Snake Game Help

[Phenomena]

Okay I've been learning turing in my grade 11 Computer Engineering class, and as the final project for this unit we have to make a video game. I decided to make a simple snake game. The only problem is, we never learnt how to identify if a character has been pressed, so my question how do i tell if the one of the arrow keys has been pressed.

so far for my snake i have this

code:

colourback (grey) cls var ch:string (1) var cx,cy,x,y:int :=0 var s,g:int := 0 var e,m,d,l:string e:="Easy" m:="Medium" d:="Hard" Text.Locate (10,30) put ("Select Difficulty:") Text.Locate (11,35) put e Text.Locate (11,39) put (" - 1") Text.Locate (12,35) put m Text.Locate (12,41) put (" - 2") Text.Locate (13,35) put d Text.Locate (13,39) put (" - 3") Text.Locate (14,28) put ("Enter Difficulty Number:") Text.Locate (15,39) get g cls Text.Locate (8,20) put ("Instructions: Use the arrow keys to direct your snake") Text.Locate (9,20) put ("to the GREEN apples, but watch out for the poisnous") Text.Locate (10,20) put ("RED apples. Eat a red apple and its game over for you") delay (5000) cls for i: 1 .. maxx by 20     drawline (i,0,i,400,white) end for for h: 1 .. maxy by 20     drawline (0,h,750,h,white) end for randint (cx,1,120) randint (cy,1,75) proc screen if     g = 1     then l := e end if if     g = 2     then l := m end if if     g = 3     then l := d  end if put ("Score:") Text.Locate (1,8) put s Text.Locate (1,65) put ("Level:") Text.Locate (1,73) put l drawfilloval (cx * 5, cy * 5, 5, 5,green) end screen screen proc snake for x: 293 .. 321 by 14     drawfilloval (x,y+200,7,7,black) end for end snake snake

its my first application with turing so it may be bit rough >_>

[neufelni]

To use the arrow keys you need to use Input.KeyDown. Here is a little program that I wrote to show how to use it.

code:

View.Set ("offscreenonly") var input : array char of boolean var x, y : int := 200 var direction : string := "right" loop     Input.KeyDown (input)     if input (KEY_RIGHT_ARROW) then         direction := "right"     elsif input (KEY_LEFT_ARROW) then         direction := "left"     elsif input (KEY_UP_ARROW) then         direction := "up"     elsif input (KEY_DOWN_ARROW) then         direction := "down"     end if     if direction = "right" then         x += 1     elsif direction = "left" then         x -= 1     elsif direction = "up" then         y += 1     elsif direction = "down" then         y -= 1     end if     Draw.FillOval (x, y, 10, 10, 7)     delay (5)     View.Update     cls end loop

This tutorial might also help.
http://www.compsci.ca/v2/viewtopic.php?t=114
You might also want to go through the Turing Walkthroug.
http://compsci.ca/v2/viewtopic.php?t=8808

[ericfourfour]

Here is exactly the same thing that Nick did, except it uses arrays. I thought it would be useful since you will need arrays in your snake game if you want to track where the snake has turned etc.

code:

View.Set ("offscreenonly") const UP := 0 const DOWN := 1 const LEFT := 2 const RIGHT := 3 var input : array char of boolean var x, y := 200 var dir := RIGHT var dirs : array 0 .. 3 of char dirs (UP) := KEY_UP_ARROW dirs (DOWN) := KEY_DOWN_ARROW dirs (LEFT) := KEY_LEFT_ARROW dirs (RIGHT) := KEY_RIGHT_ARROW loop     Input.KeyDown (input)     for i : 0 .. upper (dirs)         if input (dirs (i)) then             dir := i             exit         end if     end for     if dir = UP then         %action for going right         y += 1     elsif dir = DOWN then         %action for going left         y -= 1     elsif dir = LEFT then         %action for going up         x -= 1     elsif dir = RIGHT then         %action for going down         x += 1     end if     Draw.FillOval (x, y, 10, 10, 7)     Time.DelaySinceLast (5)     View.Update     cls end loop

[Phenomena]

heh thanks guys it helped out alot

now i have to set up the collision... sounds fun >_>

[ericfourfour]

In my previous post I wrote in the wrong directions in the comments. It should be:

code:

if dir = UP then     %action for going up     y += 1 elsif dir = DOWN then     %action for going down     y -= 1 elsif dir = LEFT then     %action for going left     x -= 1 elsif dir = RIGHT then     %action for going right     x += 1 end if

[Phenomena]

heh thanks to you guys this is almost done. Im just having troubles with the last few things

im actually proud of myself, although ive probably done in this in the most ineffecient way its actually kinda fun and its my first app

[Phenomena]

sorry for double post but i cant edit my last post.

anyways maybe you guys could help me with one last thing. I need to create the red (poisnous) apples. But my problem is since the red apples dont disappear, but just add new ones to the board the way I see it id need to have an infinite amount of variables to do that. Which obvisouly wont work

anyways maybe you guys could just point me in the right direction, i wont learn if you guys just give me the code XD

[ericfourfour]

You should probably look up flexible arrays (resizable arrays) and types/records. This would be a simple solution. You could have the types hold the data for the apples and the flexible array could hold the data type.

If you want to go overboard try using classes (OOP). It will take more than a week or maybe a month to learn how to use classes. Then you have to learn how to use them effectively which will take even longer.

[Phenomena]

well since i only have about a week left ill go with the first

thanks