; tinyfrac.asm
;
; teeny program displays the Mandelbrot set.
;
; written on Sun 03-26-1995 by Ed Beroset (Fidonet 1:3641/1.250)
;
; This program was based on a program by Frank Hommers, later optimized
; for size by Mikko Hyvarinen and posted in Fidonet's 80XXX echo.
;
; This new version has many new features and was based on my own
; optimization of Hyvarinen's version. Some features:
;
; pan using the arrow keys, one can navigate the fractal.
;
; Home Up PgUp
; Left Right correspond to 8 obvious directions
; End Dn PgDn
;
; zoom there are now ten levels of magnification available. If the
; program is assembled with FEATURES defined, the number
; corresponding to the zoom level (0-9, zero is most zoomed in)
; is displayed in the upper left hand corner of the screen just
; before each new fractal is drawn. The gray '+' key zooms out,
; the gray '-' key zooms in.
;
; beep the program will beep at the completion of each fractal
; drawing or if the user attempts to zoom past either limit.
;
; mode if the program is assembled with MODECHANGE defined, the
; will change to the next video mode if the 'v' key is pressed.
; This is handy because drawing fractals at high resolution can
; be very timeconsuming. The user can find an interesting spot
; in a low res mode and then change to a high res mode to see it
; more fully rendered.
;
; size this whole project was started off as a size optimization
; exercise, so there have been some rather ugly tradeoffs to
; sacrifice speed for size.
;
; 8086 yes, it runs on an 8086 although only if you leave out either
; the FEATURES option or the MODECHANGE option and it would be
; slower and more painful than oral surgery.
;
; cost there IS such a thing as a free lunch! This code is hereby
; released to the public domain by the author.
;
;
; to assemble & link:
; TASM /m2 tinyfrac (assemble using two pass mode if required)
; TLINK /Tdc tinyfrac (link Target platform is DOS, COM file)
;
;
PIXWIDTH equ 512
PIXHEIGHT equ 256
ZOOMLIMIT equ 13 ; can change to up to 13 for extended zoom in
; feel free to experiment with the following constants:
DELTA equ 200 ; the unit of pan movement in pixels
THRESHOLD equ 7 ; must be in the range of (0,255)
STARTSCALE equ 5 ; a number from 0 to ZOOMLIMIT, inclusive
IMGBUF equ 0x1000
; ************************************************************
;
; KolibriOS header
;
; ************************************************************
use32
org 0x0
db 'MENUET01'
dd 0x01
dd START
dd I_END
dd PIXWIDTH*PIXHEIGHT*3+IMGBUF+I_END
dd 0x1000
dd 0,0
include 'lang.inc'
include '..\..\..\macros.inc'
START:
call draw_fractal
redraw:
call draw_window
still:
mcall 10
dec eax
jz redraw
dec eax
jz key
button:
mcall 17
cmp ah,1
jne still
mcall -1
key:
mcall 2
shr eax,16
cmp al,24 ;'o'
je cycle
cmp al,23 ;'i'
je cycle
jmp no_cycle
cycle:
call color_cycle
jmp still
no_cycle:
cmp al,13 ;'+'
jne no_in
inc byte [scale]
mov ebx,[STARTX]
imul ebx,2
sub ebx,[scaleaddx]
mov [STARTX],ebx
mov ebx,[STARTY]
imul ebx,2
sub ebx,[scaleaddy]
mov [STARTY],ebx
call draw_fractal
jmp still
no_in:
cmp al,12 ;'-'
jne no_out
dec byte [scale]
mov ebx,[STARTX]
add ebx,[scaleaddx]
shr ebx,1
mov [STARTX],ebx
mov ebx,[STARTY]
add ebx,[scaleaddy]
shr ebx,1
mov [STARTY],ebx
call draw_fractal
jmp still
no_out:
cmp al,72
jne no_up
sub [STARTY],100
call draw_fractal
jmp still
no_up:
cmp al,80
jne no_down
add [STARTY],100
call draw_fractal
jmp still
no_down:
cmp al,75
jne no_left
sub [STARTX],100
call draw_fractal
jmp still
no_left:
cmp al,77
jne no_right
add [STARTX],100
call draw_fractal
jmp still
no_right:
cmp al,19 ;'r'
jne no_red
mov ah,3
call colorize
jmp still
no_red:
cmp al,34 ;'g'
jne no_green
mov ah,4
call colorize
jmp still
no_green:
cmp al,48 ;'b'
jne no_blue
mov ah,5
call colorize
jmp still
no_blue:
cmp al,17 ;'w'
jne no_set_as_wallpaper
mcall 15, 1, PIXWIDTH, PIXHEIGHT
mcall 15, 4, 1 ;mode 1-tiled, 0-stretch
mcall 15, 5, IMGBUF, 0, PIXWIDTH*3*PIXHEIGHT
mcall 15, 3
no_set_as_wallpaper:
jmp still
colorize:
shr eax,8
sub eax,3
imul eax,8
add eax,8
not eax
and eax,11000b
mov [shlc],al
call draw_fractal
ret
color_cycle:
pusha
mov ecx,0x08080808
mov esi,(PIXHEIGHT/8)*5
cmp al,24
je f_out
mov ecx,-0x08080808
mov esi,(PIXHEIGHT/8)*5-1
f_out:
newcycle:
mov edi,IMGBUF
newpix:
mov eax,[edi]
add eax,ecx
mov [edi],eax
add edi,4
cmp edi,IMGBUF+PIXWIDTH*PIXHEIGHT*3
jb newpix
call put_image
mov eax,5
mov ebx,1
mcall
dec esi
jnz newcycle
mov eax,0
mov edi,IMGBUF
mov ecx,PIXWIDTH*PIXHEIGHT*3 / 4 +50
cld
rep stosd
popa
call draw_fractal
ret
; **********************************************************************
;
; Tinyfrac
;
; **********************************************************************
draw_fractal:
pusha
mcall 4, 10*65536+10, 0xD0ffffff, calc_txt, 0
popa
pusha
movzx ebp,word [STARTX]
movzx edi,word [STARTY]
; This routine is the fractal drawing engine. It has been
; optimized for size, sacrificing speed.
mov cx, PIXHEIGHT ; height of screen in pixels
sub di,cx ; adjust our Y offset
@@CalcRow:
push cx
mov cx, PIXWIDTH ; width of screen in pixels
sub bp,cx ;
@@CalcPixel:
push cx ; save the column counter on stack
xor cx, cx ; clear out color loop counter
xor bx, bx ; zero i coefficient
xor dx, dx ; zero j coefficient
@@CycleColors:
push dx ; save j value for later
mov ax, bx ; ax = i
sub ax, dx ; ax = i - j
add dx, bx ; dx = i + j
stc ; one additional shift, please
call Shifty ; ax = ((i+j)*(i-j)) shifted right
pop dx ; retrieve our saved value for j
add ax,bp ; account for base offset...
cmp ah,THRESHOLD ; Q: is i > THRESHOLD * 256?
xchg bx,ax ; now swap new i with old i
jg @@draw ; Y: draw this pixel
clc ; no additional shifts here, please
call Shifty ; now dx:ax = old i * j
xchg dx,ax ;
add dx,di ; account for base offset...
inc cl ; increment color
jnz @@CycleColors ; keep going until we're done
@@draw:
xchg ax, cx ; mov color into al
pop cx ; retrieve our column counter
pop dx ; fetch row (column already in cx)
push dx ; must leave a copy on the stack
xor bx,bx ; write to video page zero
call put_pixel
inc bp
loop @@CalcPixel
inc di
pop cx
loop @@CalcRow
call put_image
popa
ret
shlc db 0
put_pixel:
pusha
sub edi,[STARTY]
sub ebp,[STARTX]
and edi,0xff
and ebp,0x1ff
shl edi,9
mov ebx,edi ; * 3 - Y
add edi,ebx
add edi,ebx
mov ebx,ebp
add ebp,ebx
add ebp,ebx
add edi,ebp
mov cl,[shlc]
mov ebx,0xff
shl ebx,cl
add cl,3
shl eax,cl
and eax,ebx
mov [IMGBUF+edi],eax
popa
ret
;****************************************************************************
;
; This routine multiplies AX by DX and shifts the result (in
; DX:AX) to the right by scale bits (or scale+1 bits if CY is
; set). The resulting value is left in AX. DX is destroyed.
;
;****************************************************************************
Shifty:
push cx ; save middle bits (i*i - j*j)
db 0b1h ; code for mov cl,immed8
scale db STARTSCALE
adc cl,0 ; adjust per CY flag
imul dx ; do the multiply
xchg ax,dx ;
shl eax,16 ; put hi part in hi 16 bits
xchg ax,dx
shr eax,cl ;
pop cx ;
ret ;
; **********************************************************************
;
; WINDOW DEFINITIONS AND DRAW
;
; **********************************************************************
draw_window:
pusha
mcall 12, 1
mcall 48, 4 ;get skin height
lea ecx, [50*65536+PIXHEIGHT+4+eax]
mcall 0,<50,PIXWIDTH+9>,,0x74000000,,header_txt ;draw window
call put_image
mcall 12, 2
popa
ret
put_image:
pusha
mcall 7, IMGBUF, PIXWIDTH*65536+PIXHEIGHT, 0*65536+0
popa
ret
; **********************************************************************
;
; DATA AREA
;
; **********************************************************************
header_txt db 'Move by Arrows, zoom +/-, cycle O/I, bgr W, color R/G/B',0
calc_txt db 'Calculating...',0
STARTX dd 200
STARTY dd 120
scaleaddy dd 120
scaleaddx dd 200
I_END: