Looping Track Generation

-=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- (c) WidthPadding Industries 1987 0\|509\|0 -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=-
SoCoder -> Article Home -> Advanced Techniques

Jayenkai	Created : 17 October 2020 Edited : 18 October 2020 System : Windows Language : Blitz Looping Track Generation Track Generator
You know what's a pain in the arse? Generating a looping track, that loops properly, and doesn't break. Always trying to get the start and end points to join up is SUCH an annoying thing to code. Yesterday whilst playing Mario Kart Live, I (for some reason) found myself thinking about track generation. Can't imagine why.. And something popped into my head. It's a little bit bland, in that it won't generate crossovers or anything, but.. Graphics 512,512,0,2 SetBuffer BackBuffer() SeedRnd MilliSecs() Global grid[5000] ;64x64=4096 Global higrid[300000] ;512x512=262144 Global higrid2[300000] ;512x512=262144 Global Track#[500000] ; lots of pairs of co-ords Global FinalTrack#[500000] ; lots of pairs of co-ords Global Smooth Global Push#=2.5 Global TrackLong=0 MakeTrack() Repeat DrawFinal() If KeyDown(203) Then SmoothTrack(Smooth-1) If KeyDown(205) Then SmoothTrack(Smooth+1) If KeyDown(200) Then Push=Push-0.05:SmoothTrack(Smooth) If KeyDown(208) Then Push=Push+0.05:SmoothTrack(Smooth) If KeyDown(57) Then MakeTrack() Until KeyDown(1) Function MakeTrack() ; 1 - Reset For n=0 To 4999:grid[n]=0:Next For n=0 To 299999:higrid[n]=0:higrid2[n]=0:Next For n=0 To 499999:Track[n]=0:FinalTrack[n]=0:Next ; 2 - Mark Middle x=32:y=32 grid[y64+x]=1 ; 3 - Expand outward randomly p=0:z=Rand(8,64) Repeat ; Random xy x=Rand(1,62):y=Rand(1,62):d=0 If grid[y64+x]=0 ; If joined to another marked spot If grid[y64+(x-1)]=1 Then grid[y64+x]=1:d=1 If grid[y64+(x+1)]=1 Then grid[y64+x]=1:d=1 If grid[(y-1)64+x]=1 Then grid[y64+x]=1:d=1 If grid[(y+1)64+x]=1 Then grid[y64+x]=1:d=1 EndIf If d=1 Then p=p+1 ; Mark spot Until p>z ; 4 - Convert to higher resolution For x=0 To 511 For y=0 To 511 gx=Floor(x/8) gy=Floor(y/8) higrid[y512+x]=grid[gy64+gx] Next Next ; 5 - Trace Outlines For x=1 To 510 For y=1 To 510 a=1 If higrid[y512+x]=1 If higrid[y512+(x+1)]=0 Or higrid[y512+(x-1)]=0 Or higrid[(y-1)512+x]=0 Or higrid[(y+1)512+x]=0 Then higrid2[y512+x]=1 EndIf Next Next ; 6 - Find a spot for the start x=256:y=0 For n=0 To 256 If higrid2[n512+x]=1 And y=0 Then y=n Next Track[0]=x:Track[1]=y:TrackLong=0 ; Drive along the track, placing points into the Track array d=1 x=Track[0]+1:y=Track[1] If higrid2[y512+x]=0 Then d=0:x=Track[0]:y=Track[1]-1 While x<>Track[0] Or y<>Track[1] ; Check next step If (d=0 And higrid2[(y-1)512+x]=0) Or (d=2 And higrid2[(y+1)512+x]=0) ; If No track, turn If higrid2[y512+(x-1)]=1 Then d=3 If higrid2[y512+(x+1)]=1 Then d=1 EndIf If (d=1 And higrid2[(y)512+(x+1)]=0) Or (d=3 And higrid2[(y)512+(x-1)]=0) If higrid2[(y+1)512+(x)]=1 Then d=2 If higrid2[(y-1)512+(x)]=1 Then d=0 EndIf ; Move If d=0 Then y=y-1:If y<1 Then y=1:d=-1 If d=1 Then x=x+1:If x>511 Then x=511:d=-1 If d=2 Then y=y+1:If y>511 Then y=511:d=-1 If d=3 Then x=x-1:If x<1 Then x=1:d=-1 ; Store point TrackLong=TrackLong+1 Track[TrackLong2]=x:Track[TrackLong2+1]=y If TrackLong>200000 Or d=-1 Then x=Track[0]:y=Track[1] Wend SmoothTrack(Rand(4,32)) End Function Function SmoothTrack(Smoother) ; 7 - For each point, take average of pieces before and after, to help smooth turns Smooth=Smoother If Smooth<1 Then Smooth=1 If Smooth>64 Then Smooth=64 If Push<2 Then Push=2 If Push>4 Then Push=4 For n=0 To TrackLong UnSmooth#=1.0/(Float(Smooth)Push) avgx#=0:avgy#=0 For s=-Smooth To Smooth t=n+s If t<=0 Then t=t+(TrackLong) If t>=TrackLong Then t=t-(TrackLong) t=t2 avgx=avgx+(Track[n2]-Track[t]):avgy=avgy+(Track[n2+1]-Track[t+1]) Next avgx=avgxUnSmooth avgy=avgyUnSmooth FinalTrack[n2]=Track[n2]-avgx:FinalTrack[n2+1]=Track[n2+1]-avgy Next End Function Function DrawFinal() Cls ; Draw Grid Color 48,48,48 For x=0 To 63 For y=0 To 63 If grid[y64+x]=1 Then Rect(x8,y8,8,8) Next Next ; Overlay Border Color 150,150,150 lf=0:rt=0:up=0:dwn=0 For x=0 To 511 For y=0 To 511 If higrid2[y512+x]=1 Plot x,y If x-256<lf Then lf=x-256 If x-256>rt Then rt=x-256 If y-256<up Then up=y-256 If y-256>dwn Then dwn=y-256 EndIf Next Next sc#=Abs(lf) If rt>sc# Then sc#=rt If Abs(up)>sc# Then sc#=Abs(up) If dwn>sc# Then sc#=dwn sc=250.0/sc cx#=256.0+(Float(rt+lf)/2):cy#=256.0+(Float(dwn+up)/2) ; Overlay enlarged form of Track For n=0 To TrackLong d=(((Floor(MilliSecs()/64)-n) Mod 8)25)+50 Color d,d,d x1=((FinalTrack[n2]-(cx))sc)+(256.0) y1=((FinalTrack[n2+1]-cy)sc)+256.0 x2=((FinalTrack[n2+2]-(cx))sc)+(256.0) y2=((FinalTrack[n2+3]-cy)sc)+(256.0) If n=TrackLong x2=((FinalTrack[0]-(cx))sc)+(256.0) y2=((FinalTrack[1]-cy)sc)+256.0 EndIf Plot x1,y1 Next Color 255,255,255 Text 10,4, "Length : "+TrackLong Text 10,15,"Smooth : "+Smooth+" (Left/Right)" Text 10,26,"Angular : "+(Floor(Push100.0)/100.0)+" (Up/Down)" Text 10,37,"Space : New Track" Delay 4 Flip End Function --v

Comments
Saturday, 17 October 2020, 08:53
Pakz	The track looks nice and rounded. Interesting how the blocks seem to be the base on which the final track is created from. I installed b3d from itch and ran this code. The screen is flickering between black and the blocks and track line.
Saturday, 17 October 2020, 09:01
Jayenkai	OMG, skills forgotten.. I forgot to add the SetBuffer BackBuffer() to the top!!!
Saturday, 17 October 2020, 09:26
Pakz	The drive along the path part. Is that a wall tracing type thing? I just had my own idea to create a path with a homing missile from points clockwise offset from the center But I really should concentrate on learning more how to do pixel art!
Saturday, 17 October 2020, 09:32
Jayenkai	Yeah, it simply finds the topmost pixel in the x-middle, then moves along one step at a time always searching for the next step, until it reaches the starting point.. .... hopefully it loops, or that bit's knackered!!!
Saturday, 17 October 2020, 11:43
Pakz	In that move along the path part. The d variable is set to -1 I do not understand this. It seems to not be used in the loop? Is that part where it is set to -1 triggered when the position is out of bounds?
Saturday, 17 October 2020, 12:07
Jayenkai	Oh yeah! LOL. Normally I add an error/fail/break-from-loop if d=-1 Forgot that but. I really did rush this!!! The loop still breaks, mind. If d=-1 then nothing else will happen until TrackLong hits the limit, then it'll break from the loop.
Saturday, 17 October 2020, 12:49
Jayenkai	Updated with a couple of nice visual tweaks. You can now use left/right cursor to change the amount of smoothing!
Wednesday, 21 October 2020, 13:37
Jayenkai	View on YouTube Currently working on a game using this functionality. All players are currently AI, with the orange kart highlighted for clarity, whilst I try to get the AI playing like it oughta.

Looping Track Generation

Comments