Space invaders - speed of enemies

[chipanpriest]

Hey I was wondering if there is a way to make the enemies move down slower without having a delay in the game thanks

[Aange10]

A: You can lower their velocity.
B: You can setup a timer.
C: You could delay it but that'd be stupid. (However in this case, you should delay it to at least 60FPS ... Time.DelaySinceLast (17)

[chipanpriest]

So Time.DelaySinceLast is just a better version of delay?? cause ive always used delay before

[Aange10]

Yes, read up on this post: http://compsci.ca/v3/viewtopic.php?t=30297

[Dreadnought]

Time.DelaySinceLast is really useful in the common situation where you would like to regulate the frequency of a loop's repetition. But it shouldn't be a direct substitute for delay, since it does not really do what delay does. Take this example:

Turing:

put "Hello" Time.DelaySinceLast(2000) % First delay cls for i:1..100000     locate (1,1)     put i end for put "Done!" Time.DelaySinceLast(2000) % Second delay cls put "Have a nice day!"

The "second delay" is almost non-existent. So the word "Done!" might not be seen by the user. However, using Time.Delay (2000) would have made a 2 second delay each time. The functionality is not identical.

I doubt you would actually use this procedure in such a way, but I just wanted to clarify that although it is often more useful than delay, it should not be seen as a direct substitute.

As a side note, you could actually implement it yourself if you wanted to. This is the code for Time.DelaySinceLast taken directly from the code for the Time module:

Turing:

var timeOfLastCall := 0 procedure DelaySinceLast (delayTime : int)     if Time.Elapsed < timeOfLastCall + delayTime then         Time.Delay (timeOfLastCall + delayTime - Time.Elapsed)     end if     timeOfLastCall := Time.Elapsed end DelaySinceLast

[chipanpriest]

This is another, kind of separate question but based on the same idea. Could i not do something like:

Turing:

var t : int := Time.Elapsed if t = 5000 then Ey -= 20 %first row of enemies moving down Ey2 -= 20 %second row of enemies moving down end if

Would this work? And if so, could I somehow make it so it would move down every 5000 milliseconds without doing the code above multiple times?

[Aange10]

Indeed, here is an example of a timer.

[chipanpriest]

But what I'm trying to say is, is there a way to make something happen in intervals with only one set of code?

For example, It would be a pain to do this:

Turing:

if Time.Elapsed() = 5000 then Ey -= 1 elsif Time.Elapsed() = 10000 then Ey -= 1 elsif Time.Elapsed() = 15000 then Ey -= 1 %etc %etc

Would there be a way to make it so the y value decreases every 5000 milliseconds in just one set of code instead of doing that^?

[Aange10]

Mhm.....

Turing:

var timer : int := 0 loop  if Time.Elapsed () - timer >= 5000 then    Ey -= 1    timer := Time.Elapsed () end if end loop

Now ever 5 seconds it moves down... Just like the code in the thing I uploaded. You could hard code it all if you wanted, but whats the point?

[chipanpriest]

yea i got it thanks Ima upload it soon