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Mr. T

Fri Mar 18, 2005 10:10 pm


Snake Wall Collision

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I am trying to get my program to exit when the snake hits the black wall.
Can someone explain what I'm doing wrong in my whatdotcolour. thanks
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%variable declaration
View.Set ("graphics:400;300")
var box1 : int := 0
var box2 := maxy
var box3 := maxx
var box4 := 0
var col : int := 31
var countdown : int := 6
var ballx1 : int := 200
var bally1 : int := 150
var ballsize : int := 5
var move, move2, move3, move4 := false
var key : array char of boolean
move3 := true %starting direction of snake

%gives time for user to get ready
loop
    locate (9, 20)
    put "Starting in...", countdown - 1
    delay (300)
    countdown := countdown - 1
    cls
    exit when countdown = 0
end loop

%ball movement
loop
    drawbox (box1, box2, box3, box4, 7)
    drawfilloval (ballx1, bally1, ballsize, ballsize, col)
    if move then
        bally1 += 5
    elsif move2 then
        bally1 -= 5
    elsif move3 then
        ballx1 += 5
    elsif move4 then
        ballx1 -= 5
    end if
    Input.KeyDown (key)
    if key (KEY_UP_ARROW) then         %if up arrow is pressed
        move2 := false
        move3 := false
        move4 := false
        move := true
    elsif key (KEY_DOWN_ARROW) then          %if down arrow is pressed
        move := false
        move3 := false
        move4 := false
        move2 := true
    elsif key (KEY_RIGHT_ARROW) then              %if right arrow is pressed
        move := false
        move2 := false
        move4 := false
        move3 := true
    elsif key (KEY_LEFT_ARROW) then          %if left arrow is pressed
        move := false
        move2 := false
        move4 := true
        move3 := false
    end if
    drawfilloval (ballx1, bally1, ballsize, ballsize, 12)     %deletes the tail
    delay (100)
    if whatdotcolour (ballx1, bally1) = black then
        exit
    end if
end loop