dodec.glsl

#define GDFVector0 vec3(1, 0, 0)
#define GDFVector1 vec3(0, 1, 0)
#define GDFVector2 vec3(0, 0, 1)

#define GDFVector3 normalize(vec3(1, 1, 1 ))
#define GDFVector4 normalize(vec3(-1, 1, 1))
#define GDFVector5 normalize(vec3(1, -1, 1))
#define GDFVector6 normalize(vec3(1, 1, -1))

#define GDFVector7 normalize(vec3(0, 1, PHI+1.))
#define GDFVector8 normalize(vec3(0, -1, PHI+1.))
#define GDFVector9 normalize(vec3(PHI+1., 0, 1))
#define GDFVector10 normalize(vec3(-PHI-1., 0, 1))
#define GDFVector11 normalize(vec3(1, PHI+1., 0))
#define GDFVector12 normalize(vec3(-1, PHI+1., 0))

#define GDFVector13 normalize(vec3(0, PHI, 1))
#define GDFVector13b normalize(vec3(0, PHI, -1))
#define GDFVector14 normalize(vec3(0, -PHI, 1))
#define GDFVector14b normalize(vec3(0, -PHI, -1))
#define GDFVector15 normalize(vec3(1, 0, PHI))
#define GDFVector15b normalize(vec3(1, 0, -PHI))
#define GDFVector16 normalize(vec3(-1, 0, PHI))
#define GDFVector16b normalize(vec3(-1, 0, -PHI))
#define GDFVector17 normalize(vec3(PHI, 1, 0))
#define GDFVector17b normalize(vec3(PHI, -1, 0))
#define GDFVector18 normalize(vec3(-PHI, 1, 0))
#define GDFVector18b normalize(vec3(-PHI, -1, 0))

#define fGDFBegin float d = 0.;

// Version with variable exponent.
// This is slow and does not produce correct distances, but allows for bulging of objects.
#define fGDFExp(v) d += pow(abs(dot(p, v)), e);

// Version with without exponent, creates objects with sharp edges and flat faces
#define fGDF(v) d = max(d, abs(dot(p, v)));

#define fGDFExpEnd return pow(d, 1./e) - r;
#define fGDFEnd return d - r;

// Primitives follow:

float fDodecahedron(vec3 p, float r) {
    fGDFBegin
    fGDF(GDFVector13) fGDF(GDFVector14) fGDF(GDFVector15) fGDF(GDFVector16)
    fGDF(GDFVector17) fGDF(GDFVector18)
    fGDFEnd
}

#pragma glslify: export(fDodecahedron)