Code archives/3D Graphics - Misc/Fast Entity Find

This code has been declared by its author to be Public Domain code.

Download source code

Fast Entity Find by David Bird(Birdie)
(Posted 25 years ago)
This is a method of storing a pointer(handle) to an entity so that information can be quickly found and used effectivly. 
Graphics3D 640,480
SetBuffer BackBuffer()

piv=CreatePivot()
cam=CreateCamera(piv)
PositionEntity cam,0,0,-40

Type entity
	Field ent
	Field name$
	Field inf1$
	Field inf2$
End Type

CreateLight()

For r=1 To 2000
	a.entity=New entity
	a\ent=CreateCube()
	EntityPickMode a\ent,2
	PositionEntity a\ent,Rnd(-120,120),Rnd(-120,120),Rnd(0,240)
	a\name$=Handle( a )
	NameEntity a\ent,a\name
	a\inf1$="System num="+r
	a\inf2$="Planets "+Rand(12)
Next
old.entity=Null

While Not KeyDown(1)
	UpdateWorld
	RenderWorld
	xm=MouseX()
	ym=MouseY()
	If MouseDown(1)						;new method
		ent=CameraPick(cam,xm,ym)
		If ent<>0 Then
			t=MilliSecs()
			tempint=EntityName(ent)
			old=e.entity
			For test=1 To 15000
			e=FindEntityFast(ent);Object.entity(tempint)
			Next
			tk=MilliSecs()-t
			searchtype=0

		End If
	End If

	If MouseHit(2)						;old method
		ent=CameraPick(cam,xm,ym)
		If ent<>0 Then
			old=e
			t=MilliSecs()
			For test=1 To 15000
			e=FindEntity(ent)
			Next
			tk=MilliSecs()-t
			searchtype=1
		End If
	End If

	Color 0,0,100
	Rect 0,0,GraphicsWidth(),105
	Color 255,255,0

	If e<>Null Then 
		EntityColor e\ent,Rnd(255),Rnd(255),Rnd(255)
		If searchtype=0 Then
			Text 320,0,&quot;New search been done Results&quot;,1
		Else
			Text 320,0,&quot;Old search been done Results&quot;,1
		End If

		Text 320,15,&quot;Time taken to pick type *15000 times=&quot;+tk+&quot; Millisecs&quot;,1
	End If
	If old<>Null Then 
		If old<>e Then EntityColor old\ent,255,255,255
	End If
	Text 320,30,&quot;(c)2002 David Bird  enquire@davebird.fsnet.co.uk&quot;,1
	Text 0,60,&quot;Search function. Old sys intterates all 2000 new sys direct pointer to type&quot;
	Text 0,75,&quot;Click LMB for new search&quot;
	Text 0,90,&quot;Click RMB for old search&quot;
	Color 255,0,0
	Line xm,ym,xm+10,ym+10
	Rect xm-1,ym-1,3,3
	Flip
Wend

Function FindEntity.entity(ent)
	For e.entity=Each entity
		If e\ent=ent Then Return e
	Next
End Function

Function FindEntityFast.entity(ent)
	ti=EntityName(ent)
	Return Object.entity(ti)
End Function