editmode_undo.c

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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) 2004 Blender Foundation
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "MEM_guardedalloc.h"

#include "DNA_object_types.h"
#include "DNA_screen_types.h"

#include "BLI_blenlib.h"
#include "BLI_dynstr.h"
#include "BLI_utildefines.h"


#include "BKE_context.h"
#include "BKE_depsgraph.h"
#include "BKE_global.h"

#include "ED_util.h"
#include "ED_mesh.h"

#include "UI_interface.h"
#include "UI_resources.h"

#include "util_intern.h"

/* ***************** generic editmode undo system ********************* */
/*

Add this in your local code:

void undo_editmode_push(bContext *C, const char *name, 
        void * (*getdata)(bContext *C),     // use context to retrieve current editdata
        void (*freedata)(void *),           // pointer to function freeing data
        void (*to_editmode)(void *, void *),        // data to editmode conversion
        void * (*from_editmode)(void *))      // editmode to data conversion
        int  (*validate_undo)(void *, void *))      // check if undo data is still valid


Further exported for UI is:

void undo_editmode_step(bContext *C, int step);  // undo and redo
void undo_editmode_clear(void)              // free & clear all data
void undo_editmode_menu(void)               // history menu


*/
/* ********************************************************************* */

/* ****** XXX ***** */
static void error(const char *UNUSED(arg)) {}
/* ****** XXX ***** */


#define MAXUNDONAME 64
typedef struct UndoElem {
    struct UndoElem *next, *prev;
    ID id;          // copy of editmode object ID
    Object *ob;     // pointer to edited object
    int type;       // type of edited object
    void *undodata;
    uintptr_t undosize;
    char name[MAXUNDONAME];
    void * (*getdata)(bContext *C);
    void (*freedata)(void *);
    void (*to_editmode)(void *, void *);
    void * (*from_editmode)(void *);
    int (*validate_undo)(void *, void *);
} UndoElem;

static ListBase undobase={NULL, NULL};
static UndoElem *curundo= NULL;


/* ********************* xtern api calls ************* */

static void undo_restore(UndoElem *undo, void *editdata)
{
    if(undo) {
        undo->to_editmode(undo->undodata, editdata);    
    }
}

/* name can be a dynamic string */
void undo_editmode_push(bContext *C, const char *name, 
                        void * (*getdata)(bContext *C),
                        void (*freedata)(void *), 
                        void (*to_editmode)(void *, void *),  
                        void *(*from_editmode)(void *),
                        int (*validate_undo)(void *, void *))
{
    UndoElem *uel;
    Object *obedit= CTX_data_edit_object(C);
    void *editdata;
    int nr;
    uintptr_t memused, totmem, maxmem;

    /* at first here was code to prevent an "original" key to be insterted twice
       this was giving conflicts for example when mesh changed due to keys or apply */
    
    /* remove all undos after (also when curundo==NULL) */
    while(undobase.last != curundo) {
        uel= undobase.last;
        uel->freedata(uel->undodata);
        BLI_freelinkN(&undobase, uel);
    }
    
    /* make new */
    curundo= uel= MEM_callocN(sizeof(UndoElem), "undo editmode");
    BLI_strncpy(uel->name, name, sizeof(uel->name));
    BLI_addtail(&undobase, uel);
    
    uel->getdata= getdata;
    uel->freedata= freedata;
    uel->to_editmode= to_editmode;
    uel->from_editmode= from_editmode;
    uel->validate_undo= validate_undo;
    
    /* limit amount to the maximum amount*/
    nr= 0;
    uel= undobase.last;
    while(uel) {
        nr++;
        if(nr==U.undosteps) break;
        uel= uel->prev;
    }
    if(uel) {
        while(undobase.first!=uel) {
            UndoElem *first= undobase.first;
            first->freedata(first->undodata);
            BLI_freelinkN(&undobase, first);
        }
    }

    /* copy  */
    memused= MEM_get_memory_in_use();
    editdata= getdata(C);
    curundo->undodata= curundo->from_editmode(editdata);
    curundo->undosize= MEM_get_memory_in_use() - memused;
    curundo->ob= obedit;
    curundo->id= obedit->id;
    curundo->type= obedit->type;

    if(U.undomemory != 0) {
        /* limit to maximum memory (afterwards, we can't know in advance) */
        totmem= 0;
        maxmem= ((uintptr_t)U.undomemory)*1024*1024;

        uel= undobase.last;
        while(uel && uel->prev) {
            totmem+= uel->undosize;
            if(totmem>maxmem) break;
            uel= uel->prev;
        }

        if(uel) {
            if(uel->prev && uel->prev->prev)
                uel= uel->prev;

            while(undobase.first!=uel) {
                UndoElem *first= undobase.first;
                first->freedata(first->undodata);
                BLI_freelinkN(&undobase, first);
            }
        }
    }
}

/* helper to remove clean other objects from undo stack */
static void undo_clean_stack(bContext *C)
{
    UndoElem *uel, *next;
    Object *obedit= CTX_data_edit_object(C);
    
    /* global undo changes pointers, so we also allow identical names */
    /* side effect: when deleting/renaming object and start editing new one with same name */
    
    uel= undobase.first; 
    while(uel) {
        void *editdata= uel->getdata(C);
        int isvalid= 0;
        next= uel->next;
        
        /* for when objects are converted, renamed, or global undo changes pointers... */
        if(uel->type==obedit->type) {
            if(strcmp(uel->id.name, obedit->id.name)==0) {
                if(uel->validate_undo==NULL)
                    isvalid= 1;
                else if(uel->validate_undo(uel->undodata, editdata))
                    isvalid= 1;
            }
        }
        if(isvalid) 
            uel->ob= obedit;
        else {
            if(uel == curundo)
                curundo= NULL;

            uel->freedata(uel->undodata);
            BLI_freelinkN(&undobase, uel);
        }
        
        uel= next;
    }
    
    if(curundo == NULL) curundo= undobase.last;
}

/* 1= an undo, -1 is a redo. we have to make sure 'curundo' remains at current situation */
void undo_editmode_step(bContext *C, int step)
{
    Object *obedit= CTX_data_edit_object(C);
    
    /* prevent undo to happen on wrong object, stack can be a mix */
    undo_clean_stack(C);
    
    if(step==0) {
        undo_restore(curundo, curundo->getdata(C));
    }
    else if(step==1) {
        
        if(curundo==NULL || curundo->prev==NULL) error("No more steps to undo");
        else {
            if(G.f & G_DEBUG) printf("undo %s\n", curundo->name);
            curundo= curundo->prev;
            undo_restore(curundo, curundo->getdata(C));
        }
    }
    else {
        /* curundo has to remain current situation! */
        
        if(curundo==NULL || curundo->next==NULL) error("No more steps to redo");
        else {
            undo_restore(curundo->next, curundo->getdata(C));
            curundo= curundo->next;
            if(G.f & G_DEBUG) printf("redo %s\n", curundo->name);
        }
    }
    
    /* special case for editmesh, mode must be copied back to the scene */
    if(obedit->type == OB_MESH) {
        EM_selectmode_to_scene(CTX_data_scene(C), obedit);
    }

    DAG_id_tag_update(&obedit->id, OB_RECALC_DATA);

    /* XXX notifiers */
}

void undo_editmode_clear(void)
{
    UndoElem *uel;
    
    uel= undobase.first;
    while(uel) {
        uel->freedata(uel->undodata);
        uel= uel->next;
    }
    BLI_freelistN(&undobase);
    curundo= NULL;
}

/* based on index nr it does a restore */
void undo_editmode_number(bContext *C, int nr)
{
    UndoElem *uel;
    int a=1;
    
    for(uel= undobase.first; uel; uel= uel->next, a++) {
        if(a==nr) break;
    }
    curundo= uel;
    undo_editmode_step(C, 0);
}

void undo_editmode_name(bContext *C, const char *undoname)
{
    UndoElem *uel;
    
    for(uel= undobase.last; uel; uel= uel->prev) {
        if(strcmp(undoname, uel->name)==0)
            break;
    }
    if(uel && uel->prev) {
        curundo= uel->prev;
        undo_editmode_step(C, 0);
    }
}

/* undoname optionally, if NULL it just checks for existing undo steps */
int undo_editmode_valid(const char *undoname)
{
    if(undoname) {
        UndoElem *uel;
        
        for(uel= undobase.last; uel; uel= uel->prev) {
            if(strcmp(undoname, uel->name)==0)
                break;
        }
        return uel != NULL;
    }
    return undobase.last != undobase.first;
}


/* get name of undo item, return null if no item with this index */
/* if active pointer, set it to 1 if true */
const char *undo_editmode_get_name(bContext *C, int nr, int *active)
{
    UndoElem *uel;
    
    /* prevent wrong numbers to be returned */
    undo_clean_stack(C);
    
    if(active) *active= 0;
    
    uel= BLI_findlink(&undobase, nr);
    if(uel) {
        if(active && uel==curundo)
            *active= 1;
        return uel->name;
    }
    return NULL;
}


void *undo_editmode_get_prev(Object *ob)
{
    UndoElem *ue= undobase.last;
    if(ue && ue->prev && ue->prev->ob==ob) return ue->prev->undodata;
    return NULL;
}