Sprite thrusters lag me!

I'm working on creating a thruster system for my space game with sprites. So far, it looks very pretty and I can run the thing at a good 60 FPS with my ship and a bot or two. However, when I add another AI bot, lag occurs heavily. Is there something i'm doing wrong with my thruster system?

;MY TYPES: ;;;;;;;;;;;

Type EFFECT
	Field kind,active,parent
	Field startscale#,endscale#,scalemodpercycle#
	Field startalpha#,endalpha#,alphamodpercycle#
	Field randompositioning,randomoffset#
	Field entitytocopy
	Field parentship.SHIP
End Type

Type SHIP
	Field ship,x#,y#,z#,xv#,yv#,zv#,throttle#,shipmaxspd#
	Field camera,camtrailpiv,cymod#,czmod#,tx#,ty#,tz#
	Field thrusterpiv[2]
	Field ai,aiVars.AIVARCOLLECTION
End Type

Type THRUSTER
	Field flame,parent.EFFECT
	Field scale#,alpha#
End Type

;;;;;;;;;;;;;;;;;;;;;;

Local PX#,PY#,PZ#
Local TX#,TY#,TZ#
Local RX#,RY#,RZ#
Local PSS,TRO#

For t.THRUSTER = Each THRUSTER
	If t\alpha# > t\parent\endalpha# Or t\scale# > t\parent\endscale#
		ScaleSprite t\flame,t\scale#,t\scale#
		EntityAlpha t\flame,t\alpha#
		
		t\scale# = t\scale# - t\parent\scalemodpercycle#
		t\alpha# = t\alpha# - t\parent\alphamodpercycle#
	EndIf
	
	If t\alpha# =< t\parent\endalpha# Or t\scale# =< t\parent\endscale# Then
		FreeEntity t\flame
		Delete t.THRUSTER
	EndIf
Next

For e.EFFECT = Each EFFECT
	PSS = e\parentship\ship
	
	Select e\kind
		Case 1
			If e\parentship\throttle# > 0 Then
				PX# = EntityX#(e\parent,True)
				PY# = EntityY#(e\parent,True)
				PZ# = EntityZ#(e\parent,True)
				
				t.THRUSTER = New THRUSTER
				t\parent.EFFECT = e.EFFECT
				t\flame = CopyEntity(e\entitytocopy)
				t\scale# = e\startscale# * e\parentship\throttle#
				t\alpha# = e\startalpha#
				
				If t\alpha# =< e\endalpha# Or t\scale# =< e\endscale# Then
					FreeEntity t\flame
					Delete t.THRUSTER
				Else
					If e\randompositioning = False
						PositionEntity t\flame,PX#,PY#,PZ#
					Else If e\randompositioning = True
						TRO# = t\parent\randomoffset#
						
						TX# = Rnd(-TRO#,TRO#) * e\parentship\throttle#
						TY# = Rnd(-TRO#,TRO#) * e\parentship\throttle#
						TZ# = Rnd(-TRO#,TRO#) * e\parentship\throttle#
											
						RX# = PX# + TX#
						RY# = PY# + TY#
						RZ# = PZ# + TZ#
						
						PositionEntity t\flame,RX#,RY#,RZ#
					EndIf
					
					ScaleSprite t\flame,t\scale#,t\scale#
					EntityAlpha t\flame,t\alpha#
				EndIf
			EndIf
	End Select
Next

Sorry if the code is a bit messy. I originally have it in a function and I pulled the types out from earlier in the program so that you can see what each field is.

Alright I fixed it a bit (I was using cube waypoints so I could see where my bots were going) but it still lags with 6-7 bots on screen, still way too few for a good game.

All I can think of is that maybe you are creating too many sprites with alpha...more than your GPU can handle easily.

If you are using blitz sprites, they are the problem... in version 1.99 for some reason, sprites are extremely slow... not sure why. Try re-installing 1.64 and not updating. It should go faster.

How many sprites are you actually creating for the thruster?

As people are saying sprites are slow - full stop. By winding back to v1.64 they may be faster but you'll loose other features which you'll probably need so not recommended. For a speed up :

1. Use a single surface system
2. Recycle your thruster particles rather than creating and deleting.

If you search for either term you should find plenty of threads and code on the subject.

Stevie

Don't use sprites at all. Doesn't matter what version of Blitz you have, they're still slow. In Blitz, a single sprite takes one surface and it's just a waste of processing power.

Do a single surface particle system or buy a lib that does it for you. I've done pretty much what you are doing. A single surface system can handle around 10000 particles until problems occur. And that plenty more than you need.