;* VGATEXT.ASM
;*
;* VGA text output routines for MIDAS Sound System
;*
;* $Id: vgatext.asm,v 1.3 1997/01/16 18:41:59 pekangas Exp $
;*
;* Copyright 1996,1997 Housemarque Inc.
;*
;* This file is part of the MIDAS Sound System, and may only be
;* used, modified and distributed under the terms of the MIDAS
;* Sound System license, LICENSE.TXT. By continuing to use,
;* modify or distribute this file you indicate that you have
;* read the license and understand and accept it fully.
;*
IDEAL
P386
INCLUDE "lang.inc"
INCLUDE "vgatext.inc"
DATASEG
IFDEF __PASCAL__
IFDEF __PROTMODE__
EXTRN SegB800 : word
ENDIF
ENDIF
D_int scrWidth ; Screen width in _bytes_ (!!)
IDATASEG
hextable DB "0123456789ABCDEF"
CODESEG
;/***************************************************************************\
;*
;* Macro: STARTADDR
;*
;* Description: Calculates the start address in display memory
;*
;* Input: segreg segment register for address
;* indexreg index register for address
;* xc starting x coordinate
;* yc starting y coordinate
;*
;* Returns: points segreg:indexreg to correct display memory byte
;*
;* Destroys: _ax
;*
;\***************************************************************************/
MACRO STARTADDR segreg, indexreg, xc, yc
mov _ax,yc
dec _ax
mul [scrWidth]
mov indexreg,xc ; point indexter to dest in display
dec indexreg ; memory (160*y + 2*x)
shl indexreg,1
add indexreg,_ax
IFDEF __REALMODE__
mov ax,0B800h ; point segreg to display memory
mov segreg,ax
ELSE
IFDEF __16__
mov segreg,[SegB800]
ELSE
add indexreg,0B8000h
ENDIF
ENDIF
ENDM
;/***************************************************************************\
;*
;* Function: void vgaSetWidth(int width);
;*
;* Description: Sets the screen width used by text output routines
;*
;* Input: int width screen width in characters
;*
;\***************************************************************************/
PROC vgaSetWidth _funct width : _int
mov _ax,[width]
shl _ax,1
mov [scrWidth],_ax
ret
ENDP
;/***************************************************************************\
;*
;* Function: void vgaWriteText(int x, int y, char *txt);
;*
;* Description: Writes text on the screen
;*
;* Input: int x X coordinate of string (up-left
;* corner is (1,1))
;* int y Y coordinate
;* char *txt pointer to null-terminated text
;* string, which may contain also the
;* following special characters:
;* \xFF - next char is attribute
;* \x7F - next char is RLE count for
;* the character following it
;*
;\***************************************************************************/
PROC vgaWriteText _funct x : _int, y : _int, txt : _ptr
USES _si,_di,_bx
STARTADDR es, _di, [x], [y]
PUSHSEGREG ds
LOADPTR ds,_si,[txt] ; point ds:si to string
mov ah,07h ; default attribute is 07h - white
; on black
@@lp: mov al,[_si] ; get byte from string
inc _si
test al,al ; zero? (string termination)
jz @@done
cmp al,0FFh ; is next byte attribute?
je @@attr
cmp al,07Fh ; is next byte RLE count?
je @@rle
mov [_esdi],ax ; normal character - write to screen
add _di,2
jmp @@lp ; and get next character
@@attr:
mov ah,[_si] ; get next attribute
inc _si
jmp @@lp ; get next character
@@rle:
xor _cx,_cx
mov cl,[_si] ; get RLE count
mov al,[_si+1] ; get RLE byte
add _si,2
rep stosw ; draw characters
jmp @@lp ; get next character
@@done:
POPSEGREG ds
ret
ENDP
;/***************************************************************************\
;*
;* Function: void vgaWriteStr(int x, int y, char *str, char attr,
;* int txtlen);
;*
;* Description: Writes a string on the screen
;*
;* Input: int x X coordinate of the string
;* int y Y coordinate
;* char *str pointer to a ASCIIZ string
;* char attr attribute for the string
;* int txtlen number of characters to be printed on
;* screen - padded with spaces
;*
;\***************************************************************************/
PROC vgaWriteStr _funct x : _int, y : _int, str : _ptr, attr : _int,\
maxlen : _int
USES _si,_di,_bx
STARTADDR es, _di, [x], [y]
PUSHSEGREG ds
LOADPTR ds,_si,[str] ; point ds:si to string
mov ah,[byte attr] ; attribute
mov _cx,[maxlen] ; maximum number of characters
test _cx,_cx
jz @@done
@@lp: lodsb ; get character
test al,al ; zero? (end of string)
jz @@send ; if is, stop
stosw ; write character and attribute
loop @@lp ; and get next character
jmp @@done
@@send:
mov al,' ' ; string end - pad with spaces
rep stosw
@@done:
POPSEGREG ds
ret
ENDP
;/***************************************************************************\
;*
;* Function: void vgaWriteByte(int x, int y, uchar byte, char attr);
;*
;* Description: Writes a hex byte on the screen
;*
;* Input: int x X coordinate
;* int y Y coordinate
;* uchar byte byte to be written
;* char attr attribute for the byte
;*
;\***************************************************************************/
PROC vgaWriteByte _funct x : _int, y : _int, b : _int, attr : _int
USES _di,_bx
STARTADDR es, _di, [x], [y]
mov ah,[byte attr] ; attribute
mov bl,[byte b]
shr _bx,4 ; upper nybble
and _bx,0Fh
mov al,[hextable+_bx] ; upper nybble character
mov [_esdi],ax ; write upper nybble
mov bl,[byte b]
and bx,0Fh ; lower nybble
mov al,[hextable+_bx] ; lower nybble character
mov [_esdi+2],ax ; write lower nybble
ret
ENDP
;/***************************************************************************\
;*
;* Function: void vgaFillRect(int x1, int y1, int x2, int y2, char attr);
;*
;* Description: Draws a filled rectangle on the screen
;*
;* Input: int x1 X-coordinate of upper left corner
;* int y1 Y-coordinate of upper left corner
;* int x2 X-coordinate of lower left corner
;* int y2 Y-coordinate of lower left corner
;* char attr rectangle attribute
;*
;\***************************************************************************/
PROC vgaFillRect _funct x1 : _int, y1 : _int, x2 : _int, y2 : _int, \
attr : _int
USES _si,_di,_bx
cld
STARTADDR es, _di, [x1], [y1]
mov _bx,[y2]
sub _bx,[y1] ; _bx = row counter (y2-y1+1)
inc _bx
mov _dx,[x2]
sub _dx,[x1] ; _dx = number of columns (x2-x1+1)
inc _dx
mov _ax,_dx
shl _ax,1 ; _si = number of bytes to skip
mov _si,160 ; at the end of each row
sub _si,_ax ; (160 - 2*width)
mov ah,[byte attr] ; ah = attribute
mov al,' '
@@rowlp:
mov _cx,_dx
rep stosw ; draw one row's space+attr pairs
add _di,_si ; point di to beginning of next row
dec _bx
jnz @@rowlp ; do next row
ret
ENDP
;/***************************************************************************\
;*
;* Function: void vgaDrawChar(int x, int y, char ch, char attr);
;*
;* Description: Draws a single character on the screen
;*
;* Input: int x character X-coordinate
;* int y character Y-coordinate
;* char ch character
;* char attr character attribute
;*
;\***************************************************************************/
PROC vgaDrawChar _funct x : _int, y : _int, cha : _int, attr : _int
USES _bx
STARTADDR es, _bx, [x], [y]
mov ah,[byte attr] ; ah = attribute
mov al,[byte cha] ; al = character
mov [_esbx],ax ; draw character & attribute
ret
ENDP
;/***************************************************************************\
;*
;* Function: void vgaSetMode(int mode)
;*
;* Description: Sets a VGA BIOS display mode
;*
;* Input: int mode BIOS mode number
;*
;\***************************************************************************/
PROC vgaSetMode _funct mode : _int
USES _bx
mov al,[byte mode]
xor ah,ah ; int 10h, function 0 - set display
int 10h ; mode
ret
ENDP
;/***************************************************************************\
;*
;* Function: void vgaMoveCursor(int x, int y);
;*
;* Description: Moves the text mode cursor to a new location
;*
;* Input: int x cursor X-coordinate
;* int y cursor Y-coordinate
;*
;\***************************************************************************/
PROC vgaMoveCursor _funct x : _int, y : _int
USES _bx
mov ax,0200h ; int 10h, function 2 - set cursor
; location
xor bx,bx ; bh = display page (0)
mov dl,[byte x] ; dl = column (0-based)
dec dl
mov dh,[byte y] ; dh = row (0-based)
dec dh
int 10h
ret
ENDP
;/***************************************************************************\
;*
;* Function: void vgaDrawChars(int x, int y, char ch, char attr, int num);
;*
;* Description: Draws many charactersr on the screen
;*
;* Input: int x character X-coordinate
;* int y character Y-coordinate
;* char ch character
;* char attr character attribute
;* int num number characters to draw
;*
;\***************************************************************************/
PROC vgaDrawChars _funct x : _int, y : _int, cha : _int, attr : _int, \
num : _int
USES _di
STARTADDR es, _di, [x], [y]
mov ah,[byte attr] ; ah = attribute
mov al,[byte cha] ; al = character
mov _cx,[num] ; number of characters to draw
cld
rep stosw ; draw characted-attribute pairs
ret
ENDP
;* $Log: vgatext.asm,v $
;* Revision 1.3 1997/01/16 18:41:59 pekangas
;* Changed copyright messages to Housemarque
;*
;* Revision 1.2 1996/08/04 11:34:55 pekangas
;* All functions now preserve _bx
;*
;* Revision 1.1 1996/05/22 20:49:33 pekangas
;* Initial revision
;*
END
