src/engine/scene.c

   1 #include <stdlib.h>
   2
   3 #include "engine/logger.h"
   4
   5 #include "geometry.h"
   6 #include "scene.h"
   7
   8 Scene* currentScene = NULL;
   9
  10
  11
  12 Scene* newScene() {
  13         Scene* scene = malloc(sizeof(Scene));
  14         *scene = (Scene) { .parent = NULL,
  15                            .numChildren = 0u,
  16                            .children = NULL,
  17                            .transform = identity(),
  18                            .solid = NULL };
  19         return scene;
  20 }
  21
  22 void insertChildScene(Scene* scene, Scene* newChild) {
  23         if (!scene || !newChild) {
  24                 return;
  25         }
  26         if (newChild->parent) {
  27                 logError(
  28                         "Cannot insert scene 0x%p as child of 0x%p, because it is already child of 0x%p",
  29                         newChild,
  30                         scene,
  31                         newChild->parent);
  32                 return;
  33         }
  34
  35         scene->children = realloc(scene->children, ++(scene->numChildren) * sizeof(Scene*));
  36         scene->children[scene->numChildren - 1] = newChild;
  37
  38         newChild->parent = scene;
  39 }
  40
  41 void reparentScene(Scene* scene, Scene* newParent) {
  42         if (!scene) {
  43                 return;
  44         }
  45
  46         if (scene->parent) {
  47                 Scene* parent = scene->parent;
  48                 size_t indexInParent = parent->numChildren;
  49                 for (size_t i = 0; i < parent->numChildren; ++i) {
  50                         if (parent->children[i] == scene) {
  51                                 indexInParent = i;
  52                                 break;
  53                         }
  54                 }
  55                 // This includes the hopefully impossible case where parent->numChildren == 0
  56                 if (indexInParent == parent->numChildren) {
  57                         logError("Scene %p not found in children of parent %p", scene, parent);
  58                 }
  59                 else {
  60                         for (size_t i = indexInParent; i < parent->numChildren - 1; ++i) {
  61                                 parent->children[i] = parent->children[i + 1];
  62                         }
  63                         parent->children = realloc(parent->children, --(parent->numChildren) * sizeof(Scene*));
  64                 }
  65         }
  66
  67         scene->parent = NULL;
  68
  69         insertChildScene(newParent, scene);
  70 }