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Fix buffer overflow in 2D BVH
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Some areas of code were missed and assumed Vector3.
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pouleyKetchoupp committed Sep 29, 2021
1 parent f72419d commit d3c6395
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Showing 3 changed files with 23 additions and 22 deletions.
2 changes: 1 addition & 1 deletion core/math/bvh_cull.inc
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ struct CullParams {
uint32_t pairable_type;

// optional components for different tests
Vector3 point;
Point point;
BVHABB_CLASS abb;
typename BVHABB_CLASS::ConvexHull hull;
typename BVHABB_CLASS::Segment segment;
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27 changes: 12 additions & 15 deletions core/math/bvh_debug.inc
Original file line number Diff line number Diff line change
Expand Up @@ -6,24 +6,21 @@ void _debug_recursive_print_tree(int p_tree_id) const {
}

String _debug_aabb_to_string(const BVHABB_CLASS &aabb) const {
String sz = "(";
sz += itos(aabb.min.x);
sz += " ~ ";
sz += itos(-aabb.neg_max.x);
sz += ") (";
Point size = aabb.calculate_size();

sz += itos(aabb.min.y);
sz += " ~ ";
sz += itos(-aabb.neg_max.y);
sz += ") (";
String sz;
float vol = 0.0;

sz += itos(aabb.min.z);
sz += " ~ ";
sz += itos(-aabb.neg_max.z);
sz += ") ";
for (int i = 0; i < Point::AXES_COUNT; ++i) {
sz += "(";
sz += itos(aabb.min[i]);
sz += " ~ ";
sz += itos(-aabb.neg_max[i]);
sz += ") ";

vol += size[i];
}

Vector3 size = aabb.calculate_size();
float vol = size.x * size.y * size.z;
sz += "vol " + itos(vol);

return sz;
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16 changes: 10 additions & 6 deletions core/math/bvh_split.inc
Original file line number Diff line number Diff line change
Expand Up @@ -28,11 +28,15 @@ void _split_leaf_sort_groups_simple(int &num_a, int &num_b, uint16_t *group_a, u
Point centre = full_bound.calculate_centre();
Point size = full_bound.calculate_size();

int order[3];
int order[Point::AXIS_COUNT];

order[0] = size.min_axis();
order[2] = size.max_axis();
order[1] = 3 - (order[0] + order[2]);
order[Point::AXIS_COUNT - 1] = size.max_axis();

static_assert(Point::AXIS_COUNT <= 3);
if (Point::AXIS_COUNT == 3) {
order[1] = 3 - (order[0] + order[2]);
}

// simplest case, split on the longest axis
int split_axis = order[0];
Expand All @@ -54,7 +58,7 @@ void _split_leaf_sort_groups_simple(int &num_a, int &num_b, uint16_t *group_a, u

// detect when split on longest axis failed
int min_threshold = MAX_ITEMS / 4;
int min_group_size[3];
int min_group_size[Point::AXIS_COUNT];
min_group_size[0] = MIN(num_a, num_b);
if (min_group_size[0] < min_threshold) {
// slow but sure .. first move everything back into a
Expand All @@ -64,7 +68,7 @@ void _split_leaf_sort_groups_simple(int &num_a, int &num_b, uint16_t *group_a, u
num_b = 0;

// now calculate the best split
for (int axis = 1; axis < 3; axis++) {
for (int axis = 1; axis < Point::AXIS_COUNT; axis++) {
split_axis = order[axis];
int count = 0;

Expand All @@ -82,7 +86,7 @@ void _split_leaf_sort_groups_simple(int &num_a, int &num_b, uint16_t *group_a, u
// best axis
int best_axis = 0;
int best_min = min_group_size[0];
for (int axis = 1; axis < 3; axis++) {
for (int axis = 1; axis < Point::AXIS_COUNT; axis++) {
if (min_group_size[axis] > best_min) {
best_min = min_group_size[axis];
best_axis = axis;
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