;=============================================================================
; worm.asm - Worm Hole palette demostration.
; File created: 10/04/93
; Copyright (c) 1993, Carlos Hasan Last modified: 10/04/93
;
; Description:
; This file demostrates a palette animation routine, the main piccy
; was created using the pascal source file. This one uses the VGA card
; in 320x200x256 graphics mode.
;
; Portability:
; Requires Turbo Assembler 3.2 or better to be assembled.
; Dependent on the IBM PC 286 and the VGA graphics card.
;
; Modifications:
; 10/22/93 - Startup Code and Picture on .OBJ file.
;=============================================================================
.model small,pascal
.286
dosseg ; used to link like
.stack 1024 ; and standalone program.
global WormHole:proc
global WormPic:byte ; in WORMRAW.OBJ file.
;====================== Demo Equates and Data ================================
TIMEOUT equ 70 * 8 ; About 8 sec for timeout.
.data
Palette db 768 dup (?) ; hold the color palette
FadePalette db 768 dup (?) ; and the faded palette.
Timer dw ? ; timer counter.
;========================== Demo routines ====================================
.code
;-----------------------------------------------------------------------------
; SetPalette - set the 256 entries of the VGA color palette.
; In:
; DS:SI - Palette structure address.
;-----------------------------------------------------------------------------
SetPalette proc near
mov cx,768
mov dx,3C8h
xor al,al
out dx,al
mov dx,3DAh
WaitVRT1: in al,dx ; wait the start of
test al,8 ; vertical retrace.
jz WaitVRT1
WaitVRT2: in al,dx ; wait the end of
test al,8 ; vertical retrace.
jnz WaitVRT2
mov dx,3C9h
rep outsb
ret
SetPalette endp
;-----------------------------------------------------------------------------
; RotPalette - Rotates the palette and do fading.
; In:
; Palette - Source palette.
; Fade - Fading level.
;-----------------------------------------------------------------------------
RotPalette proc near Fade:word
mov ax,ds
mov es,ax
lea di,[FadePalette]
mov cx,16*3
xor ax,ax
cld
rep stosb
lea si,[Palette+32*3]
mov cx,224*3
cld
rep movsb
lea si,[Palette+16*3]
mov cx,16*3
rep movsb
lea bx,[FadePalette]
mov cx,16
RotLoop: push cx
mov si,bx
mov di,bx
lodsb
mov ah,al
lodsb
mov dl,al
lodsb
mov dh,al
mov cx,15*3
rep movsb
mov al,ah
stosb
mov al,dl
stosb
mov al,dh
stosb
add bx,16*3
pop cx
loop RotLoop
lea si,[FadePalette]
lea di,[Palette]
mov cx,768
rep movsb
lea si,[FadePalette]
mov cx,768
mov dx,[Fade]
FadeLoop: mov al,[si]
mul dl
shr ax,7
mov [si],al
inc si
loop FadeLoop
lea si,[FadePalette]
call SetPalette
ret
RotPalette endp
;-----------------------------------------------------------------------------
; WormHole - Worm Hole demostration.
; In:
; DS - Data segment.
; PicSeg - 320x200x256 picture segment address.
;-----------------------------------------------------------------------------
WormHole proc PicPtr:dword
local Fade:word
mov ax,0013h ; set 320x200x256 mode.
int 10h
mov ax,ds ; set black palette.
mov es,ax
lea di,[Palette]
mov cx,768
xor ax,ax
cld
rep stosb
lea si,[Palette]
call SetPalette
lea di,[Palette] ; generate the palette.
mov cx,256
xor bx,bx
GenPalette: mov ax,bx
shr ax,4
and ax,0Fh
shl ax,2
mov [di+0],al
mov ax,bx
and ax,0Fh
shl ax,1
mov [di+1],al
mov al,3Fh
mov [di+2],al
add di,3
inc bx
loop GenPalette
push ds ; write the picture.
mov ax,0A000h
mov es,ax
lds si,[PicPtr]
xor di,di
mov cx,320*200
cld
rep movsb
pop ds
mov [Fade],0
mov [Timer],0
WormIn: call RotPalette,[Fade] ; rotate palette.
cmp [Fade],128 ; adjust fade level.
jae WormTime
inc [Fade]
WormTime: inc [Timer] ; check if timeout,
cmp [Timer],TIMEOUT
jae WormOut
WormKey: mov ah,1 ; or any key pressed.
int 16h
jz WormIn
WormOut: cmp [Fade],128 ; start fading-out.
ja WormExit
call RotPalette,[Fade]
dec [Fade]
jmp WormOut
WormExit: mov ax,03h ; restore 80x25x16 textmode.
int 10h
ret
WormHole endp
;-----------------------------------------------------------------------------
; Start - Startup Code called from DOS.
; In:
; ES - Program Segment Prefix.
;-----------------------------------------------------------------------------
Start proc
mov ax,@Data
mov ds,ax
call WormHole,SEG WormPic,OFFSET WormPic
mov ax,4C00h
int 21h
Start endp
end Start
