Need Help Making Graphics Move By Themselves In Turing

[The Lone Ranger]

Tony @ Sat Dec 12, 2009 3:29 pm wrote:

You are drawing the asteroid outside of the loop, always at the same location. You want to draw it together with the player

code:

Pic.Draw (pic, x, y, picCopy) Pic.Draw (asteroid, x1, y1, picCopy)

And you would obviously have to change the x1/y1 in the same loop as you change x/y.

P.S. there is no need to do "Unable to load JPEG:" checks inside the loop. The check is for loading the image, not drawing it.

Sorry for the double post, but I just put the asteroid inside the loop , and I did change the x1/y1 in the same loop as the x/y, but my asteroids still don't fall down. The picture of the asteroid just keeps poping up every where on the screen. I dont know if it was something I did, but could you please tell me if this was my fault, or something that you told me to do. I would really appreciate that,

Here's what I changed the program to,
View.Set ("graphics:640,427")

var name : string
var chars : array char of boolean
var pic : int := Pic.FileNew ("F:\\images2.jpg")
var backGround : int := Pic.FileNew ("F:\\back.jpg")
var asteroid : int := Pic.FileNew ("F:\\Asteroid.jpg")
var x, y : int
var x1, y1 : int
x := 10
y := 10

put "Please enter your name player one: " ..
put skip
get name

loop
Pic.Draw (backGround, 0, 0, picCopy)

if backGround = 0 then
put "Unable to load JPEG: ", Error.LastMsg
end if

if asteroid = 0 then
put "Unable to load BMP: ", Error.LastMsg
end if

loop

Input.KeyDown (chars)

if chars (KEY_RIGHT_ARROW) then
x := x + 5
elsif chars (KEY_LEFT_ARROW) then
x := x - 5
elsif chars (KEY_UP_ARROW) then
y := y + 5
elsif chars (KEY_DOWN_ARROW) then
y := y - 5
end if
randint (x1, 0, maxx)
randint (y1, 0, maxy)
if pic = 0 then
put "Unable to load JPEG: ", Error.LastMsg
end if
Pic.Draw (pic, x, y, picCopy)
Pic.Draw (asteroid, x1, y1, picCopy)
delay (10)


end loop


end loop

[Tony]

could you explain those two lines that you've added?

code:

randint (x1, 0, maxx) randint (y1, 0, maxy)

[The Lone Ranger]

The zeroes make it so that asteroids pop up anywhere, I will change it so that they are alawys at the top later on, once I figure out how to make the asteroids fall.

[TheGuardian001]

I think what tony meant is, Is there a reason you put those in the loop? Is randomly generating coordinates something you want to repeat?

[The Lone Ranger]

I thought that randomly generating coordinates would make the asteroids appear anywhere, which they do, but the picture of the asteroid still doesn't fall down from the top of the screen.

[TheGuardian001]

That's because you aren't moving them. There is no gravity in programming. If you want something to move, you have to do it yourself.

In your loop, you randomly generate a new coordinate each time, then draw the picture at that new coordinate. This will produce asteroids popping up randomly around the screen.

If you want the asteroid to move down, what should you be doing to the coordinates in the loop, instead of randomizing them?

[The Lone Ranger]

I don't know. Maye take the coordinates out of the loop?

[Tony]

You want to have something like

code:

set-up/initialize your variables loop    move player    move asteroid end loop

The random initial position does the "initialization" type of work, something you want to happen just once, so it's a good idea to put that outside of the loop.

You would still need to add more code to describe how the asteroid moves while inside the loop; and I've hinted that you should take a look at how the player moves.

[TheGuardian001]

Take the randomization out? Yes. But that won't move the thing down.

Draw a dot on a piece of graph paper, then draw another dot down 3 units. What have you done to the coordinates to get it to move down? Do this in your program, and the asteroid will fall.

[The Lone Ranger]

I just made some changes to the program, I'vegot the asteroid to fall down, but a new problem has come up. The asteroid only falls in the same place and I can't move my character anymore. Can anyone help me out?

Here's the new program,

View.Set ("graphics:640,427")

var name : string
var chars : array char of boolean
var pic : int := Pic.FileNew ("F:\\images2.jpg")
var backGround : int := Pic.FileNew ("F:\\back.jpg")
var asteroid : int := Pic.FileNew ("F:\\Asteroid.jpg")
var x, y : int
var x1, y1 : int
x := 10
y := 10
y1 := 427

put "Please enter your name player one: " ..
put skip
get name

procedure game
randint (x1, 100, 599)
Pic.Draw (pic, x, y, picCopy)
Pic.Draw (asteroid, x1, y1, picCopy)
loop
Pic.Draw (asteroid, x1, y1, picCopy)
y1 := y1 - 10
delay (10)
if y1 < 0 then
y1 := 427
Pic.Draw (asteroid, x1, y1, picCopy)
y1 := y1-10
end if
end loop

end game


loop
Pic.Draw (backGround, 0, 0, picCopy)

if backGround = 0 then
put "Unable to load JPEG: ", Error.LastMsg
end if

if asteroid = 0 then
put "Unable to load BMP: ", Error.LastMsg
end if

loop

Input.KeyDown (chars)

if chars (KEY_RIGHT_ARROW) then
x := x + 5
elsif chars (KEY_LEFT_ARROW) then
x := x - 5
elsif chars (KEY_UP_ARROW) then
y := y + 5
elsif chars (KEY_DOWN_ARROW) then
y := y - 5
end if

if pic = 0 then
put "Unable to load JPEG: ", Error.LastMsg
end if
randint (x1, 100, maxx)
randint (y1, 280, maxy)
game
delay (10)


end loop


end loop

[TheGuardian001]

The reason you can no longer move your character is that you suddenly added a new procedure called game, and are now running in a loop inside that procedure. When you have a loop inside of a procedure, that procedure becomes blocking. Since there is a loop inside the procedure, that procedure will never end, and the rest of the code will be ignored.

Instead of having loops inside of a procedure, you should loop the call to the procedure. For example this:

code:

proc game     loop         x -= 1         Pic.Draw(img,x,20,0)         %Never exits, nothing else will run.     end loop end game loop     %stuff     %more stuff     game end loop

Is wrong. Game will never exit and the rest of your main program will never run.
This:

code:

proc game     x -= 1     Pic.Draw(img,x,20,0) end game loop     %stuff     %more stuff     game end loop

Is right. Since there is no loop inside of game, the program will continue once the end of game is reached.

[The Lone Ranger]

OK, but what about the fact that the asteroid only falls in one place during the program.

Also I took the loop out of the procedure, and I was back to where I started, the asteroids don't fall anymore, they just keep apperaring again, and again.

[TheGuardian001]

That's because inside of your loop, you still have these two lines:

code:

randint (x1, 100, maxx) randint (y1, 280, maxy)

As you know, these lines will randomize the asteroids position. If you have these in your loop, the position will randomize every single time. This is not what you want.

You also have this line:

code:

randint (x1, 100, 599)

Inside of your game procedure. This means that every time you run game to move the asteroid down, you will instead send it to a random location. If you don't want it to randomly jump around, don't randomize the position.

As for it only falling in one spot, you know when the asteroid hits the bottom, so once it does, just randomize where it will fall from. You already have code to move it back up to the top, you just need to combine that with code that will move it left or right.

[The Lone Ranger]

Ok, thank you, you guys have been so, much help. All I have to do is make the asteroid not fall in the same place and I'll be done.
Thanks again.