diff options
Diffstat (limited to 'libdimension')
| -rw-r--r-- | libdimension/prtree.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/libdimension/prtree.c b/libdimension/prtree.c index 118285f..6fa2d10 100644 --- a/libdimension/prtree.c +++ b/libdimension/prtree.c @@ -525,7 +525,8 @@ dmnsn_delete_prtree(dmnsn_prtree *tree) /* Ray-AABB intersection test */ static inline bool -dmnsn_ray_box_intersection(dmnsn_line line, dmnsn_bounding_box box, double t) +dmnsn_ray_box_intersection(dmnsn_line line, dmnsn_vector inv, + dmnsn_bounding_box box, double t) { double tmin = -INFINITY, tmax = INFINITY; @@ -534,8 +535,9 @@ dmnsn_ray_box_intersection(dmnsn_line line, dmnsn_bounding_box box, double t) return false; if (line.n.x != 0.0) { - double tx1 = (box.min.x - line.x0.x)/line.n.x; - double tx2 = (box.max.x - line.x0.x)/line.n.x; + /* inv.x == 1.0/line.n.x */ + double tx1 = (box.min.x - line.x0.x)*inv.x; + double tx2 = (box.max.x - line.x0.x)*inv.x; tmin = dmnsn_max(tmin, dmnsn_min(tx1, tx2)); tmax = dmnsn_min(tmax, dmnsn_max(tx1, tx2)); @@ -547,8 +549,8 @@ dmnsn_ray_box_intersection(dmnsn_line line, dmnsn_bounding_box box, double t) } if (line.n.y != 0.0) { - double ty1 = (box.min.y - line.x0.y)/line.n.y; - double ty2 = (box.max.y - line.x0.y)/line.n.y; + double ty1 = (box.min.y - line.x0.y)*inv.y; + double ty2 = (box.max.y - line.x0.y)*inv.y; tmin = dmnsn_max(tmin, dmnsn_min(ty1, ty2)); tmax = dmnsn_min(tmax, dmnsn_max(ty1, ty2)); @@ -560,8 +562,8 @@ dmnsn_ray_box_intersection(dmnsn_line line, dmnsn_bounding_box box, double t) } if (line.n.z != 0.0) { - double tz1 = (box.min.z - line.x0.z)/line.n.z; - double tz2 = (box.max.z - line.x0.z)/line.n.z; + double tz1 = (box.min.z - line.x0.z)*inv.z; + double tz2 = (box.max.z - line.x0.z)*inv.z; tmin = dmnsn_max(tmin, dmnsn_min(tz1, tz2)); tmax = dmnsn_min(tmax, dmnsn_max(tz1, tz2)); @@ -577,14 +579,14 @@ dmnsn_ray_box_intersection(dmnsn_line line, dmnsn_bounding_box box, double t) static void dmnsn_prtree_intersection_recursive(const dmnsn_prtree_node *node, - dmnsn_line ray, + dmnsn_line ray, dmnsn_vector inv, dmnsn_intersection *intersection, double *t) { for (size_t i = 0; i < DMNSN_PRTREE_B; ++i) { if (!node->children[i]) break; - if (dmnsn_ray_box_intersection(ray, node->bounding_boxes[i], *t)) { + if (dmnsn_ray_box_intersection(ray, inv, node->bounding_boxes[i], *t)) { if (node->is_leaf) { dmnsn_object *object = node->children[i]; @@ -596,7 +598,7 @@ dmnsn_prtree_intersection_recursive(const dmnsn_prtree_node *node, } } } else { - dmnsn_prtree_intersection_recursive(node->children[i], ray, + dmnsn_prtree_intersection_recursive(node->children[i], ray, inv, intersection, t); } } @@ -620,9 +622,12 @@ dmnsn_prtree_intersection(const dmnsn_prtree *tree, dmnsn_line ray, } } + /* Precalculate 1.0/ray.n.{x,y,z} to save time in intersection tests */ + dmnsn_vector inv = dmnsn_new_vector(1.0/ray.n.x, 1.0/ray.n.y, 1.0/ray.n.z); + /* Search the bounded objects */ - if (dmnsn_ray_box_intersection(ray, tree->root->bounding_box, t)) { - dmnsn_prtree_intersection_recursive(tree->root, ray, intersection, &t); + if (dmnsn_ray_box_intersection(ray, inv, tree->root->bounding_box, t)) { + dmnsn_prtree_intersection_recursive(tree->root, ray, inv, intersection, &t); } return !isinf(t); |