From ac8cacd2fce568025817034a760f50df05596ff7 Mon Sep 17 00:00:00 2001
From: Sara <sara@saragerretsen.nl>
Date: Sat, 25 Nov 2023 11:33:11 +0100
Subject: [PATCH] feat(render): added render depth to behaviour entities

---
 core/src/behaviour_entity.h |  5 ++++-
 core/src/game_world.c       | 24 +++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/core/src/behaviour_entity.h b/core/src/behaviour_entity.h
index e9d5938..c5b8391 100644
--- a/core/src/behaviour_entity.h
+++ b/core/src/behaviour_entity.h
@@ -9,6 +9,7 @@ typedef struct {
     void (*const update)(void* self, float dt);
     void (*const start)(void* self);
     void (*const draw)(void* self);
+    long (*const get_depth)(void* self);
 } IEntityBehaviour;
 
 typedef struct {
@@ -17,15 +18,17 @@ typedef struct {
     IDrop const* drop;
 } BehaviourEntity;
 
-#define impl_BehaviourEntity_for(T, start_f, update_f, draw_f)\
+#define impl_BehaviourEntity_for(T, start_f, update_f, draw_f, get_depth_f)\
 static inline BehaviourEntity T##_as_BehaviourEntity(T* x) {\
     TC_FN_TYPECHECK(void, start_f, T*);\
     TC_FN_TYPECHECK(void, update_f, T*, float);\
     TC_FN_TYPECHECK(void, draw_f, T*);\
+    TC_FN_TYPECHECK(long, get_depth_f, T*);\
     static IEntityBehaviour const tc = {\
         .update =  (void(*const)(void*, float))  update_f,\
         .start =   (void(*const)(void*))         start_f,\
         .draw =    (void(*const)(void*))         draw_f,\
+        .get_depth=(long(*const)(void*))         get_depth_f,\
     };\
     TC_FN_TYPECHECK(Drop, T##_as_Drop, T*);\
     IDrop const* drop = T##_as_Drop(x).tc;\
diff --git a/core/src/game_world.c b/core/src/game_world.c
index b93a029..8c83b08 100644
--- a/core/src/game_world.c
+++ b/core/src/game_world.c
@@ -3,6 +3,7 @@
 #include "behaviour_entity.h"
 #include "list.h"
 #include "program.h"
+#include "debug.h"
 
 static List _add_queue;
 static List _remove_queue;
@@ -73,8 +74,29 @@ void game_world_update() {
     _internal_clear_removed();
 }
 
+static
+int _internal_compare_depth(const BehaviourEntity* a, const BehaviourEntity* b) {
+    return b->tc->get_depth(b->data) - a->tc->get_depth(a->data);
+}
+
+#define AS_COMPARISON(__FN) ((int(*)(const void*, const void*))__FN)
+
 void game_world_draw() {
-    list_foreach(BehaviourEntity*, entity, &_game_entities) {
+    List draw_order = list_copy(&_game_entities);
+    
+    LOG_INFO("before");
+    list_foreach(BehaviourEntity*, entity, &draw_order) {
+        LOG_INFO("Entity: %p depth %d", entity->data, entity->tc->get_depth(entity->data));
+    }
+
+    qsort(_game_entities.data, _game_entities.len, _game_entities.element_size,
+        AS_COMPARISON(_internal_compare_depth));
+
+    LOG_INFO("after");
+    list_foreach(BehaviourEntity*, entity, &draw_order) {
+        LOG_INFO("Entity: %p depth %d", entity->data, entity->tc->get_depth(entity->data));
         entity->tc->draw(entity->data);
     }
+    
+    list_empty(&draw_order);
 }