Scene tree

src/scene/scenetree.h

@@ -0,0 +1,91 @@
+/**
+ * Copyright (c) 2025 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "ecs/ecs.h"
+
+#define SCENE_ITEM_CHILD_MAX 16
+
+typedef struct {
+  ecsentityid_t children[SCENE_ITEM_CHILD_MAX];
+  uint8_t childCount;
+  ecsentityid_t parent;
+} scenetreenode_t;
+
+typedef struct scene_s {
+  scenetreenode_t items[ECS_ENTITY_COUNT_MAX];
+} scenetree_t;
+
+extern scenetree_t SCENE_TREE;
+
+/**
+ * Initialize the scene tree.
+ * 
+ * This will initialize the ECS system and prepare the scene tree for use.
+ */
+void sceneTreeInit(void);
+
+/**
+ * Create a new scene item in the scene tree.
+ * This will create a new entity in the ECS and return its ID.
+ * 
+ * @return The ID of the newly created scene item.
+ */
+ecsentityid_t sceneTreeCreate(void);
+
+/**
+ * Get the parent of a given scene item.
+ * 
+ * @param id The ID of the scene item.
+ * @return The ID of the parent scene item, or -1 if it has no parent.
+ */
+ecsentityid_t sceneTreeParentGet(const ecsentityid_t child);
+
+/**
+ * Get the children of a given scene item. If children is NULL only the count
+ * will be returned.
+ * 
+ * @param id The ID of the scene item.
+ * @param children Pointer to an array where the children IDs will be stored.
+ * @return The number of children found.
+ */
+uint8_t sceneTreeChildGetAll(const ecsentityid_t id, ecsentityid_t *children);
+
+/**
+ * Add a child to a parent in the scene tree.
+ * 
+ * @param parent The ID of the parent scene item.
+ * @param child The ID of the child scene item to add.
+ */
+void sceneTreeChildAdd(const ecsentityid_t parent, const ecsentityid_t child);
+
+/**
+ * Remove a child from a parent in the scene tree.
+ * 
+ * @param prnt The ID of the parent scene item.
+ * @param child The ID of the child scene item to remove.
+ */
+void sceneTreeChildRemove(const ecsentityid_t prnt, const ecsentityid_t child);
+
+/**
+ * Remove all children from a parent in the scene tree.
+ * 
+ * @param parent The ID of the parent scene item.
+ */
+void sceneTreeChildRemoveAll(const ecsentityid_t parent);
+
+/**
+ * Returns true if the child is within the parent's children, recursively.
+ * 
+ * @param parent The ID of the parent scene item.
+ * @param child The ID of the child scene item to check.
+ * @return True if the child is in the parent's children, false otherwise.
+ */
+bool_t sceneTreeChildInTree(
+  const ecsentityid_t parent,
+  const ecsentityid_t child
+);