skip redundant manifold based on manifold iteration

src/common.h

@@ -226,15 +226,14 @@ void __asan_unpoison_memory_region(void const volatile *add, size_t);
 #define TERABYTE(n) (n*GIGABYTE(1024ULL))
 
 /* typeof */
-
 #if COMPILER_MSVC
 /* Typeof not supported in MSVC */
-#  define typeof(type) ASSERT(false)
 #  define TYPEOF_DEFINED 0
+#  define typeof(type) ASSERT(false)
 #else
+# define TYPEOF_DEFINED 1
 # if LANGUAGE_CPP || (__STDC_VERSION__ < 202311L)
 #  define typeof(type) __typeof__(type)
-#  define TYPEOF_DEFINED 1
 # endif
 #endif
 
@@ -307,17 +306,6 @@ void __asan_unpoison_memory_region(void const volatile *add, size_t);
 #define STRINGIZE2(x) #x
 #define STRINGIZE(x) STRINGIZE2(x)
 
-
-#if 0
-/* ========================== *
- * Bit utils
- * ========================== */
-
-#define bit_set(i, mask) (i |= mask)
-#define bit_clear(i, mask) (i &= ~mask)
-#define bit_flip(i, mask) (i ^= mask)
-#endif
-
 /* ========================== *
  * Primitive types
  * ========================== */

src/entity.h

@@ -132,6 +132,7 @@ struct entity {
     struct entity_handle manifold_e0;
     struct entity_handle manifold_e1;
     struct v2 manifold_normal;   /* Normal vector of collision from e0 -> e1 */
+    u64 last_manifold_iteration;
     struct contact contacts[2];
     u32 num_contacts;
 

src/game.c

@@ -246,6 +246,10 @@ INTERNAL void spawn_test_entities(void)
 
 INTERNAL void create_contact_manifolds(void)
 {
+    /* TODO: Remove this */
+    static u64 manifold_iteration = 0;
+    ++manifold_iteration;
+
     struct entity_store *store = G.tick.entity_store;
     struct sprite_scope *sprite_frame_scope = G.sprite_frame_scope;
     struct entity *root = G.root;
@@ -253,8 +257,8 @@ INTERNAL void create_contact_manifolds(void)
         struct entity *e0 = &store->entities[e0_index];
         if (!(e0->valid && entity_has_prop(e0, ENTITY_PROP_ACTIVE))) continue;
         if (!entity_has_prop(e0, ENTITY_PROP_PHYSICAL)) continue;
-        if (!entity_has_prop(e0, ENTITY_PROP_PLAYER_CONTROLLED) && !entity_has_prop(e0, ENTITY_PROP_BULLET)) continue;
 
+        /* Calculate entity 0 shape */
         struct xform e0_xf = entity_get_xform(e0);
         struct quad e0_quad;
         struct v2_array e0_poly;
@@ -274,8 +278,41 @@ INTERNAL void create_contact_manifolds(void)
             if (e1 == e0) continue;
             if (!(e1->valid && entity_has_prop(e1, ENTITY_PROP_ACTIVE))) continue;
             if (!entity_has_prop(e1, ENTITY_PROP_PHYSICAL)) continue;
-            if (entity_has_prop(e1, ENTITY_PROP_PLAYER_CONTROLLED)) continue;
 
+            /* TODO: Remove this */
+            static struct arena dict_arena = ZI;
+            static struct fixed_dict dict = ZI;
+            if (dict.buckets_count == 0) {
+                dict_arena = arena_alloc(GIGABYTE(64));
+                dict = fixed_dict_init(&dict_arena, 4096);
+            }
+
+            /* Retrieve manifold */
+            u64 manifold_hash;
+            struct string manifold_key;
+            {
+                struct entity_handle h0 = e0->handle;
+                struct entity_handle h1 = e1->handle;
+                if (h0.idx > h1.idx) {
+                    h0 = e1->handle;
+                    h1 = e0->handle;
+                }
+                manifold_hash = hash_fnv64(HASH_FNV64_BASIS, BUFFER_FROM_STRUCT(&h0));
+                manifold_hash = hash_fnv64(manifold_hash, BUFFER_FROM_STRUCT(&h1));
+                manifold_key = STRING_FROM_BUFFER(BUFFER_FROM_STRUCT(&manifold_hash));
+            }
+            struct entity *manifold = fixed_dict_get(&dict, manifold_key);
+
+            /* Ensure manifold hasn't already been computed this iteration */
+            if (manifold) {
+                if (manifold->last_manifold_iteration == manifold_iteration) {
+                    /* Already iterated this manifold from The other entity's perspective, skip */
+                    continue;
+                }
+                manifold->last_manifold_iteration = manifold_iteration;
+            }
+
+            /* Calculate entity 1 shape */
             struct xform e1_xf = entity_get_xform(e1);
             struct quad e1_quad;
             struct v2_array e1_poly;
@@ -290,29 +327,6 @@ INTERNAL void create_contact_manifolds(void)
                 };
             }
 
-
-            /* TODO: Remove this */
-            static struct arena dict_arena = ZI;
-            static struct fixed_dict dict = ZI;
-            if (dict.buckets_count == 0) {
-                dict_arena = arena_alloc(GIGABYTE(64));
-                dict = fixed_dict_init(&dict_arena, 4096);
-            }
-
-            u64 manifold_hash;
-            struct string manifold_key;
-            {
-                manifold_hash = hash_fnv64(HASH_FNV64_BASIS, BUFFER_FROM_STRUCT(&e0->handle));
-                /* FIXME: Contact should be same regardless of entity order */
-                manifold_hash = hash_fnv64(manifold_hash, BUFFER_FROM_STRUCT(&e1->handle));
-                manifold_key = STRING_FROM_BUFFER(BUFFER_FROM_STRUCT(&manifold_hash));
-            }
-
-            struct entity *manifold = fixed_dict_get(&dict, manifold_key);
-
-
-
-
 #if 1
             const f32 remove_contact_threshold_global_dist_sq = 0.005f * 0.005f;
             const f32 insert_contact_threshold_global_dist_sq = 0.005f * 0.005f;
@@ -321,8 +335,6 @@ INTERNAL void create_contact_manifolds(void)
             const f32 insert_contact_threshold_global_dist_sq = 0;
 #endif
 
-
-
             struct gjk_contact_points_result res = gjk_contact_points(e0_poly, e1_poly);
             if (res.num_pairs > 0) {
                 if (!manifold) {
@@ -337,19 +349,12 @@ INTERNAL void create_contact_manifolds(void)
                 }
 
 
-
-
                 /* TODO: Remove this (debugging) */
                 manifold->prototype = res.prototype;
                 manifold->simplex = res.simplex;
 
 
 
-
-
-
-
-
                 /* Update contact depths, and remove contacts that are no longer penetrating or have drifted too far from original position */
                 struct v2 old_normal = manifold->manifold_normal;
                 for (i32 j = 0; j < (i32)manifold->num_contacts; ++j) {

src/gjk.c

@@ -34,6 +34,8 @@ b32 gjk_boolean(struct v2_array shape0, struct v2_array shape1)
 {
     struct { struct v2 a, b, c; } s = ZI;
 
+    /* FIXME: Infinite loop when shapes exactly overlap same space */
+
     /* First point is support point in shape's general directions to eachother */
     s.a = menkowski_point(shape0, shape1, v2_sub(shape1.points[0], shape0.points[0]));
 
@@ -187,6 +189,8 @@ struct gjk_contact_points_result gjk_contact_points(struct v2_array shape0, stru
      * ========================== */
 
     {
+        /* FIXME: Collision is false when 2 shapes exactly overlap */
+
         /* First point is support point in shape's general directions to eachother */
         s.a = menkowski_point_extended(shape0, shape1, v2_sub(shape1.points[0], shape0.points[0]));
         s.len = 1;
@@ -194,7 +198,7 @@ struct gjk_contact_points_result gjk_contact_points(struct v2_array shape0, stru
         /* Second point is support point towards origin */
         dir = v2_neg(s.a.p);
         m = menkowski_point_extended(shape0, shape1, dir);
-        if (v2_dot(dir, m.p) >= 0) {
+        if (v2_dot(dir, m.p) > 0) {
             s.b = s.a;
             s.a = m;
             s.len = 2;
@@ -217,13 +221,13 @@ struct gjk_contact_points_result gjk_contact_points(struct v2_array shape0, stru
                 struct v2 a_to_origin = v2_neg(s.a.p);
 
                 dir = v2_perp_towards_dir(vab, v2_neg(vac));  /* Normal of ab pointing away from c */
-                if (v2_dot(dir, a_to_origin) >= 0) {
+                if (v2_dot(dir, a_to_origin) > 0) {
                     /* Point is in region ab, remove c from simplex */
                     s.len = 2;
                 } else {
                     /* Point is not in region ab */
                     dir = v2_perp_towards_dir(vac, v2_neg(vab));  /* Normal of ac pointing away from b */
-                    if (v2_dot(dir, a_to_origin) >= 0) {
+                    if (v2_dot(dir, a_to_origin) > 0) {
                         /* Point is in region ac, remove b from simplex */
                         s.b = s.c;
                         s.len = 2;