--- /dev/null
+
+/*] Copyright (c) 2009-2010, Charles McGarvey [**************************
+**] All rights reserved.
+*
+* vi:ts=4 sw=4 tw=75
+*
+* Distributable under the terms and conditions of the 2-clause BSD license;
+* see the file COPYING for a complete text of the license.
+*
+**************************************************************************/
+
+#ifndef _MOOF_SPHERE_HH_
+#define _MOOF_SPHERE_HH_
+
+/**
+ * \file sphere.hh
+ * A round shape like a circle or sphere.
+ * TODO: This class needs some work.
+ */
+
+#include <moof/contact.hh>
+#include <moof/cullable.hh>
+#include <moof/drawable.hh>
+#include <moof/frustum.hh>
+#include <moof/math.hh>
+#include <moof/opengl.hh>
+#include <moof/shape.hh>
+
+
+namespace moof {
+
+
+/**
+ * A round object.
+ */
+template <int D = 3>
+struct sphere : public cullable, public drawable, public shape<D>
+{
+ typedef moof::vector< scalar, fixed<D> > vector;
+
+ vector point;
+ scalar radius;
+
+
+ sphere() {}
+
+ sphere(const vector& p, scalar r) :
+ point(p),
+ radius(r) {}
+
+
+ void init(const vector& p, scalar r)
+ {
+ point = p;
+ radius = r;
+ }
+
+ void init(const vector& p, const vector& o)
+ {
+ point = p;
+ radius = (o - p).length();
+ }
+
+ //void enclose_vertices(const vector vertices[], unsigned count);
+
+ //void draw(scalar alpha = 0.0) const;
+ //bool is_visible(const frustum& frustum) const;
+
+ void enclose_vertices(const vector vertices[], unsigned count)
+ {
+ // TODO
+ }
+
+ void draw(scalar alpha = 0.0) const;
+
+ bool is_visible(const frustum& frustum) const
+ {
+ return true;
+ }
+
+
+ bool intersect(const sphere<D>& sphere, contact<D>& hit) const
+ {
+ vector n = sphere.point - point;
+ scalar distance = n.length();
+ scalar limit = radius + sphere.radius;
+
+ if (distance > limit) return false;
+
+ hit.normal = n.normalize();
+ hit.distance = limit - distance;
+ hit.point = hit.normal * radius;
+
+ return true;
+ }
+
+ bool intersect(const vector& point2, contact<D>& hit) const
+ {
+ vector n = point2 - point;
+ scalar distance = n.length();
+
+ if (distance > radius) return false;
+
+ hit.normal = n.normalize();
+ hit.distance = radius - distance;
+ hit.point = point2;
+
+ return true;
+ }
+
+ // a ray inside the sphere will not intersect on its way out
+ bool intersect(const ray<D>& ray, typename ray<D>::contact& hit) const
+ {
+ vector b = point - ray.point;
+ scalar z = dot(b, ray.direction);
+
+ // check if the ball is behind the ray
+ if (z < SCALAR(0.0)) return false;
+
+ scalar d2 = dot(b, b) - z*z;
+ scalar r2 = radius * radius;
+
+ // check for an intersection
+ if (d2 > r2) return false;
+
+ hit.distance = z - std::sqrt(r2 - d2);
+ if (hit.distance < SCALAR(0.0)) return false;
+
+ vector surfacePoint;
+ ray.solve(surfacePoint, hit.distance);
+ hit.normal = surfacePoint - point;
+ return true;
+ }
+};
+
+
+template <>
+inline bool sphere<3>::is_visible(const frustum& frustum) const
+{
+ return frustum.contains(*this);
+}
+
+template <>
+inline void sphere<2>::draw(scalar alpha) const
+{
+ GLUquadricObj* sphereObj = gluNewQuadric();
+ gluQuadricDrawStyle(sphereObj, GLU_LINE);
+
+ glPushMatrix();
+
+ glTranslate(promote(point));
+ gluSphere(sphereObj, GLdouble(radius), 16, 16);
+
+ glPopMatrix();
+
+ gluDeleteQuadric(sphereObj);
+}
+
+template <>
+inline void sphere<3>::draw(scalar alpha) const
+{
+ GLUquadricObj* sphereObj = gluNewQuadric();
+ gluQuadricDrawStyle(sphereObj, GLU_LINE);
+
+ glPushMatrix();
+
+ glTranslate(point);
+ gluSphere(sphereObj, GLdouble(radius), 16, 16);
+
+ glPopMatrix();
+
+ gluDeleteQuadric(sphereObj);
+}
+
+template <int D>
+inline bool checkCollision(const sphere<D>& a, const sphere<D>& b)
+{
+ scalar d = (a.point - b.point).length();
+ return d < (a.radius + b.radius);
+}
+
+
+typedef sphere<2> sphere2;
+typedef sphere2 circle;
+typedef sphere<3> sphere3;
+
+
+} // namespace moof
+
+#endif // _MOOF_SPHERE_HH_
+