From 1afe4876cb8133c5b47fdcfeb07decc5565c4844 Mon Sep 17 00:00:00 2001
From: Omniscient <17525998+omnisci3nce@users.noreply.github.com>
Date: Sun, 17 Mar 2024 14:59:35 +1100
Subject: wip: transform propagation

---
 src/transform_hierarchy.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'src/transform_hierarchy.c')

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
-- 
cgit v1.2.3-70-g09d2