wip: transform propagation

3 files changed, 35 insertions, 4 deletions

diff --git a/src/maths/maths.h b/src/maths/maths.h
index d832739..390b611 100644
--- a/src/maths/maths.h
+++ b/src/maths/maths.h
@@ -207,8 +207,10 @@ static transform transform_create(vec3 pos, quat rot, f32 scale) {
 }
 
 static inline mat4 transform_to_mat(transform *tf) {
-  // TODO: rotation
-  return mat4_mult(mat4_translation(tf->position), mat4_scale(tf->scale));
+  mat4 trans = mat4_translation(tf->position);
+  mat4 rot = mat4_rotation(tf->rotation);
+  mat4 scale = mat4_scale(tf->scale);
+  return mat4_mult(trans, mat4_mult(rot, scale));
 }
 
 // --- Sizing asserts
diff --git a/src/transform_hierarchy.c b/src/transform_hierarchy.c
index 25ace6c..468be56 100644
--- a/src/transform_hierarchy.c
+++ b/src/transform_hierarchy.c
@@ -117,4 +117,31 @@ void transform_hierarchy_dfs(transform_node* start_node,
     // post-order
     visit_node(start_node, ctx_data);
   }
+}
+
+// Update matrix for the current node
+bool update_matrix(transform_node* node, void* _ctx_data) {
+  if (!node) return true;  // leaf node
+
+  if (node->parent->tf.is_dirty) {
+    node->tf.is_dirty = true;
+  }
+
+  if (node->tf.is_dirty) {
+    // invalidates children
+    mat4 updated_local_transform = transform_to_mat(&node->tf);
+    node->local_matrix_tf = updated_local_transform;
+    if (node->parent) {
+      mat4 updated_world_transform =
+          mat4_mult(node->parent->world_matrix_tf, updated_local_transform);
+      node->world_matrix_tf = updated_world_transform;
+    }
+  }
+
+  return true;
+}
+
+void transform_hierarchy_propagate_transforms(transform_hierarchy* tfh) {
+  // kickoff traversal
+  transform_hierarchy_dfs(&tfh->root, update_matrix, false, NULL);
 }
\ No newline at end of file
diff --git a/src/transform_hierarchy.h b/src/transform_hierarchy.h
index 703baa8..9af8a97 100644
--- a/src/transform_hierarchy.h
+++ b/src/transform_hierarchy.h
@@ -58,8 +58,10 @@ void transform_hierarchy_delete_node(transform_node* node);
  * @param ctx_data An optional pointer to data that is be passed on each call to `visit_node`. Can be used to carry additional information or context.
  *
  * @note The main use-cases are:
-            1. traversing the whole tree to update cached 4x4 affine transform matrices (pre-order)
+            1. traversing the whole tree to update cached 4x4 affine transform matrices (post-order)
             2. freeing child nodes after deleting a node in the tree (post-order)
             3. debug pretty printing the whole tree (post-order)
  */
-void transform_hierarchy_dfs(transform_node* start_node, bool (*visit_node)(transform_node* node, void* ctx_data), bool is_pre_order, void* ctx_data);
\ No newline at end of file
+void transform_hierarchy_dfs(transform_node* start_node, bool (*visit_node)(transform_node* node, void* ctx_data), bool is_pre_order, void* ctx_data);
+
+void transform_hierarchy_debug_print(transform_node* start_node, )
\ No newline at end of file