Dogcows Code - chaz/yoink/blob - src/Moof/Sphere.hh

   1
   2 /*******************************************************************************
   3
   4  Copyright (c) 2009, Charles McGarvey
   5  All rights reserved.
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  10    * Redistributions  of  source  code  must retain the above copyright notice,
  11      this list of conditions and the following disclaimer.
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  13      this  list of conditions and the following disclaimer in the documentation
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  16  THIS  SOFTWARE  IS  PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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  27 *******************************************************************************/
  28
  29 #ifndef _MOOF_SPHERE_HH_
  30 #define _MOOF_SPHERE_HH_
  31
  32 #include <Moof/Cullable.hh>
  33 #include <Moof/Drawable.hh>
  34 #include <Moof/Frustum.hh>
  35 #include <Moof/Math.hh>
  36 #include <Moof/OpenGL.hh>
  37 #include <Moof/Shape.hh>
  38
  39
  40 namespace Mf {
  41
  42
  43 /**
  44  * A round object.
  45  */
  46
  47 template <int D = 3>
  48 struct Sphere : public Cullable, public Drawable, public Shape<D>
  49 {
  50         typedef cml::vector< Scalar, cml::fixed<D> >    Vector;
  51
  52         // (solution - point)^2 - radius^2 = 0
  53         Vector  point;
  54         Scalar  radius;
  55
  56         Sphere() {}
  57
  58         Sphere(const Vector& p, Scalar r) :
  59                 point(p),
  60                 radius(r) {}
  61
  62         //Sphere(Scalar x, Scalar y, Scalar z, Scalar r) :
  63                 //point(x, y, z),
  64                 //radius(r) {}
  65
  66         void init(const Vector& p, Scalar r)
  67         {
  68                 point = p;
  69                 radius = r;
  70         }
  71
  72         void init(const Vector& p, const Vector& o)
  73         {
  74                 point = p;
  75                 radius = (o - p).length();
  76         }
  77
  78
  79         // a ray inside the sphere will not intersect on its way out
  80         bool intersectRay(const Ray<D>& ray, typename Ray<D>::Intersection& hit)
  81         {
  82                 Vector b = point - ray.point;
  83                 Scalar z = cml::dot(b, ray.direction);
  84
  85                 // check if the ball is behind the ray
  86                 if (z < SCALAR(0.0)) return false;
  87
  88                 Scalar d2 = cml::dot(b, b) - z*z;
  89                 Scalar r2 = radius * radius;
  90
  91                 // check for an intersection
  92                 if (d2 > r2) return false;
  93
  94                 hit.distance = z - std::sqrt(r2 - d2);
  95                 if (hit.distance < SCALAR(0.0)) return false;
  96
  97                 Vector surfacePoint;
  98                 ray.solve(surfacePoint, hit.distance);
  99                 hit.normal = surfacePoint - point;
 100                 return true;
 101         }
 102
 103
 104         //void encloseVertices(const Vector vertices[], unsigned count);
 105
 106         //void draw(Scalar alpha = 0.0) const;
 107         //bool isVisible(const Frustum& frustum) const;
 108
 109 void encloseVertices(const Vector vertices[], unsigned count)
 110 {
 111         // TODO
 112 }
 113
 114 void draw(Scalar alpha = 0.0) const;
 115 //{
 116         //GLUquadricObj* sphereObj = gluNewQuadric();
 117         //gluQuadricDrawStyle(sphereObj, GLU_LINE);
 118
 119         //glPushMatrix();
 120
 121         //glTranslate(point);
 122         //gluSphere(sphereObj, GLdouble(radius), 16, 16);
 123
 124         //glPopMatrix();
 125
 126         //gluDeleteQuadric(sphereObj);
 127 //}
 128
 129 bool isVisible(const Frustum& frustum) const
 130 {
 131         return true;
 132 }
 133 };
 134
 135
 136 template <>
 137 inline bool Sphere<3>::isVisible(const Frustum& frustum) const
 138 {
 139         return frustum.contains(*this);
 140 }
 141
 142 template <>
 143 inline void Sphere<2>::draw(Scalar alpha) const
 144 {
 145         GLUquadricObj* sphereObj = gluNewQuadric();
 146         gluQuadricDrawStyle(sphereObj, GLU_LINE);
 147
 148         glPushMatrix();
 149
 150         glTranslate(promote(point));
 151         gluSphere(sphereObj, GLdouble(radius), 16, 16);
 152
 153         glPopMatrix();
 154
 155         gluDeleteQuadric(sphereObj);
 156 }
 157
 158 template <>
 159 inline void Sphere<3>::draw(Scalar alpha) const
 160 {
 161         GLUquadricObj* sphereObj = gluNewQuadric();
 162         gluQuadricDrawStyle(sphereObj, GLU_LINE);
 163
 164         glPushMatrix();
 165
 166         glTranslate(point);
 167         gluSphere(sphereObj, GLdouble(radius), 16, 16);
 168
 169         glPopMatrix();
 170
 171         gluDeleteQuadric(sphereObj);
 172 }
 173
 174 template <int D>
 175 inline bool checkCollision(const Sphere<D>& a, const Sphere<D>& b)
 176 {
 177         Scalar d = (a.point - b.point).length();
 178         return d < (a.radius + b.radius);
 179 }
 180
 181
 182 } // namespace Mf
 183
 184 #endif // _MOOF_SPHERE_HH_
 185
 186 /** vim: set ts=4 sw=4 tw=80: *************************************************/
 187