godot/servers/rendering/renderer_rd/shaders/cubemap_downsampler.glsl
2020-12-04 18:39:46 -03:00

192 lines
5.6 KiB
GLSL

// Copyright 2016 Activision Publishing, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#[compute]
#version 450
VERSION_DEFINES
#define BLOCK_SIZE 8
layout(local_size_x = BLOCK_SIZE, local_size_y = BLOCK_SIZE, local_size_z = 1) in;
layout(set = 0, binding = 0) uniform samplerCube source_cubemap;
layout(rgba16f, set = 1, binding = 0) uniform restrict writeonly imageCube dest_cubemap;
layout(push_constant, binding = 1, std430) uniform Params {
uint face_size;
}
params;
#define M_PI 3.14159265359
void get_dir_0(out vec3 dir, in float u, in float v) {
dir[0] = 1.0;
dir[1] = v;
dir[2] = -u;
}
void get_dir_1(out vec3 dir, in float u, in float v) {
dir[0] = -1.0;
dir[1] = v;
dir[2] = u;
}
void get_dir_2(out vec3 dir, in float u, in float v) {
dir[0] = u;
dir[1] = 1.0;
dir[2] = -v;
}
void get_dir_3(out vec3 dir, in float u, in float v) {
dir[0] = u;
dir[1] = -1.0;
dir[2] = v;
}
void get_dir_4(out vec3 dir, in float u, in float v) {
dir[0] = u;
dir[1] = v;
dir[2] = 1.0;
}
void get_dir_5(out vec3 dir, in float u, in float v) {
dir[0] = -u;
dir[1] = v;
dir[2] = -1.0;
}
float calcWeight(float u, float v) {
float val = u * u + v * v + 1.0;
return val * sqrt(val);
}
void main() {
uvec3 id = gl_GlobalInvocationID;
uint face_size = params.face_size;
if (id.x < face_size && id.y < face_size) {
float inv_face_size = 1.0 / float(face_size);
float u0 = (float(id.x) * 2.0 + 1.0 - 0.75) * inv_face_size - 1.0;
float u1 = (float(id.x) * 2.0 + 1.0 + 0.75) * inv_face_size - 1.0;
float v0 = (float(id.y) * 2.0 + 1.0 - 0.75) * -inv_face_size + 1.0;
float v1 = (float(id.y) * 2.0 + 1.0 + 0.75) * -inv_face_size + 1.0;
float weights[4];
weights[0] = calcWeight(u0, v0);
weights[1] = calcWeight(u1, v0);
weights[2] = calcWeight(u0, v1);
weights[3] = calcWeight(u1, v1);
const float wsum = 0.5 / (weights[0] + weights[1] + weights[2] + weights[3]);
for (int i = 0; i < 4; i++) {
weights[i] = weights[i] * wsum + .125;
}
vec3 dir;
vec4 color;
switch (id.z) {
case 0:
get_dir_0(dir, u0, v0);
color = textureLod(source_cubemap, normalize(dir), 0.0) * weights[0];
get_dir_0(dir, u1, v0);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[1];
get_dir_0(dir, u0, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[2];
get_dir_0(dir, u1, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[3];
break;
case 1:
get_dir_1(dir, u0, v0);
color = textureLod(source_cubemap, normalize(dir), 0.0) * weights[0];
get_dir_1(dir, u1, v0);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[1];
get_dir_1(dir, u0, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[2];
get_dir_1(dir, u1, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[3];
break;
case 2:
get_dir_2(dir, u0, v0);
color = textureLod(source_cubemap, normalize(dir), 0.0) * weights[0];
get_dir_2(dir, u1, v0);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[1];
get_dir_2(dir, u0, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[2];
get_dir_2(dir, u1, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[3];
break;
case 3:
get_dir_3(dir, u0, v0);
color = textureLod(source_cubemap, normalize(dir), 0.0) * weights[0];
get_dir_3(dir, u1, v0);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[1];
get_dir_3(dir, u0, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[2];
get_dir_3(dir, u1, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[3];
break;
case 4:
get_dir_4(dir, u0, v0);
color = textureLod(source_cubemap, normalize(dir), 0.0) * weights[0];
get_dir_4(dir, u1, v0);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[1];
get_dir_4(dir, u0, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[2];
get_dir_4(dir, u1, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[3];
break;
default:
get_dir_5(dir, u0, v0);
color = textureLod(source_cubemap, normalize(dir), 0.0) * weights[0];
get_dir_5(dir, u1, v0);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[1];
get_dir_5(dir, u0, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[2];
get_dir_5(dir, u1, v1);
color += textureLod(source_cubemap, normalize(dir), 0.0) * weights[3];
break;
}
imageStore(dest_cubemap, ivec3(id), color);
}
}