universe@21: /*
universe@21:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@21:  * Copyright 2023 Mike Becker. All rights reserved.
universe@21:  *
universe@21:  * Redistribution and use in source and binary forms, with or without
universe@21:  * modification, are permitted provided that the following conditions are met:
universe@21:  *
universe@21:  *   1. Redistributions of source code must retain the above copyright
universe@21:  *      notice, this list of conditions and the following disclaimer.
universe@21:  *
universe@21:  *   2. Redistributions in binary form must reproduce the above copyright
universe@21:  *      notice, this list of conditions and the following disclaimer in the
universe@21:  *      documentation and/or other materials provided with the distribution.
universe@21:  *
universe@21:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@21:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@21:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@21:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@21:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@21:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@21:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@21:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@21:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@21:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@21:  * POSSIBILITY OF SUCH DAMAGE.
universe@21:  */
universe@21: 
universe@21: #include "ascension/scene.h"
universe@21: #include "ascension/error.h"
universe@21: 
universe@29: #include <cx/tree.h>
universe@29: 
universe@21: #include <assert.h>
universe@21: 
universe@30: #define node_layout_ \
universe@29:     offsetof(AscSceneNode, parent), offsetof(AscSceneNode, children), \
universe@29:     offsetof(AscSceneNode, prev), offsetof(AscSceneNode, next)
universe@30: #define child_list_off_ \
universe@30:     offsetof(AscSceneNode, children), offsetof(AscSceneNode, next)
universe@29: 
universe@21: void asc_scene_init(AscScene *scene) {
universe@21:     if (scene->root != NULL) {
universe@21:         asc_error("Scene is already initialized.");
universe@21:         return;
universe@21:     }
universe@29:     scene->root = asc_scene_node_empty();
universe@21: }
universe@21: 
universe@21: void asc_scene_destroy(AscScene *scene) {
universe@21:     asc_scene_node_free(scene->root);
universe@21: }
universe@21: 
universe@29: void asc_scene_add(AscScene *scene, AscSceneNode *node) {
universe@29:     asc_scene_node_link(scene->root, node);
universe@29: }
universe@29: 
universe@30: void asc_scene_draw(AscScene const *scene) {
universe@30:     // TODO: don't visit the tree, visit the render groups
universe@30:     CxTreeIterator iter = cx_tree_iterator(scene->root, false, child_list_off_);
universe@30:     cx_foreach(AscSceneNode*, node, iter) {
universe@30:         if (node->draw_func != NULL) {
universe@30:             node->draw_func(node);
universe@30:         }
universe@29:     }
universe@29: }
universe@29: 
universe@29: AscSceneNode *asc_scene_node_empty(void) {
universe@27:     // TODO: check if this can remain a calloc or if it's too expensive
universe@27:     AscSceneNode *node = calloc(1, sizeof(AscSceneNode));
universe@21:     assert(node != NULL);
universe@29:     node->free_func = (asc_scene_free_func) free;
universe@21:     return node;
universe@21: }
universe@21: 
universe@21: void asc_scene_node_free(AscSceneNode *node) {
universe@21:     if (node == NULL) return;
universe@27: 
universe@27:     // remove this node from its parent
universe@27:     asc_scene_node_unlink(node);
universe@27: 
universe@31:     // free the entire subtree
universe@31:     CxTreeIterator iter = cx_tree_iterator(node, true, child_list_off_);
universe@31:     cx_foreach(AscSceneNode*, child, iter) {
universe@31:         if (!iter.exiting) continue;
universe@31:         if (child->free_func != NULL) {
universe@31:             child->free_func(child);
universe@31:         } else {
universe@31:             free(child);
universe@31:         }
universe@21:     }
universe@21: }
universe@21: 
universe@29: void asc_scene_node_link(AscSceneNode * restrict parent, AscSceneNode * restrict node) {
universe@30:     cx_tree_link(parent, node, node_layout_);
universe@29: }
universe@29: 
universe@21: void asc_scene_node_unlink(AscSceneNode *node) {
universe@30:     cx_tree_unlink(node, node_layout_);
universe@21: }