i_video.h

//
// Copyright (C) 1993-1996 Id Software, Inc.
// Copyright (C) 1993-2008 Raven Software
// Copyright (C) 2015 Alexey Khokholov (Nuke.YKT)
// Copyright (C) 2017 Alexandre-Xavier Labonté-Lamoureux
//
// 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.
//
// DESCRIPTION:
//	System specific interface stuff.
//


#ifndef __I_VIDEO__
#define __I_VIDEO__


#include "doomtype.h"

/*
=============================================================================

CONSTANTS

=============================================================================
*/

#define SC_INDEX                0x3C4
#define SC_RESET                0
#define SC_CLOCK                1
#define SC_MAPMASK              2
#define SC_CHARMAP              3
#define SC_MEMMODE              4

#define CRTC_INDEX              0x3D4
#define CRTC_H_TOTAL    0
#define CRTC_H_DISPEND  1
#define CRTC_H_BLANK    2
#define CRTC_H_ENDBLANK 3
#define CRTC_H_RETRACE  4
#define CRTC_H_ENDRETRACE 5
#define CRTC_V_TOTAL    6
#define CRTC_OVERFLOW   7
#define CRTC_ROWSCAN    8
#define CRTC_MAXSCANLINE 9
#define CRTC_CURSORSTART 10
#define CRTC_CURSOREND  11
#define CRTC_STARTHIGH  12
#define CRTC_STARTLOW   13
#define CRTC_CURSORHIGH 14
#define CRTC_CURSORLOW  15
#define CRTC_V_RETRACE  16
#define CRTC_V_ENDRETRACE 17
#define CRTC_V_DISPEND  18
#define CRTC_OFFSET             19
#define CRTC_UNDERLINE  20
#define CRTC_V_BLANK    21
#define CRTC_V_ENDBLANK 22
#define CRTC_MODE               23
#define CRTC_LINECOMPARE 24


#define GC_INDEX                0x3CE
#define GC_SETRESET             0
#define GC_ENABLESETRESET 1
#define GC_COLORCOMPARE 2
#define GC_DATAROTATE   3
#define GC_READMAP              4
#define GC_MODE                 5
#define GC_MISCELLANEOUS 6
#define GC_COLORDONTCARE 7
#define GC_BITMASK              8

#define ATR_INDEX               0x3c0
#define ATR_MODE                16
#define ATR_OVERSCAN    17
#define ATR_COLORPLANEENABLE 18
#define ATR_PELPAN              19
#define ATR_COLORSELECT 20

#define STATUS_REGISTER_1    0x3da

#define PEL_WRITE_ADR   0x3c8
#define PEL_READ_ADR    0x3c7
#define PEL_DATA                0x3c9
#define PEL_MASK                0x3c6


// Called by D_DoomMain,
// determines the hardware configuration
// and sets up the video mode
void I_InitGraphics (void);


void I_ShutdownGraphics(void);

// Takes full 8 bit values.
void I_SetPalette (byte* palette);

void I_UpdateNoBlit (void);
void I_FinishUpdate (void);

// Wait for vertical retrace or pause a bit.
void I_WaitVBL(int count);

void I_ReadScreen (byte* scr);

void I_BeginRead (void);
void I_EndRead (void);



#endif