geometry.h Source File

00001 /*
00002   File: geometry.h
00003 
00004   Copyright(C) C. Kotterink, Computed Graphics
00005 */
00006 #ifndef GEOMETRY_H
00007 #define GEOMETRY_H
00008 
00009 #include<Vertex3.h>
00010 
00013 namespace Geo
00014 {};
00015 
00016 // interpolation curves
00017 inline real linear(real x)
00018 {
00019     return 1.0 - x;
00020 }
00021 inline real scurve(real x)
00022 {
00023     return x*x*(2.0*x-3.0) + 1.0;
00024 }
00025 
00026 // Geometric fuctions
00027 inline real distanceToPlane(
00028     const Vertex3 &p, const Vertex3 &n, const Vertex3 &v)
00029 {
00030     return (v-p)*n;
00031 }
00032 inline real projectOnPlane(
00033     const Vertex3 &p, const Vertex3 &n, const Vertex3 &v, Vertex3 &vv)
00034 {
00035     real d = (v-p)*n;
00036     vv = v - n*d;
00037     return d;
00038 }
00039 inline float intersectPlane(
00040     const Vertex3 &p, const Vertex3 &n, const Vertex3 &o, const Vertex3 &d)
00041 {
00042     real dn = d*n;
00043     if (fabs(dn) > ZERO) {
00044         return (p - o)*n / dn;
00045     } else {
00046         return -1.0;
00047     }  
00048 }
00049 inline float intersectSphere(
00050     const Vertex3 &p, float r, const Vertex3 &o, const Vertex3 &d)
00051 {
00052     Vertex3 Q = p - o;
00053     real c = Q.norm();
00054     real v = Q * d;
00055     real t = r*r - (c*c - v*v);
00056     
00057     if (t < 0.0) {
00058         return -1.0;
00059     }
00060     // Return the distance to the first intersection
00061     return v - sqrt(t);
00062 }
00063 
00064 // Polygon tests
00065 bool pointInConvexPoly(
00066     const Vertex3 *v, const unsigned short *f,
00067     int N, const Vertex3 &p, const Vertex3 &n);
00068 
00069 void closestPointOnLine(
00070     const Vertex3 &a, const Vertex3 &b, const Vertex3 &p,
00071     Vertex3 &closestPoint);
00072 Vertex3 closestPointOnPoly(
00073     const Vertex3 *v, const unsigned short *f, int N, const Vertex3 &p);
00074 
00075 // Bezier
00076 real solveQuadric(real a, real b, real c);
00077 real distanceToBezierSeg(Vertex3 *bezier, Vertex3 &v);
00078 
00079 #endif