/*
	d_init.c

	rasterization driver initialization

	Copyright (C) 1996-1997  Id Software, Inc.

	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:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

	$Id$
*/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "bothdefs.h"
#include "d_local.h"

#define NUM_MIPS	4

cvar_t     *d_subdiv16;
cvar_t     *d_mipcap;
cvar_t     *d_mipscale;

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 };

extern int  d_aflatcolor;

void        (*d_drawspans) (espan_t *pspan);


/*
	D_Init
*/
void
D_Init (void)
{
	r_skydirect = 1;

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

void
D_Init_Cvars (void)
{
	d_subdiv16 = Cvar_Get ("d_subdiv16", "1", CVAR_NONE, NULL, "Set to enable extreme perspective correction");
	d_mipcap = Cvar_Get ("d_mipcap", "0", CVAR_NONE, NULL, "Detail level. 0 is highest, 3 is lowest.");
	d_mipscale = Cvar_Get ("d_mipscale", "1", CVAR_NONE, NULL, "Detail level of objects. 0 is highest, 3 is lowest.");
}

/*
	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 = (void *) (byte *) vid.buffer;

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

	d_roverwrapped = false;
	d_initial_rover = sc_rover;

	d_minmip = bound (0, d_mipcap->value, 3);

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

#ifdef USE_INTEL_ASM
	if (d_subdiv16->int_val)
		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);
}