/**
 ** VESADRV.C ---- EGA, VGA, VESA Super VGA driver for GRX 1.03
 **
 ** Copyright (C) 1991 DJ Delorie, 24 Kirsten Ave, Rochester NH 03867-2954
 ** Copyright (C) 1992 Csaba Biegl, 820 Stirrup Dr, Nashville, TN 37221
 ** Copyright (C) 1993 Grzegorz Mazur, gbm@ii.pw.edu.pl
 **
 ** This file is distributed under the terms listed in the document
 ** "copying.dj", available from DJ Delorie at the address above.
 ** A copy of "copying.dj" should accompany this file; if not, a copy
 ** should be available from where this file was obtained.  This file
 ** may not be distributed without a verbatim copy of "copying.dj".
 **
 ** This file is distributed WITHOUT ANY WARRANTY; without even the implied
 ** warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 **/
#pragma  inline

#include <stddef.h>
#include <dos.h>
#include "vdr.h"

char driver_name[] = {"GRX 1.03 VESA driver"};


#define MAX_TEXT_MODES	    20	/* maximum text mode table size */
#define EGA_TEXT_START	    6	/* start of the EGA mode table */
#define EGA_TEXT_MODES	    5	/* number of EGA text modes (incl end marker) */
#define VESA_TEXT_START 4

GrModeEntry text_mode_table[MAX_TEXT_MODES] =
{
  {80, 25, 2, 0x007, SETUP_STANDARD},
  {40, 25, 16, 0x001, SETUP_STANDARD},
  {80, 25, 16, 0x003, SETUP_STANDARD},
  {80, 50, 16, 0x003, SETUP_8X8_FNT},

  {132, 25, 16, 0x109, SETUP_STANDARD},
  {132, 43, 16, 0x10a, SETUP_STANDARD},
  {132, 50, 16, 0x10b, SETUP_STANDARD},
  {132, 60, 16, 0x10c, SETUP_STANDARD},

  {0, 0, 0, UNSUP, 0}
};


#define MAX_GRAPH_MODES	    40	/* maximum graphics mode table size */
#define EGA_GRAPH_START	    8	/* start of the EGA mode table */
#define EGA_GRAPH_MODES	    4	/* number of EGA graphics modes (incl end marker) */
#define VESA_GRAPHIC_START 5

GrModeEntry graphics_mode_table[MAX_GRAPH_MODES] =
{
  {320, 200, 16, 0x00d, SETUP_STANDARD},
  {640, 200, 16, 0x00e, SETUP_STANDARD},
  {640, 350, 16, 0x010, SETUP_STANDARD},
  {640, 480, 16, 0x012, SETUP_STANDARD},
  {320, 200, 256, 0x013, SETUP_STANDARD},

  {640, 350, 256, 0x11c, SETUP_STANDARD},
  {640, 400, 256, 0x100, SETUP_STANDARD},
  {640, 480, 256, 0x101, SETUP_STANDARD},
  {800, 600, 256, 0x103, SETUP_STANDARD},
  {1024, 768, 256, 0x105, SETUP_STANDARD},
  {1280, 1024, 256, 0x107, SETUP_STANDARD},

  {320, 200, 32768U, 0x10d, SETUP_STANDARD},
  {640, 350, 32768U, 0x11d, SETUP_STANDARD},
  {640, 400, 32768U, 0x11e, SETUP_STANDARD},
  {640, 480, 32768U, 0x110, SETUP_STANDARD},
  {800, 600, 32768U, 0x113, SETUP_STANDARD},
  {1024, 768, 32768U, 0x116, SETUP_STANDARD},
  {1280, 1024, 32768U, 0x119, SETUP_STANDARD},

  {320, 200, 0xc010U, 0x10e, SETUP_STANDARD},
  {640, 350, 0xc010U, 0x11f, SETUP_STANDARD},
  {640, 400, 0xc010U, 0x120, SETUP_STANDARD},
  {640, 480, 0xc010U, 0x111, SETUP_STANDARD},
  {800, 600, 0xc010U, 0x114, SETUP_STANDARD},
  {1024, 768, 0xc010U, 0x117, SETUP_STANDARD},
  {1280, 1024, 0xc010U, 0x11a, SETUP_STANDARD},

  {320, 200, 0xc018U, 0x10f, SETUP_STANDARD},
  {640, 350, 0xc018U, 0x121, SETUP_STANDARD},
  {640, 400, 0xc018U, 0x122, SETUP_STANDARD},
  {640, 480, 0xc018U, 0x112, SETUP_STANDARD},
  {800, 600, 0xc018U, 0x115, SETUP_STANDARD},
  {1024, 768, 0xc018U, 0x118, SETUP_STANDARD},
  {1280, 1024, 0xc018U, 0x11b, SETUP_STANDARD},

  {0, 0, 0, UNSUP, 0}
};


#include "pieces/vesainfo.c"
#include "paging/vesa.c"

int do_driver_init(void)
{
  VgaInfoBlock *vb;
  short far *modeptr;
  int mode, table_mode;
  GrModeEntry *table;

  HDR->memory_size = 0;
  vb = VESAgetInfo();
  if (vb == NULL) {
    for (table = text_mode_table + VESA_TEXT_START; table->width > 0;
         ++table)
      table->mode.vdr.BIOS_mode = UNSUP;
    for (table = graphics_mode_table + VESA_GRAPHIC_START; table->width > 0;
         ++table)
      table->mode.vdr.BIOS_mode = UNSUP;
  }
  else {
    for (table = text_mode_table + VESA_TEXT_START; table->width > 0;
         ++table) {
      modeptr = vb->VideoModePtr;
      table_mode = table->mode.vdr.BIOS_mode;
      while ((mode = *modeptr++) != (-1)) {
        if (table_mode == mode) break;
      }
      if (mode == (-1))
        table->mode.vdr.BIOS_mode = UNSUP;
    }
    for (table = graphics_mode_table + VESA_GRAPHIC_START; table->width > 0;
         ++table) {
      modeptr = vb->VideoModePtr;
      table_mode = table->mode.vdr.BIOS_mode;
      while ((mode = *modeptr++) != (-1)) {
        if (table_mode == mode) break;
      }
      if (mode == (-1))
        table->mode.vdr.BIOS_mode = UNSUP;
    }
  }
  HDR->driver_flags = GRD_VGA | GRD_NEW_DRIVER | GRD_NO_RW | GRD_4096K;
  return (1);
}

#include "pieces/textfont.c"


int do_mode_set(GrModeEntry * md, int noclear, int *vw, int *vh, char *vflag)
{
  int BIOSno, memmode, pgmode;

  switch (md->mode.vdr.custom_setup_index) {
    case SETUP_8X8_FNT:
      return (mode_set_8x8_font(md, noclear));
  }
  if ((BIOSno = md->mode.vdr.BIOS_mode) > 0x13) {
    if (noclear)
      BIOSno |= 0x8000;
    _AX = VESA_FUNC + VESA_SET_MODE;
    _BX = BIOSno;
    geninterrupt(0x10);
    if (_AX != VESA_SUCCESS)
      return (-1);
  }
  else {
    if (noclear)
      BIOSno |= 0x80;
    _AX = BIOSno;
    geninterrupt(0x10);
  }
  pgmode = setup_VESA_paging(md);
  if (pgmode == (-1))
    return (-1);
  switch ((unsigned) md->number_of_colors) {
    case 2U:
      memmode = GRD_1_PLANE;
      break;
    case 16U:
      memmode = GRD_4_PLANES;
      break;
    case 256U:
      memmode = GRD_8_PLANES;
      break;
    case 32768U:
      memmode = GRD_16_PLANES;
      break;
    case 0xc000U + 16:
      memmode = GRD_16_R_PLANES;
      break;
    case 0xc000U + 24:
      memmode = GRD_24_PLANES;
      break;
    default:
      return (-1);
  }

#if 0
  if ((md->number_of_colors > 256) && (VESAversion >= VESA_VERSION(1, 2))) {
    ModeInfoBlock *mb = VESAgetModeInfo(md->mode.vdr.BIOS_mode);
    if (mb) {
      HDR->r_mask = mb->RedMaskSize;
      HDR->r_offs = mb->RedMaskPos;
      HDR->g_mask = mb->GreenMaskSize;
      HDR->g_offs = mb->GreenMaskPos;
      HDR->b_mask = mb->BlueMaskSize;
      HDR->b_offs = mb->BlueMaskPos;
      HDR->f_mask = mb->ReservedMaskSize;
      HDR->f_offs = mb->ReservedMaskPos;
      /* is that 16 really only 15 ? */
      if ((memmode == GRD_16_R_PLANES) && (HDR->f_mask > 0))
     	memmode = GRD_16_PLANES;
    }
  }
#endif

#if 0
  if ((*vw > md->width) || (*vh > md->height)) {
    int virw = *vw;
    int virh = *vh;
    _BX = (virw > md->width) ? 0 : 1;	/* inquire only if width stays the same */
    _CX = virw;
    _AX = VESA_FUNC + VESA_SCAN_LNLEN;
    geninterrupt(0x10);
    if (_AX == VESA_SUCCESS) {
      virw = _CX;
      virh = _DX;
      HDR->line_offset = _BX;
      if ((virw > md->width) || (virh > md->height)) {
     	*vw = virw;
     	*vh = virh;
     	*vflag = 1;
      }
    }       
  }
#endif

  return ((HDR->driver_flags & ~(GRD_PLANE_MASK | GRD_PAGING_MASK)) | memmode | pgmode);
}


void do_screen_start_set(int *cp, int *rp)
{
  _CX = *cp;
  _DX = *rp;
  _BX = 0;
  _AX = VESA_FUNC + VESA_DISP_START;
  geninterrupt(0x10);
  if (_AX == VESA_SUCCESS) {
    *cp = _CX;
    *rp = _DX;
  }
}

#include "pieces/vdrmain.c"