Implemented but didn't test the entity-untagging function and fixed a potentially unwanted behaviour when getting a tag's value.

core/src-c/entity_tagging.c

@@ -2,23 +2,29 @@
 #include <state.h>
 #include <stdlib.h>
 
-MtTag * mt_get_entity_tag_slot(MtEntity *entity, char *name)
+i16_t mt_get_entity_tag_slot_index(MtEntity *entity, const char *name)
 {
     MtState *state = entity->parent_state;
 
-    // Find the correct slot if it already exist
-
     u32_t tag_id = mt_get_tag_id(&state->tag_registry, name);
     usz_t tag_index = 0;
     while(tag_index < entity->num_tags)
     {
         if(entity->tags[tag_index].identifier == tag_id)
-            return &entity->tags[tag_index];
+            return tag_index;
 
         ++tag_index;
     }
+    return -1;
+}
 
-    // Create a new slot if needed
+MtTag * mt_get_entity_tag_slot(MtEntity *entity, char *name)
+{
+    i16_t tag_slot_index = mt_get_entity_tag_slot_index(entity, name);
+    if(tag_slot_index >= 0)
+        return &entity->tags[tag_slot_index];
+
+    // A new slot is needed
 
     if(entity->num_tags >= entity->tags_capacity)
     {
@@ -74,46 +80,97 @@ void mt_tag_vec4(MtEntity *entity, char *name, rr_vec4f_s vector)
 
 
 
-void mt_untag(MtEntity *entity, char *name);
+void mt_untag(MtEntity *entity, char *name)
+{
+    i64_t tag_slot_index = mt_get_entity_tag_slot_index(entity, name);
+    entity->tags[tag_slot_index] = entity->tags[entity->num_tags-1];
+    --entity->num_tags;
+}
+
+
 
 i64_t mt_get_i64_tag(MtEntity *entity, char *name)
 {
+    i16_t slot_index = mt_get_entity_tag_slot_index(entity, name);
+    if(slot_index < 0)
+        return 0;
+
     MtTag *tag = mt_get_entity_tag_slot(entity, name);
+    
     return tag->data.integer;
 }
 
 f64_t mt_get_f64_tag(MtEntity *entity, char *name)
 {
+    i16_t slot_index = mt_get_entity_tag_slot_index(entity, name);
+    if(slot_index < 0)
+        return 0.0f;
+    
     MtTag *tag = mt_get_entity_tag_slot(entity, name);
     return tag->data.real;
 }
 
 char * mt_get_str_tag(MtEntity *entity, char *name)
 {
+    i16_t slot_index = mt_get_entity_tag_slot_index(entity, name);
+    if(slot_index < 0)
+        return NULL;
+    
     MtTag *tag = mt_get_entity_tag_slot(entity, name);
     return tag->data.string;
 }
 
 void * mt_get_ptr_tag(MtEntity *entity, char *name)
 {
+    i16_t slot_index = mt_get_entity_tag_slot_index(entity, name);
+    if(slot_index < 0)
+        return NULL;
+    
     MtTag *tag = mt_get_entity_tag_slot(entity, name);
     return tag->data.pointer;
 }
 
 rr_vec2f_s mt_get_vec2_tag(MtEntity *entity, char *name)
 {
+    i16_t slot_index = mt_get_entity_tag_slot_index(entity, name);
+    if(slot_index < 0)
+    {
+        rr_vec2f_s err_vector;
+        err_vector.x = 0.0f;
+        err_vector.y = 0.0f;
+        return err_vector;
+    }
     MtTag *tag = mt_get_entity_tag_slot(entity, name);
     return tag->data.vec2f;
 }
 
 rr_vec3f_s mt_get_vec3_tag(MtEntity *entity, char *name)
 {
+    i16_t slot_index = mt_get_entity_tag_slot_index(entity, name);
+    if(slot_index < 0)
+    {
+        rr_vec3f_s err_vector;
+        err_vector.x = 0.0f;
+        err_vector.y = 0.0f;
+        err_vector.z = 0.0f;
+        return err_vector;
+    }
     MtTag *tag = mt_get_entity_tag_slot(entity, name);
     return tag->data.vec3f;
 }
 
 rr_vec4f_s mt_get_vec4_tag(MtEntity *entity, char *name)
 {
+    i16_t slot_index = mt_get_entity_tag_slot_index(entity, name);
+    if(slot_index < 0)
+    {
+        rr_vec4f_s err_vector;
+        err_vector.x = 0.0f;
+        err_vector.y = 0.0f;
+        err_vector.z = 0.0f;
+        err_vector.w = 0.0f;
+        return err_vector;
+    }
     MtTag *tag = mt_get_entity_tag_slot(entity, name);
     return tag->data.vec4f;
 }