From 9b04b4e2a1147ed2a30e4f86dd403851036b3b51 Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Tue, 27 Apr 2010 21:25:50 -0600 Subject: Replace BVSTs with priority R-trees. --- libdimension/bvst.c | 388 ---------------------------------------------------- 1 file changed, 388 deletions(-) delete mode 100644 libdimension/bvst.c (limited to 'libdimension/bvst.c') diff --git a/libdimension/bvst.c b/libdimension/bvst.c deleted file mode 100644 index 7a57c76..0000000 --- a/libdimension/bvst.c +++ /dev/null @@ -1,388 +0,0 @@ -/************************************************************************* - * Copyright (C) 2010 Tavian Barnes * - * * - * 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 * - * . * - *************************************************************************/ - -#include "dimension_impl.h" -#include - -/* Return an empty tree */ -dmnsn_bvst * -dmnsn_new_bvst() -{ - dmnsn_bvst *tree = dmnsn_malloc(sizeof(dmnsn_bvst)); - tree->root = NULL; - return tree; -} - -static dmnsn_bvst_node * -dmnsn_new_bvst_node() -{ - dmnsn_bvst_node *node = dmnsn_malloc(sizeof(dmnsn_bvst_node)); - return node; -} - -/* Recursively copy the nodes of a BVST */ -static dmnsn_bvst_node * -dmnsn_bvst_copy_recursive(dmnsn_bvst_node *root) -{ - dmnsn_bvst_node *node = dmnsn_new_bvst_node(); - *node = *root; - if (node->contains) { - node->contains = dmnsn_bvst_copy_recursive(node->contains); - node->contains->parent = node; - } - if (node->container) { - node->container = dmnsn_bvst_copy_recursive(node->container); - node->container->parent = node; - } - return node; -} - -/* Copy a BVST */ -dmnsn_bvst * -dmnsn_copy_bvst(dmnsn_bvst *tree) -{ - dmnsn_bvst *copy = dmnsn_new_bvst(); - if (tree->root) - copy->root = dmnsn_bvst_copy_recursive(tree->root); - else - copy->root = NULL; - return copy; -} - -static void -dmnsn_delete_bvst_node(dmnsn_bvst_node *node) -{ - free(node); -} - -/* Recursively free a BVST */ -static void -dmnsn_delete_bvst_recursive(dmnsn_bvst_node *node) -{ - if (node) { - dmnsn_delete_bvst_recursive(node->contains); - dmnsn_delete_bvst_recursive(node->container); - dmnsn_delete_bvst_node(node); - } -} - -/* Free a BVST */ -void -dmnsn_delete_bvst(dmnsn_bvst *tree) -{ - if (tree) { - dmnsn_delete_bvst_recursive(tree->root); - free(tree); - } -} - -/* Expand node to contain the bounding box from min to max */ -static void dmnsn_bvst_node_swallow(dmnsn_bvst_node *node, - dmnsn_bounding_box box); - -/* Insert an object into the tree */ -void -dmnsn_bvst_insert(dmnsn_bvst *tree, dmnsn_object *object) -{ - dmnsn_object_precompute(object); - - dmnsn_bvst_node *node = dmnsn_new_bvst_node(), *parent = tree->root; - - node->contains = NULL; - node->container = NULL; - node->parent = NULL; - node->object = object; - node->bounding_box = object->bounding_box; - - /* Now insert the node */ - - while (parent) { - if (dmnsn_bounding_box_contains(parent->bounding_box, - node->bounding_box.min) - && dmnsn_bounding_box_contains(parent->bounding_box, - node->bounding_box.max)) - { - /* parent fully contains node */ - if (parent->contains) { - parent = parent->contains; - } else { - /* We found our parent; insert node into the tree */ - parent->contains = node; - node->parent = parent; - break; - } - } else { - /* Expand node's bounding box to fully contain parent's if it doesn't - already */ - dmnsn_bvst_node_swallow(node, parent->bounding_box); - /* node now fully contains parent */ - if (parent->container) { - parent = parent->container; - } else { - /* We found our parent; insert node into the tree */ - parent->container = node; - node->parent = parent; - break; - } - } - } - - dmnsn_bvst_splay(tree, node); -} - -/* Expand node to contain the bounding box from min to max */ -static void -dmnsn_bvst_node_swallow(dmnsn_bvst_node *node, dmnsn_bounding_box box) -{ - node->bounding_box.min = dmnsn_vector_min(node->bounding_box.min, box.min); - node->bounding_box.max = dmnsn_vector_max(node->bounding_box.max, box.max); -} - -/* Tree rotations */ -static void dmnsn_bvst_rotate(dmnsn_bvst_node *node); - -/* Splay a node: move it to the root via tree rotations */ -void -dmnsn_bvst_splay(dmnsn_bvst *tree, dmnsn_bvst_node *node) -{ - while (node->parent) { - if (!node->parent->parent) { - /* Zig step - we are a child of the root node */ - dmnsn_bvst_rotate(node); - break; - } else if ((node == node->parent->contains - && node->parent == node->parent->parent->contains) - || (node == node->parent->container - && node->parent == node->parent->parent->container)) { - /* Zig-zig step - we are a child on the same side as our parent */ - dmnsn_bvst_rotate(node->parent); - dmnsn_bvst_rotate(node); - } else { - /* Zig-zag step - we are a child on a different side than our parent is */ - dmnsn_bvst_rotate(node); - dmnsn_bvst_rotate(node); - } - } - tree->root = node; -} - -/* Rotate a tree on the edge connecting node and node->parent */ -static void -dmnsn_bvst_rotate(dmnsn_bvst_node *node) -{ - dmnsn_bvst_node *P, *Q, *B; - if (node == node->parent->contains) { - /* We are a left child; perform a right rotation: - * - * Q P - * / \ / \ - * P C ---> A Q - * / \ / \ - * A B B C - */ - Q = node->parent; - P = node; - /* A = node->contains; */ - B = node->container; - /* C = node->parent->container; */ - - /* First fix up the parents */ - if (Q->parent) { - if (Q->parent->contains == Q) - Q->parent->contains = P; - else - Q->parent->container = P; - } - P->parent = Q->parent; - Q->parent = P; - if (B) B->parent = Q; - - /* Then the children */ - P->container = Q; - Q->contains = B; - } else { - /* We are a right child; perform a left rotation: - * - * P Q - * / \ / \ - * A Q ---> P C - * / \ / \ - * B C A B - */ - P = node->parent; - Q = node; - /* A = node->parent->contains; */ - B = node->contains; - /* C = node->container; */ - - /* First fix up the parents */ - if (P->parent) { - if (P->parent->contains == P) - P->parent->contains = Q; - else - P->parent->container = Q; - } - Q->parent = P->parent; - P->parent = Q; - if (B) B->parent = P; - - /* Then the children */ - Q->contains = P; - P->container = B; - } -} - -typedef struct { - dmnsn_bvst_node *node; - bool intersected; - dmnsn_intersection intersection; -} dmnsn_bvst_search_result; - -static dmnsn_bvst_search_result -dmnsn_bvst_search_recursive(dmnsn_bvst_node *node, dmnsn_line ray, double t); - -bool -dmnsn_bvst_search(dmnsn_bvst *tree, dmnsn_line ray, - dmnsn_intersection *intersection) -{ - dmnsn_bvst_search_result result - = dmnsn_bvst_search_recursive(tree->root, ray, -1.0); - - if (result.intersected) { - dmnsn_bvst_splay(tree, result.node); - *intersection = result.intersection; - } - - return result.intersected; -} - -static bool dmnsn_ray_box_intersection(dmnsn_line ray, dmnsn_bounding_box box, - double t); - -static dmnsn_bvst_search_result -dmnsn_bvst_search_recursive(dmnsn_bvst_node *node, dmnsn_line ray, double t) -{ - dmnsn_bvst_search_result result_temp, result = { - .node = NULL, - .intersected = false - }; - - if (!node) - return result; - - /* Go down the right subtree first because the closest object is more likely - to lie in the larger bounding boxes */ - result_temp = dmnsn_bvst_search_recursive(node->container, ray, t); - if (result_temp.node && (t < 0.0 || result_temp.intersection.t < t)) { - result = result_temp; - t = result.intersection.t; - } - - if (dmnsn_bounding_box_contains(node->bounding_box, ray.x0) - || dmnsn_ray_box_intersection(ray, node->bounding_box, t)) - { - if (dmnsn_bounding_box_contains(node->object->bounding_box, ray.x0) - || dmnsn_ray_box_intersection(ray, node->object->bounding_box, t)) - { - result_temp.intersected = - (*node->object->intersection_fn)(node->object, ray, - &result_temp.intersection); - - if (result_temp.intersected - && (t < 0.0 || result_temp.intersection.t < t)) { - result.node = node; - result.intersected = true; - result.intersection = result_temp.intersection; - t = result.intersection.t; - } - } - - /* Go down the left subtree */ - result_temp = dmnsn_bvst_search_recursive(node->contains, ray, t); - if (result_temp.node && (t < 0.0 || result_temp.intersection.t < t)) { - result = result_temp; - } - } - - return result; -} - -static bool -dmnsn_ray_box_intersection(dmnsn_line line, dmnsn_bounding_box box, double t) -{ - double t_temp; - dmnsn_vector p; - - if (line.n.x != 0.0) { - /* x == box.min.x */ - t_temp = (box.min.x - line.x0.x)/line.n.x; - p = dmnsn_line_point(line, t_temp); - if (p.y >= box.min.y && p.y <= box.max.y - && p.z >= box.min.z && p.z <= box.max.z - && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) - return true; - - /* x == box.max.x */ - t_temp = (box.max.x - line.x0.x)/line.n.x; - p = dmnsn_line_point(line, t_temp); - if (p.y >= box.min.y && p.y <= box.max.y - && p.z >= box.min.z && p.z <= box.max.z - && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) - return true; - } - - if (line.n.y != 0.0) { - /* y == box.min.y */ - t_temp = (box.min.y - line.x0.y)/line.n.y; - p = dmnsn_line_point(line, t_temp); - if (p.x >= box.min.x && p.x <= box.max.x - && p.z >= box.min.z && p.z <= box.max.z - && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) - return true; - - /* y == box.max.y */ - t_temp = (box.max.y - line.x0.y)/line.n.y; - p = dmnsn_line_point(line, t_temp); - if (p.x >= box.min.x && p.x <= box.max.x - && p.z >= box.min.z && p.z <= box.max.z - && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) - return true; - } - - if (line.n.z != 0.0) { - /* z == box.min.z */ - t_temp = (box.min.z - line.x0.z)/line.n.z; - p = dmnsn_line_point(line, t_temp); - if (p.x >= box.min.x && p.x <= box.max.x - && p.y >= box.min.y && p.y <= box.max.y - && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) - return true; - - /* z == box.max.z */ - t_temp = (box.max.z - line.x0.z)/line.n.z; - p = dmnsn_line_point(line, t_temp); - if (p.x >= box.min.x && p.x <= box.max.x - && p.y >= box.min.y && p.y <= box.max.y - && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) - return true; - } - - return false; -} -- cgit v1.2.3