227 lines
6.0 KiB
GLSL
227 lines
6.0 KiB
GLSL
/* clang-format off */
|
|
[vertex]
|
|
|
|
#version 450
|
|
|
|
VERSION_DEFINES
|
|
|
|
layout(location = 0) out highp vec2 uv_interp;
|
|
/* clang-format on */
|
|
|
|
void main() {
|
|
|
|
vec2 base_arr[4] = vec2[](vec2(0.0, 0.0), vec2(0.0, 1.0), vec2(1.0, 1.0), vec2(1.0, 0.0));
|
|
uv_interp = base_arr[gl_VertexIndex];
|
|
gl_Position = vec4(uv_interp * 2.0 - 1.0, 0.0, 1.0);
|
|
}
|
|
|
|
/* clang-format off */
|
|
[fragment]
|
|
|
|
#version 450
|
|
|
|
VERSION_DEFINES
|
|
|
|
#ifdef MODE_SOURCE_PANORAMA
|
|
layout(set = 0, binding = 0) uniform sampler2D source_panorama;
|
|
/* clang-format on */
|
|
#endif
|
|
|
|
#ifdef MODE_SOURCE_CUBEMAP
|
|
layout(set = 0, binding = 0) uniform samplerCube source_cube;
|
|
#endif
|
|
|
|
layout(push_constant, binding = 1, std430) uniform Params {
|
|
uint face_id;
|
|
uint sample_count;
|
|
float roughness;
|
|
bool use_direct_write;
|
|
} params;
|
|
|
|
layout(location = 0) in vec2 uv_interp;
|
|
|
|
layout(location = 0) out vec4 frag_color;
|
|
|
|
#define M_PI 3.14159265359
|
|
|
|
vec3 texelCoordToVec(vec2 uv, uint faceID) {
|
|
mat3 faceUvVectors[6];
|
|
/*
|
|
// -x
|
|
faceUvVectors[0][0] = vec3(0.0, 0.0, 1.0); // u -> +z
|
|
faceUvVectors[0][1] = vec3(0.0, -1.0, 0.0); // v -> -y
|
|
faceUvVectors[0][2] = vec3(-1.0, 0.0, 0.0); // -x face
|
|
|
|
// +x
|
|
faceUvVectors[1][0] = vec3(0.0, 0.0, -1.0); // u -> -z
|
|
faceUvVectors[1][1] = vec3(0.0, -1.0, 0.0); // v -> -y
|
|
faceUvVectors[1][2] = vec3(1.0, 0.0, 0.0); // +x face
|
|
|
|
// -y
|
|
faceUvVectors[2][0] = vec3(1.0, 0.0, 0.0); // u -> +x
|
|
faceUvVectors[2][1] = vec3(0.0, 0.0, -1.0); // v -> -z
|
|
faceUvVectors[2][2] = vec3(0.0, -1.0, 0.0); // -y face
|
|
|
|
// +y
|
|
faceUvVectors[3][0] = vec3(1.0, 0.0, 0.0); // u -> +x
|
|
faceUvVectors[3][1] = vec3(0.0, 0.0, 1.0); // v -> +z
|
|
faceUvVectors[3][2] = vec3(0.0, 1.0, 0.0); // +y face
|
|
|
|
// -z
|
|
faceUvVectors[4][0] = vec3(-1.0, 0.0, 0.0); // u -> -x
|
|
faceUvVectors[4][1] = vec3(0.0, -1.0, 0.0); // v -> -y
|
|
faceUvVectors[4][2] = vec3(0.0, 0.0, -1.0); // -z face
|
|
|
|
// +z
|
|
faceUvVectors[5][0] = vec3(1.0, 0.0, 0.0); // u -> +x
|
|
faceUvVectors[5][1] = vec3(0.0, -1.0, 0.0); // v -> -y
|
|
faceUvVectors[5][2] = vec3(0.0, 0.0, 1.0); // +z face
|
|
*/
|
|
|
|
// -x
|
|
faceUvVectors[1][0] = vec3(0.0, 0.0, 1.0); // u -> +z
|
|
faceUvVectors[1][1] = vec3(0.0, -1.0, 0.0); // v -> -y
|
|
faceUvVectors[1][2] = vec3(-1.0, 0.0, 0.0); // -x face
|
|
|
|
// +x
|
|
faceUvVectors[0][0] = vec3(0.0, 0.0, -1.0); // u -> -z
|
|
faceUvVectors[0][1] = vec3(0.0, -1.0, 0.0); // v -> -y
|
|
faceUvVectors[0][2] = vec3(1.0, 0.0, 0.0); // +x face
|
|
|
|
// -y
|
|
faceUvVectors[3][0] = vec3(1.0, 0.0, 0.0); // u -> +x
|
|
faceUvVectors[3][1] = vec3(0.0, 0.0, -1.0); // v -> -z
|
|
faceUvVectors[3][2] = vec3(0.0, -1.0, 0.0); // -y face
|
|
|
|
// +y
|
|
faceUvVectors[2][0] = vec3(1.0, 0.0, 0.0); // u -> +x
|
|
faceUvVectors[2][1] = vec3(0.0, 0.0, 1.0); // v -> +z
|
|
faceUvVectors[2][2] = vec3(0.0, 1.0, 0.0); // +y face
|
|
|
|
// -z
|
|
faceUvVectors[5][0] = vec3(-1.0, 0.0, 0.0); // u -> -x
|
|
faceUvVectors[5][1] = vec3(0.0, -1.0, 0.0); // v -> -y
|
|
faceUvVectors[5][2] = vec3(0.0, 0.0, -1.0); // -z face
|
|
|
|
// +z
|
|
faceUvVectors[4][0] = vec3(1.0, 0.0, 0.0); // u -> +x
|
|
faceUvVectors[4][1] = vec3(0.0, -1.0, 0.0); // v -> -y
|
|
faceUvVectors[4][2] = vec3(0.0, 0.0, 1.0); // +z face
|
|
|
|
// out = u * s_faceUv[0] + v * s_faceUv[1] + s_faceUv[2].
|
|
vec3 result = (faceUvVectors[faceID][0] * uv.x) + (faceUvVectors[faceID][1] * uv.y) + faceUvVectors[faceID][2];
|
|
return normalize(result);
|
|
}
|
|
|
|
vec3 ImportanceSampleGGX(vec2 Xi, float Roughness, vec3 N) {
|
|
float a = Roughness * Roughness; // DISNEY'S ROUGHNESS [see Burley'12 siggraph]
|
|
|
|
// Compute distribution direction
|
|
float Phi = 2.0 * M_PI * Xi.x;
|
|
float CosTheta = sqrt((1.0 - Xi.y) / (1.0 + (a * a - 1.0) * Xi.y));
|
|
float SinTheta = sqrt(1.0 - CosTheta * CosTheta);
|
|
|
|
// Convert to spherical direction
|
|
vec3 H;
|
|
H.x = SinTheta * cos(Phi);
|
|
H.y = SinTheta * sin(Phi);
|
|
H.z = CosTheta;
|
|
|
|
vec3 UpVector = abs(N.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(1.0, 0.0, 0.0);
|
|
vec3 TangentX = normalize(cross(UpVector, N));
|
|
vec3 TangentY = cross(N, TangentX);
|
|
|
|
// Tangent to world space
|
|
return TangentX * H.x + TangentY * H.y + N * H.z;
|
|
}
|
|
|
|
// http://graphicrants.blogspot.com.au/2013/08/specular-brdf-reference.html
|
|
float GGX(float NdotV, float a) {
|
|
float k = a / 2.0;
|
|
return NdotV / (NdotV * (1.0 - k) + k);
|
|
}
|
|
|
|
// http://graphicrants.blogspot.com.au/2013/08/specular-brdf-reference.html
|
|
float G_Smith(float a, float nDotV, float nDotL) {
|
|
return GGX(nDotL, a * a) * GGX(nDotV, a * a);
|
|
}
|
|
|
|
float radicalInverse_VdC(uint bits) {
|
|
bits = (bits << 16u) | (bits >> 16u);
|
|
bits = ((bits & 0x55555555u) << 1u) | ((bits & 0xAAAAAAAAu) >> 1u);
|
|
bits = ((bits & 0x33333333u) << 2u) | ((bits & 0xCCCCCCCCu) >> 2u);
|
|
bits = ((bits & 0x0F0F0F0Fu) << 4u) | ((bits & 0xF0F0F0F0u) >> 4u);
|
|
bits = ((bits & 0x00FF00FFu) << 8u) | ((bits & 0xFF00FF00u) >> 8u);
|
|
return float(bits) * 2.3283064365386963e-10; // / 0x100000000
|
|
}
|
|
|
|
vec2 Hammersley(uint i, uint N) {
|
|
return vec2(float(i) / float(N), radicalInverse_VdC(i));
|
|
}
|
|
|
|
#ifdef MODE_SOURCE_PANORAMA
|
|
|
|
vec4 texturePanorama(vec3 normal, sampler2D pano) {
|
|
|
|
vec2 st = vec2(
|
|
atan(normal.x, -normal.z),
|
|
acos(normal.y));
|
|
|
|
if (st.x < 0.0)
|
|
st.x += M_PI * 2.0;
|
|
|
|
st /= vec2(M_PI * 2.0, M_PI);
|
|
|
|
return textureLod(pano, st, 0.0);
|
|
}
|
|
|
|
#endif
|
|
|
|
void main() {
|
|
|
|
vec2 uv = (uv_interp * 2.0) - 1.0;
|
|
vec3 N = texelCoordToVec(uv, params.face_id);
|
|
|
|
//vec4 color = color_interp;
|
|
|
|
if (params.use_direct_write) {
|
|
|
|
#ifdef MODE_SOURCE_PANORAMA
|
|
|
|
frag_color = vec4(texturePanorama(N, source_panorama).rgb, 1.0);
|
|
#endif
|
|
|
|
#ifdef MODE_SOURCE_CUBEMAP
|
|
frag_color = vec4(texture(source_cube, N).rgb, 1.0);
|
|
#endif
|
|
|
|
} else {
|
|
|
|
vec4 sum = vec4(0.0, 0.0, 0.0, 0.0);
|
|
|
|
for (uint sampleNum = 0u; sampleNum < params.sample_count; sampleNum++) {
|
|
vec2 xi = Hammersley(sampleNum, params.sample_count);
|
|
|
|
vec3 H = ImportanceSampleGGX(xi, params.roughness, N);
|
|
vec3 V = N;
|
|
vec3 L = (2.0 * dot(V, H) * H - V);
|
|
|
|
float ndotl = clamp(dot(N, L), 0.0, 1.0);
|
|
|
|
if (ndotl > 0.0) {
|
|
#ifdef MODE_SOURCE_PANORAMA
|
|
sum.rgb += texturePanorama(L, source_panorama).rgb * ndotl;
|
|
#endif
|
|
|
|
#ifdef MODE_SOURCE_CUBEMAP
|
|
sum.rgb += textureLod(source_cube, L, 0.0).rgb * ndotl;
|
|
#endif
|
|
sum.a += ndotl;
|
|
}
|
|
}
|
|
sum /= sum.a;
|
|
|
|
frag_color = vec4(sum.rgb, 1.0);
|
|
}
|
|
}
|