only re-calculate all xforms before publishing game tick

src/entity.h

@@ -81,8 +81,7 @@ struct entity {
     struct string sprite_span_name;
     u32 sprite_tint;
 
-    struct xform sprite_local_xform;  /* Sprite transform in relation to xform_world */
+    struct xform sprite_local_xform;  /* Sprite transform in relation to entity */
-    struct xform sprite_global_xform;
 
     /* ====================================================================== */
     /* Animation */

src/game.c

@@ -197,74 +197,6 @@ INTERNAL void publish_game_tick(void)
     sys_mutex_unlock(&lock);
 }
 
-
-
-
-
-
-/* TODO: Remove this(?) */
-#if 0
-INTERNAL void recalculate_world_xforms_recurse(struct entity *parent)
-{
-    struct temp_arena scratch = scratch_begin_no_conflict();
-
-    struct stack_node {
-        struct entity *entity;
-        struct xform parent_xform_world;
-    };
-
-    /* Depth first iteration */
-    *arena_push(scratch.arena, struct stack_node) = (struct stack_node) { .entity = parent, .parent_xform_world = XFORM_IDENT };
-    u64 stack_count = 1;
-    while (stack_count > 0) {
-        /* Pull from top of stack */
-        struct stack_node node;
-        arena_pop(scratch.arena, struct stack_node, &node);
-        --stack_count;
-
-        struct entity *child = node.entity;
-
-        /* Calculate world xform */
-        struct xform xform_world = xform_mul(node.parent_xform_world, child->_xform);
-        child->_xform_world = xform_world;
-
-        /* Calculate sprite world xform */
-        struct xform sprite_xform_world = xform_mul(xform_world, child->sprite_xform);
-        child->sprite_xform_world = sprite_xform_world;
-
-        /* Append sub-children to stack */
-        struct entity *subchild = entity_from_handle(G.world.entity_store, child->last);
-        while (subchild->valid) {
-            *arena_push(scratch.arena, struct stack_node) = (struct stack_node) { .entity = subchild, .parent_xform_world = xform_world };
-            ++stack_count;
-            subchild = entity_from_handle(G.world.entity_store, subchild->prev);
-        }
-    }
-
-    scratch_end(scratch);
-}
-#else
-INTERNAL void recalculate_world_xforms_recurse(struct entity *ent)
-{
-    struct xform xform_global = entity_get_xform(ent);
-    //struct xform xform_local = entity_get_local_xform(ent);
-    (UNUSED)xform_global;
-    //(UNUSED)xform_local;
-
-    struct entity_store *store = G.world.entity_store;
-    struct xform sprite_global_xform = xform_mul(xform_global, ent->sprite_local_xform);
-    ent->sprite_global_xform = sprite_global_xform;
-    for (struct entity *child = entity_from_handle(store, ent->first); child->valid; child = entity_from_handle(store, child->next)) {
-        recalculate_world_xforms_recurse(child);
-    }
-}
-#endif
-
-
-
-
-
-
 INTERNAL void game_update(void)
 {
     __prof;
@@ -339,20 +271,13 @@ INTERNAL void game_update(void)
     /* ---------------------------------------------------------------------- */
     /* ---------------------------------------------------------------------- */
 
+    struct entity *root = entity_from_handle(store, store->root);
     struct entity_array entities_array = entity_store_as_array(store);
 
     /* ========================== *
      * Update sprite
      * ========================== */
 
-    /* Recalculate world xforms */
-    for (u64 entity_index = 0; entity_index < entities_array.count; ++entity_index) {
-        struct entity *ent = &entities_array.entities[entity_index];
-        if (ent->valid && ent->is_top) {
-            recalculate_world_xforms_recurse(ent);
-        }
-    }
-
     for (u64 entity_index = 0; entity_index < entities_array.count; ++entity_index) {
         struct entity *ent = &entities_array.entities[entity_index];
         if (!ent->valid) continue;
@@ -410,14 +335,6 @@ INTERNAL void game_update(void)
      * Update entities pre-physics
      * ========================== */
 
-    /* Recalculate world xforms */
-    for (u64 entity_index = 0; entity_index < entities_array.count; ++entity_index) {
-        struct entity *ent = &entities_array.entities[entity_index];
-        if (ent->valid && ent->is_top) {
-            recalculate_world_xforms_recurse(ent);
-        }
-    }
-
     /* Find active camera */
     struct entity *active_camera;
     {
@@ -540,14 +457,6 @@ INTERNAL void game_update(void)
      * Update entity physics
      * ========================== */
 
-    /* Recalculate world xforms */
-    for (u64 entity_index = 0; entity_index < entities_array.count; ++entity_index) {
-        struct entity *ent = &entities_array.entities[entity_index];
-        if (ent->valid && ent->is_top) {
-            recalculate_world_xforms_recurse(ent);
-        }
-    }
-
     for (u64 entity_index = 0; entity_index < entities_array.count; ++entity_index) {
         struct entity *ent = &entities_array.entities[entity_index];
         if (!ent->valid) continue;
@@ -587,14 +496,6 @@ INTERNAL void game_update(void)
      * Update entities post-physics
      * ========================== */
 
-    /* Recalculate world xforms */
-    for (u64 entity_index = 0; entity_index < entities_array.count; ++entity_index) {
-        struct entity *ent = &entities_array.entities[entity_index];
-        if (ent->valid && ent->is_top) {
-            recalculate_world_xforms_recurse(ent);
-        }
-    }
-
     for (u64 entity_index = 0; entity_index < entities_array.count; ++entity_index) {
         struct entity *ent = &entities_array.entities[entity_index];
         if (!ent->valid) continue;
@@ -666,12 +567,46 @@ INTERNAL void game_update(void)
      * Publish tick
      * ========================== */
 
-    /* Recalculate world xforms */
+    /* Update cached global xforms to ensure they're accurate in published tick */
-    for (u64 entity_index = 0; entity_index < entities_array.count; ++entity_index) {
+    {
-        struct entity *ent = &entities_array.entities[entity_index];
+        struct temp_arena temp = arena_temp_begin(scratch.arena);
-        if (ent->valid && ent->is_top) {
+
-            recalculate_world_xforms_recurse(ent);
+        struct stack_node {
+            struct entity *entity;
+            struct xform parent_global_xform;
+        };
+
+        /* Depth first iteration */
+        *arena_push(temp.arena, struct stack_node) = (struct stack_node) { .entity = root, .parent_global_xform = XFORM_IDENT };
+        u64 stack_count = 1;
+        while (stack_count > 0) {
+            /* Pull from top of stack */
+            struct stack_node node;
+            arena_pop(temp.arena, struct stack_node, &node);
+            --stack_count;
+
+            struct entity *child = node.entity;
+
+            /* Calculate world xform */
+            struct xform xf;
+            if (child->cached_global_xform_dirty) {
+                xf = xform_mul(node.parent_global_xform, child->local_xform);
+                child->cached_global_xform = xf;
+                child->cached_global_xform_dirty = false;
+            } else {
+                xf = child->cached_global_xform;
             }
+
+            /* Append sub-children to stack */
+            struct entity *subchild = entity_from_handle(store, child->last);
+            while (subchild->valid) {
+                *arena_push(temp.arena, struct stack_node) = (struct stack_node) { .entity = subchild, .parent_global_xform = xf };
+                ++stack_count;
+                subchild = entity_from_handle(store, subchild->prev);
+            }
+        }
+
+        arena_temp_end(temp);
     }
 
     /* Publish tick */

src/user.c

@@ -359,6 +359,10 @@ INTERNAL void debug_draw_xform(struct xform xf)
     struct v2 x_ray = xform_basis_mul_v2(G.world_view, xform_get_right(xf));
     struct v2 y_ray = xform_basis_mul_v2(G.world_view, xform_get_up(xf));
 
+    f32 ray_scale = 1;
+    x_ray = v2_mul(x_ray, ray_scale);
+    y_ray = v2_mul(y_ray, ray_scale);
+
     struct quad quad = quad_from_rect(RECT(0, 0, 1, -1));
     quad = quad_mul_xform(quad_scale(quad, 0.075f), xf);
 
@@ -454,6 +458,7 @@ INTERNAL void user_update(void)
                 struct entity *e0 = &t0_entities.entities[i];
                 struct entity *e1 = &t1_entities.entities[i];
                 struct entity *e = &world_entities.entities[i];
+                ASSERT(e->cached_global_xform_dirty == false);  /* Game thread should have cached all global xforms before publishing */
                 if (e0->handle.gen == e1->handle.gen && e0->continuity_gen == e1->continuity_gen) {
                     e->local_xform = xform_lerp(e0->local_xform, e1->local_xform, tick_blend);
                     e->cached_global_xform = xform_lerp(e0->cached_global_xform, e1->cached_global_xform, tick_blend);
@@ -464,7 +469,6 @@ INTERNAL void user_update(void)
                     e->focus = v2_lerp(e0->focus, e1->focus, tick_blend);
 
                     e->sprite_local_xform = xform_lerp(e0->sprite_local_xform, e1->sprite_local_xform, tick_blend);
-                    e->sprite_global_xform = xform_lerp(e0->sprite_global_xform, e1->sprite_global_xform, tick_blend);
                     e->animation_time_in_frame = math_lerp64(e0->animation_time_in_frame, e1->animation_time_in_frame, (f64)tick_blend);
                     e->animation_frame = (u32)math_round_to_int(math_lerp(e0->animation_frame, e1->animation_frame, tick_blend));
 
@@ -774,11 +778,16 @@ INTERNAL void user_update(void)
         b32 skip_debug_draw = !G.debug_camera && ent == active_camera;
         b32 skip_debug_draw_transform = entity_has_prop(ent, ENTITY_PROP_CAMERA);
 
+        struct xform sprite_xform = xf;
+
         /* Draw sprite */
         if (!sprite_tag_is_nil(ent->sprite)) {
-            struct sprite_tag sprite = ent->sprite;
+            /* Calculate sprite xform */
+            sprite_xform = xform_mul(xf, ent->sprite_local_xform);
+
 
             /* Async load */
+            struct sprite_tag sprite = ent->sprite;
             struct sprite_sheet *sheet = sprite_sheet_from_tag_async(sprite_frame_scope, sprite);
             struct sprite_texture *texture = sprite_texture_from_tag_async(sprite_frame_scope, sprite);
             (UNUSED)texture;
@@ -786,7 +795,7 @@ INTERNAL void user_update(void)
             /* TODO: Fade in placeholder if texture isn't loaded */
             if (sheet->loaded) {
                 struct sprite_sheet_frame frame = sprite_sheet_get_frame(sheet, ent->animation_frame);
-                struct quad quad = quad_mul_xform(QUAD_UNIT_SQUARE_CENTERED, ent->sprite_global_xform);
+                struct quad quad = quad_mul_xform(QUAD_UNIT_SQUARE_CENTERED, sprite_xform);
                 struct draw_sprite_params params = DRAW_SPRITE_PARAMS(.sprite = sprite, .tint = ent->sprite_tint, .clip = frame.clip);
                 draw_sprite_quad(G.world_canvas, params, quad);
             }
@@ -843,7 +852,7 @@ INTERNAL void user_update(void)
             if (entity_has_prop(ent, ENTITY_PROP_PLAYER_CONTROLLED)) {
                 struct sprite_sheet *sheet = sprite_sheet_from_tag_async(sprite_frame_scope, ent->sprite);
                 struct sprite_sheet_slice slice = sprite_sheet_get_slice(sheet, STR("hold"), ent->animation_frame);
-                struct v2 start = xform_mul_v2(ent->sprite_global_xform, slice.center);
+                struct v2 start = xform_mul_v2(sprite_xform, slice.center);
                 start = xform_mul_v2(G.world_view, start);
                 struct v2 end = v2_add(xf.og, ent->focus);
                 end = xform_mul_v2(G.world_view, end);
@@ -862,12 +871,12 @@ INTERNAL void user_update(void)
                     for (u32 j = 0; j < group->per_frame_count; ++j) {
                         struct sprite_sheet_slice slice = group->frame_slices[(ent->animation_frame * group->per_frame_count) + j];
 
-                        struct v2 center = xform_mul_v2(ent->sprite_global_xform, slice.center);
+                        struct v2 center = xform_mul_v2(sprite_xform, slice.center);
                         center = xform_mul_v2(G.world_view, center);
 
                         if (!slice.has_ray) {
                             struct quad quad = quad_from_rect(slice.rect);
-                            quad = quad_mul_xform(quad, ent->sprite_global_xform);
+                            quad = quad_mul_xform(quad, sprite_xform);
                             quad = quad_mul_xform(quad, G.world_view);
                             draw_solid_quad_line(G.viewport_canvas, quad, 2, RGBA_32_F(1, 0, 0.5, 1));
                         }
@@ -875,7 +884,7 @@ INTERNAL void user_update(void)
                         draw_solid_circle(G.viewport_canvas, center, 3, RGBA_32_F(1, 0, 0, 1), 20);
 
                         if (slice.has_ray) {
-                            struct v2 ray = xform_basis_mul_v2(ent->sprite_global_xform, slice.dir);
+                            struct v2 ray = xform_basis_mul_v2(sprite_xform, slice.dir);
                             ray = xform_basis_mul_v2(G.world_view, ray);
                             ray = v2_mul(v2_norm(ray), 25);
                             draw_solid_arrow_ray(G.viewport_canvas, center, ray, 2, 10, RGBA_32_F(1, 0, 0.5, 1));