//-------------------------------------------------------------------------
/*
Copyright (C) 1996, 2003 - 3D Realms Entertainment
Copyright (C) 2000, 2003 - Matt Saettler (EDuke Enhancements)
Copyright (C) 2020 - Christoph Oelckers

This file is part of Enhanced Duke Nukem 3D version 1.5 - Atomic Edition

Duke Nukem 3D 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

Original Source: 1996 - Todd Replogle
Prepared for public release: 03/21/2003 - Charlie Wiederhold, 3D Realms

EDuke enhancements integrated: 04/13/2003 - Matt Saettler

Note: EDuke source was in transition.  Changes are in-progress in the
source as it is released.

*/
//-------------------------------------------------------------------------



void updateinterpolations()  //Stick at beginning of domovethings
{
	long i;

	for(i=numinterpolations-1;i>=0;i--) oldipos[i] = *curipos[i];
}


void setinterpolation(long *posptr)
{
	long i;

	if (numinterpolations >= MAXINTERPOLATIONS) return;
	for(i=numinterpolations-1;i>=0;i--)
		if (curipos[i] == posptr) return;
	curipos[numinterpolations] = posptr;
	oldipos[numinterpolations] = *posptr;
	numinterpolations++;
}

void stopinterpolation(long *posptr)
{
	long i;

	for(i=numinterpolations-1;i>=startofdynamicinterpolations;i--)
		if (curipos[i] == posptr)
		{
			numinterpolations--;
			oldipos[i] = oldipos[numinterpolations];
			bakipos[i] = bakipos[numinterpolations];
			curipos[i] = curipos[numinterpolations];
		}
}

void dointerpolations(long smoothratio)       //Stick at beginning of drawscreen
{
	long i, j, odelta, ndelta;

	ndelta = 0; j = 0;
	for(i=numinterpolations-1;i>=0;i--)
	{
		bakipos[i] = *curipos[i];
		odelta = ndelta; ndelta = (*curipos[i])-oldipos[i];
		if (odelta != ndelta) j = mulscale16(ndelta,smoothratio);
		*curipos[i] = oldipos[i]+j;
	}
}

void restoreinterpolations()  //Stick at end of drawscreen
{
	long i;

	for(i=numinterpolations-1;i>=0;i--) *curipos[i] = bakipos[i];
}


void setsectinterpolate(short i)
{
    long j, k, startwall,endwall;

    startwall = sector[SECT].wallptr;
    endwall = startwall+sector[SECT].wallnum;

    for(j=startwall;j<endwall;j++)
    {
        setinterpolation(&wall[j].x);
        setinterpolation(&wall[j].y);
        k = wall[j].nextwall;
        if(k >= 0)
        {
            setinterpolation(&wall[k].x);
            setinterpolation(&wall[k].y);
            k = wall[k].point2;
            setinterpolation(&wall[k].x);
            setinterpolation(&wall[k].y);
        }
    }
}

void clearsectinterpolate(short i)
{
    short j,startwall,endwall;

    startwall = sector[SECT].wallptr;
    endwall = startwall+sector[SECT].wallnum;
    for(j=startwall;j<endwall;j++)
    {
        stopinterpolation(&wall[j].x);
        stopinterpolation(&wall[j].y);
        if(wall[j].nextwall >= 0)
        {
            stopinterpolation(&wall[wall[j].nextwall].x);
            stopinterpolation(&wall[wall[j].nextwall].y);
        }
    }
}