Rename kD splay trees to Bounding Volume Splay Trees.

1 files changed, 65 insertions, 0 deletions

diff --git a/libdimension/bvst.h b/libdimension/bvst.h
new file mode 100644
index 0000000..57b71b8
--- /dev/null
+++ b/libdimension/bvst.h
@@ -0,0 +1,65 @@
+/*************************************************************************
+ * Copyright (C) 2009 Tavian Barnes <tavianator@gmail.com>               *
+ *                                                                       *
+ * This file is part of The Dimension Library.                           *
+ *                                                                       *
+ * The Dimension Library is free software; you can redistribute it and/  *
+ * or modify it under the terms of the GNU Lesser General Public License *
+ * as published by the Free Software Foundation; either version 3 of the *
+ * License, or (at your option) any later version.                       *
+ *                                                                       *
+ * The Dimension 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  *
+ * Lesser General Public License for more details.                       *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+/*
+ * Bounding Volume Splay Trees for storing object bounding boxes.
+ * Each node's bounding box entirely contains the bounding boxes of the nodes
+ * to its left, and is entirely contained by the bounding boxes of the nodes to
+ * its right.  Splay trees are used for the implementation, to bring commonly-
+ * used objects (the most recent object which a ray has hit) near the root of
+ * the tree for fast access.  Object's bounding boxes are expanded as needed
+ * when inserted into the tree: if they intersect an existing bounding box, they
+ * are expanded to contain it.
+ */
+
+#ifndef DIMENSION_IMPL_BVST_H
+#define DIMENSION_IMPL_BVST_H
+
+typedef struct dmnsn_bvst dmnsn_bvst;
+typedef struct dmnsn_bvst_node dmnsn_bvst_node;
+
+struct dmnsn_bvst {
+  dmnsn_bvst_node *root;
+};
+
+struct dmnsn_bvst_node {
+  /* Tree children */
+  dmnsn_bvst_node *contains, *container;
+
+  /* Parent node for easy backtracking */
+  dmnsn_bvst_node *parent;
+
+  /* Bounding box corners */
+  dmnsn_vector min, max;
+
+  /* Node payload */
+  dmnsn_object *object;
+};
+
+dmnsn_bvst *dmnsn_new_bvst();
+dmnsn_bvst *dmnsn_bvst_copy(dmnsn_bvst *tree);
+void dmnsn_delete_bvst(dmnsn_bvst *tree);
+
+void dmnsn_bvst_insert(dmnsn_bvst *tree, dmnsn_object *object);
+void dmnsn_bvst_splay(dmnsn_bvst *tree, dmnsn_bvst_node *node);
+
+dmnsn_intersection *dmnsn_bvst_search(dmnsn_bvst *tree, dmnsn_line ray);
+
+#endif /* DIMENSION_IMPL_BVST_H */