From 09e52d007a95c572b90d76e5d489aff8c0f0594a Mon Sep 17 00:00:00 2001
From: Sara <sara@saragerretsen.nl>
Date: Fri, 13 Sep 2024 11:28:02 +0200
Subject: [PATCH] fix: transform updating is now _actually_ recursive through
 the whole tree

---
 src/core/scene.c         | 51 +++++++++++++++++++++++-----------------
 src/core/transformable.h |  5 ++--
 2 files changed, 31 insertions(+), 25 deletions(-)

diff --git a/src/core/scene.c b/src/core/scene.c
index d53d542..c29477a 100644
--- a/src/core/scene.c
+++ b/src/core/scene.c
@@ -5,6 +5,29 @@
 #include "utils/drop.h"
 #include "utils/mirror.h"
 
+//! Tick a node and all children recursively
+static
+void Internal_SceneNodeTick(SceneNode *self, double delta) {
+    // tick self first
+    self->entity.tc->tick(self->entity.data, delta);
+    // fix the number of elements to update now,
+    // so that if/when new children are added, they don't get ticked until next frame
+    size_t const len = self->children.len;
+    for(size_t i = 0; i < len; ++i)
+        Internal_SceneNodeTick(*list_at_as(SceneNode*, &self->children, i), delta);
+}
+
+//! Update global transform of a node
+static
+void Internal_SceneNodeUpdateTransform(SceneNode *self) {
+    if(TC_MIRRORS(self->entity, Transformable)) {
+        Transformable transformable = TC_CAST(self->entity, Transformable);
+        if(transformable.tc->get_dirty_bit(transformable.data)) {
+            transformable.tc->force_update(transformable.data);
+        }
+    }
+}
+
 //! Remove a single node (does NOT recurse to children children) from this scene.
 static
 void Internal_SceneRemoveNode(Scene *self, SceneNode *node) {
@@ -44,34 +67,18 @@ void Internal_SceneAddNode(Scene *self, SceneNode *node) {
     list_add(&self->nodes, &node);
     // establish two-way relationship
     Internal_SceneNodeSetScene(node, self);
+    Internal_SceneNodeUpdateTransform(node);
     // do the same for all children (and their children) recursively
     list_foreach(SceneNode **,child, &node->children)
         Internal_SceneAddNode(self, *child);
 }
 
-//! Tick a node and all children recursively
-static
-void Internal_SceneNodeTick(SceneNode *self, double delta) {
-    // tick self first
-    self->entity.tc->tick(self->entity.data, delta);
-    // fix the number of elements to update now,
-    // so that if/when new children are added, they don't get ticked until next frame
-    size_t const len = self->children.len;
-    for(size_t i = 0; i < len; ++i)
-        Internal_SceneNodeTick(*list_at_as(SceneNode*, &self->children, i), delta);
-}
-
 //! Update global transforms of all children recursively
 static
-void Internal_SceneNodeUpdateTransform(SceneNode *self) {
-    if(TC_MIRRORS(self->entity, Transformable)) {
-        Transformable transformable = TC_CAST(self->entity, Transformable);
-        if(transformable.tc->get_dirty_bit(transformable.data)) {
-            transformable.tc->force_update(transformable.data);
-        }
-    }
+void Internal_SceneNodeUpdateTransformRecursive(SceneNode *self) {
+    Internal_SceneNodeUpdateTransform(self);
     list_foreach(SceneNode **,child, &self->children)
-        Internal_SceneNodeUpdateTransform(*child);
+        Internal_SceneNodeUpdateTransformRecursive(*child);
 }
 
 SceneNode *CreateSceneNode(SceneNodeEntity entity) {
@@ -159,12 +166,12 @@ Scene *CreateScene(SceneNode *root) {
 }
 
 void DestroyScene(Scene *self) {
-    DestroySceneNode(self->root);
+    DestroySceneNode(self->root); // recurses to the rest of the scene
     list_empty(&self->nodes);
     free(self);
 }
 
 void SceneTick(Scene* self, double delta_time) {
     Internal_SceneNodeTick(self->root, delta_time);
-    Internal_SceneNodeUpdateTransform(self->root);
+    Internal_SceneNodeUpdateTransformRecursive(self->root);
 }
diff --git a/src/core/transformable.h b/src/core/transformable.h
index 294d98d..097eece 100644
--- a/src/core/transformable.h
+++ b/src/core/transformable.h
@@ -58,16 +58,15 @@ extern Transform InverseTransformTransform(Transform const *self, Transform cons
 //! Macro implements the interface functions itself to ensure consistent behaviour.
 #define impl_Transformable_for(T)\
 static Transform T##_get_transform_GEN_(T* self) { return self->transform; }\
-static void T##_set_transform_GEN_(T* self, Transform value) { self->transform = value; self->dirty_bit |= 0x1; } /*!< sets local dirty bit */\
+static void T##_set_transform_GEN_(T* self, Transform value) { self->transform = value; self->dirty_bit |= 1u; } /*!< sets dirty bit */\
 static Transform T##_get_global_transform_GEN_(T* self) { return self->global_transform; }\
 static void T##_set_global_transform_GEN_(T* self, Transform value) {\
     self->global_transform = value;\
     if(tc_is_null(self->parent_transformable)) {\
         self->transform = value;\
     } else {\
-        self->parent_transformable.tc->force_update(self->parent_transformable.data); /* Force a transform update for the parent, to ensure its global transform is up-to-date */\
         Transform parent_global = self->parent_transformable.tc->get_global_transform(self->parent_transformable.data);\
-        self->transform = InverseTransformTransform(&parent_global, &value); /* Use up-to-date parent transform to get the local transform to the new global transform */\
+        self->transform = InverseTransformTransform(&parent_global, &value); /* Use parent transform to transform the local transform to the new global transform */\
     }\
 }\
 static void T##_force_update_GEN_(T *self) {\