sorted layers first pass

src/entity.h

@@ -104,6 +104,12 @@ struct entity {
     struct entity_handle first;
     struct entity_handle last;
 
+    /* ====================================================================== */
+    /* Layer */
+
+    i32 layer;
+    i32 final_layer;  /* Calculated each tick from entity tree */
+
     /* ====================================================================== */
     /* Collider */
 

src/game.c

@@ -202,6 +202,7 @@ INTERNAL void spawn_test_entities(void)
         //e->sprite_span_name = STR("idle.unarmed");
         //e->sprite_span_name = STR("idle.one_handed");
         e->sprite_span_name = STR("idle.two_handed");
+        e->layer = GAME_LAYER_SHOULDERS;
 
         struct xform xf = XFORM_TRS(.t = pos, .r = r, .s = size);
         //xf.bx.y = -1.f;
@@ -235,6 +236,7 @@ INTERNAL void spawn_test_entities(void)
 
         e->sprite = sprite_tag_from_path(STR("res/graphics/tim.ase"));
         e->sprite_collider_slice = STR("shape");
+        e->layer = GAME_LAYER_SHOULDERS;
 
         entity_enable_prop(e, ENTITY_PROP_PHYSICAL_DYNAMIC);
         e->mass_unscaled = 10;
@@ -258,6 +260,7 @@ INTERNAL void spawn_test_entities(void)
 
         e->sprite = sprite_tag_from_path(STR("res/graphics/box.ase"));
         e->sprite_collider_slice = STR("shape");
+        e->layer = GAME_LAYER_SHOULDERS;
 
         entity_enable_prop(e, ENTITY_PROP_PHYSICAL_DYNAMIC);
         e->mass_unscaled = 100;
@@ -280,6 +283,7 @@ INTERNAL void spawn_test_entities(void)
 
         e->sprite = sprite_tag_from_path(STR("res/graphics/bullet.ase"));
         e->sprite_collider_slice = STR("shape");
+        e->layer = GAME_LAYER_SHOULDERS;
 
         entity_enable_prop(e, ENTITY_PROP_PHYSICAL_DYNAMIC);
         e->mass_unscaled = 0.5;
@@ -295,6 +299,7 @@ INTERNAL void spawn_test_entities(void)
 
         entity_enable_prop(e, ENTITY_PROP_ATTACHED);
         e->attach_slice = STR("attach.wep");
+        e->layer = GAME_LAYER_RELATIVE_WEAPON;
 
         entity_enable_prop(e, ENTITY_PROP_WEAPON);
         e->trigger_delay = 1.0f / 10.0f;
@@ -418,6 +423,7 @@ INTERNAL PHYS_COLLISION_CALLBACK_FUNC_DEF(on_collision, array)
                         struct entity *decal = entity_alloc(root);
                         decal->sprite = sprite_tag_from_path(STR("res/graphics/blood.ase"));
                         decal->sprite_tint = RGBA_32_F(1, 1, 1, 0.25f);
+                        decal->layer = GAME_LAYER_FLOOR_DECALS;
                         entity_set_xform(decal, xf);
 
                         f32 perp_range = 0.5;
@@ -860,6 +866,7 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
                 bullet->bullet_knockback = 10;
                 bullet->mass_unscaled = 0.04f;
                 bullet->inertia_unscaled = 0.00001f;
+                bullet->layer = GAME_LAYER_BULLETS;
 
 #if 1
                 /* Point collider */
@@ -878,6 +885,7 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
             {
                 struct entity *tracer = entity_alloc(root);
                 tracer->tracer_fade_duration = 0.025f;
+                tracer->layer = GAME_LAYER_TRACERS;
                 entity_enable_prop(tracer, ENTITY_PROP_TRACER);
 
                 bullet->bullet_tracer = tracer->handle;
@@ -1228,6 +1236,35 @@ INTERNAL void game_update(struct game_cmd_array game_cmds)
         }
     }
 
+    /* ========================== *
+     * Update relative layers
+     * ========================== */
+
+    {
+        struct temp_arena temp = arena_temp_begin(scratch.arena);
+
+        struct entity **stack = arena_push(temp.arena, struct entity *);
+        u64 stack_count = 1;
+        *stack = root;
+
+        while (stack_count > 0) {
+            struct entity *parent;
+            arena_pop(temp.arena, struct entity *, &parent);
+            --stack_count;
+
+            i32 parent_layer = parent->final_layer;
+            for (struct entity *child = entity_from_handle(store, parent->first); child->valid; child = entity_from_handle(store, child->next)) {
+                if (entity_is_valid_and_active(child)) {
+                    child->final_layer = parent_layer + child->layer;
+                    *arena_push(temp.arena, struct entity *) = child;
+                    ++stack_count;
+                }
+            }
+        }
+
+        arena_temp_end(temp);
+    }
+
     /* ========================== *
      * Update sound emitters
      * ========================== */

src/game.h

@@ -30,6 +30,16 @@ enum game_cmd_kind {
     GAME_CMD_KIND_COUNT
 };
 
+/* Absolute layers */
+#define GAME_LAYER_FLOOR_DECALS         -300
+#define GAME_LAYER_BULLETS              -200
+#define GAME_LAYER_TRACERS              -100
+#define GAME_LAYER_SHOULDERS            0
+
+/* Relative layers */
+#define GAME_LAYER_RELATIVE_DEFAULT     0
+#define GAME_LAYER_RELATIVE_WEAPON      1
+
 struct game_cmd {
     enum game_cmd_kind kind;
     enum game_cmd_state state;

src/string.c

@@ -312,6 +312,25 @@ b32 string_eq(struct string str1, struct string str2)
     return eq;
 }
 
+i32 string_cmp(struct string str1, struct string str2)
+{
+    i32 res = 0;
+    for (u64 i = 0; i < min_u64(str1.len, str2.len); ++i) {
+        res = str1.text[i] - str2.text[i];
+        if (res != 0) {
+            break;
+        }
+    }
+    if (res == 0) {
+        if (str1.len > str2.len) {
+            res = str1.text[str2.len];
+        } else if (str2.len > str1.len) {
+            res = str2.text[str1.len];
+        }
+    }
+    return res;
+}
+
 b32 string_contains(struct string str, struct string substring)
 {
     if (substring.len > str.len) {

src/string.h

@@ -28,6 +28,7 @@ struct string_array string_split(struct arena *arena, struct string str, struct
 struct string string_indent(struct arena *arena, struct string str, u32 indent);
 struct string string_lower(struct arena *arena, struct string str);
 b32 string_eq(struct string str1, struct string str2);
+i32 string_cmp(struct string str1, struct string str2);
 b32 string_contains(struct string str, struct string substring);
 b32 string_starts_with(struct string str, struct string substring);
 b32 string_ends_with(struct string str, struct string substring);

src/user.c

@@ -439,10 +439,28 @@ INTERNAL SORT_COMPARE_FUNC_DEF(sort_entities, arg_a, arg_b, udata)
     struct entity *a = *(struct entity **)arg_a;
     struct entity *b = *(struct entity **)arg_b;
 
-    u64 a_index = a->handle.idx;
+    i32 res = 0;
-    u64 b_index = b->handle.idx;
 
-    return (a_index < b_index) - (a_index > b_index);
+    if (res == 0) {
+        /* Sort by layer */
+        i32 a_cmp = a->layer;
+        i32 b_cmp = b->layer;
+        res = (a_cmp < b_cmp) - (a_cmp > b_cmp);
+    }
+    if (res == 0) {
+        /* Sort by sprite */
+        u64 a_cmp = a->sprite.hash;
+        u64 b_cmp = b->sprite.hash;
+        res = (a_cmp < b_cmp) - (a_cmp > b_cmp);
+    }
+    if (res == 0) {
+        /* Sort by activation */
+        u64 a_cmp = a->activation_tick;
+        u64 b_cmp = b->activation_tick;
+        res = (a_cmp < b_cmp) - (a_cmp > b_cmp);
+    }
+
+    return res;
 }
 
 /* ========================== *