/*
 * d_init.c -- rasterization driver initialization
 * $Id: d_init.c,v 1.9 2007-08-09 06:12:45 sezero Exp $
 *
 * Copyright (C) 1996-1997  Id Software, Inc.
 * Copyright (C) 1997-1998  Raven Software Corp.
 *
 * 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
 */

#include "quakedef.h"
#include "d_local.h"

#define NUM_MIPS	4

static	cvar_t	d_subdiv16 = {"d_subdiv16", "1", CVAR_NONE};
static	cvar_t	d_mipcap = {"d_mipcap", "0", CVAR_NONE};
static	cvar_t	d_mipscale = {"d_mipscale", "1", CVAR_NONE};

surfcache_t		*d_initial_rover;
qboolean		d_roverwrapped;
int			d_minmip;
float			d_scalemip[NUM_MIPS-1];

static float	basemip[NUM_MIPS-1] = {1.0, 0.5*0.8, 0.25*0.8};

void (*d_drawspans) (espan_t *pspan);


/*
===============
D_Init
===============
*/
void D_Init (void)
{
	Cvar_RegisterVariable (&d_subdiv16);
	Cvar_RegisterVariable (&d_mipcap);
	Cvar_RegisterVariable (&d_mipscale);

	r_drawpolys = false;
	r_worldpolysbacktofront = false;
	r_recursiveaffinetriangles = true;
	r_pixbytes = 1;
	r_aliasuvscale = 1.0;
}


/*
===============
D_CopyRects
===============
*/
void D_CopyRects (vrect_t *prects, int transparent)
{
// this function is only required if the CPU doesn't have direct access to the
// back buffer, and there's some driver interface function that the driver
// doesn't support and requires Quake to do in software (such as drawing the
// console); Quake will then draw into wherever the driver points vid.buffer
// and will call this function before swapping buffers
	UNUSED(prects);
	UNUSED(transparent);
}


/*
===============
D_EnableBackBufferAccess
===============
*/
void D_EnableBackBufferAccess (void)
{
	VID_LockBuffer ();
}


/*
===============
D_TurnZOn
===============
*/
void D_TurnZOn (void)
{
// not needed for software version
}


/*
===============
D_DisableBackBufferAccess
===============
*/
void D_DisableBackBufferAccess (void)
{
	VID_UnlockBuffer ();
}


/*
===============
D_SetupFrame
===============
*/
void D_SetupFrame (void)
{
	int		i;

	if (r_dowarp)
		d_viewbuffer = r_warpbuffer;
	else
		d_viewbuffer = vid.buffer;

	if (r_dowarp)
		screenwidth = WARP_WIDTH;
	else
		screenwidth = vid.rowbytes;

	d_roverwrapped = false;
	d_initial_rover = sc_rover;

	d_minmip = d_mipcap.integer;
	if (d_minmip > 3)
		d_minmip = 3;
	else if (d_minmip < 0)
		d_minmip = 0;

	for (i = 0; i < (NUM_MIPS-1); i++)
		d_scalemip[i] = basemip[i] * d_mipscale.value;

#if	id386
	if (d_subdiv16.integer)
		d_drawspans = D_DrawSpans16;
	else
		d_drawspans = D_DrawSpans8;
#else
	d_drawspans = D_DrawSpans8;
#endif

	d_aflatcolor = 0;
}


/*
===============
D_UpdateRects
===============
*/
void D_UpdateRects (vrect_t *prect)
{
// the software driver draws these directly to the vid buffer
	UNUSED(prect);
}

