"Apple" not moving after colliding with it once

Question

After first colliding with the apple it somtimes moves but after that u have no chance of getting it to move. this is checked using the check_collision function the compers both the x and y of the apple to the x and y of the snake.

IDEAL
MODEL small
STACK 100h
DATASEG
; --------------------------

Y dw 100
X dw 100
Board dw 200
TIME_AUX DB 0
PressFlag db 0
SnakeBody dw 8  
Xapple dw 80
yapple dw 80
Random dw 50
; --------------------------
CODESEG
    


PROC moves
    MOV AH, 01h       ; Function 01h - Check for Key Press
    INT 16h
    JZ exit_moves     ; Jump if ZF is set (no key pressed)

    MOV AH, 00h       ; Function 00h - Read Key Stroke
    INT 16h

    ; Check if AH contains 'W' (ASCII value 87)
    CMP AL, 'w'
    je w_pressed
    
    ; Check if AH contains 'S' (ASCII value 83)
    CMP AL, 's'
    je s_pressed
    ; Check if AH contains 'D' (ASCII value 68)
    CMP AL, 'd'
    je d_pressed
    ; Check if AH contains 'A' (ASCII value 65)
    CMP AL, 'a'
    je a_pressed
    ; Check if AH contains '1B' (Escape key)
    

exit_moves:
    RET

ENDP moves

PROC w_pressed
    mov [PressFlag], 1
    SUB [Y], 5
    

    CHECK_TIME1:         ;time checking loop
    MOV AH,2Ch                   ;get the system time
    INT 21h              ;is the current time equal to the previous one(TIME_AUX)?
    CMP DL,[TIME_AUX]            ;is the current time equal to the previous one(TIME_AUX)?

    JE CHECK_TIME1
    MOV [TIME_AUX],DL 

    CALL draw_player
    
    call moves
    CMP [PressFlag],1
    je w_pressed
    
    RET
ENDP w_pressed

PROC d_pressed
    mov [PressFlag], 2
    ADD [X], 5
    

    CHECK_TIME2:          ;time checking loop
    MOV AH,2Ch                   ;get the system time
    INT 21h              ;is the current time equal to the previous one(TIME_AUX)?
    CMP DL,[TIME_AUX]            ;is the current time equal to the previous one(TIME_AUX)?

    JE CHECK_TIME2
    MOV [TIME_AUX],DL 

    CALL draw_player
    
    call moves
    cmp [PressFlag],2
    je d_pressed
    ret
ENDP d_pressed

PROC a_pressed
    mov [PressFlag], 3
    SUB [X], 5
    

    CHECK_TIME3:           ;time checking loop
    MOV AH,2Ch                   ;get the system time
    INT 21h              ;is the current time equal to the previous one(TIME_AUX)?
    CMP DL,[TIME_AUX]            ;is the current time equal to the previous one(TIME_AUX)?

    JE CHECK_TIME3
    MOV [TIME_AUX],DL 

    CALL draw_player
    
    call moves
    CMP [PressFlag],3
    je a_pressed
    ret
ENDP a_pressed

 PROC s_pressed
    ADD [Y], 5
    
    mov [PressFlag], 4
    

    CHECK_TIME4:           ;time checking loop
    MOV AH,2Ch                   ;get the system time
    INT 21h              ;is the current time equal to the previous one(TIME_AUX)?
    CMP DL,[TIME_AUX]            ;is the current time equal to the previous one(TIME_AUX)?

    JE CHECK_TIME4
    MOV [TIME_AUX],DL 

    CALL draw_player
    
    call moves
    CMP [PressFlag],4
    je s_pressed
    RET
ENDP s_pressed

PROC draw_player
    MOV AX, 13h
    INT 10h
    
    MOV AX, 0C07h     ; Function 0Ch, Set Pixel Color
    MOV BH, 0         ; Page number (usually 0 in mode 13h)
    
    MOV CX, [X]       ; X-coordinate
    MOV DX, [Y]       ; Y-coordinate
    MOV SI, 0
    MOV DI, 0
    MOV AL, 2; Color green
    
    draw_row_loop:
    
        draw_pixel_loop:
        
            INC CX
            INC DI
            
            INT 10h
            CMP DI, [SnakeBody]
            JNE draw_pixel_loop
            
            SUB CX, [SnakeBody]
            MOV DI, 0
            INC DX
            INC SI
            
            CMP SI, [SnakeBody]
            
            JNE draw_row_loop
            
            
            
            
        CALL check_collision
            CALL draw_apple
            
            
    
            
    
    RET
ENDP draw_player
 PROC check_collision
    mov ax, [yapple]
    cmp ax, [Y]
    jne skip_draw_apple

    mov bx, [Xapple]
    cmp bx, [X]
    jne skip_draw_apple

    call rnd
    mov dx, [Random]
    mov [Xapple], dx

    CALL draw_apple
    RET

skip_draw_apple:
    RET
ENDP check_collision
            
PROC draw_apple
    
    
    MOV AX, 0C07h     ; Function 0Ch, Set Pixel Color
    MOV BH, 0         ; Page number (usually 0 in mode 13h)
    
    MOV CX, [Xapple]       ; X-coordinate
    MOV DX, [yapple]       ; Y-coordinate
    MOV AL, 2; Color red
    INT 10h
    
    
    
    RET
ENDP draw_apple

        Proc rnd
    mov ah, 2ch
    int 21h
    mov ax , [Random]
    mov [byte ptr Random], dl
    ADD [Random] , AX
    ret
ENDP rnd

PROC game_logic
    CHECK_TIME:                      ;time checking loop
        MOV AH, 2Ch                  ;get the system time
        INT 21h                      ;is the current time equal to the previous one(TIME_AUX)?
        CMP DL, [TIME_AUX]           ;is the current time equal to the previous one(TIME_AUX)?

        JE CHECK_TIME                ;if it is the same, check again

        ; If it reaches this point, it's because the time has passed
        MOV [TIME_AUX], DL           ;update time
        CALL moves
        
        CALL draw_player
        
        

        RET

ENDP game_logic
MOV AX, 13h
INT 10h ; Set video mode 13h (320x200 pixels, 256 colors)

start:
    MOV AX, @data
    MOV DS, AX

    MOV AX, 13h
    INT 10h ; Set video mode 13h (320x200 pixels, 256 colors)

    game_loop:
    
    CALL game_logic
    
    JMP game_loop

exit:
    MOV AX, 4C00h
    INT 21h

END start

I dont even know what to do to fix this im a begginer of x86 Tasm assembly and I was excpecting for this to be straight forward

Answer 1

The pixels were not correctly aligned so when the code tried to check for collision it check all the y values of the snake and all the y values of the apple and same thing for the x values, that would not work because they are not the same size making the into a lucky draw if you will collide or not. I patched it by setting both the apple and the snake to the same size.