# aux.h

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```00001
00011 #ifndef DOXYGEN_SHOULD_SKIP_THIS
00012 #ifndef __AUX_OBJECTS_H__
00013 #define __AUX_OBJECTS_H__
00014
00015 #include <Curve.h>
00016
00017 // Routines for a circle
00018 void pointat_circle(float rad, float s, Vector3& p, Vector3& t) {
00019   // s in [0,1]
00021   t = Vector3(cos(2.*M_PI*s),-sin(2.*M_PI*s),0.);
00022   t.normalize();
00023 }
00024
00025 Curve<Vector3>* gen_circle(float rad, int nodes) {
00026   Curve<Vector3>* circle = new Curve<Vector3>;
00027   Vector3 p,t;
00029
00030   for (int i=0;i<nodes;i++) {
00032     circle->append(p,t);
00033   }
00035   circle->make_default();
00036
00037   return circle;
00038 }
00039
00040 // Routines for an ellipse
00041 void pointat_ellipse(float a, float b, float s, Vector3& p, Vector3& t) {
00042   // s in [0,1]
00043   float omega = 2*M_PI;
00044   p = Vector3(a*cos(s*omega), b*sin(s*omega),0);
00045   t = Vector3(-a*sin(s*omega), b*cos(s*omega),0);
00046   t.normalize();
00047 }
00048
00049 Curve<Vector3>* gen_ellipse(float a, float b, int nodes) {
00050   Curve<Vector3>* ellipse = new Curve<Vector3>;
00051   Vector3 p,t;
00053   for (int i=0;i<nodes;i++) {
00054     pointat_ellipse(a,b,(float)i/(float)nodes,p,t);
00055     ellipse->append(p,t);
00056   }
00058   ellipse->make_default();
00059
00060   return ellipse;
00061 }
00062
00063 // TODO
00064 // helix
00065 // solenoid
00066
00067 // bone shaped curve
00068 void pointat_bone(float a, float b, float scale, float s,
00069                   Vector3& p, Vector3& t) {
00070   // s in [0,1]
00071   float omega = 2*M_PI;
00072   float ex0 = exp(-pow(s*omega*2.-3.*M_PI,2.));
00073   float ex0p = ex0*(12.*M_PI-8.*s*omega);
00074   float ex1 = exp(-pow(s*omega*2.-M_PI,2.));
00075   float ex1p = ex1*(4.*M_PI-8.*s*omega);
00076
00077   p = Vector3(a*cos(s*omega),
00078               b*sin(s*omega)+scale*(ex0-ex1),
00079               0.);
00080   t = Vector3(-a*sin(s*omega),
00081               b*cos(s*omega)+scale*(ex0p-ex1p),
00082               0.);
00083
00084 /*
00085   float ss = (s+0.1)*7*2.*M_PI;
00086   p = Vector3(s*2.,
00087               sin(ss)/ss, //-ex1),
00088               0.);
00089   t = Vector3(1.,
00090               (cos(ss)*ss-sin(ss))/ss/ss,0.);
00091  */
00092   //t.normalize();
00093 }
00094
00095 Curve<Vector3>* gen_bone(float a, float b, float scale, int nodes) {
00096   Curve<Vector3>* bone = new Curve<Vector3>;
00097   Vector3 p,t;
00099   for (int i=0;i<nodes;i++) {
00100     pointat_bone(a,b,scale,(float)i/(float)nodes,p,t);
00101     bone->append(p,t);
00102   }
00104   bone->computeTangents();
00105   return bone;
00106 }
00107
00108 // Eight shaped curve without intersection
00109 void pointat_inf(float a, float b, float scale, float s,
00110                  Vector3& p, Vector3& t) {
00111   // s in [0,1]
00112   float omega = 2*M_PI;
00113   float ex0 = exp(-pow(s*omega*2.-3.*M_PI,2.));
00114   float ex0p = ex0*(12.*M_PI-8.*s*omega);
00115   float ex1 = exp(-pow(s*omega*2.-M_PI,2.));
00116   float ex1p = ex1*(4.*M_PI-8.*s*omega);
00117
00118   p = Vector3(a*cos(s*omega),b*sin(2.*s*omega),scale*(ex0-ex1));
00119   t = Vector3(-a*sin(s*omega),2.*b*cos(2.*s*omega),scale*(ex0p-ex1p));
00120   t.normalize();
00121 }
00122
00123 Curve<Vector3>* gen_inf(float a, float b, float scale, int nodes) {
00124   Curve<Vector3>* inf = new Curve<Vector3>;
00125   Vector3 p,t;
00127   for (int i=0;i<nodes;i++) {
00128     pointat_inf(a,b,scale,(float)i/(float)nodes,p,t);
00129     inf->append(p,t);
00130   }
00131   return inf;
00132 }
00133
00134 // Routines for a stadium curve
00135 void pointat_stadium(float rad, float l, float s, Vector3& p, Vector3& t) {
00136   // s in [0,1]
00137   float ss = s*(2.*M_PI*rad+2.*l);
00138   if (ss>=0. && ss<l) {
00139     p = Vector3(l/2.,rad,0.)+Vector3(-1,0,0)*ss;
00140     t = Vector3(-1,0,0);
00141   }
00142   else if (ss>=l && ss<(l+M_PI*rad)) {
00143     p = -Vector3(l/2.,0,0)+Vector3(-rad*sin(ss-l),
00145     t = Vector3(-cos(ss-l),-sin(ss-l),0.);
00146   }
00147   else if (ss>=(l+M_PI*rad) && ss<(2.*l+M_PI*rad)) {
00149     t = Vector3(1,0,0);
00150   }
00151   else {
00152     p = Vector3(l/2.,0,0)+Vector3(-rad*sin(ss-2.*l),
00154     t = Vector3(-cos(ss-2.*l),-sin(ss-2.*l),0.);
00155   }
00156   t.normalize();
00157 }
00158
00159 Curve<Vector3>* gen_stadium(float rad, float l, int nodes) {
00160   Curve<Vector3>* stadium = new Curve<Vector3>;
00161   Vector3 p,t;