urn mix(f0, f90, ret);\\n}\\n\\nfn ScalarTriple(u: float3, v: float3, w: float3) -> float\\n{\\n return dot(cross(u, v), w);\\n}\\n\\nfn TestQuadTrace(\\n rayPos: float3,\\n rayDir: float3,\\n info: ptr,\\n _a: float3,\\n _b: float3,\\n _c: float3,\\n _d: float3)\\n -> bool\\n{\\n var a = _a;\\n var b = _b;\\n var c = _c;\\n var d = _d;\\n // calculate normal and flip vertices order if needed\\n var normal = normalize(cross(c-a, c-b));\\n if (dot(normal, rayDir) > 0.)\\n {\\n normal *= -1.;\\n\\n var temp = d;\\n d = a;\\n a = temp;\\n\\n temp = b;\\n b = c;\\n c = temp;\\n }\\n\\n let p = rayPos;\\n let q = rayPos + rayDir;\\n let pq = q - p;\\n let pa = a - p;\\n let pb = b - p;\\n let pc = c - p;\\n\\n // determine which triangle to test against by testing against diagonal first\\n let m = cross(pc, pq);\\n var v = dot(pa, m);\\n var intersectPos = float3(0.);\\n if (v >= 0.)\\n {\\n // test against triangle a,b,c\\n var u = -dot(pb, m);\\n if (u < 0.) { return false; }\\n var w = ScalarTriple(pq, pb, pa);\\n if (w < 0.) { return false; }\\n let denom = 1. / (u+v+w);\\n u*=denom;\\n v*=denom;\\n w*=denom;\\n intersectPos = u*a+v*b+w*c;\\n }\\n else\\n {\\n let pd = d - p;\\n var u = dot(pd, m);\\n if (u < 0.) { return false; }\\n var w = ScalarTriple(pq, pa, pd);\\n if (w < 0.) { return false; }\\n v = -v;\\n let denom = 1. / (u+v+w);\\n u*=denom;\\n v*=denom;\\n w*=denom;\\n intersectPos = u*a+v*d+w*c;\\n }\\n\\n var dist = 0.;\\n if (abs(rayDir.x) > 0.)\\n {\\n dist = (intersectPos.x - rayPos.x) / rayDir.x;\\n }\\n else if (abs(rayDir.y) > 0.)\\n {\\n dist = (intersectPos.y - rayPos.y) / rayDir.y;\\n }\\n else\\n {\\n dist = (intersectPos.z - rayPos.z) / rayDir.z;\\n }\\n\\n if (dist > MINIMUM_RAY_HIT_TIME && dist < (*info).dist)\\n {\\n (*info).dist = dist;\\n (*info).normal = normal;\\n return true;\\n }\\n\\n return false;\\n}\\n\\nfn TestSphereTrace(\\n rayPos: float3,\\n rayDir: float3,\\n info: ptr,\\n sphere: float4)\\n -> bool\\n{\\n //get the vector from the center of this sphere to where the ray begins.\\n let m = rayPos - sphere.xyz;\\n\\n //get the dot product of the above vector and the ray's vector\\n let b = dot(m, rayDir);\\n\\n let c = dot(m, m) - sphere.w * sphere.w;\\n\\n //exit if r's origin outside s (c > 0) and r pointing away from s (b > 0)\\n if(c > 0.0 && b > 0.0)\\n {\\n return false;\\n }\\n\\n //calculate discriminant\\n let discr = b * b - c;\\n\\n //a negative discriminant corresponds to ray missing sphere\\n if(discr < 0.0)\\n {\\n return false;\\n }\\n\\n //ray now found to intersect sphere, compute smallest t value of intersection\\n var fromInside = false;\\n var dist = -b - sqrt(discr);\\n if (dist < 0.)\\n {\\n fromInside = true;\\n dist = -b + sqrt(discr);\\n }\\n\\n if (dist > MINIMUM_RAY_HIT_TIME && dist < (*info).dist)\\n {\\n (*info).dist = dist;\\n (*info).normal = normalize((rayPos+rayDir*dist) - sphere.xyz) * select(1., -1., fromInside);\\n return true;\\n }\\n\\n return false;\\n}\\n\\nfn TestSceneTrace(rayPos: float3, rayDir: float3, hitInfo: ptr)\\n{\\n // to move the scene around, since we can't move the camera yet\\n let sceneTranslation = float3(0., 0., 10.);\\n let sceneTranslation4 = float4(sceneTranslation, 0.);\\n\\n // back wall\\n {\\n let A = float3(-12.6, -12.6, 25.) + sceneTranslation;\\n let B = float3( 12.6, -12.6, 25.) + sceneTranslation;\\n let C = float3( 12.6, 12.6, 25.) + sceneTranslation;\\n let D = float3(-12.6, 12.6, 25.) + scen

@compute.toys