Help with spawning enemies

[Tamaranian]

What is it you are trying to achieve?
I'm attempting to spawn enemies from the right of the screen. They should come in from a random y coordinate then move out of the screen from the left side (x decreases)


What is the problem you are having?
I'm fairly new with working with turing sprites and games and I have no idea how to do this. I know my code is completely wrong, but I hope it gives you guys an idea of what I'm trying to do. I'm not sure where to put the loops and other lines and the sprite won't show up at all :/


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

Turing:

setscreen ("graphics:max;max") var enemy,enemyX,enemyY, picEnemy : int := 0 enemyX := maxx picEnemy := Pic.FileNew ("sprite.JPG") enemy := Sprite.New (picEnemy) loop       randint (enemyY,200,700)       Sprite.SetPosition (enemy, enemyX,enemyY,true)       Sprite.Show (enemy)       enemyX := enemyX - 50 end loop

Please specify what version of Turing you are using
Turing 4.1.1

[evildaddy911]

what you are doing every loop is setting the enemyY to something random, then putting that sprite at the random location. hundreds of times per second. what you want to do is set the y-coord, move it until its offscreen, THEN randomize the y-coord and reset the X.
What you have is pretty close, you just need an inner loop to move the sprite, exiting when its offscreen

[Tamaranian]

evildaddy911 @ Tue Jun 11, 2013 7:52 pm wrote:

what you are doing every loop is setting the enemyY to something random, then putting that sprite at the random location. hundreds of times per second. what you want to do is set the y-coord, move it until its offscreen, THEN randomize the y-coord and reset the X.
What you have is pretty close, you just need an inner loop to move the sprite, exiting when its offscreen

Sorry, could you show me an example or something? I don't really follow..

[evildaddy911]

what you have:

code:

loop     randomize Y     reset X     move left 50 end loop

What you need:

code:

loop     randomize Y     reset X     loop % <- add this loop         move left 50 until offscreen % <- add "until offscreen" condition     end loop end loop

[Tamaranian]

evildaddy911 @ Tue Jun 11, 2013 8:11 pm wrote:

what you have:

code:

loop     randomize Y     reset X     move left 50 end loop

What you need:

code:

loop     randomize Y     reset X     loop % <- add this loop         move left 50 until offscreen % <- add "until offscreen" condition     end loop end loop

code:

setscreen ("graphics:max;max") var enemy,enemyX,enemyY, picEnemy : int := 0 enemyX := maxx picEnemy := Pic.FileNew ("sprite.JPG") enemy := Sprite.New (picEnemy) loop     randint (enemyY,200,700)     Sprite.SetPosition (enemy,enemyX,enemyY,true)     Sprite.Show (enemy)     loop         enemyX := enemyX - 50         if enemyX < 5 then         exit %Testing (Could I use Sprite.Hide/Sprite.Free here?)   end if end loop end loop

Nothing shows up on the screen, but if I put a delay before the first loop it does weird jumps before disappearing. It's randomizing the same enemies Y coordinate instead of different enemy's Y coordinates right?

[Raknarg]

Here's the same code with slight adjustments:

Turing:

setscreen ("graphics:max;max") var enemy, enemyX, enemyY, picEnemy : int := 0 enemyX := maxx picEnemy := Pic.FileNew ("sprite.jpg") enemy := Sprite.New (picEnemy) loop     enemyX := maxx     randint (enemyY, 200, 700)     loop         Sprite.SetPosition (enemy, enemyX, enemyY, true)         Sprite.Show (enemy)         enemyX := enemyX - 1         if enemyX < 5 then             exit %Testing (Could I use Sprite.Hide/Sprite.Free here?)         end if         delay (1)     end loop end loop

First, you need to understand that the first loop is where the initial parameters are set. The second loop is where all the updating happens. In the second loop you tell it to update the position and draw it on screen

Next, you forgot to set the enemy's x position.

Then, you're subracting way too much from x for smooth movement, anbd because there's no delay (even slight) the program just whizzes by rediculously fast, so you can't see anything. Try running this instead.

[Tamaranian]

Raknarg @ Tue Jun 11, 2013 9:31 pm wrote:

Here's the same code with slight adjustments:

Turing:

setscreen ("graphics:max;max") var enemy, enemyX, enemyY, picEnemy : int := 0 enemyX := maxx picEnemy := Pic.FileNew ("sprite.jpg") enemy := Sprite.New (picEnemy) loop     enemyX := maxx     randint (enemyY, 200, 700)     loop         Sprite.SetPosition (enemy, enemyX, enemyY, true)         Sprite.Show (enemy)         enemyX := enemyX - 1         if enemyX < 5 then             exit %Testing (Could I use Sprite.Hide/Sprite.Free here?)         end if         delay (1)     end loop end loop

First, you need to understand that the first loop is where the initial parameters are set. The second loop is where all the updating happens. In the second loop you tell it to update the position and draw it on screen

Next, you forgot to set the enemy's x position.

Then, you're subracting way too much from x for smooth movement, anbd because there's no delay (even slight) the program just whizzes by rediculously fast, so you can't see anything. Try running this instead.

Thank you, that worked perfectly

[Raknarg]

The important thing is that you understand what you did wrong.