From f33fb7eeb3d5d354a991089053a158dcb5e724c1 Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@gmail.com>
Date: Wed, 2 Nov 2011 22:10:34 -0400
Subject: Clean up PR-tree intersection code.
---
libdimension/prtree.c | 47 +++++++++++++++++++++++------------------------
1 file changed, 23 insertions(+), 24 deletions(-)
(limited to 'libdimension')
diff --git a/libdimension/prtree.c b/libdimension/prtree.c
index d47d89a..cfcc5a8 100644
--- a/libdimension/prtree.c
+++ b/libdimension/prtree.c
@@ -581,6 +581,22 @@ dmnsn_get_intersection_cache(size_t id)
return dmnsn_array_at(caches, id);
}
+/** Test for a closer object intersection than we've found so far. */
+static inline bool
+dmnsn_closer_intersection(dmnsn_object *object, dmnsn_line ray,
+ dmnsn_intersection *intersection, double *t)
+{
+ dmnsn_intersection local_intersection;
+ if (dmnsn_object_intersection(object, ray, &local_intersection)) {
+ if (local_intersection.t < *t) {
+ *intersection = local_intersection;
+ *t = local_intersection.t;
+ return true;
+ }
+ }
+ return false;
+}
+
DMNSN_HOT bool
dmnsn_prtree_intersection(const dmnsn_prtree *tree, dmnsn_line ray,
dmnsn_intersection *intersection, bool reset)
@@ -589,13 +605,7 @@ dmnsn_prtree_intersection(const dmnsn_prtree *tree, dmnsn_line ray,
/* Search the unbounded objects */
DMNSN_ARRAY_FOREACH (dmnsn_object **, object, tree->unbounded) {
- dmnsn_intersection local_intersection;
- if (dmnsn_object_intersection(*object, ray, &local_intersection)) {
- if (local_intersection.t < t) {
- *intersection = local_intersection;
- t = local_intersection.t;
- }
- }
+ dmnsn_closer_intersection(*object, ray, intersection, &t);
}
/* Precalculate 1.0/ray.n.{x,y,z} to save time in intersection tests */
@@ -611,13 +621,8 @@ dmnsn_prtree_intersection(const dmnsn_prtree *tree, dmnsn_line ray,
cached = cache->objects[cache->i];
}
if (cached && dmnsn_ray_box_intersection(optline, cached->bounding_box, t)) {
- dmnsn_intersection local_intersection;
- if (dmnsn_object_intersection(cached, ray, &local_intersection)) {
- if (local_intersection.t < t) {
- *intersection = local_intersection;
- t = local_intersection.t;
- found = cached;
- }
+ if (dmnsn_closer_intersection(cached, ray, intersection, &t)) {
+ found = cached;
}
}
@@ -628,16 +633,10 @@ dmnsn_prtree_intersection(const dmnsn_prtree *tree, dmnsn_line ray,
{
if (dmnsn_ray_box_intersection(optline, node->bounding_box, t)) {
if (node->object && node->object != cached) {
- dmnsn_intersection local_intersection;
- if (dmnsn_object_intersection(node->object, ray, &local_intersection)) {
- if (local_intersection.t < t) {
- *intersection = local_intersection;
- t = local_intersection.t;
- found = node->object;
- }
+ if (dmnsn_closer_intersection(node->object, ray, intersection, &t)) {
+ found = node->object;
}
}
-
++node;
} else {
node += node->skip;
@@ -646,7 +645,8 @@ dmnsn_prtree_intersection(const dmnsn_prtree *tree, dmnsn_line ray,
/* Update the cache */
if (cache->i < DMNSN_PRTREE_CACHE_SIZE) {
- cache->objects[cache->i++] = found;
+ cache->objects[cache->i] = found;
+ ++cache->i;
}
return !isinf(t);
@@ -670,7 +670,6 @@ dmnsn_prtree_inside(const dmnsn_prtree *tree, dmnsn_vector point)
if (node->object && dmnsn_object_inside(node->object, point)) {
return true;
}
-
++node;
} else {
node += node->skip;
--
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