[scene] Add functions for scene and entity create/delete

Scene creation was already there, but now can be deleted, as can
entities.

include/QF/render.h

@@ -172,8 +172,8 @@ typedef struct renderer_s {
 
 typedef struct entity_s {
 	struct entity_s *next;
-
 	struct transform_s *transform;
+	int         id;		///< scene id
 	animation_t animation;
 	visibility_t visibility;
 	renderer_t  renderer;

include/QF/scene/scene.h

@@ -40,21 +40,16 @@
 */
 ///@{
 
-typedef struct hierarchyset_s DARRAY_TYPE (struct hierarchy_s *)
-	hierarchyset_t;
-typedef struct visibilityset_s DARRAY_TYPE (struct visibility_s *)
-	visibilityset_t;
-
 typedef struct scene_s {
 	struct scene_resources_s *const resources;
-	hierarchyset_t  roots;
-	xformset_t  transforms;
-	entityset_t entities;
-	visibilityset_t visibility;
+	xformset_t  roots;
 } scene_t;
 
 scene_t *Scene_NewScene (void);
+void Scene_DeleteScene (scene_t *scene);
 struct entity_s *Scene_CreateEntity (scene_t *scene);
+struct entity_s *Scene_GetEntity (scene_t *scene, int id);
+void Scene_DestroyEntity (scene_t *scene, struct entity_s *entity);
 void Scene_FreeAllEntities (scene_t *scene);
 
 

include/QF/scene/transform.h

@@ -43,10 +43,12 @@
 
 typedef struct transform_s {
 	struct hierarchy_s *hierarchy;
-	uint32_t    index;
+	uint32_t    index;	///< index in hierarchy
+	int32_t     id;		///< scene id
 } transform_t;
 
 transform_t *Transform_New (transform_t *parent);
+/* Deletes all child transforms, and transform names */
 void Transform_Delete (transform_t *transform);
 transform_t *Transform_NewNamed (transform_t *parent, const char *name);
 uint32_t Transform_ChildCount (const transform_t *transform) __attribute__((pure));

libs/scene/scene.c

@@ -36,6 +36,7 @@
 #endif
 
 #include "QF/progs.h"	// for PR_RESMAP
+#include "QF/sys.h"
 
 #include "QF/scene/entity.h"
 #include "QF/scene/scene.h"
@@ -56,34 +57,105 @@ Scene_NewScene (void)
 	*(scene_resources_t **)&scene->resources = res;
 
 	DARRAY_INIT (&scene->roots, 16);
-	DARRAY_INIT (&scene->transforms, 16);
-	DARRAY_INIT (&scene->entities, 16);
-	DARRAY_INIT (&scene->visibility, 16);
 
 	return scene;
 }
 
+void
+Scene_DeleteScene (scene_t *scene)
+{
+	Scene_FreeAllEntities (scene);
+
+	scene_resources_t *res = scene->resources;
+	for (unsigned i = 0; i < res->entities._size; i++) {
+		free (res->entities._map[i]);
+	}
+	free (res->entities._map);
+
+	DARRAY_CLEAR (&scene->roots);
+
+	free (scene->resources);
+	free (scene);
+}
+
 entity_t *
 Scene_CreateEntity (scene_t *scene)
 {
 	scene_resources_t *res = scene->resources;
 
 	entity_t   *ent = PR_RESNEW_NC (res->entities);
-	ent->transform = 0;
-	DARRAY_APPEND (&scene->entities, ent);
+	ent->transform = Transform_New (0);
+	ent->id = PR_RESINDEX (res->entities, ent);
+
+	hierarchy_t *h = ent->transform->hierarchy;
+	h->entity.a[ent->transform->index] = ent;
+
+	DARRAY_APPEND (&scene->roots, ent->transform);
 	return ent;
 }
 
+entity_t *
+Scene_GetEntity (scene_t *scene, int id)
+{
+	scene_resources_t *res = scene->resources;
+	return PR_RESGET (res->entities, id);
+}
+
+static void
+unroot_transform (scene_t *scene, transform_t *transform)
+{
+	if (!Transform_GetParent (transform)) {
+		for (size_t i = 0; i < scene->roots.size; i++) {
+			if (scene->roots.a[i] == transform) {
+				DARRAY_REMOVE_AT (&scene->roots, i);
+				break;
+			}
+		}
+	}
+}
+
+static void
+destroy_entity (scene_t *scene, entity_t *ent)
+{
+	scene_resources_t *res = scene->resources;
+	// ent->transform will be trampled by the loop below
+	transform_t *transform = ent->transform;
+
+	// Transform_Delete takes care of all hierarchy stuff (transforms
+	// themselves, name strings, hierarchy table)
+	hierarchy_t *h = transform->hierarchy;
+	for (size_t i = 0; i < h->entity.size; i++) {
+		entity_t   *e = h->entity.a[0];
+		e->transform = 0;
+		PR_RESFREE (res->entities, ent);
+	}
+	Transform_Delete (transform);
+}
+
+void
+Scene_DestroyEntity (scene_t *scene, entity_t *ent)
+{
+	scene_resources_t *res = scene->resources;
+
+	if (PR_RESGET (res->entities, ent->id) != ent) {
+		Sys_Error ("Scene_DestroyEntity: entity not owned by scene");
+	}
+	unroot_transform (scene, ent->transform);
+	// pull the transform out of the hierarchy to make it easier to destory
+	// all the child entities
+	Transform_SetParent (ent->transform, 0);
+	destroy_entity (scene, ent);
+}
+
 void
 Scene_FreeAllEntities (scene_t *scene)
 {
-	scene_resources_t *res = scene->resources;
-	for (size_t i = 0; i < scene->entities.size; i++) {
-		entity_t   *ent = scene->entities.a[i];
-		if (ent->transform) {
-			Transform_Delete (ent->transform);
-			ent->transform = 0;
-		}
+	for (size_t i = 0; i < scene->roots.size; i++) {
+		hierarchy_t *h = scene->roots.a[i]->hierarchy;
+		// deleting the root entity deletes all child entities
+		entity_t   *ent = h->entity.a[0];
+		destroy_entity (scene, ent);
 	}
+	scene_resources_t *res = scene->resources;
 	PR_RESRESET (res->entities);
 }