Dogcows Code - chaz/yoink/blob - src/moof/sphere.hh

   1
   2 /*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
   3 **]  All rights reserved.
   4 *
   5 * vi:ts=4 sw=4 tw=75
   6 *
   7 * Distributable under the terms and conditions of the 2-clause BSD license;
   8 * see the file COPYING for a complete text of the license.
   9 *
  10 **************************************************************************/
  11
  12 #ifndef _MOOF_SPHERE_HH_
  13 #define _MOOF_SPHERE_HH_
  14
  15 /**
  16  * \file sphere.hh
  17  * A round shape like a circle or sphere.
  18  * TODO: This class needs some work.
  19  */
  20
  21 #include <moof/contact.hh>
  22 #include <moof/cullable.hh>
  23 #include <moof/drawable.hh>
  24 #include <moof/frustum.hh>
  25 #include <moof/math.hh>
  26 #include <moof/opengl.hh>
  27 #include <moof/shape.hh>
  28
  29
  30 namespace moof {
  31
  32
  33 /**
  34  * A round object.
  35  */
  36 template <int D = 3>
  37 struct sphere : public cullable, public drawable, public shape<D>
  38 {
  39         typedef moof::vector< scalar, fixed<D> > vector;
  40
  41         vector  point;
  42         scalar  radius;
  43
  44
  45         sphere() {}
  46
  47         sphere(const vector& p, scalar r) :
  48                 point(p),
  49                 radius(r) {}
  50
  51
  52         void init(const vector& p, scalar r)
  53         {
  54                 point = p;
  55                 radius = r;
  56         }
  57
  58         void init(const vector& p, const vector& o)
  59         {
  60                 point = p;
  61                 radius = (o - p).length();
  62         }
  63
  64         //void enclose_vertices(const vector vertices[], unsigned count);
  65
  66         //void draw(scalar alpha = 0.0) const;
  67         //bool is_visible(const frustum& frustum) const;
  68
  69         void enclose_vertices(const vector vertices[], unsigned count)
  70         {
  71                 // TODO
  72         }
  73
  74         void draw(scalar alpha = 0.0) const;
  75
  76         bool is_visible(const frustum& frustum) const
  77         {
  78                 return true;
  79         }
  80
  81
  82         bool intersect(const sphere<D>& sphere, contact<D>& hit) const
  83         {
  84                 vector n = sphere.point - point;
  85                 scalar distance = n.length();
  86                 scalar limit = radius + sphere.radius;
  87
  88                 if (distance > limit) return false;
  89
  90                 hit.normal = n.normalize();
  91                 hit.distance = limit - distance;
  92                 hit.point = hit.normal * radius;
  93
  94                 return true;
  95         }
  96
  97         bool intersect(const vector& point2, contact<D>& hit) const
  98         {
  99                 vector n = point2 - point;
 100                 scalar distance = n.length();
 101
 102                 if (distance > radius) return false;
 103
 104                 hit.normal = n.normalize();
 105                 hit.distance = radius - distance;
 106                 hit.point = point2;
 107
 108                 return true;
 109         }
 110
 111         // a ray inside the sphere will not intersect on its way out
 112         bool intersect(const ray<D>& ray,
 113                                    typename moof::ray<D>::contact& hit) const
 114         {
 115                 vector b = point - ray.point;
 116                 scalar z = dot(b, ray.direction);
 117
 118                 // check if the ball is behind the ray
 119                 if (z < SCALAR(0.0)) return false;
 120
 121                 scalar d2 = dot(b, b) - z*z;
 122                 scalar r2 = radius * radius;
 123
 124                 // check for an intersection
 125                 if (d2 > r2) return false;
 126
 127                 hit.distance = z - std::sqrt(r2 - d2);
 128                 if (hit.distance < SCALAR(0.0)) return false;
 129
 130                 vector surfacePoint;
 131                 ray.solve(surfacePoint, hit.distance);
 132                 hit.normal = surfacePoint - point;
 133                 return true;
 134         }
 135 };
 136
 137
 138 template <>
 139 inline bool sphere<3>::is_visible(const frustum& frustum) const
 140 {
 141         return frustum.contains(*this);
 142 }
 143
 144 template <>
 145 inline void sphere<2>::draw(scalar alpha) const
 146 {
 147         GLUquadricObj* sphereObj = gluNewQuadric();
 148         gluQuadricDrawStyle(sphereObj, GLU_LINE);
 149
 150         glPushMatrix();
 151
 152         glTranslate(promote(point));
 153         gluSphere(sphereObj, GLdouble(radius), 16, 16);
 154
 155         glPopMatrix();
 156
 157         gluDeleteQuadric(sphereObj);
 158 }
 159
 160 template <>
 161 inline void sphere<3>::draw(scalar alpha) const
 162 {
 163         GLUquadricObj* sphereObj = gluNewQuadric();
 164         gluQuadricDrawStyle(sphereObj, GLU_LINE);
 165
 166         glPushMatrix();
 167
 168         glTranslate(point);
 169         gluSphere(sphereObj, GLdouble(radius), 16, 16);
 170
 171         glPopMatrix();
 172
 173         gluDeleteQuadric(sphereObj);
 174 }
 175
 176 template <int D>
 177 inline bool checkCollision(const sphere<D>& a, const sphere<D>& b)
 178 {
 179         scalar d = (a.point - b.point).length();
 180         return d < (a.radius + b.radius);
 181 }
 182
 183
 184 typedef sphere<2>       sphere2;
 185 typedef sphere2         circle;
 186 typedef sphere<3>       sphere3;
 187
 188
 189 } // namespace moof
 190
 191 #endif // _MOOF_SPHERE_HH_
 192