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#ifdef DESC
[program]
type: graphics
vertex: main
fragment: main
[binding]
name: mesh
rate: vertex
[attribute]
name: position
type: vec3
[attribute]
name: normal
type: vec3
[attribute]
name: tangent
type: vec3
[attribute]
name: uv
type: vec2
[interpolator]
name: uv
type: vec2
[interpolator]
name: position
type: vec4
[interpolator]
name: tbn
type: mat3
[struct]
name: MVP
[variable]
name: model
type: mat4
[variable]
name: view_projection
type: mat4
[struct]
name: Material
[variable]
name: albedo
type: vec3
[variable]
name: metalness
type: float
[variable]
name: roughness
type: float
[variable]
name: ao
type: float
[variable]
name: camera_pos
type: vec3
[cbuffer]
name: c_mvp
type: MVP
stage: vertex
[cbuffer]
name: material
type: Material
stage: fragment
[texture]
name: albedo
stage: fragment
dimension: 2
[texture]
name: ao
stage: fragment
dimension: 2
[texture]
name: metal
stage: fragment
dimension: 2
[texture]
name: rough
stage: fragment
dimension: 2
[texture]
name: normal
stage: fragment
dimension: 2
[texture]
name: env_cube
stage: fragment
dimension: cube
[target]
name: colour
type: vec4
#endif
#ifdef VERTEX_SHADER
void main() {
vec4 pos = c_mvp.model * vec4(position, 1.0);
vec3 t = normalize((c_mvp.model * vec4(tangent, 0.0)).xyz);
vec3 n = normalize((c_mvp.model * vec4(normal, 0.0)).xyz);
vec3 b = cross(t, n);
interpolator.tbn = mat3(t, b, n);
interpolator.uv = uv;
interpolator.position = pos;
interpolator.tbn = mat3(t, b, n);
gl_Position = c_mvp.view_projection * pos;
}
#endif
#ifdef FRAGMENT_SHADER
#define pi 3.14159265358979323846
vec3 diffuse_brdf(vec2 uv) {
vec3 a = material.albedo * texture(albedo, uv).rgb;
return a / pi;
}
float specular_G1(float a, vec3 v, vec3 n) {
float ndv = max(dot(n, v), 0.0);
float a1 = a + 1.0;
float k = (a1 * a1) / 8.0;
return ndv / (ndv * (1.0 - k) + k);
}
float specular_brdf(vec2 uv, vec3 ref, vec3 l, vec3 v, vec3 n) {
float ndl = max(dot(n, l), 0.0);
float ndv = max(dot(n, v), 0.0);
float a = texture(rough, uv).r * material.roughness;
float a2 = a * a;
float ndr = max(dot(n, ref), 0.0);
float b = ((ndr * ndr) * (a2 - 1) + 1);
float D =
a2 / (pi * b * b);
float G = specular_G1(a, l, n) * specular_G1(a, v, n);
float F0 = 0.04;
float F = F0 + (1.0 - F0) *
pow(2, ((-5.55473 * ndr - 6.98316), ndr));
return (D * F * G) / (4.0 * ndl * ndv + 0.001);
}
void main() {
vec2 uv = interpolator.uv;
vec3 p = interpolator.position.xyz;
vec3 nrmsample = texture(normal, uv).rgb;
vec2 nrmxy = nrmsample.xy * 2.0 - 1.0;
vec3 nrm = normalize(vec3(nrmxy, 1.0));
if (nrmsample.b == 1.0) /* default texture */
nrm = normalize(interpolator.tbn[2]);
else
nrm = normalize(interpolator.tbn * nrm);
vec3 light_dir = vec3(0, 0, 1);
vec3 col = texture(albedo, uv).rgb * material.albedo;
float cos_theta_i = max(dot(nrm, light_dir), 0.0);
vec3 view_dir = normalize(material.camera_pos - p);
float met = texture(metal, uv).r * material.metalness;
vec3 ref = reflect(-view_dir, nrm);
vec3 spec_col = texture(env_cube, ref, material.roughness * 8.0).rgb;
vec3 amb_col = textureLod(env_cube, nrm, 8.0).rgb;
vec3 diffuse =
diffuse_brdf(uv) *
(1.0 - met) *
cos_theta_i;
vec3 spec =
mix(spec_col, col, met) *
specular_brdf(uv, ref, light_dir, view_dir, nrm) *
cos_theta_i;
vec3 ambient =
min(amb_col, 0.05) *
texture(ao, uv).r;
colour = vec4(ambient + diffuse + spec, 1.0);
}
#endif
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