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[vertex]
layout(location=0) in highp vec2 vertex;
layout(location=4) in highp vec2 uv;
out highp vec2 uv_interp;
void main() {
uv_interp=uv;
gl_Position=vec4(vertex,0,1);
}
[fragment]
precision highp float;
precision highp int;
#ifdef USE_SOURCE_PANORAMA
uniform sampler2D source_panorama; //texunit:0
#endif
#ifdef USE_SOURCE_DUAL_PARABOLOID_ARRAY
uniform sampler2DArray source_dual_paraboloid_array; //texunit:0
uniform int source_array_index;
#endif
#if !defined(USE_SOURCE_DUAL_PARABOLOID_ARRAY) && !defined(USE_SOURCE_PANORAMA)
uniform samplerCube source_cube; //texunit:0
#endif
uniform int face_id;
uniform float roughness;
in highp vec2 uv_interp;
layout(location = 0) out vec4 frag_color;
#define M_PI 3.14159265359
vec3 texelCoordToVec(vec2 uv, int faceID)
{
mat3 faceUvVectors[6];
/*
// -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
*/
// -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
// 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 LOW_QUALITY
#define SAMPLE_COUNT 64u
#else
#define SAMPLE_COUNT 512u
#endif
uniform bool z_flip;
#ifdef USE_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
#ifdef USE_SOURCE_DUAL_PARABOLOID_ARRAY
vec4 textureDualParaboloidArray(vec3 normal) {
vec3 norm = normalize(normal);
norm.xy/=1.0+abs(norm.z);
norm.xy=norm.xy * vec2(0.5,0.25) + vec2(0.5,0.25);
if (norm.z<0.0) {
norm.y=0.5-norm.y+0.5;
}
return textureLod(source_dual_paraboloid_array, vec3(norm.xy, float(source_array_index) ), 0.0);
}
#endif
void main() {
#ifdef USE_DUAL_PARABOLOID
vec3 N = vec3( uv_interp * 2.0 - 1.0, 0.0 );
N.z = 0.5 - 0.5*((N.x * N.x) + (N.y * N.y));
N = normalize(N);
if (z_flip) {
N.y=-N.y; //y is flipped to improve blending between both sides
N.z=-N.z;
}
#else
vec2 uv = (uv_interp * 2.0) - 1.0;
vec3 N = texelCoordToVec(uv, face_id);
#endif
//vec4 color = color_interp;
#ifdef USE_DIRECT_WRITE
#ifdef USE_SOURCE_PANORAMA
frag_color=vec4(texturePanorama(N,source_panorama).rgb,1.0);
#endif
#ifdef USE_SOURCE_DUAL_PARABOLOID_ARRAY
frag_color=vec4(textureDualParaboloidArray(N).rgb,1.0);
#endif
#if !defined(USE_SOURCE_DUAL_PARABOLOID_ARRAY) && !defined(USE_SOURCE_PANORAMA)
N.y=-N.y;
frag_color=vec4(texture(N,source_cube).rgb,1.0);
#endif
#else
vec4 sum = vec4(0.0, 0.0, 0.0, 0.0);
for(uint sampleNum = 0u; sampleNum < SAMPLE_COUNT; sampleNum++) {
vec2 xi = Hammersley(sampleNum, SAMPLE_COUNT);
vec3 H = ImportanceSampleGGX( xi, roughness, N );
vec3 V = N;
vec3 L = normalize(2.0 * dot( V, H ) * H - V);
float ndotl = clamp(dot(N, L),0.0,1.0);
if (ndotl>0.0) {
#ifdef USE_SOURCE_PANORAMA
sum.rgb += texturePanorama(H,source_panorama).rgb *ndotl;
#endif
#ifdef USE_SOURCE_DUAL_PARABOLOID_ARRAY
sum.rgb += textureDualParaboloidArray(H).rgb *ndotl;
#endif
#if !defined(USE_SOURCE_DUAL_PARABOLOID_ARRAY) && !defined(USE_SOURCE_PANORAMA)
H.y=-H.y;
sum.rgb += textureLod(source_cube, H, 0.0).rgb *ndotl;
#endif
sum.a += ndotl;
}
}
sum /= sum.a;
frag_color = vec4(sum.rgb, 1.0);
#endif
}
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