void SphericalMapping2D::sphere(const Point &p, float *s, float *t) const {
Vector vec = Normalize(WorldToTexture(p) - Point(0,0,0));
float theta = SphericalTheta(vec);
float phi = SphericalPhi(vec);
*s = theta * INV_PI;
*t = phi * INV_TWOPI;
}
void CylindricalMapping2D::cylinder(const Point &p,
float *s, float *t) const {
Vector vec =
Normalize(WorldToTexture(p) - Point(0,0,0));
*s = (M_PI + atan2f(vec.y, vec.x)) / (2.f * M_PI);
*t = vec.z;
}
Point IdentityMapping3D::Map(const DifferentialGeometry &dg,
Vector *dpdx, Vector *dpdy) const {
*dpdx = WorldToTexture(dg.dpdx);
*dpdy = WorldToTexture(dg.dpdy);
return WorldToTexture(dg.p);
}
Point3f IdentityMapping3D::Map(const SurfaceInteraction &isect, Vector3f *dpdx,
Vector3f *dpdy) const {
*dpdx = WorldToTexture(isect.dpdx);
*dpdy = WorldToTexture(isect.dpdy);
return WorldToTexture(isect.p);
}
Point2f SphericalMapping2D::sphere(const Point3f &p) const {
Vector3f vec = Normalize(WorldToTexture(p) - Point3f(0, 0, 0));
Float theta = SphericalTheta(vec), phi = SphericalPhi(vec);
return Point2f(theta * InvPi, phi * Inv2Pi);
}