org 100h
section .text
%macro init_gfx 0
mov ax,0x13
int 0x10
%endmacro
%macro usleep 2 ; usecs hi, lo
mov ax,0x8600
mov cx, %1
mov dx, %2
int 0x15
%endmacro
%macro create_texture 0
mov di,texture
mov dx,4
mov bx,80
mov cx,20
mov ax,1
%%again:
rep stosb
mov cx,ax
mov ax,1
sub ax,cx
mov cx,20
dec bx
jnz %%again
mov cx,ax
mov ax,1
sub ax,cx
mov bx,80
mov cx,20
dec dx
jnz %%again
%endmacro
%macro blit 5 ; src, x,y, w,h
mov ax,0xA000
mov es,ax
mov si,%1
mov di,%2+320*%3
mov bx,%4
mov cx,%5
%%again:
rep movsb
add di,320-%4
mov cx,%4
dec bx
jnz %%again
%endmacro
%macro cls 0
mov ax,0xA000
mov es,ax
mov si,0
mov di,0
mov cx,320*200
mov ax,0
rep stosb
%endmacro
%macro puts 1 ; str
mov dx,%1
mov ah,0x09
int 0x21
%endmacro
%macro exit 0
int 0x20
%endmacro
start:
; program code
init_gfx
; create_texture
; blit texture, 100, 100, 80, 80
; usleep 0x1,0xFFFF
; cls
; exit
mov ax,0xA000
mov es,ax
mov cx,360
; mov cx,45
; loop for different angles
loop1:
mov word [angle],cx
push cx
mov ax,word [angle2]
sub ax,3
mov word [angle2],ax
usleep 0,0x0100
cls
; loop over the points
mov si,24+24
more_pnts:
call xform_display
sub si,6
jne more_pnts
pop cx
loop loop1
exit
xform_display:
; d - dist of screen from COP
; x / z = sx / d
; d * (x/z) = screen-x
mov ax,0
mov word [tmp1w],ax
fild word [tmp1w]
fild word [angle]
fild word [Rads]
fdivp ; deg2rad
fsincos ; sin(a) and cos(a)
; fp[2] = sin(a)
; fp[1] = cos(a)
; fp[0] = 0
; Goal: x = -y *sin + x * cos
fild word [si+Points-6] ; y
fmulp ; y *= sin(a)
; fp[2] = y * sin(a)
; fp[1] = cos(a)
; fp[0] = 0
fistp dword [tmp1d]
fild word [si+Points-4] ; x
fmulp ; x * cos(a)
fild dword [tmp1d]
; fp[2] = y * sin(a)
; fp[1] = x * cos(a)
; fp[0] = 0
fsubp
fsubp
fistp dword [tmp1d]
; tmp1d = 0 - (y * sin(a) - x * cos(a))
; tmp1d = -y * sin(a) + x * cos(a))
fild word [angle]
fild word [Rads]
fdivp ; deg2rad
fsincos ; sin(a) and cos(a)
; fp[1] = sin(a)
; fp[0] = cos(a)
; Goal: y = x * sin + y * cos
fild word [si+Points-4] ; x
fmulp ; x *= sin(a)
; fp[1] = x * sin(a)
; fp[0] = cos(a)
fistp dword [tmp2d]
fild word [si+Points-6] ; y
fmulp ; y * cos(a)
fild dword [tmp2d]
; fp[1] = x * sin(a)
; fp[0] = y * cos(a)
faddp
fistp dword [tmp2d]
; tmp2d = x * sin(a) + y * cos(a)
mov ax,0
mov word [tmp1w],ax
fild word [tmp1w]
fild word [angle]
fild word [Rads]
fdivp ; deg2rad
fsincos ; sin(a) and cos(a)
; fp[2] = sin(a)
; fp[1] = cos(a)
; fp[0] = 0
; Goal: y = -z * sin + y * cos
fild word [si+Points-2] ; z
fmulp ; z *= sin(a)
; fp[2] = z * sin(a)
; fp[1] = cos(a)
; fp[0] = 0
fistp dword [tmp3d]
fild word [tmp2d] ; y
fmulp ; y * cos(a)
fild dword [tmp3d]
; fp[2] = z * sin(a)
; fp[1] = y * cos(a)
; fp[0] = 0
fsubp
fsubp
fistp dword [tmp3d]
; tmp3d = -z * sin(a) + y * cos(a)
fild word [angle]
fild word [Rads]
fdivp ; deg2rad
fsincos ; sin(a) and cos(a)
; fp[1] = sin(a)
; fp[0] = cos(a)
; Goal: z = y * sin + z * cos
fild word [tmp2d] ; y
fmulp ; y *= sin(a)
; fp[1] = y * sin(a)
; fp[0] = cos(a)
fistp dword [tmp4d]
fild word [si+Points-2] ; z
fmulp ; z * cos(a)
fild dword [tmp4d]
; fp[1] = y * sin(a)
; fp[0] = z * cos(a)
faddp
fistp dword [tmp4d]
; tmp4d = y * sin(a) + z * cos(a)
; fild word [si+Points-6] ; y
; fmulp ; y *= sin(a)
; fistp dword [tmp2d]
; fild word [si+Points-4] ; x
; fmulp ; x * cos(a)
; fistp dword [tmp1d]
;mov ax,[si+Points-4] ; tmp2w]
;mov bx,[si+Points-6] ; tmp2w]
mov cx,[tmp3d] ; [si+Points-2] ; z
add cx,150
;mov cx,[si+Points-2] ; z
; X
mov ax,0
mov ax,[tmp1d] ; x
mov dx,45
imul dx
idiv cx
add ax,160
mov di,ax
; Y
mov ax,[tmp4d] ; [tmp2d] ; y
;mov ax,[tmp2d] ; y
mov dx,45
imul dx
idiv cx
add ax,100
mov dx,320
imul dx
add di,ax
; draw
mov ax,1
stosb
stosb
add di,318
stosb
stosb
ret
section .data
;Hello db 'Hello world', 0xD, 0xA, '$'
Rads dw 58
; Dist dw 45
Points dw -50,-50,-50, -50,50,-50, -50,50,50, -50,-50,50
Points2 dw 50,-50,-50, 50,50,-50, 50,50,50, 50,-50,50
section .bss
; uninitialized data
angle: resw 1
angle2: resw 1
tmp1w: resw 1
tmp2w: resw 1
tmp1d: resd 1
tmp2d: resd 1
tmp3d: resd 1
tmp4d: resd 1
sine: resd 1
cosine: resd 1
texture: resb 6400 ; 80x80
offscreen: resb 64000
