gpencil_undo.c

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/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2011 Blender Foundation.
 * All rights reserved.
 */
 
#include <stdlib.h>
#include <string.h>
 
#include "MEM_guardedalloc.h"
 
#include "DNA_gpencil_types.h"
#include "DNA_listBase.h"
#include "DNA_object_types.h"
#include "DNA_windowmanager_types.h"
 
#include "BLI_listbase.h"
 
#include "BKE_blender_undo.h"
#include "BKE_context.h"
#include "BKE_gpencil.h"
#include "BKE_undo_system.h"
 
#include "ED_gpencil.h"
 
#include "WM_api.h"
#include "WM_types.h"
 
#include "DEG_depsgraph.h"
 
#include "gpencil_intern.h"
 
typedef struct bGPundonode {
  struct bGPundonode *next, *prev;
 
  char name[BKE_UNDO_STR_MAX];
  struct bGPdata *gpd;
} bGPundonode;
 
static ListBase undo_nodes = {NULL, NULL};
static bGPundonode *cur_node = NULL;
 
int ED_gpencil_session_active(void)
{
  return (BLI_listbase_is_empty(&undo_nodes) == false);
}
 
int ED_undo_gpencil_step(bContext *C, const int step)
{
  bGPdata **gpd_ptr = NULL, *new_gpd = NULL;
 
  gpd_ptr = ED_gpencil_data_get_pointers(C, NULL);
 
  const eUndoStepDir undo_step = (eUndoStepDir)step;
  if (undo_step == STEP_UNDO) {
    if (cur_node->prev) {
      cur_node = cur_node->prev;
      new_gpd = cur_node->gpd;
    }
  }
  else if (undo_step == STEP_REDO) {
    if (cur_node->next) {
      cur_node = cur_node->next;
      new_gpd = cur_node->gpd;
    }
  }
 
  if (new_gpd) {
    if (gpd_ptr) {
      if (*gpd_ptr) {
        bGPdata *gpd = *gpd_ptr;
        bGPDlayer *gpld;
 
        BKE_gpencil_free_layers(&gpd->layers);
 
        /* copy layers */
        BLI_listbase_clear(&gpd->layers);
 
        LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
          /* make a copy of source layer and its data */
          gpld = BKE_gpencil_layer_duplicate(gpl, true, true);
          BLI_addtail(&gpd->layers, gpld);
        }
      }
    }
    /* drawing batch cache is dirty now */
    DEG_id_tag_update(&new_gpd->id, ID_RECALC_TRANSFORM | ID_RECALC_GEOMETRY);
    new_gpd->flag |= GP_DATA_CACHE_IS_DIRTY;
  }
 
  WM_event_add_notifier(C, NC_GPENCIL | NA_EDITED, NULL);
 
  return OPERATOR_FINISHED;
}
 
void gpencil_undo_init(bGPdata *gpd)
{
  gpencil_undo_push(gpd);
}
 
static void gpencil_undo_free_node(bGPundonode *undo_node)
{
  /* HACK: animdata wasn't duplicated, so it shouldn't be freed here,
   * or else the real copy will segfault when accessed
   */
  undo_node->gpd->adt = NULL;
 
  BKE_gpencil_free(undo_node->gpd, false);
  MEM_freeN(undo_node->gpd);
}
 
void gpencil_undo_push(bGPdata *gpd)
{
  bGPundonode *undo_node;
 
  // printf("\t\tGP - undo push\n");
 
  if (cur_node) {
    /* Remove all undone nodes from stack. */
    undo_node = cur_node->next;
 
    while (undo_node) {
      bGPundonode *next_node = undo_node->next;
 
      gpencil_undo_free_node(undo_node);
      BLI_freelinkN(&undo_nodes, undo_node);
 
      undo_node = next_node;
    }
  }
 
  /* limit number of undo steps to the maximum undo steps
   * - to prevent running out of memory during **really**
   *   long drawing sessions (triggering swapping)
   */
  /* TODO: Undo-memory constraint is not respected yet,
   * but can be added if we have any need for it. */
  if (U.undosteps && !BLI_listbase_is_empty(&undo_nodes)) {
    /* remove anything older than n-steps before cur_node */
    int steps = 0;
 
    undo_node = (cur_node) ? cur_node : undo_nodes.last;
    while (undo_node) {
      bGPundonode *prev_node = undo_node->prev;
 
      if (steps >= U.undosteps) {
        gpencil_undo_free_node(undo_node);
        BLI_freelinkN(&undo_nodes, undo_node);
      }
 
      steps++;
      undo_node = prev_node;
    }
  }
 
  /* create new undo node */
  undo_node = MEM_callocN(sizeof(bGPundonode), "gpencil undo node");
  undo_node->gpd = BKE_gpencil_data_duplicate(NULL, gpd, true);
 
  cur_node = undo_node;
 
  BLI_addtail(&undo_nodes, undo_node);
}
 
void gpencil_undo_finish(void)
{
  bGPundonode *undo_node = undo_nodes.first;
 
  while (undo_node) {
    gpencil_undo_free_node(undo_node);
    undo_node = undo_node->next;
  }
 
  BLI_freelistN(&undo_nodes);
 
  cur_node = NULL;
}