src/scene.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * Copyright 2023 Mike Becker. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "ascension/scene.h"
#include "ascension/error.h"

#include <cx/linked_list.h>
#include <assert.h>

void asc_scene_init(AscScene *scene) {
    if (scene->root != NULL) {
        asc_error("Scene is already initialized.");
        return;
    }
    scene->root = asc_scene_node_create(NULL);
}

void asc_scene_destroy(AscScene *scene) {
    asc_scene_node_free(scene->root);
}

AscSceneNode *asc_scene_node_create(AscSceneNode *parent) {
    AscSceneNode *node = malloc(sizeof(AscSceneNode));
    assert(node != NULL);
    node->children = cxLinkedListCreateSimple(CX_STORE_POINTERS);
    assert(node->children != NULL);
    node->parent = NULL;
    asc_scene_node_link(node, parent);
    return node;
}

void asc_scene_node_free(AscSceneNode *node) {
    if (node == NULL) return;
    while (cxListSize(node->children) > 0) {
        AscSceneNode *child = cxListAt(node->children, 0);
        asc_scene_node_free(child);
    }
    if (node->parent != NULL) {
        cxListFindRemove(node->parent->children, node);
    }
    free(node);
}

void asc_scene_node_link(
        AscSceneNode *node,
        AscSceneNode *parent
) {
    if (node->parent == parent) return;
    if (node->parent != NULL || parent == NULL) asc_scene_node_unlink(node);
    if (parent != NULL) {
        cxListAdd(parent->children, node);
        node->parent = parent;
    }
}

void asc_scene_node_unlink(AscSceneNode *node) {
    if (node->parent == NULL) return;
    cxListFindRemove(node->parent->children, node);
    node->parent = NULL;
}