src/game/level/level_editor/undo_history.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3
   4 #include <SDL.h>
   5
   6 #include "system/nth_alloc.h"
   7 #include "system/lt.h"
   8 #include "system/stacktrace.h"
   9 #include "undo_history.h"
  10 #include "config.h"
  11
  12 typedef struct {
  13     RevertAction revert;
  14     void *context_data;
  15     size_t context_data_size;
  16 } HistoryItem;
  17
  18 static
  19 void undo_history_destroy_item(void *item)
  20 {
  21     free(((HistoryItem*)item)->context_data);
  22 }
  23
  24 UndoHistory create_undo_history(void)
  25 {
  26     UndoHistory result;
  27     result.actions = create_ring_buffer(
  28         sizeof(HistoryItem),
  29         UNDO_HISTORY_CAPACITY,
  30         undo_history_destroy_item);
  31     return result;
  32 }
  33
  34 void undo_history_push(UndoHistory *undo_history,
  35                        RevertAction revert,
  36                        void *context_data,
  37                        size_t context_data_size)
  38 {
  39     trace_assert(undo_history);
  40
  41     HistoryItem item = {
  42         .revert = revert,
  43         .context_data = malloc(context_data_size),
  44         .context_data_size = context_data_size
  45     };
  46     trace_assert(item.context_data);
  47     memcpy(item.context_data, context_data, context_data_size);
  48
  49     ring_buffer_push(&undo_history->actions, &item);
  50 }
  51
  52 void undo_history_pop(UndoHistory *undo_history)
  53 {
  54     trace_assert(undo_history);
  55
  56     if (undo_history->actions.count > 0) {
  57         HistoryItem *item = ring_buffer_top(&undo_history->actions);
  58         item->revert(item->context_data, item->context_data_size);
  59         ring_buffer_pop(&undo_history->actions);
  60     }
  61 }