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-rwxr-xr-xMaster/texmf-dist/asymptote/shaders/fragment.glsl316
1 files changed, 231 insertions, 85 deletions
diff --git a/Master/texmf-dist/asymptote/shaders/fragment.glsl b/Master/texmf-dist/asymptote/shaders/fragment.glsl
index b6a85597451..cdcc0b49e83 100755
--- a/Master/texmf-dist/asymptote/shaders/fragment.glsl
+++ b/Master/texmf-dist/asymptote/shaders/fragment.glsl
@@ -1,85 +1,231 @@
-struct Material
-{
- vec4 diffuse,ambient,emissive,specular;
- float shininess;
-};
-
-struct Light
-{
- vec4 direction;
- vec4 diffuse,ambient,specular;
-};
-
-uniform int nlights;
-
-uniform Light lights[Nlights];
-
-uniform MaterialBuffer {
- Material Materials[Nmaterials];
-};
-
-in vec3 Normal;
-
-#ifdef EXPLICIT_COLOR
-in vec4 Color;
-#endif
-flat in int materialIndex;
-
-out vec4 outColor;
-
-void main()
-{
- vec4 Diffuse;
- vec4 Ambient;
- vec4 Emissive;
- vec4 Specular;
- float Shininess;
-
-#ifdef EXPLICIT_COLOR
- if(materialIndex < 0) {
- int index=-materialIndex-1;
- Material m=Materials[index];
- Diffuse=Color;
- Ambient=Color;
- Emissive=vec4(0.0,0.0,0.0,1.0);
- Specular=m.specular;
- Shininess=m.shininess;
- } else {
- Material m=Materials[materialIndex];
- Diffuse=m.diffuse;
- Ambient=m.ambient;
- Emissive=m.emissive;
- Specular=m.specular;
- Shininess=m.shininess;
- }
-#else
- Material m=Materials[materialIndex];
- Diffuse=m.diffuse;
- Ambient=m.ambient;
- Emissive=m.emissive;
- Specular=m.specular;
- Shininess=m.shininess;
-#endif
- // Phong-Blinn model
- if(nlights > 0) {
- vec3 diffuse=vec3(0,0,0);
- vec3 specular=vec3(0,0,0);
- vec3 ambient=vec3(0,0,0);
- vec3 Z=vec3(0,0,1);
-
- for(int i=0; i < nlights; ++i) {
- vec3 L=normalize(lights[i].direction.xyz);
- diffuse += lights[i].diffuse.rgb*abs(dot(Normal,L));
- ambient += lights[i].ambient.rgb;
- specular += pow(abs(dot(Normal,normalize(L+Z))),Shininess)*
- lights[i].specular.rgb;
- }
-
- vec3 color=diffuse*Diffuse.rgb+
- ambient*Ambient.rgb+
- specular*Specular.rgb+
- Emissive.rgb;
- outColor=vec4(color,Diffuse[3]);
- } else
- outColor=Diffuse;
-}
+struct Material
+{
+ vec4 diffuse,emissive,specular;
+ vec4 parameters;
+};
+
+struct Light
+{
+ vec3 direction;
+ vec3 color;
+};
+
+uniform int nlights;
+uniform Light lights[max(Nlights,1)];
+
+uniform MaterialBuffer {
+ Material Materials[Nmaterials];
+};
+
+#ifdef NORMAL
+#ifndef ORTHOGRAPHIC
+in vec3 ViewPosition;
+#endif
+in vec3 Normal;
+vec3 normal;
+#endif
+
+#ifdef COLOR
+in vec4 Color;
+#endif
+
+flat in int materialIndex;
+out vec4 outColor;
+
+// PBR material parameters
+vec3 Diffuse; // Diffuse for nonmetals, reflectance for metals.
+vec3 Specular; // Specular tint for nonmetals
+float Metallic; // Metallic/Nonmetals parameter
+float Fresnel0; // Fresnel at zero for nonmetals
+float Roughness2; // roughness squared, for smoothing
+
+#ifdef ENABLE_TEXTURE
+uniform sampler2D environmentMap;
+const float PI=acos(-1.0);
+const float twopi=2*PI;
+const float halfpi=PI/2;
+
+const int numSamples=7;
+
+// (x,y,z) -> (r,theta,phi);
+// theta -> [0,\pi]: colatitude
+// phi -> [0, 2\pi]: longitude
+vec3 cart2sphere(vec3 cart)
+{
+ float x=cart.z;
+ float y=cart.x;
+ float z=cart.y;
+
+ float r=length(cart);
+ float phi=atan(y,x);
+ float theta=acos(z/r);
+
+ return vec3(r,phi,theta);
+}
+
+vec2 normalizedAngle(vec3 cartVec)
+{
+ vec3 sphericalVec=cart2sphere(cartVec);
+ sphericalVec.y=sphericalVec.y/(2*PI)-0.25;
+ sphericalVec.z=sphericalVec.z/PI;
+ return sphericalVec.yz;
+}
+#endif
+
+#ifdef NORMAL
+// h is the halfway vector between normal and light direction
+// GGX Trowbridge-Reitz Approximation
+float NDF_TRG(vec3 h)
+{
+ float ndoth=max(dot(normal,h),0.0);
+ float alpha2=Roughness2*Roughness2;
+ float denom=ndoth*ndoth*(alpha2-1.0)+1.0;
+ return denom != 0.0 ? alpha2/(denom*denom) : 0.0;
+}
+
+float GGX_Geom(vec3 v)
+{
+ float ndotv=max(dot(v,normal),0.0);
+ float ap=1.0+Roughness2;
+ float k=0.125*ap*ap;
+ return ndotv/((ndotv*(1.0-k))+k);
+}
+
+float Geom(vec3 v, vec3 l)
+{
+ return GGX_Geom(v)*GGX_Geom(l);
+}
+
+// Schlick's approximation
+float Fresnel(vec3 h, vec3 v, float fresnel0)
+{
+ float a=1.0-max(dot(h,v),0.0);
+ float b=a*a;
+ return fresnel0+(1.0-fresnel0)*b*b*a;
+}
+
+vec3 BRDF(vec3 viewDirection, vec3 lightDirection)
+{
+ vec3 lambertian=Diffuse;
+ // Cook-Torrance model
+ vec3 h=normalize(lightDirection+viewDirection);
+
+ float omegain=max(dot(viewDirection,normal),0.0);
+ float omegaln=max(dot(lightDirection,normal),0.0);
+
+ float D=NDF_TRG(h);
+ float G=Geom(viewDirection,lightDirection);
+ float F=Fresnel(h,viewDirection,Fresnel0);
+
+ float denom=4.0*omegain*omegaln;
+ float rawReflectance=denom > 0.0 ? (D*G)/denom : 0.0;
+
+ vec3 dielectric=mix(lambertian,rawReflectance*Specular,F);
+ vec3 metal=rawReflectance*Diffuse;
+
+ return mix(dielectric,metal,Metallic);
+}
+#endif
+
+void main()
+{
+ vec4 diffuse;
+ vec4 emissive;
+
+ Material m;
+#ifdef TRANSPARENT
+ m=Materials[abs(materialIndex)-1];
+ if(materialIndex >= 0) {
+ diffuse=m.diffuse;
+ emissive=m.emissive;
+ } else {
+ diffuse=Color;
+#if Nlights > 0
+ emissive=vec4(0.0);
+#else
+ emissive=Color;
+#endif
+ }
+#else
+ m=Materials[int(materialIndex)];
+#ifdef COLOR
+ diffuse=Color;
+#if Nlights > 0
+ emissive=vec4(0.0);
+#else
+ emissive=Color;
+#endif
+#else
+ diffuse=m.diffuse;
+ emissive=m.emissive;
+#endif
+#endif
+
+#if defined(NORMAL) && Nlights > 0
+ Specular=m.specular.rgb;
+ vec4 parameters=m.parameters;
+ Roughness2=1.0-parameters[0];
+ Roughness2=Roughness2*Roughness2;
+ Metallic=parameters[1];
+ Fresnel0=parameters[2];
+ Diffuse=diffuse.rgb;
+
+ // Given a point x and direction \omega,
+ // L_i=\int_{\Omega}f(x,\omega_i,\omega) L(x,\omega_i)(\hat{n}\cdot \omega_i)
+ // d\omega_i, where \Omega is the hemisphere covering a point,
+ // f is the BRDF function, L is the radiance from a given angle and position.
+
+ normal=normalize(Normal);
+ normal=gl_FrontFacing ? normal : -normal;
+#ifdef ORTHOGRAPHIC
+ vec3 viewDir=vec3(0.0,0.0,1.0);
+#else
+ vec3 viewDir=-normalize(ViewPosition);
+#endif
+ // For a finite point light, the rendering equation simplifies.
+ vec3 color=emissive.rgb;
+ for(int i=0; i < nlights; ++i) {
+ Light Li=lights[i];
+ vec3 L=Li.direction;
+ float cosTheta=max(dot(normal,L),0.0); // $\omega_i \cdot n$ term
+ vec3 radiance=cosTheta*Li.color;
+ color += BRDF(viewDir,L)*radiance;
+ }
+
+#if defined(ENABLE_TEXTURE) && !defined(COLOR)
+ // Experimental environment radiance using Riemann sums;
+ // can also do importance sampling.
+ vec3 envRadiance=vec3(0.0,0.0,0.0);
+
+ vec3 normalPerp=vec3(-normal.y,normal.x,0.0);
+ if(length(normalPerp) == 0.0)
+ normalPerp=vec3(1.0,0.0,0.0);
+
+ // we now have a normal basis;
+ normalPerp=normalize(normalPerp);
+ vec3 normalPerp2=normalize(cross(normal,normalPerp));
+
+ const float step=1.0/numSamples;
+ const float phistep=twopi*step;
+ const float thetastep=halfpi*step;
+ for (int iphi=0; iphi < numSamples; ++iphi) {
+ float phi=iphi*phistep;
+ for (int itheta=0; itheta < numSamples; ++itheta) {
+ float theta=itheta*thetastep;
+
+ vec3 azimuth=cos(phi)*normalPerp+sin(phi)*normalPerp2;
+ vec3 L=sin(theta)*azimuth+cos(theta)*normal;
+
+ vec3 rawRadiance=texture(environmentMap,normalizedAngle(L)).rgb;
+ vec3 surfRefl=BRDF(Z,L);
+ envRadiance += surfRefl*rawRadiance*sin(2.0*theta);
+ }
+ }
+ envRadiance *= halfpi*step*step;
+ color += envRadiance.rgb;
+#endif
+ outColor=vec4(color,diffuse.a);
+#else
+ outColor=emissive;
+#endif
+}