diff options
author | Karl Berry <karl@freefriends.org> | 2021-02-25 19:22:25 +0000 |
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committer | Karl Berry <karl@freefriends.org> | 2021-02-25 19:22:25 +0000 |
commit | ad547a6b5986815fda458221149728d9d9ab1d87 (patch) | |
tree | 16296910eb3eca724371474ea9aea3994dc69614 /Build/source/utils/asymptote/base/shaders | |
parent | 947b43de3dd21d58ccc2ffadefc4441ea1c2a813 (diff) |
restore Build,TODO from r57911
git-svn-id: svn://tug.org/texlive/trunk@57915 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Build/source/utils/asymptote/base/shaders')
-rw-r--r-- | Build/source/utils/asymptote/base/shaders/fragment.glsl | 227 | ||||
-rw-r--r-- | Build/source/utils/asymptote/base/shaders/vertex.glsl | 49 |
2 files changed, 276 insertions, 0 deletions
diff --git a/Build/source/utils/asymptote/base/shaders/fragment.glsl b/Build/source/utils/asymptote/base/shaders/fragment.glsl new file mode 100644 index 00000000000..057acbc744f --- /dev/null +++ b/Build/source/utils/asymptote/base/shaders/fragment.glsl @@ -0,0 +1,227 @@ +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]; + emissive=m.emissive; + if(materialIndex >= 0) + diffuse=m.diffuse; + else { + diffuse=Color; +#if Nlights == 0 + emissive += Color; +#endif + } +#else + m=Materials[int(materialIndex)]; + emissive=m.emissive; +#ifdef COLOR + diffuse=Color; +#if Nlights == 0 + emissive += Color; +#endif +#else + diffuse=m.diffuse; +#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 +} diff --git a/Build/source/utils/asymptote/base/shaders/vertex.glsl b/Build/source/utils/asymptote/base/shaders/vertex.glsl new file mode 100644 index 00000000000..4b2a54b9897 --- /dev/null +++ b/Build/source/utils/asymptote/base/shaders/vertex.glsl @@ -0,0 +1,49 @@ +in vec3 position; + +uniform mat3 normMat; + +#ifdef NORMAL +#ifndef ORTHOGRAPHIC +out vec3 ViewPosition; +#endif +in vec3 normal; +out vec3 Normal; +#endif + +in int material; + +#ifdef COLOR +in vec4 color; +out vec4 Color; +#endif + +#ifdef WIDTH +in float width; +#endif + +uniform mat4 projViewMat; +uniform mat4 viewMat; + +flat out int materialIndex; + +void main() +{ + vec4 v=vec4(position,1.0); + gl_Position=projViewMat*v; +#ifdef NORMAL +#ifndef ORTHOGRAPHIC + ViewPosition=(viewMat*v).xyz; +#endif + Normal=normalize(normal*normMat); +#endif + +#ifdef COLOR + Color=color; +#endif + +#ifdef WIDTH + gl_PointSize=width; +#endif + + materialIndex=material; +} |