снежинка

        .model small
        locals
        .stack 100h
        .386

Mode_6 = 06h ; 640 X 200, 2 colors
Mode_13 = 0Dh ; 320 X 200, 16 colors
Mode_14 = 0Eh ; 640 X 200, 16 colors
Mode_15 = 0Fh ; 640 X 350, 2 colors
Mode_16 = 10h ; 640 X 350, 16 colors
Mode_17 = 11h ; 640 X 480, 2 colors
Mode_18 = 12h ; 640 X 480, 16 colors
Mode_19 = 13h ; 320 X 200, 256 colors
Mode_6A = 6Ah ; 800 X 600, 16 colors

        .data
saveMode db ? ; Сохранить текущий видео режим


temp dw ?
half dd 0.5
sqrt2div2 dd 0.707106781165
video_page dd 0A000h

; В 2 цветном режиме 1 = белый, в 16 цветном 1 = синий

        .code

main proc
        mov ax,@data
        mov ds,ax

; Получить текущий видео режим

        mov ah,0Fh
        int 10h
        mov saveMode,al

; ; Переключиться в графический режим

        mov ah,0 ; установка видео режима
        mov al,Mode_17 ; номер режима
        int 10h

        finit

        mov ax, 100
        mov bx, 100
        mov cx, 400
        mov dx, 100


fall:

        push ax
        mov eax, video_page
        xor eax, 19600h
        mov video_page, eax
        pop ax

        call cls

        inc bx
        inc dx

        cmp bx, 480
        jge end_fall

        push cx dx ax bx
        call find_triangle_top
        pop di si
; ;
        push ax bx cx dx 4
        call koch_curve

        push cx dx si di 4
        call koch_curve

        push si di ax bx 4
        call koch_curve
; 10011011000000000
; 01010000000000000
; 11001011000000000
        push ax
        mov ah, 05h
        cmp video_page, 0A000h
        je first
        mov al, 0
        jmp second
first:
        mov al, 1
second:
        int 10h
        pop ax

        jmp fall

end_fall:

;         ; Ожидаем нажатия клавиши

        ; mov ah,0
        ; int 16h

;         ; Возврат в прежний видео режим

        mov ah,0 ; установить видео режим
        mov al,saveMode ; сохраненный видео режим
        int 10h

;         ; Выход из программы

        mov ax,4c00h
        int 21h


main endp

cls proc far
        pusha
        push es
        xor ax, ax
        mov es, ax

        mov edi, video_page
        xor ax,ax
        mov cx,32000d
@@l:
        mov es:[edi], ax
        inc edi
        inc edi
        loop @@l

        pop es
        popa
        ret
cls endp

koch_curve proc far
        ; p1x, p1y, p2x, p2y, n
        push bp
        mov bp, sp
        push ax bx cx dx di si

        cmp word ptr [bp + 6], 0
        jg @@n_more_zero

        push word ptr [bp + 14]
        push word ptr [bp + 12]
        push word ptr [bp + 10]
        push word ptr [bp + 8]
        push 1
        call print_line
        jmp @@exit

@@n_more_zero:

; dec n
        mov si, [bp + 6]
        dec si
        mov [bp + 6], si

;find top of triangle

        push word ptr [bp + 14]
        push word ptr [bp + 12]
        push word ptr [bp + 10]
        push word ptr [bp + 8]
        call trisection
        pop dx cx bx ax

        push ax bx cx dx
        call find_triangle_top
        pop di si

; recursion

        push word ptr [bp + 14] word ptr [bp + 12]
        push ax bx
        push word ptr [bp + 6]
        call koch_curve

        push ax bx si di
        push word ptr [bp + 6]
        call koch_curve

        push si di cx dx
        push word ptr [bp + 6]
        call koch_curve

        push cx dx
        push word ptr [bp + 10] word ptr [bp + 8]
        push word ptr [bp + 6]
        call koch_curve

@@exit:
        pop si di dx cx bx ax bp
        ret 10
koch_curve endp

trisection proc far
        ; p1x, p1y, p2x, p2y
        push bp
        mov bp, sp
        push ax bx cx dx di si

        mov ax, [bp + 12] ; p1x
        mov bx, [bp + 10] ; p1y
        mov cx, [bp + 8] ; p2x
        mov dx, [bp + 6] ; p2y

; a.x a.y b.x b.y

        mov si, dx
        shl si, 1
        add si, bx
        push si

        mov si, cx
        shl si, 1
        add si, ax
        push si

        mov si, bx
        shl si, 1
        add si, dx
        push si

        mov si, ax
        shl si, 1
        add si, cx
        push si

; div a.x a.y b.x b.y 3

        mov bx, 3

        xor dx, dx
        pop ax
        div bx
        mov [bp + 12], ax

        xor dx, dx
        pop ax
        div bx
        mov [bp + 10], ax

        xor dx, dx
        pop ax
        div bx
        mov [bp + 8], ax

        xor dx, dx
        pop ax
        div bx
        mov [bp + 6], ax


        pop si di dx cx bx ax bp
        ret
trisection endp

find_triangle_top proc far
        ; p1x, p1y, p2x, p2y

        push bp
        mov bp, sp
        push ax bx cx dx si di

; vector m

        mov ax, [bp + 8]
        sub ax, [bp + 12]
        push ax

        mov ax, [bp + 6]
        sub ax, [bp + 10]
        push ax

        call rotate_on_60

        pop bx ax

        add ax, [bp + 12]
        add bx, [bp + 10]

        mov [bp + 12], ax
        mov [bp + 10], bx

@@exit:
        pop di si dx cx bx ax bp
        ret 4

find_triangle_top endp

rotate_on_60 proc far
        ; ax, ay

        push bp
        mov bp, sp
        push ax bx cx dx si di

        fild word ptr [bp + 8]
        fld half
        fmulp

        fld sqrt2div2
        fild word ptr [bp + 6]
        fmulp

        faddp

        fild word ptr [bp + 6]
        fld half
        fmulp

        fild word ptr [bp + 8]
        fld sqrt2div2
        fmulp

        fsubp

        frndint
        fistp word ptr [bp + 6]

        frndint
        fistp word ptr [bp + 8]

@@exit:
        pop di si dx cx bx ax bp
        ret

rotate_on_60 endp


print_line proc far
        ; x1, x2, y1, y2, color

        push bp
        mov bp, sp
        push ax bx cx dx si di

        mov ax, [bp + 14]
        mov bx, [bp + 10]
        cmp ax, bx
        jl @g

        mov [bp + 14], bx
        mov [bp + 10], ax
        mov ax, [bp + 12]
        mov bx, [bp + 8]
        mov [bp + 12], bx
        mov [bp + 8], ax

@g:
        x1 equ [bp + 14]
        y1 equ [bp + 12]
        x2 equ [bp + 10]
        y2 equ [bp + 8]
        color equ [bp + 6]

        mov ax, x2
        mov bx, x1
        sub ax, bx ; ax - delta x

        mov bx, y2
        mov cx, y1
        sub bx, cx ; bx - delta y

        cmp bx, 0
        jl ydown

        cmp ax, bx
        jl up

        mov di, bx
        add di, di ; D
        xor si, si
        sub si, ax ; e

        mov cx, x1 ; x
        mov dx, y1 ; y
        push cx dx word ptr color
        call print_point
        inc cx
@l:
        add si, di
        cmp si, 0
        jl @l1
        sub si, ax
        sub si, ax
        inc dx

@l1:
        push cx dx word ptr color
        call print_point
        inc cx
        cmp cx, x2
        jl @l

        jmp @exitl
up: ; то же самое, только dy > dx
        mov di, ax
        add di, di ; D
        xor si, si
        sub si, bx ; e

        mov cx, x1 ; x
        mov dx, y1 ; y
        push cx dx word ptr color
        call print_point
        inc cx
@ll:
        add si, di
        cmp si, 0
        jl @ll1
        sub si, bx
        sub si, bx
        inc cx

@ll1:
        push cx dx word ptr color
        call print_point
        inc dx
        cmp dx, y2
        jl @ll
        jmp @exitl

ydown:
        neg bx
        cmp ax, bx
        jl upd

        mov di, bx
        add di, di ; D
        xor si, si
        sub si, ax ; e

        mov cx, x1 ; x
        mov dx, y1 ; y
        push cx dx word ptr color
        call print_point
        inc cx
@ld:
        add si, di
        cmp si, 0
        jl @l1d
        sub si, ax
        sub si, ax
        dec dx

@l1d:
        push cx dx word ptr color
        call print_point
        inc cx
        cmp cx, x2
        jl @ld

        jmp @exitl
upd: ; то же самое, только dy > dx
        mov di, ax
        add di, di ; D
        xor si, si
        sub si, bx ; e

        mov cx, x1 ; x
        mov dx, y1 ; y
        push cx dx word ptr color
        call print_point
        dec dx
@lld:
        add si, di
        cmp si, 0
        jl @ll1d
        sub si, bx
        sub si, bx
        inc cx

@ll1d:
        push cx dx word ptr color
        call print_point
        dec dx
        cmp dx, y2
        jg @lld
        jmp @exitl


@exitl:
        pop di si dx cx bx ax bp
        ret 10

print_line endp

print_point proc far
        ; x y color
        push bp
        mov bp, sp
        pusha
        push es
        xor ax, ax
        mov es, ax

        ; mov ax,video_page
        ; mov es,ax

        movzx eax, word ptr [bp + 8]
        mov ebx, 80
        mul ebx
        mov edi, eax

        movzx ebx, word ptr [bp + 10]
        mov ecx, ebx
        shr ebx, 3
        add edi, ebx

        and ecx, 111b
        xor ecx, 111b
        mov edx, 1
        shl edx, cl

        add edi, video_page

        mov cl, es:[edi];byte ptr es:[edi]
        or cl, dl
        mov es:[edi], cl;byte ptr es:[edi], cl

        ; mov ax, word ptr [bp + 6]
        ; mov byte ptr es:[edi], al

        pop es
        popa
        pop bp
        ret 6
print_point endp

print_point2 proc far
        ; x, y, color
        push bp
        mov bp, sp
        push ax bx cx dx

        mov cx, [bp + 10] ; left
        mov dx, [bp + 8] ; right
        color equ [bp + 6] ; color

        mov ah, 0ch
        mov al, color
        xor bx, bx ; видео страница
        int 10h

        pop dx cx bx ax bp
        ret 6

print_point2 endp

end main