Pointers in types??
Blitz3D Forums/Blitz3D Programming/Pointers in types??
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| Ello again, my Blitz-addicted friends!! Eres one I just can't figure ... can you put a pointer to another type IN a type? Heres the situation .. I have a shed-load (200+) of waypoints stored in types. Rather than iterate through them all looking for an ID, since they're always read in sequence (start to finish!) it would be great if it was possible to put a pointer to the the current waypoint in the player's type. That way, I could just use AFTER to move along to the next waypoint... in theory!??!! Anyone tried this or know if it'll work? I started out with this test code to see if it worked in principle, but my head is frazzled and I'll have to go away and think about it all a bit before carrying on!! Type norbert Field number End Type Type hismate Field norb.norbert End Type For i=1 To 100 a.norbert=New norbert a\number=I Next For i=1 To 4 b.hismate=New hismate b\norb=First norbert Next c=1 d.hismate=First hismate For i=1 To Rnd(10) d\norb=After d\norb Next For i=1 To 4 Print i+".."+d\norb\number d=After d Next While Not KeyHit(1) Wend |
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I think this is what you're after:Graphics 800,600,16,2 Type waypoint Field number Field x#,y# End Type Type player Field waypoint.waypoint End Type For n=1 To 10 w.waypoint=New waypoint w\number=n w\x=Rnd(780) w\y=Rnd(580) Next player.player=New player player\waypoint=First waypoint Repeat Cls Text 400,20,"Press space to go to next waypoint",True Text 400,40,"Current waypoint : "+player\waypoint\number,True For w.waypoint=Each waypoint Oval w\x,w\y,18,18,False Text w\x+9,w\y+9,w\number,True,True Next If Sin(Float(MilliSecs())*10.0)>0 Oval player\waypoint\x+6,player\waypoint\y+6,6,6 Else Oval player\waypoint\x-3,player\waypoint\y-3,24,24,False EndIf If KeyHit(57) player\waypoint=After player\waypoint If player\waypoint=Null player\waypoint=First waypoint EndIf EndIf Flip Until KeyDown(1) End |
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| Jeppe you are a star... your code is definately some of the most useful stuff I have on my hdd - THANK YOU!!! :D Sooo glad it actually works, because TBH I didn't expect it to .. I was just waiting for someone to say 'dont be insane that'll never work because ...' ;) Thanks again - brilliant stuff! |
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| My head just popped. |
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| Yeah ... next, the task is to try and get my head around doing multiple sets of waypoints!! ARGH!! :D :D |
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| Ok. Got a plan ... I load the waypoints in to a field in the player type, then have a waypoint pointer (also in the player type) that points to those waypoints in the player waypoint field. Then my head explodes and they donate my body to medical science ;) |
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Glad you could use it, I have however modified it to include mutiply paths with any set of waypoints each:Graphics 800,600,16,2 ;create a new blue path path1.path=PathNew(0,0,255) ;assign 4 waypoints to it For n=1 To 4 WaypointNew( path1,Rnd(780),Rnd(580) ) Next ;create a new yellow path path2.path=PathNew(255,255,0) ;assign 7 waypoints to it For n=1 To 7 WaypointNew( path2,Rnd(780),Rnd(580) ) Next Type player Field waypoint.waypoint End Type ;create player 1 and let it follow path1 player1.player=New player player1\waypoint=PathFirstWaypoint(path1) ;create player 1 and let it follow path2 player2.player=New player player2\waypoint=PathFirstWaypoint(path2) Repeat Cls Color 255,255,255 Text 400,20,"Press 1 to let player 1 go to next waypoint in path 1 (blue)",True Text 400,40,"Press 2 to let player 2 go to next waypoint in path 2 (yellow)",True ;draw waypoints For w.waypoint=Each waypoint Color w\path\r,w\path\g,w\path\b Oval w\x,w\y,18,18,False Text w\x+9,w\y+9,w\number,True,True Next Color 0,0,255 If Sin(Float(MilliSecs())*10.0)>0 Oval player1\waypoint\x+6,player1\waypoint\y+6,6,6 Else Oval player1\waypoint\x-3,player1\waypoint\y-3,24,24,False EndIf Color 255,255,0 If Sin(Float(MilliSecs())*10.0)>0 Oval player2\waypoint\x+6,player2\waypoint\y+6,6,6 Else Oval player2\waypoint\x-3,player2\waypoint\y-3,24,24,False EndIf If KeyHit(2) player1\waypoint=WaypointNext(player1\waypoint) EndIf If KeyHit(3) player2\waypoint=WaypointNext(player2\waypoint) EndIf Flip Until KeyDown(1) End Type path Field r,g,b Field f.waypoint ;first waypoint Field l.waypoint ;last waypoint End Type Function PathNew.path(r,g,b) p.path=New path p\r=r p\g=g p\b=b Return p End Function Function PathFirstWaypoint.waypoint(p.path) Return p\f End Function Type waypoint Field path.path Field number Field x#,y# Field p.waypoint ;previous waypoint Field n.waypoint ;next waypoint End Type Function WaypointNew.waypoint(p.path,x#,y#) w.waypoint=New waypoint w\path=p w\x=x w\y=y ;check if path's first waypoint is empty If p\f=Null p\f=w EndIf ;check if path's last waypoint is empty If p\l=Null p\l=w EndIf ;assign path's last waypoint to the current waypoint's previous waypoint link w\p=p\l w\p\n=w p\l=w w\number=w\p\number+1 Return w End Function Function WaypointNext.waypoint(w.waypoint) If w\n=Null Return w\path\f EndIf Return w\n End Function Function WaypointPrev.waypoint(w.waypoint) If w\p=Null Return w\path\l EndIf Return w\p End Function |
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| Oh no now it'll be more than his head! |
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| BOOOOOM!!!! ;) That's it then, you are the ruler of the universe and I am but a pleb. EXCELLENT! You totally beat me to it! Thanks x10billion! Now I just got to figure out how you did it so well ... ! |
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I try not to keep things so global personally. Just a different approach.type SomeList Field ID Field otherfields End Type ;=====Main Loop MyThing = createsomething() ModifySomething(MyThing) ;====End Main Loop Function CreateSomething() local T.SomeList T.SomeList = new SomeList T\ID = handle(T.SomeList) return T\ID End Function Function ModifySomething(ID) local T.SomeList T=object.SomeList(ID) ;Just in case i deleted it somewhere and my codes isn't clean, check to make ;-sure it is still in the list if T <> null then ;modify things here Endif End Function The handle of that list (the ID) is always unique, so there is no way to get the same one twice. |
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| Thanks, Mr. Half :D I should write an article - "how to get half way through doing something really cool that melts your brain so that you have to go away and lie down for a bit".!!! Great help as always, guys. Much appreciated :) |
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| You're welcome :-) You can add as many paths as you like with any number of waypoints each. Look in the WaypointNew() function to see where the waypoints gets connected, using their previous and next pointers. (p.waypoint and n.waypoint) |
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And you will need these to delete paths:Function PathDelete(p.path) w.waypoint=p\f While w<>Null ww.waypoint=w\n WaypointDelete w w=ww Wend End Function Function WaypointDelete(w.waypoint) Delete w End Function |
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