Moving when something touches it

[J-MoNeY]

I'm doing an Air Hockey game. So far I have the paddle moving using input keydown and I need help making it so that the puck will move when the paddle collides with the puck.

[J-MoNeY]

Sorry for double posting but forgot the code

Quote:

%********************************
%name block ICS ICS ICS ICS ICS
%name - James Nguyen
%date - September 18, 2006
%program description - game using input keydown
%*********************************
%
%
%*********************************
%Algorithm
%A set of instructions in order, used to pre-plan a program
%*********************************
%
%
%*********************************
%Variables Dictionary
%declare variable by name and type
var chars : array char of boolean
var x : int := 325 %..................x location of gamepiece
var y : int := 150 %..................y location of gamepiece
var a : int := 0 %....................comp score
var b : int := 0 %....................playa score
var ballx : int := 325 %..............x location of ball
var bally : int := 250 %..............y location of ball
%*********************************
%
%
%*********************************
%Procedures/Subprograms/Subroutines
%do each seperatly in a block

%<><><><><><><><><><><><><><><><><><>THE SCREEN BACKROUND
proc settings
drawfillbox (0, 0, 700, 700, brightblue) %......backround
drawfillbox (270, 0, 400, 20, black) %..........net
drawfillbox (270, 450, 400, 430, black) %.......net
drawfillbox (0, 450, 639, 479, white) %.........top
locate (1, 1) %.................................locates the put
put "Computer score: ", a %.....................shows the score
locate (1, 30) %................................locates the put
put "Player score: ", b %.......................shows the score
end settings

%<><><><><><><><><><><><><><><><><><>THE GAMEPIECE
proc gamepiece
drawfilloval (x, y, 25, 25, red) %.............draws the main gamepiece
drawfilloval (x, y, 10, 10, grey) %............part of the gamepiece
end gamepiece

%<><><><><><><><><><><><><><><><><><>THE BALL
proc ball
drawfilloval (ballx, bally, 15, 15, black) %...draws the ball
end ball

%*********************************
%
%
%*********************************
%Mainline
%step by step enter the program
settings %...................................draws backround

loop %.......................................repeats forever
setscreen ("offscreenonly") %............puts things into memory
settings %...............................puts backround up again
gamepiece %..............................puts gamepiece on screen
ball %...................................puts ball on screen

Input.KeyDown (chars) %..................checks for what characters are touched
if chars (KEY_UP_ARROW) then %...........checks if the player touches up key
delay (2) %..........................slows the game
View.Update %........................puts things into memory
y := y + 1
end if
if chars (KEY_RIGHT_ARROW) then %........checks if player touches right arrow
delay (2) %..........................slows the game
View.Update %........................puts things into memory
x := x + 1
end if
if chars (KEY_LEFT_ARROW) then %.........checks if player touches left key
delay (2) %..........................slows the game
View.Update %........................puts things into memory
x := x - 1
end if
if chars (KEY_DOWN_ARROW) then %.........checks if player touches down key
delay (2) %..........................slows the game
View.Update %........................puts things into memory
y := y - 1
end if

%.......................................prevents game piece from goin left off screen
if x < 30 then %........................checks if gamepiece goes too far left
x := x + 1
end if
%.......................................prevents game piece from going off screen
if y > 420 then %.......................checks if game piece goes too far off screen
y := y - 1
end if
%.......................................prevents game piece from going off screen
if x > 610 then %.......................checks if game piece goes too far off screen
x := x - 1
end if
%.......................................prevents game piece from going off the screen
if y < 30 then %........................checks if game piece goes too far off screen
y := y + 1
end if

end loop
%*********************************

[Clayton]

What you are looking for is Collision Detection

also, your commenting could use a little work. you dont need to comment every single line of code you produce, variables should rarely need to be commented as their names should be all you need to tell you what they do. var a,b : int is not going to tell you in their names that what they do is hold the scores for the computer and player respectively. naming for variables also applies to procedures as well, the procedure "settings" sounds to me like it should control settings of the game, instead it draws the background

also:

Turing:

if chars (KEY_UP_ARROW) then %...........checks if the player touches up key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         y := y + 1     end if     if chars (KEY_RIGHT_ARROW) then %........checks if player touches right arrow         delay (2) %..........................slows the game         View.Update %........................puts things into memory         x := x + 1     end if     if chars (KEY_LEFT_ARROW) then %.........checks if player touches left key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         x := x - 1     end if     if chars (KEY_DOWN_ARROW) then %.........checks if player touches down key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         y := y - 1

would be better as a single if construct using the elsif keyword instead of separate ifs. the reason for this is, if you hold down both the up and down arrow keys at the same time, you wont move! because "chars" is an [/b]array char of boolean[/b] (meaning it is an array with the number of elements being equal to the number of accessible characters with the type being boolean) you can have more than one char being pressed and Input.KeyDown will register all of them. Check out this tutorial if you need help on anything, as well, check out the entire Turing Walkthrough if you want to find out anything more.

One last thing, remember to post code within [code ][/code ] or [syntax=][/syntax ] tags (without the spaces) as it allows your code to keep its indentation on the site

[J-MoNeY]

Thanks Freakman. I have another question. When I run my program and I click off the screen everything but the backround and score disapears until I touch any of the moving keys.

[Clayton]

its just because you catch it whenever the screen buffer is cleared (due to the effects of Draw.Cls) which you should consequentially read about here as your commenting about it suggests that you dont really understand whats going on.

[J-MoNeY]

Ok...heres what my code looks like now. Its really messed up.

code:

%******************************** %name block    ICS    ICS     ICS     ICS     ICS %name - James Nguyen %date - September 18, 2006 %program description - game using input keydown %********************************* % % %********************************* %Algorithm %A set of instructions in order, used to pre-plan a program %********************************* % % %********************************* %Variables Dictionary %declare variable by name and type var chars : array char of boolean var x : int := 325 %..................x location of gamepiece var y : int := 150 %..................y location of gamepiece var compscore : int := 0 %............comp score var playerscore : int := 0 %..........playa score var ballx : int := 325 %..............x location of ball var bally : int := 250 %..............y location of ball var ballr : int := 15 %...............radius of ball var radius : int := 25 %..............radius of the paddle var nx, ny, nx2, ny2 : int := 1 %.....vars for the chage in qroadents %********************************* % % %********************************* %Procedures/Subprograms/Subroutines %do each seperatly in a block %<><><><><><><><><><><><><><><><><><>THE SCREEN BACKROUND proc backround     drawfillbox (0, 0, 700, 700, brightblue) %......backround     drawfillbox (270, 0, 400, 20, black) %..........net     drawfillbox (270, 450, 400, 430, black) %.......net     drawfillbox (0, 450, 639, 479, white) %.........top     locate (1, 1) %.................................locates the put     put "Computer score: ", compscore .. %..........shows the score     locate (1, 30) %................................locates the put     put "Player score: ", playerscore .. %..........shows the score end backround %<><><><><><><><><><><><><><><><><><>THE GAMEPIECE proc gamepiece     drawfilloval (x, y, 25, radius, red) %..........draws the main gamepiece     drawfilloval (x, y, 10, 10, grey) %.............part of the gamepiece end gamepiece %<><><><><><><><><><><><><><><><><><>THE BALL proc ball     drawfilloval (ballx, bally, ballr, ballr, black) %...draws the ball end ball %********************************* % % %********************************* %Mainline %step by step enter the program backround %..................................draws backround gamepiece %..................................draws gamepiece ball %.......................................draws ball loop %.......................................repeats forever     setscreen ("offscreenonly") %............puts things into memory     backround %..............................puts backround up again     gamepiece %..............................puts gamepiece on screen     ball %...................................puts ball on screen     Input.KeyDown (chars) %..................checks for what characters are touched     if chars (KEY_UP_ARROW) then %...........checks if the player touches up key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         y := y + 1     elsif chars (KEY_RIGHT_ARROW) then %.....checks if player touches right arrow         delay (2) %..........................slows the game         View.Update %........................puts things into memory         x := x + 1     elsif chars (KEY_LEFT_ARROW) then %......checks if player touches left key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         x := x - 1     elsif chars (KEY_DOWN_ARROW) then %......checks if player touches down key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         y := y - 1     end if     if ballx + ballr > x - radius and ballx - ballr < x + radius and bally + ballr > y - radius and bally - ballr < y + radius then         nx := nx * -1         ny := ny * -1         nx2 := nx2 * -1         ny2 := ny2 * -1     end if     x += nx     y += ny     ballx += nx2     bally += ny2     delay (15)     %........................................prevents game piece from goin left off screen     if x < 30 then %.........................checks if gamepiece goes too far left         x := x + 1     end if     %........................................prevents game piece from going off screen     if y > 420 then %........................checks if game piece goes too far off screen         y := y - 1     end if     %........................................prevents game piece from going off screen     if x > 610 then %........................checks if game piece goes too far off screen         x := x - 1     end if     %........................................prevents game piece from going off the screen     if y < 30 then %.........................checks if game piece goes too far off screen         y := y + 1     end if end loop %*********************************

[Clayton]

this is gonna require some good knowledge of trig to pull off and make it look half decent, not to say give up on it completely, but maybe start with something a bit less complex for now, unless you want to figure out all of the trig etc, i dont think you are quite up to this task right now

for your collision detection though, as both of your objects that are colliding are circles, use Math.Distance (x1, y1, x2, y2 : int), which uses the distance formula to calculate the distance between two points (x1,y1) (x2,y2).

[J-MoNeY]

We haven't learned Math.Distance yet in our class and our teacher isn't very smart, so could you explain how I would use Math.Distance for my program?

[NikG]

All you need to do is search this site!
But I did it for you: Math.Distance tutorial

For future reference, check out the Turing Walkthrough page before asking for help on something. I'm sure it'll cover most of the questions you'll have.

[J-MoNeY]

I've read that tutorial but I'm still not sure how to use it in my program.

[TheOneTrueGod]

If the distance between two objects is less than the combined radius, then they have collided.

code:

ob2Rad         V ob1     |   |     ob2             ^           ob1Rad

omg they have collided

Then you just apply trig ratios. You can get the angle between the two by using Math.Angle (Though I prefer my function, as it proves that I actually know what i'm doing, as opposed to proving that the people who created Turing knew what they were doing ).

Use this angle, and the paddle's speed (if you are using the mouse) to calculate how much force you should apply to the puck. I suggest you use the mouse, only because it allows you to hit the puck based on how hard you move the mouse... Though you would have to do some extra checks to see if you actually hit the puck or not.

[[Gandalf]]

TheOneTrueGod wrote:

You can get the angle between the two by using Math.Angle (Though I prefer my function, as it proves that I actually know what i'm doing, as opposed to proving that the people who created Turing knew what they were doing ).

Incidentally, Math.Angle is your function.

Math.Angle is not a function that comes with any official version of Turing, so either you created it and added it in, or someone else created it and you added it in.

[TheOneTrueGod]

Quote:

Incidentally, Math.Angle is your function.

Incidentally, yes it is, however, I wrote it before coming on this site, and before seeing any other implementations of it, so i'm proud of my work

Anyways, since math.Angle apparantly doesn't come with Turing, i'll give you a l'il tutorial, but this is meant to be followed up by classwork...

[syntax="ASCII Art Involved"]
Note: FOR RIGHT TRIANGLES ONLY.
Hypoteneuse
|| /|
|V/ |Opposite
|/o |
-------------
|Adjacent
|
|

o = "theta" (Its an angle. The others are the sides of the triangle)

O = Opposite (Called thus because it is OPPOSITE theta)
A = Adjacent (Called thus because it is ADJACENT to theta, and it isn't the hypoteneuse)
H = Hypoteneuse (Called thus because some guy thought it would be cool to give the longest side the longest name )

SOH CAH TOA
Sin(theta) = O/H
Cos(theta) = A/H
tan(theta) = O/A

Now, you can apply these concepts something like this

[calculator notation]
tan^-1(O/A) = theta

[turing notation]
arctand(O/A)

Where "arctan" is what tan^-1 is called, and "d" tells it you are working in degrees (And "arctan(O/A)" would be in

radians)

Remember, when A = 0, this is a special case.
[/syntax]

Hopefully that helps... If there isn't a tutorial on this stuff allready, I could try turning this into one if necessary...

[J-MoNeY]

I think I've got the collision detection working, but I can only get the puck moving in 1 direction (the left) and when it moves its moving too fast for me to see so its like disapering to the left everytime my paddle collides with it and when i hit the puck to the far left my ifs don't stop the puck from going off the screen and bouncing off somewhere else. I'm using input keydown because this is our first assignment and our teacher wants it to be a game using keydown only.

code:

%******************************** %name block    ICS    ICS     ICS     ICS     ICS %name - James Nguyen %date - September 18, 2006 %program description - air hockey game using input keydown %********************************* % % %********************************* %Algorithm %A set of instructions in order, used to pre-plan a program %********************************* % % %********************************* %Variables Dictionary %declare variable by name and type var chars : array char of boolean var x1 : int := 325 %..................x location of gamepiece var y1 : int := 150 %..................y location of gamepiece var compscore : int := 0 %.............comp score var playerscore : int := 0 %...........playa score var x2 : int := 325 %..................x location of ball var y2 : int := 250 %..................y location of ball var r2 : int := 15 %...................radius of ball var r : int := 25 %....................radius of the paddle var xchange, ychange : int := 1 var xchange2, ychange2 : int := 200 %********************************* % % %********************************* %Procedures/Subprograms/Subroutines %do each seperatly in a block %<><><><><><><><><><><><><><><><><><>THE SCREEN BACKROUND proc backround     drawfillbox (0, 0, 700, 700, brightblue) %......backround     drawfillbox (270, 0, 400, 20, black) %..........net     drawfillbox (270, 450, 400, 430, black) %.......net     drawfillbox (0, 450, 639, 479, white) %.........top     locate (1, 1) %.................................locates the put     put "Computer score: ", compscore .. %..........shows the score     locate (1, 30) %................................locates the put     put "Player score: ", playerscore .. %..........shows the score     drawfilloval (600, 250, 25, 25, grey) %.........trap1     drawfilloval (35, 250, 25, 25, grey) %..........trap2 end backround %<><><><><><><><><><><><><><><><><><>GAMEPIECE OF THE PADDLE proc gamepiece     drawfilloval (x1, y1, r, r, red) %..............draws the main part of game piece     drawfilloval (x1, y1, 20, 20, yellow) %.........draws the handle of the paddle'     drawfilloval (x1, y1, 18, 18, brightblue) %.....draws the handle of the paddle'     drawfilloval (x1, y1, 15, 15, brightred)    %...draws the handle of the paddle'     drawfilloval (x1, y1, 12, 12, grey)        %....draws the handle of the paddle'     drawfilloval (x1, y1, 10, 10, 6)        %.......draws the handle of the paddle'     drawfilloval (x1, y1, 8, 8, 10)            %....draws the handle of the paddle'     drawfilloval (x1, y1, 6, 6, 13)             %...draws the handle of the paddle' end gamepiece %<><><><><><><><><><><><><><><><><><>THE BALL proc puck     drawfilloval (x2, y2, r, r, black) %..........draws the ball end puck %********************************* % % %********************************* %Mainline %step by step enter the program backround %..................................draws backround gamepiece %..................................draws gamepiece puck %.......................................draws ball loop %.......................................repeats forever     setscreen ("offscreenonly") %............puts things into memory     backround %..............................puts backround up again     gamepiece %..............................puts gamepiece on screen     puck %...................................puts ball on screen     Input.KeyDown (chars) %..................checks for what characters are touched     if chars (KEY_UP_ARROW) then %...........checks if the player touches up key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         y1 := y1 + 1     elsif chars (KEY_RIGHT_ARROW) then %.....checks if player touches right arrow         delay (2) %..........................slows the game         View.Update %........................puts things into memory         x1 := x1 + 1     elsif chars (KEY_LEFT_ARROW) then %......checks if player touches left key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         x1 := x1 - 1     elsif chars (KEY_DOWN_ARROW) then %......checks if player touches down key         delay (2) %..........................slows the game         View.Update %........................puts things into memory         y1 := y1 - 1     end if     if Math.Distance (x1, y1, x2, y2) < r * 2 then         x1 += xchange         x2 -= xchange2     end if     %........................................prevents game piece from goin left off screen     if x1 < 30 then %........................checks if gamepiece goes too far left         x1 := x1 + 1     end if     %........................................prevents game piece from going off screen     if y1 > 420 then %.......................checks if game piece goes too far off screen         y1 := y1 - 1     end if     %........................................prevents game piece from going off screen     if x1 > 610 then %.......................checks if game piece goes too far off screen         x1 := x1 - 1     end if     %........................................prevents game piece from going off the screen     if y1 < 30 then %........................checks if game piece goes too far off screen         y1 := y1 + 1     end if     %........................................prevents game piece from goin left off screen     if x2 < 30 then %.........................checks if gamepiece goes too far left         x2 := x2 + 1     end if     %........................................prevents game piece from going off screen     if y2 > 420 then %.......................checks if game piece goes too far off screen         y2 := y2 - 1     end if     %........................................prevents game piece from going off screen     if x2 > 610 then %.......................checks if game piece goes too far off screen         x2 := x2 - 1     end if     %........................................prevents game piece from going off the screen     if y2 < 30 then %........................checks if game piece goes too far off screen         y2 := y2 + 1     end if end loop %*********************************