvw, 0.0).rgb;
} else {
//did not hit a triangle, reach out for the sky
vec3 sky_dir = normalize(mat3(params.env_transform) * ray_dir);
vec2 st = vec2(
atan(sky_dir.x, sky_dir.z),
acos(sky_dir.y));
if (st.x < 0.0)
st.x += PI * 2.0;
st /= vec2(PI * 2.0, PI);
light = textureLod(sampler2D(environment, linear_sampler), st, 0.0).rgb;
}
{
float c[9] = float[](
0.282095, //l0
0.488603 * ray_dir.y, //l1n1
0.488603 * ray_dir.z, //l1n0
0.488603 * ray_dir.x, //l1p1
1.092548 * ray_dir.x * ray_dir.y, //l2n2
1.092548 * ray_dir.y * ray_dir.z, //l2n1
//0.315392 * (ray_dir.x * ray_dir.x + ray_dir.y * ray_dir.y + 2.0 * ray_dir.z * ray_dir.z), //l20
0.315392 * (3.0 * ray_dir.z * ray_dir.z - 1.0), //l20
1.092548 * ray_dir.x * ray_dir.z, //l2p1
0.546274 * (ray_dir.x * ray_dir.x - ray_dir.y * ray_dir.y) //l2p2
);
for (uint j = 0; j < 9; j++) {
probe_sh_accum[j].rgb += light * c[j];
}
}
}
if (params.ray_from > 0) {
for (uint j = 0; j < 9; j++) { //accum from existing
probe_sh_accum[j] += light_probes.data[probe_index * 9 + j];
}
}
if (params.ray_to == params.ray_count) {
for (uint j = 0; j < 9; j++) { //accum from existing
probe_sh_accum[j] *= 4.0 / float(params.ray_count);
}
}
for (uint j = 0; j < 9; j++) { //accum from existing
light_probes.data[probe_index * 9 + j] = probe_sh_accum[j];
}
#endif
#ifdef MODE_DILATE
vec4 c = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0);
//sides first, as they are closer
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, 0), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(0, 1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, 0), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(0, -1), params.atlas_slice), 0);
//endpoints second
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, -1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, 1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, -1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, 1), params.atlas_slice), 0);
//far sides third
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, 0), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(0, 2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, 0), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(0, -2), params.atlas_slice), 0);
//far-mid endpoints
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, -1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, 1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, -1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, 1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, -2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, 2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, -2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, 2), params.atlas_slice), 0);
//far endpoints
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, -2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, 2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, -2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, 2), params.atlas_slice), 0);
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice), c);
#endif
}