Big Cube Of Dots...

Posted April 24, 200718 yr

Here is a little intro (with source code) of dots formed in to a rotating cube.

;	   Big Cube Of Dots
;		by Rebels
;	   for BP 2007
;	   coded by lord Kelvin
	org 0x100	; .COM	mov al,0x13	; \ MCGA
	int 0x10	; /	mov dx,0x3C9	; \ colors[ i ] = RGB( -i / 2, -i / 3, -i / 4 );
	mov cx,256	; |  i = 256 ... 1
pal:	mov ax,cx	; |
	neg ax		; |
	shr al,3	; |
	out dx,al	; |
	shr al,1	; |
	out dx,al	; |
	shl al,2	; |
	out dx,al	; |
	loop pal	; /	fldz		; st0=a; clear z buffer, with fade
here:	mov ch,0xFA	; do loop 320*200 times
	mov di,zbuf	; in zbuffer
fade:	mov al,[di]	; al = current z
	cmp al,8	; \ if( al < 8 ) al = 0;
	jna nofade	; | else al -= 8;
	sub al,8	; | current z = al
	jmp made	; |
nofade: xor al,al	; |
made:	stosb		; /
	loop fade	; ...
; loop through all points of the cube
points: mov ax,cx	; \ ax = cx / 40;
	xor dx,dx	; | dx = cx % 40;
	mov bx,40	; |
	div bx		; /
	sub dx,20
	push dx 	; push firstt coordinate
	xor dx,dx	; \ dx = ax % 40;
	div bx		; / ax = ax / 40;
	sub ax,20
	sub dx,20
	push ax 	; push second coordinate
	push dx 	; push third coordinate	mov bx,sp	; address stack with bx	imul dx,dx	; \ if( x * x + y * y + z * z < Max / 2 * Max / 2 * 8 / 5 &&
	imul ax,ax	; |	  x * x + y * y + z * z > Max / 2 * Max / 2 / 3 )
	add dx,ax	; |	  do not put point in zbuffer
	mov ax,[bx+4]	; |
	imul ax,ax	; |
	add ax,dx	; |
	cmp ax,20*20/3	; |
	jb sphere	; |
	cmp ax,20*20*8/5; |
	jb no		; /sphere: fild word [bx+4]; \ load coordinates of current point
	fild word [bx+2]; |
	fild word [bx]	; /	call turn	; :D
	call turn	; :D	fistp word [bx] ; \ di = ( y + 100 ) * 320;
	add word [bx],100; |
	imul di,[bx],320; /
	fistp word [bx] ; \ di += x;
	add di,[bx]	; /
	add di,160+zbuf+16; centerize.
	fistp word [bx] ; \ ax = z + 128
	mov al,128	; |
	add ax,[bx]	; /
	cmp al,[di]	; \ if ax is less than value in z buffer - do nothing
	jna no		; | else replace value
	stosb		; /
no:
	add sp,6	; return stack to normal state
	loop points	; while( --cx ) goto points;	mov di,zbuf+320 ; \ Simple blur from my intro Cheshire Cat.
	mov cx,0xFA00-320; |
lust:	xor ah,ah	; |
	mov al,[di-320] ; |
	add al,[di-1]	; |
	adc ah,ah	; |
	add al,[di+1]	; |
	adc ah,0	; |
	add al,[di+320] ; |
	adc ah,0	; |
	shr ax,2	; |
	stosb		; |
	loop lust	; /; show cube
	push es 	; preserve ex
	mov si,zbuf	; si = from
	xor di,di	; di = to
	push 0xA000
	pop es
	dec cx		; cx = 0xFFFF
	rep movsb	; copy z buffer to the screen	pop es		; recall es	fiadd word [two]; change angle	in ax,0x60	; \
	dec ax		; |
	jne here	; |
	ret		; / Sorry, no esc & exit support.two dw 88; void turn( float &x, float &y, float a ); 25b
; st0=x, st1=y, st2, st3=a.
turn:	fld st3 	; st0=a, st1=x, st2=y, st3=z, st4=a
	fsincos 	; st0=cos(a), st1=sin(a), st2=x, st3=y, st4=z, st5=a
	fmul st0,st2	; st0=x*cos(a), st1=sin(a), st2=x, st3=y, st4=z, st5=a
	fxch st1	; st0=sin(a), st1=x*cos(a), st2=x, st3=y, st4=z, st5=a
	fmul st0,st3	; st0=y*sin(a), st1=x*cos(a), st2=x, st3=y, st4=z, st5=a
	faddp st1,st0	; st0=y*sin(a)+x*cos(a)[x'], st1=x, st2=y, st3=z, st4=a
	fld st4 	; st0=a, st1=x', st2=x, st3=y, st4=z, st5=a
	fsincos 	; st0=cos(a), st1=sin(a), st2=x', st3=x, st4=y, st5=z, st6=a
	fmulp st4,st0	; st0=sin(a), st1=x', st2=x, st3=y*cos(a), st4=z, st5=a
	fmulp st2,st0	; st0=x', st1=x*sin(a), st2=y*cos(a), st3=z, st4=a
	fxch st1	; st0=x*sin(a), st1=x', st2=y*cos(a), st3=z, st4=a
	fsubp st2,st0	; st0=x', st1=y*cos(a)-x*sin(a)[y'], st2=z, st3=a
	fxch st2	; st0=z, st1=y', st2=x', st3=a
	fld st3 	; st0=a...
	fsin		; st0=sin(a)...
	fcos		; st0=cos(sin(a))
	fadd st0,st0	;	   !!! makes zoom from 1 to 2!
	fmul st3,st0	; \ mul by this koef all coordinates
	fmul st2,st0	; |
	fmulp st1,st0	; /
	ret		; return
db 'lK' 		; for lord Kelvin.
zbuf: