Plasma Fireworks

screenwidth=640
screenheight=480

Graphics3D screenwidth,screenheight,32,2
SetBuffer BackBuffer()

Global flaresprite=LoadSprite("flare.png",1):HideEntity flaresprite
Global halfwidth=screenwidth/2,halfheight=screenheight/2
Global glowsprite=LoadSprite("glow.png",1):HideEntity glowsprite

Global camera=CreateCamera()
Global light=CreateLight()

Type flare
	Field x,y
	Field angle#
	Field speed#
	Field alpha#
	Field src
End Type

Type glow
	Field x,y
	Field alpha#
	Field src
End Type

While Not KeyHit(1)
	RenderWorld:Flip:UpdateWorld
	
	If KeyHit(57)
		x=Rand(100,screenwidth-100)
		y=Rand(100,screenheight-100)
		CreateGlow(x,y)
		For i=1 To 30
			CreateExplosion(x,y)
		Next
	EndIf
	
	UpdateGlow()
	UpdateExplosion()
Wend
End

Function CreateGlow(x,y)
	g.glow=New glow
	g\x=x
	g\y=y
	g\alpha=1.0
	g\src=CopyEntity(glowsprite)
	ScaleSprite g\src,200/2,200/2
End Function

Function UpdateGlow()
	For g.glow=Each glow
		g\alpha=g\alpha-0.05
		
		If g\alpha > 0
			PositionEntity g\src,halfwidth-g\x,g\y-halfheight,halfwidth*1
			EntityAlpha g\src,g\alpha
		Else
			FreeEntity g\src
			Delete g
		EndIf
	Next
End Function

Function CreateExplosion(x,y)
	f.flare=New flare
	f\x=x
	f\y=y
	f\angle=Rand(360)
	f\speed=Rand(3,7)
	f\alpha=1.0
	f\src=CopyEntity(flaresprite)
	RotateSprite f\src,f\angle
	ScaleSprite f\src,50/2,50/2
End Function

Function UpdateExplosion()
	For f.flare=Each flare
		
		If f\alpha>0
			f\x=f\x+Sin(f\angle)*f\speed
			f\y=f\y+Cos(f\angle)*f\speed
			If f\angle > 180
				f\angle=f\angle-0.5
			ElseIf f\angle < 180
				f\angle=f\angle+0.5
			EndIf
			f\alpha=f\alpha-0.01
			PositionEntity f\src,halfwidth-f\x,f\y-halfheight,halfwidth*1
			EntityAlpha f\src,f\alpha
			RotateSprite f\src,f\angle
		Else
			FreeEntity f\src
			Delete f
		EndIf
	
	Next
End Function