Xash3D FWGS engine.
 
 
 
 

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/*
vid_dos.c - DOS VGA/VESA driver
Copyright (C) 2020 mittorn
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 3 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.
*/
#include "platform/platform.h"
#if XASH_VIDEO == VIDEO_DOS
#include "input.h"
#include "client.h"
#include "filesystem.h"
#include "vid_common.h"
#include <fcntl.h>
#include <errno.h>
#include <dos.h>
#include <i86.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/*
========================
Android_SwapBuffers
Update screen. Use native EGL if possible
========================
*/
void GL_SwapBuffers( void )
{
}
static void DOS_GetScreenRes( int *x, int *y )
{
*x = 320;
*y = 200;
}
qboolean R_Init_Video( const int type )
{
qboolean retval;
VID_StartupGamma();
if( type != REF_SOFTWARE )
return false; /// glide???
if( !(retval = VID_SetMode()) )
{
return retval;
}
host.renderinfo_changed = false;
return true;
}
void R_Free_Video( void )
{
// restore text mode
union REGS regs;
regs.w.ax = 3;
int386(0x10,&regs,&regs);
ref.dllFuncs.GL_ClearExtensions();
}
qboolean VID_SetMode( void )
{
R_ChangeDisplaySettings( 0, 0, false ); // width and height are ignored anyway
return true;
}
rserr_t R_ChangeDisplaySettings( int width, int height, qboolean fullscreen )
{
int render_w, render_h;
uint rotate = vid_rotate->value;
DOS_GetScreenRes( &width, &height );
render_w = width;
render_h = height;
Con_Reportf( "R_ChangeDisplaySettings: forced resolution to %dx%d)\n", width, height );
if( ref.dllFuncs.R_SetDisplayTransform( rotate, 0, 0, vid_scale->value, vid_scale->value ) )
{
if( rotate & 1 )
{
int swap = render_w;
render_w = render_h;
render_h = swap;
}
render_h /= vid_scale->value;
render_w /= vid_scale->value;
}
else
{
Con_Printf( S_WARN "failed to setup screen transform\n" );
}
R_SaveVideoMode( width, height, render_w, render_h );
return rserr_ok;
}
int GL_SetAttribute( int attr, int val )
{
return 0;
}
int GL_GetAttribute( int attr, int *val )
{
return 0;
}
int R_MaxVideoModes( void )
{
return 0;
}
vidmode_t* R_GetVideoMode( int num )
{
return NULL;
}
void* GL_GetProcAddress( const char *name ) // RenderAPI requirement
{
return NULL;
}
static qboolean vsync;
void GL_UpdateSwapInterval( void )
{
// disable VSync while level is loading
if( cls.state < ca_active )
{
// setup vsync here
vsync = false;
SetBits( gl_vsync->flags, FCVAR_CHANGED );
}
else if( FBitSet( gl_vsync->flags, FCVAR_CHANGED ))
{
ClearBits( gl_vsync->flags, FCVAR_CHANGED );
vsync = true;
}
}
/*
================================
VESA structures
================================
*/
typedef struct RealPointer
{
short Segment; //The real mode segment (offset is 0).
short Selector; //In protected mode, you need to chuck this dude into a segment register and use an offset 0.
} RealPointer;
typedef struct VesaInfo
{
char Signature[4];
short Version;
short OEMNameOffset;
short OEMNameSegment; //Pointer to OEM name?
char Capabilities[4];
short SupportedModesOffset;
short SupportedModesSegment; //Pointer to list of supported VESA and OEM modes (terminated with 0xffff).
char Reserved[238];
} VesaInfo;
typedef struct VesaModeData
{
short ModeAttributes;
char WindowAAttributes;
char WindowBAttributes;
short WindowGranularity;
short WindowSize;
short StartSegmentWindowA;
short StartSegmentWindowB;
void (*WindowPositioningFunction)(int page);
short BytesPerScanLine;
//Remainder of this structure is optional for VESA modes in v1.0/1.1, needed for OEM modes.
short PixelWidth;
short PixelHeight;
char CharacterCellPixelWidth;
char CharacterCellPixelHeight;
char NumberOfMemoryPlanes;
char BitsPerPixel;
char NumberOfBanks;
char MemoryModelType;
char SizeOfBank;
char NumberOfImagePages;
char Reserved1;
//VBE v1.2+
char RedMaskSize;
char RedFieldPosition;
char GreenMaskSize;
char GreenFieldPosition;
char BlueMaskSize;
char BlueFieldPosition;
char ReservedMaskSize;
char ReservedFieldPosition;
char DirectColourModeInfo;
char Reserved2[216];
} VesaModeData;
typedef struct RMREGS
{
int edi;
int esi;
int ebp;
int reserved;
int ebx;
int edx;
int ecx;
int eax;
short flags;
short es,ds,fs,gs,ip,cs,sp,ss;
} RMREGS;
static VesaInfo far *vesa_info = NULL;
static VesaModeData far *vesa_mode_data = NULL;
static int vesa_granularity;
static int vesa_page;
static int vesa_width;
static int vesa_height;
static int vesa_bits_per_pixel;
static RealPointer vesa_info_rp;
static RealPointer vesa_mode_data_rp;
static void far *allocate_dos_memory( RealPointer * rp,int bytes_to_allocate )
{
void far *ptr = NULL;
union REGS regs;
bytes_to_allocate = ((bytes_to_allocate + 15) & 0xfffffff0); //Round up to nearest paragraph.
memset(&regs,0,sizeof(regs));
regs.w.ax = 0x100;
regs.w.bx = (short)(bytes_to_allocate >> 4); //Allocate dos memory in pages, so convert bytes to pages.
int386(0x31,&regs,&regs);
if(regs.x.cflag == 0)
{ //Everything OK.
rp->Segment = regs.w.ax;
rp->Selector = regs.w.dx;
ptr = MK_FP(regs.w.dx,0);
}
return(ptr);
}
/****************************************************************************/
/* Free an area of DOS memory. */
/****************************************************************************/
static void free_dos_memory( RealPointer * rp )
{
union REGS regs;
regs.w.ax = 0x101;
regs.w.dx = rp->Selector;
int386(0x31,&regs,&regs);
}
/****************************************************************************/
/* Get information about the VESA driver. */
/* */
/* Returns: */
/* TRUE - VESA driver present. vesa_info set to point to a */
/* a structure containing capability info etc. */
/* FALSE - No VESA driver. */
/* */
/****************************************************************************/
static int vesa_get_info( void )
{
union REGS regs;
struct SREGS sregs;
RMREGS rmregs;
int ok = 0;
if((vesa_info = (VesaInfo far *)allocate_dos_memory(&vesa_info_rp,sizeof(VesaInfo))) != NULL)
{
memset(&rmregs,0,sizeof(rmregs));
memset(&regs,0,sizeof(regs));
memset(&sregs,0,sizeof(sregs));
segread(&sregs);
rmregs.eax = 0x4f00;
rmregs.es = vesa_info_rp.Segment;
rmregs.ds = vesa_info_rp.Segment;
regs.x.eax = 0x300;
regs.x.ebx = 0x10;
regs.x.ecx = 0;
sregs.es = FP_SEG(&rmregs);
regs.x.edi = FP_OFF(&rmregs);
int386x(0x31,&regs,&regs,&sregs); //Get vesa info.
if(rmregs.eax == 0x4f) ok=1;
}
return(ok);
}
/****************************************************************************/
/* Free the information allocated with vesa_get_info() */
/****************************************************************************/
static int vesa_free_info( void )
{
free_dos_memory( &vesa_info_rp );
}
/****************************************************************************/
/* Get VESA mode information. Information is loaded into vesa_mode_data. */
/* vesa_get_info() must be called before calling this function. */
/* Should error check this really. */
/* */
/* Inputs: */
/* vmode - The mode that you wish to get information about. */
/* */
/* Returns: */
/* TRUE - vesa_mode_data points to a filled VesaModeData structure. */
/* FALSE - vesa_mode_data probably invalid. Mode probably not */
/* supported. */
/* */
/****************************************************************************/
static int vesa_get_mode_info( short vmode )
{
union REGS regs;
struct SREGS sregs;
RMREGS rmregs;
int ok=0;
if((vesa_mode_data = (VesaModeData far *)allocate_dos_memory(&vesa_mode_data_rp,sizeof(VesaModeData))) != NULL)
{
memset(&rmregs,0,sizeof(rmregs));
rmregs.es = vesa_mode_data_rp.Segment;
rmregs.ds = vesa_mode_data_rp.Segment;
rmregs.edi = 0;
rmregs.eax = 0x4f01;
rmregs.ecx = vmode;
memset(&regs,0,sizeof(regs));
memset(&sregs,0,sizeof(sregs));
segread(&sregs);
regs.x.eax = 0x300;
regs.x.ebx = 0x10;
regs.x.edi = (int)&rmregs;
int386x(0x31,&regs,&regs,&sregs);
if(regs.h.al == 0)
{
//cache a few important items in protected mode memory area.
vesa_granularity = vesa_mode_data->WindowGranularity;
vesa_width = vesa_mode_data->PixelWidth;
vesa_height = vesa_mode_data->PixelHeight;
vesa_bits_per_pixel = vesa_mode_data->BitsPerPixel;
ok = 1;
}
}
return(ok);
}
/****************************************************************************/
/* Set the current vesa screen page. */
/* */
/* Inputs: */
/* vpage - Page number to set. */
/* */
/****************************************************************************/
static void vesa_set_page( int vpage )
{
union REGS regs;
vesa_page = vpage;
regs.w.ax = 0x4f05;
regs.w.bx = 0;
regs.w.cx = 0;
regs.w.dx = (short)(vpage == 0 ? 0 : (short)((vpage * 64) / vesa_granularity));
int386(0x10,&regs,&regs);
regs.w.ax = 0x4f05;
regs.w.bx = 1;
regs.w.cx = 0;
regs.w.dx = (short)(vpage == 0 ? 0 : (short)((vpage * 64) / vesa_granularity));
int386(0x10,&regs,&regs);
}
/****************************************************************************/
/* Set VESA video mode. You MUST have previously called vesa_get_info(). */
/* */
/* Inputs: */
/* vmode - The VESA mode that you want. e.g. 0x101 is 640x480 256 */
/* colours. */
/* */
/* Returns: */
/* TRUE - The mode has been set. */
/* FALSE - The mode has not been set, probably not supported. */
/* */
/****************************************************************************/
int vesa_set_mode( short vmode )
{
union REGS regs;
int ok=0;
memset(&regs,0,sizeof(regs));
regs.w.ax = 0x4f02;
regs.w.bx = vmode;
int386(0x10,&regs,&regs);
if(regs.w.ax == 0x004f)
{
vesa_get_mode_info(vmode);
vesa_set_page(0); //Probably not needed, but here for completeness.
ok = 1;
}
return(ok);
}
/****************************************************************************/
/* Free the info previously allocated with vesa_get_info() */
/****************************************************************************/
void vesa_free_mode_info( void )
{
free_dos_memory(&vesa_mode_data_rp);
}
void init_13h( void )
{
int r, g, b;
union REGS regs;
// set 13h vga mode
memset(&regs,0,sizeof(regs));
regs.w.ax = 0x13;
int386(0x10,&regs,&regs);
// set 332 palette
outp(0x3c8, 0);
for (r=0; r<8; r++)
for (b=0; b<4; b++)
for (g=0; g<8; g++)
{
outp(0x3c9, (b<<4)+8);
outp(0x3c9, (g<<3)+4);
outp(0x3c9, (r<<3)+4);
}
}
void waitvbl()
{
while (!(inp (0x3da) & 8)) {}
while (inp (0x3da) & 8) {}
}
static byte *fb;
void *SW_LockBuffer( void )
{
return fb;
}
void SW_UnlockBuffer( void )
{
int left = 320*200*2;
int done = 0;
int vpage = 0;
if( vsync )
waitvbl();
// no separate fb
if( fb == 0xa0000 )
return;
while( left )
{
int flip = left;
if( flip > 65536 )
flip = 65536;
vesa_set_page(vpage);
memcpy((void *)0xa0000, fb+done, flip);
done += flip;
left -= flip;
vpage++;
}
}
#define FB_BF_TO_MASK(x) (((1 << x.length) - 1) << (x.offset))
qboolean SW_CreateBuffer( int width, int height, uint *stride, uint *bpp, uint *r, uint *g, uint *b )
{
int i;
*stride = 320;
vesa_get_info();
if( !Sys_CheckParm("-novesa") && vesa_set_mode( 0x10E ) )
{
fb = malloc( 320*200*2 );
*bpp = 2;
*b = 31;
*g = 63 << 5;
*r = 31 << 11;
}
else
{
// fallback to 256 color
*b = 2 << 6;
*g = 7 << 0;
*r = 7 << 3;
*bpp = 1;
init_13h();
fb = 0xa0000;
}
return true;
}
#endif