Debug drawing for simulations, to aid in visualizing abstract data such

as forces, velocities, contact points etc.

This uses a hash table to store debug elements (dots, lines, vectors at
this point). The hash table allows continuous display of elements that
are generated only in certain time steps, e.g. contact points, while
avoiding massive memory allocation. In any case, this system is really
a development feature, but very helpful in finding issues with the
internal solver data.

1 files changed, 105 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/effect.c b/source/blender/blenkernel/intern/effect.c
index ced9da8d0b1..94b4af10201 100644
--- a/source/blender/blenkernel/intern/effect.c
+++ b/source/blender/blenkernel/intern/effect.c
@@ -51,6 +51,7 @@
 #include "BLI_noise.h"
 #include "BLI_rand.h"
 #include "BLI_utildefines.h"
+#include "BLI_ghash.h"
 
 #include "PIL_time.h"
 
@@ -1024,3 +1025,107 @@ void pdDoEffectors(ListBase *effectors, ListBase *colliders, EffectorWeights *we
 		}
 	}
 }
+
+/* ======== Simulation Debugging ======== */
+
+static unsigned int debug_element_hash(const void *key)
+{
+	const SimDebugElement *elem = key;
+	return elem->hash;
+}
+
+static int debug_element_compare(const void *a, const void *b)
+{
+	const SimDebugElement *elem1 = a;
+	const SimDebugElement *elem2 = b;
+
+	if (elem1->hash == elem2->hash) {
+		return 0;
+	}
+	return 1;
+}
+
+static void debug_element_free(void *val)
+{
+	SimDebugElement *elem = val;
+	MEM_freeN(elem);
+}
+
+SimDebugData *BKE_sim_debug_data_new(void)
+{
+	SimDebugData *debug_data = MEM_callocN(sizeof(SimDebugData), "sim debug data");
+	debug_data->gh = BLI_ghash_new(debug_element_hash, debug_element_compare, "sim debug element hash");
+	return debug_data;
+	
+}
+
+static void debug_data_insert(SimDebugData *debug_data, SimDebugElement *elem)
+{
+	SimDebugElement *old_elem = BLI_ghash_lookup(debug_data->gh, elem);
+	if (old_elem) {
+		*old_elem = *elem;
+		MEM_freeN(elem);
+	}
+	else
+		BLI_ghash_insert(debug_data->gh, elem, elem);
+}
+
+void BKE_sim_debug_data_add_dot(struct SimDebugData *debug_data, const float p[3], float r, float g, float b, int hash)
+{
+	SimDebugElement *elem = MEM_callocN(sizeof(SimDebugElement), "sim debug data element");
+	elem->type = SIM_DEBUG_ELEM_DOT;
+	elem->hash = hash;
+	elem->color[0] = r;
+	elem->color[1] = g;
+	elem->color[2] = b;
+	copy_v3_v3(elem->v1, p);
+	
+	debug_data_insert(debug_data, elem);
+}
+
+void BKE_sim_debug_data_add_line(struct SimDebugData *debug_data, const float p1[3], const float p2[3], float r, float g, float b, int hash)
+{
+	SimDebugElement *elem = MEM_callocN(sizeof(SimDebugElement), "sim debug data element");
+	elem->type = SIM_DEBUG_ELEM_LINE;
+	elem->hash = hash;
+	elem->color[0] = r;
+	elem->color[1] = g;
+	elem->color[2] = b;
+	copy_v3_v3(elem->v1, p1);
+	copy_v3_v3(elem->v2, p2);
+	
+	debug_data_insert(debug_data, elem);
+}
+
+void BKE_sim_debug_data_add_vector(struct SimDebugData *debug_data, const float p[3], const float d[3], float r, float g, float b, int hash)
+{
+	SimDebugElement *elem = MEM_callocN(sizeof(SimDebugElement), "sim debug data element");
+	elem->type = SIM_DEBUG_ELEM_VECTOR;
+	elem->hash = hash;
+	elem->color[0] = r;
+	elem->color[1] = g;
+	elem->color[2] = b;
+	copy_v3_v3(elem->v1, p);
+	copy_v3_v3(elem->v2, d);
+	
+	debug_data_insert(debug_data, elem);
+}
+
+void BKE_sim_debug_data_clear(SimDebugData *debug_data)
+{
+	if (!debug_data)
+		return;
+	
+	if (debug_data->gh)
+		BLI_ghash_clear(debug_data->gh, NULL, debug_element_free);
+}
+
+void BKE_sim_debug_data_free(SimDebugData *debug_data)
+{
+	if (!debug_data)
+		return;
+	
+	if (debug_data->gh)
+		BLI_ghash_free(debug_data->gh, NULL, debug_element_free);
+	MEM_freeN(debug_data);
+}