我寫的蘋果
==

在主函式加這個

call getinput
call makefloor
call makewall
...
"⭣⭣⭣⭣⭣⭣⭣⭣⭣⭣⭣⭣⭣"
call makeapple
"⭡⭡⭡⭡⭡⭡⭡⭡⭡⭡⭡⭡⭡"
...
call campus
call drawCross	

makeapple
--

;--------------------------------------------
makeapple PROC uses eax ebx ecx edx esi edi
; create apple in screen buffer (use ray-casting)
; Input: Nothing 
; Output: Nothing
;--------------------------------------------
    mov esi, camd
    sub esi, SCREEN_W/2
    cmp esi, 0
    mov edi, 0
    jl w_negative
    jmp w_positive
w_negative:
    add esi, 360
w_positive:
    mov dl, SCREEN_W-1

    mov ebx, 0
    push ebx
w_loop:
    cmp dl, 0
    jl w_loop_done    ;(counter)loop through fov angles and shoot rays
        .IF esi >= 360
            sub esi, 360
        .ENDIF
        mov eax, esi    ;save angle to eax
        call shootray_for_apple    ;shoot ray to current direction vector
        mov eax, ebx    ;save distance to eax
        cmp ebx, 0
        jl no_intersect
            .if ecx == 4
                pop ebx
                .if bl == 0
                    mov bl, dl    ;bl is right aplle
                .endif
                mov bh, dl        ;bh is left apple
                push ebx
            .endif
no_intersect:
        inc esi
        dec dl
    jmp w_loop
w_loop_done:
    pop ebx
    
    .if bl != bh
        mov cl, bl
        sub cl, bh

        mov dh, SCREEN_H/2
        mov dl, bh
        add dl, bl
        shr dl, 1
        ; 19, 12, 7, 5, 3
        .if cl > 3
            .if cl > 19
                mov ecx, 1
            .elseif cl > 12
                mov ecx, 2
            .elseif cl > 7
                mov ecx, 3
            .elseif cl > 5
                mov ecx, 4
            .else
                mov ecx, 5
            .endif
            call fillapple
        .endif

    

        
    .endif



    ret
makeapple ENDP

shootray_for_apple
---

;--------------------------------------------
shootray_for_apple PROC uses eax edx esi ebp
; cast ray to selected angle 
; Input: eax=angle
; Output: ebx=max length, ecx=type, edi=2nd length
;--------------------------------------------
mov esi, eax
	mov ebx, -1
	mov ecx, 0
	mov edi, 0
	;loop through all blocks
	mov edx, 0
	.WHILE dh < WORLD_Y	;loop y
		.WHILE dl < WORLD_X ;loop x
			call wctoi	;index is in eax
			movzx eax, world[eax]
			mov ebp, eax
			.IF  eax == 1 || eax == 4	; is a block
				call wctorc
				;south
				mov eax, tmp[0*TYPE vector].x
				mov tmp[1*TYPE vector].x, eax
				mov eax, tmp[0*TYPE vector].y
				mov tmp[1*TYPE vector].y, eax
				mov eax, tmp[1*TYPE vector].x
				add eax, BLOCK_SIZE
				mov tmp[1*TYPE vector].x, eax
				call intersect
				.IF eax < ebx || ebx == -1
					mov edi, ebx
					mov ebx, eax
					mov ecx, ebp
				.ENDIF
				;east
				add tmp[0*TYPE vector].x, BLOCK_SIZE
				add tmp[1*TYPE vector].y, BLOCK_SIZE
				call intersect
				.IF eax < ebx || ebx == -1
					mov edi, ebx
					mov ebx, eax
					mov ecx, ebp
				.ENDIF
				;south
				add tmp[0*TYPE vector].y, BLOCK_SIZE
				sub tmp[1*TYPE vector].x, BLOCK_SIZE
				call intersect
				.IF eax < ebx || ebx == -1
					mov edi, ebx
					mov ebx, eax
					mov ecx, ebp
				.ENDIF
				;west
				sub tmp[0*TYPE vector].x, BLOCK_SIZE
				sub tmp[1*TYPE vector].y, BLOCK_SIZE
				call intersect
				.IF eax < ebx || ebx == -1
					mov edi, ebx
					mov ebx, eax
					mov ecx, ebp
				.ENDIF
			.ENDIF
			inc dl
		.ENDW
		mov dl, 0
		inc dh
	.ENDW
	ret
shootray_for_apple ENDP

fillapple
--

fillapple proc uses eax esi
; fill apple in screen buffer (use ray-casting)
; Input: edx(center coordinate), ecx(apple type) 
; Output: Nothing
;--------------------------------------------

	; 將圖案字串的地址載入 esi
	.if	ecx == 1
		lea esi, apple_pic1      
	.elseif ecx == 2
		lea esi, apple_pic2
	.elseif ecx == 3
		lea esi, apple_pic3
	.elseif ecx == 4
		lea esi, apple_pic4
	.elseif ecx == 5
		lea esi, apple_pic5
	.endif
	
	
	sub dl, [esi]
	inc esi
	sub dh, [esi]
	inc esi

	mov bh, dl
loop_h:
    lodsb                   ; 載入字元到 AL
	mov bl, al

	cmp bl, 0				; 讀完了
	je done

    cmp bl, 0dh             ; 檢查是否是換行符
    je new_line             ; 如果是換行符，跳到新行

	cmp bl, '*'
	je skip

    ; 計算索引
    call ctoi               ; 呼叫 ctoi，結果存入 EAX
    mov pixels[eax], bl     ; 將圖案字元寫入 pixels 陣列
skip:
	inc dl
	
	jmp loop_h 

	
new_line:
    inc dh                  ; y 值加 1
	mov dl, bh
    jmp loop_h				; 繼續處理

done:
    ret
		
fillapple endp