Pong Help

[landfarm]

What is it you are trying to achieve?
I am currently trying to make Pong more lively.


What is the problem you are having?
I believe that I am almost done the project, but I have no clue how to add trigonometry or an alternative to add "physics" into the game of Pong. I know it sounds easy, but I have absolutely no idea how to do it. For example, when you hit the ball with the paddle to hit it further to the left, I have no clue how to do this. I'm hoping for a tutorial to help teach me the concept, rather than having someone doing it for me. Btw, I searched on the forums, but I couldn't find what I was looking for.


Post any relevant code (You may choose to attach the file instead of posting the code if it is too long)
Here is my code so far.

Turing:

import GUI var x1, x2, y1, y2, xc, yc : int %Declares the coordinate variables for the game var c, t : int %Declares the counter variables for the game var p1, p2 : int %Declares the points counter for the game var velx, vely, facy, facx : int %Declares the velocity variables for the game var timeprevious, timecurrent, timedifference : int %Declares variables for holding time var font1 : int %Declares variable for font var keys : array char of boolean c := 1 %Counter to see if the game just started t := 1 %Counter to see who's starting the game p1 := 0 p2 := 0 velx := 0 vely := 0 facy := 1 facx := 1 font1 := Font.New ("serif:40") assert font1 > 0 procedure controls1 %Controls for player1     Input.KeyDown (keys)     if keys ('a') and x1 >= 0 then         x1 -= 4     elsif keys ('d') and x1 + 60 <= maxx then         x1 += 4     elsif keys (KEY_SHIFT) then         vely := 2         velx := 2     end if end controls1 procedure controls2 %Controls for player2     Input.KeyDown (keys)     if keys (KEY_LEFT_ARROW) and x2 - 70 >= 0 then         x2 -= 4     elsif keys (KEY_RIGHT_ARROW) and x2 <= maxx then         x2 += 4     elsif keys (KEY_ENTER) then         vely := -2         velx := -2     end if end controls2 procedure player1     if c = 1 then %Intializes the coordinates for player1         x1 := 20         y1 := 30     end if     drawfillbox (x1, y1, x1 + 60, y1 + 20, blue) %Draws player1 end player1 procedure player2     if c = 1 then %Intializes the coordinates for player2         x2 := maxx - 30         y2 := maxy - 30     end if     drawfillbox (x2, y2, x2 - 60, y2 - 20, red) %Draws player2 end player2 procedure ball     drawfilloval (xc, yc, 20, 20, brown) %Draws the ball     if yc - 20 >= 0 and yc + 20 <= maxy then         yc += (vely * facy)     end if     if xc - 20 >= 0 and xc + 20 <= maxx then         xc += (velx * facx)     end if end ball procedure map     Draw.ThickLine (0, maxy div 2, maxx, maxy div 2, 5, black)     Draw.ThickLine (0, maxy, maxx, maxy, 5, black)     Draw.ThickLine (0, 0, maxx, 0, 5, black)     Draw.ThickLine (0, 0, 0, maxy, 5, black)     Draw.ThickLine (maxx, 0, maxx, maxy, 5, black) end map procedure rules     if yc + 20 >= maxy then %Sets up the points system         p1 += 1         c := 1     elsif yc - 20 <= 0 then         p2 += 1         c := 1     end if     if (((xc >= x1 and yc - 20 >= y1) and (xc <= x1 + 60 and yc - 20 <= y1 + 20)) or ((xc >= x2 - 60 and yc + 20 >= y2 - 20) and (xc <= x2 and y2 - 20 <= y2))) and timedifference > 1000 then         facy *= -1 %If the ball ever collides with the players, it rebounds into the opposite direction         facx *= -1         timeprevious := timecurrent %Time is used to prevent the endless facy *= -1 and facx *= -1 if the ball were to ever get "into" the paddles     elsif (xc + 20 >= maxx) or (xc - 20 <= 0) then %The ball rebounds if it hits the walls         facx *= -1     end if end rules procedure update %Update procedure     View.Update     delay (10)     cls end update procedure game     setscreen ("offscreenonly") %Buffers the program to prevent lag     loop         if c = 1 then             timeprevious := Time.Elapsed             xc := 300             yc := 200             vely := 0             velx := 0         end if         timecurrent := Time.Elapsed         timedifference := timecurrent - timeprevious         map         controls1         controls2         player1         player2         ball         put "Red: ", p1         put "Blue: ", p2         update         c += 1         rules %Rules is placed after the "c" counter to prevent "c" from increasing over 1 if one of the decisions in Rules are made     end loop end game var button1 : int %Declares variable for Graphic User Interface (GUI) button %%%%%%%Creates the GUI interface%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% loop     button1 := GUI.CreateButton (maxx div 2, maxy div 2, 0, "Play", game)     Font.Draw ("PONG", (maxx div 2) - 50, (maxy div 2) + 50, font1, black)     exit when GUI.ProcessEvent     View.Update end loop

Please specify what version of Turing you are using
Version 4.1.1

[DtY]

I don't get what the problem is? Is this an assignment with the requirement of using physics or trigonometry?

If that's all you need to do, you could add a display that tells you what angle the ball is coming towards your paddle at.

[landfarm]

Sorry for not being clear. The problem is I don't know how incorporate that into the program. Like, if the ball hits the paddle at 20 degrees, then what? Oh yea, I added an extra "facx *= -1". Also, I just noticed that the ball sometimes gets stuck in the walls and just slides up or down it. What's going on there?

[TerranceN]

Dont worry about angles, just reverse the y-direction (this will give the same effect) when it hits the paddles (but not the x-direction too). It gets stuck on the wall because of the if statement that stops y-axis movement when the ball is out of a certain range. Make the ball always move (get rid of the if statements), and let the walls take care of keeping the ball in the game.

Hope that helps.

[landfarm]

Oh yea, my bad. I forgot about that. K, I didn't understand what you were getting at TerranceN, but I found a work-around, so that when the ball did touch the walls, it would instantly move away 5, in addition to the negative velocities. Thanks!

[TerranceN]

Sorry, I should have been more clear. I meant this part:

Turing:

if yc - 20 >= 0 and  yc + 20 <= maxy  then     yc += (vely * facy) end if if xc - 20 >= 0 and xc + 20 <= maxx then     xc += (velx * facx) end if

Because of these if statements, when it goes out of bounds it will stop moving, and your other out of bounds checking only changes direction so it will not be moved back inside the bounds.

[landfarm]

Um, sorry for a late reply. I just checked this thread now. Anyway, thanks TerranceN for helping. Turns out that's what I fixed at the same time.

[USEC_OFFICER]

Figures.