BLI_kdtree: refactor boids specific logic into callback

Logic to for boids to avoid head-on collisions was in BLI_kdtree.

Move this into a callback which is now defined in boids.c
so the kdtree code can be kept generic.

1 files changed, 26 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/boids.c b/source/blender/blenkernel/intern/boids.c
index 54a8929a7f7..8b71aa0fb69 100644
--- a/source/blender/blenkernel/intern/boids.c
+++ b/source/blender/blenkernel/intern/boids.c
@@ -45,6 +45,23 @@
 
 #include "RNA_enum_types.h"
 
+static float len_squared_v3v3_with_normal_bias(
+        const float co_search[3], const float co_test[3], const void *user_data)
+{
+	const float *normal = user_data;
+	float d[3], dist;
+
+	sub_v3_v3v3(d, co_test, co_search);
+
+	dist = len_squared_v3(d);
+
+	/* Avoid head-on collisions. */
+	if (dot_v3v3(d, normal) < 0.0f) {
+		dist *= 10.0f;
+	}
+	return dist;
+}
+
 typedef struct BoidValues {
 	float max_speed, max_acc;
 	float max_ave, min_speed;
@@ -257,9 +274,9 @@ static int rule_avoid_collision(BoidRule *rule, BoidBrainData *bbd, BoidValues *
 
 	//check boids in own system
 	if (acbr->options & BRULE_ACOLL_WITH_BOIDS) {
-		neighbors = BLI_kdtree_range_search__normal(
-		        bbd->sim->psys->tree, pa->prev_state.co, pa->prev_state.ave,
-		        &ptn, acbr->look_ahead * len_v3(pa->prev_state.vel));
+		neighbors = BLI_kdtree_range_search_with_len_squared_cb(
+		        bbd->sim->psys->tree, pa->prev_state.co, &ptn, acbr->look_ahead * len_v3(pa->prev_state.vel),
+		        len_squared_v3v3_with_normal_bias, pa->prev_state.ave);
 		if (neighbors > 1) for (n=1; n<neighbors; n++) {
 			copy_v3_v3(co1, pa->prev_state.co);
 			copy_v3_v3(vel1, pa->prev_state.vel);
@@ -306,9 +323,9 @@ static int rule_avoid_collision(BoidRule *rule, BoidBrainData *bbd, BoidValues *
 
 		if (epsys) {
 			BLI_assert(epsys->tree != NULL);
-			neighbors = BLI_kdtree_range_search__normal(
-			        epsys->tree, pa->prev_state.co, pa->prev_state.ave,
-			        &ptn, acbr->look_ahead * len_v3(pa->prev_state.vel));
+			neighbors = BLI_kdtree_range_search_with_len_squared_cb(
+			        epsys->tree, pa->prev_state.co, &ptn, acbr->look_ahead * len_v3(pa->prev_state.vel),
+			        len_squared_v3v3_with_normal_bias, pa->prev_state.ave);
 
 			if (neighbors > 0) for (n=0; n<neighbors; n++) {
 				copy_v3_v3(co1, pa->prev_state.co);
@@ -406,7 +423,9 @@ static int rule_flock(BoidRule *UNUSED(rule), BoidBrainData *bbd, BoidValues *UN
 {
 	KDTreeNearest ptn[11];
 	float vec[3] = {0.0f, 0.0f, 0.0f}, loc[3] = {0.0f, 0.0f, 0.0f};
-	int neighbors = BLI_kdtree_find_nearest_n__normal(bbd->sim->psys->tree, pa->state.co, pa->prev_state.ave, ptn, 11);
+	int neighbors = BLI_kdtree_find_nearest_n_with_len_squared_cb(
+	        bbd->sim->psys->tree, pa->state.co, ptn, ARRAY_SIZE(ptn),
+	        len_squared_v3v3_with_normal_bias, pa->prev_state.ave);
 	int n;
 	int ret = 0;