added 3dengfx into the repo, probably not the correct version for this

[summerhack] / src / 3dengfx / src / gfx / bvol.cpp

diff --git a/src/3dengfx/src/gfx/bvol.cpp b/src/3dengfx/src/gfx/bvol.cpp
new file mode 100644 (file)
index 0000000..0ae67b8
--- /dev/null
+++ b/src/3dengfx/src/gfx/bvol.cpp
@@ -0,0 +1,76 @@
+/*
+This file is part of the graphics core library.
+
+Copyright (c) 2004, 2005 John Tsiombikas <nuclear@siggraph.org>
+
+the graphics core library is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+the graphics core library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with the graphics core library; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+/* Bounding volumes
+ *
+ * Author: John Tsiombikas 2005
+ */
+
+#include "bvol.hpp"
+
+BoundingVolume::BoundingVolume() {
+       parent = 0;
+}
+
+BoundingVolume::~BoundingVolume() {}
+
+void BoundingVolume::set_transform(const Matrix4x4 &transform) {
+       this->transform = transform;
+}
+
+BoundingSphere::BoundingSphere(const Vector3 &pos, scalar_t rad) {
+       set_position(pos);
+       set_radius(rad);
+}
+
+bool BoundingSphere::ray_hit(const Ray &ray) const {
+       Sphere sph = *this;
+       Vector3 new_pos = sph.get_position();
+       sph.set_position(new_pos.transformed(transform));
+       
+       if(!sph.check_intersection(ray)) return false;
+       if(!children.size()) return true;
+       
+       for(size_t i=0; i<children.size(); i++) {
+               if(children[i]->ray_hit(ray)) return true;
+       }
+
+       return false;
+}
+
+bool BoundingSphere::visible(const FrustumPlane *frustum) const {
+       Vector3 new_pos = pos.transformed(transform);
+       
+       for(int i=0; i<6; i++) {
+               Vector3 normal(frustum[i].a, frustum[i].b, frustum[i].c);
+               scalar_t dist = dot_product(new_pos, normal) + frustum[i].d;
+
+               if(fabs(dist) < radius) break;
+               if(dist < -radius) return false;
+       }
+
+       // the sphere is at least partially inside the frustum, check any children
+       if(!children.size()) return true;
+
+       for(size_t i=0; i<children.size(); i++) {
+               if(children[i]->visible(frustum)) return true;
+       }
+       return false;
+}