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stealth bug in grid plotting code for nms clone

Blitz3D Forums/Blitz3D Programming/stealth bug in grid plotting code for nms clone

neoshaman(Posted 2016) [#1]
Hi citizen of blitztopia

Last time I had a small bug that the eagle shoot down fast, I have new one I can't fathom what's happening.

I'm still trying to make a poor's version of no man sky planet generation. I'm trying to find in which tile I'm currently hovering, I made a bunch of prototype I'm not putting together to move to the next step. Except it don't behave as intended for no reason in a code that supposedly works correctly when extracted :| I feel like the code is trolling me.


Include "function library.bb"

.setup

Graphics3D 800,600,16,2
SetBuffer BackBuffer()

;-------------------------------------------
cam = CreateCamera ()
PositionEntity cam, 0,0,-5


l1 = CreateLight (1)
RotateEntity l1, 45,45,0

tex=LoadTexture( "testure.jpg" )


plane = CreatePlane ()
PositionEntity plane, 0,-8,0
EntityColor plane, 64,32,16
EntityTexture plane,tex

center = CreateSphere (32)
PositionEntity center, 0,-0,0
ScaleEntity center, .5,.5,.5
EntityColor center, 255,0,0
;HideEntity center

h = CreateSphere (8)
PositionEntity h, 0,-0,0
ScaleEntity h, .1,.1,.1
EntityColor h, 0,255,0
;HideEntity h

;-------------------------------------------

;put set up code here

.loop

hoveredface$ = " "

	div = 3
	div2 = div*div
	
	di = div +1
	Dim g(  di*di )
		For i = 0 To ( di*di )-1
			g(i) = CreateSphere (2)
			;FreeEntity g(i)
		Next



While Not KeyDown(1)
	
	;put runtime code and runtime 3d here
	controlentity(cam); function from the library, move object freely using keyboard or gamepad (reference x360), look at the library for reference
	
	
	PointEntity cam, center
	;-------------------------------------------
	
	brush = CreateBrush()
	BrushFX brush, 16
	
	entitypoint.point3d = New point3d
	entitypoint\x = EntityX (cam)
	entitypoint\y = EntityY (cam)
	entitypoint\z = EntityZ (cam)
	
	hoveredface = cubeface(entitypoint\x, entitypoint\y, entitypoint\z )
	
	Select hoveredface
		Case "side1"	: axis = 2
		Case "side2"	: axis = 5
		
		Case "top" 		: axis = 0
		Case "bottom"	: axis = 3
		
		Case "back"		: axis = 1
		Case "front"	: axis = 4
	End Select

	If poscell = 0 Then
		poscell = CreateMesh ()
		possurface = CreateSurface(poscell)		
		
		v1 = AddVertex (possurface, 0,0,0, 0,0,0)
		v2 = AddVertex (possurface, 1,0,0, 0,0,0)
		v3 = AddVertex (possurface, 1,1,0, 0,0,0)
		v4 = AddVertex (possurface, 0,1,0, 0,0,0)
		
		t1 = AddTriangle (possurface, v1,v3,v2)
		t2 = AddTriangle (possurface, v1,v4,v3)
		
		PaintSurface possurface, brush
		
		;If hoveredface = "side2" Or hoveredface = "bottom" Or hoveredface = "back" Then FlipMesh poscell
	
	EndIf
	UpdateNormals poscell
	
	detectplanettile(entitypoint,poscell,axis, div,1)
	
	
	c0.point3d= normalizepoint3d(entitypoint);
	PositionEntity h, c0\x,c0\y,c0\z
	
		Delete Each point3d
		
		
	;-------------------------------------------

	
	;refresh
	UpdateWorld 1
	RenderWorld 1

		


	; put 2d drawing code here
	showjoystate(100); 2d text display of joystick state
	Text 10,10, cubeface(EntityX (cam), EntityY (cam), EntityZ (cam) )

	VWait:Flip False
	
Wend

;put exit clean up code here

ClearWorld


So this is the main code, nothing fancy, just a bunch of visualization.
- g is a structure to hold visualization of the tiled enumeration
- hoveredface hold which face of a cube centered on 0,0,0 I'm hovering
- poscell is supposed to visualize as a mesh the surface of tile on the surface of the sphere
- h entity is simply the normalized, to the surface, position of the "ships"
- Cubeface() is the custom function that detect face of the cube I'm hovering, works as intended

- -- - detectPlanetTile() is where things broke down ...


Function detectplanettile(entitypoint.point3d, poscell, axis, division#=10,size#=1)

	division = division +1
	d2# = division*division
	S# = size/(division-1);step size
	
	;center = 0 -> corner, center = 1 -> center offset
	center = 0
	offset# = 0:	If center = 1 Then offset = - (size) / 2
	
	surface = GetSurface (poscell,1) 
	
	close# = Abs( 2^30 )
	
	;detect side
		;enumerate cell division
			;find corner
			;compute centroid
			;project to sphere
			;detect rightcell
			;store cell within radius
			;find current cell
				;if not max depth -> enumerate cell division

	
	;for each face relative to current face hovered
		
	p1.point3d = New point3d
	p2.point3d = New point3d
	p3.point3d = New point3d
	p4.point3d = New point3d
	centroid.point3d = New point3d
	
	rightcell.point3d = Null

	s# = 1
	;--------------------------------------------------------------
	For i=0 To d2-1:;Stop;

		;generate position, depend on axis xz=0, xy=1, zy=2

		w1 = i
		w2 = i+1
		w3 = i+division +1
		w4 = i+division
		
		p1 = pointtile(w1, offset, division, s, axis)
		p2 = pointtile(w2, offset, division, s, axis)
		p3 = pointtile(w3, offset, division, s, axis)
		p4 = pointtile(w4, offset, division, s, axis)
		
					
			
		If (i Mod division) = (division -1) Then Goto skip
		;If i => d2 - division Then Goto skip
		
		centroid\x = (p1\x + p2\x + p3\x + p4\x)/4
		centroid\y = (p1\y + p2\y + p3\y + p4\y)/4
		centroid\z = (p1\z + p2\z + p3\z + p4\z)/4
		
		.skip	

		p1c.point3d = p1;catspherepoint(p1)
		p2c.point3d = p2;catspherepoint(p2)
		p3c.point3d = p3;catspherepoint(p3)
		p4c.point3d = p4;catspherepoint(p4)
		centroidcat.point3d = centroid ;catspherepoint( centroid )
		
;		PositionEntity g(i), centroidcat\x, centroidcat\y, centroidcat\z
			PositionEntity g(i), p1c\x, p1c\y, p1c\z
;			PositionEntity g(i), p2\x, p2\y, p2\z
;			PositionEntity g(i), p3\x, p3\y, p3\z
;			PositionEntity g(i), p4\x, p4\y, p4\z
		ScaleEntity g(i), .05,.05,.05
		EntityColor g(i), 0,0,255
		
;;;;;;;;;;;;;
		
		;select right cell
		; if cell = null, this cell = right, check distance to normalize ship, if distance to centroid less, then cell is new cell
		If rightcell = Null Then 
		
			rightcell = centroidcat;
			
				VertexCoords surface, v1, p1c\x, p1c\y, p1c\z
				VertexCoords surface, v2, p2c\x, p2c\y, p2c\z
				VertexCoords surface, v3, p3c\x, p3c\y, p3c\z
				VertexCoords surface, v4, p4c\x, p4c\y, p4c\z
			
		Else 
			n.point3d = normalizepoint3d(entitypoint);
			
			m# = magnitude3d(n\x - centroidcat\x, n\y - centroidcat\y, n\z - centroidcat\z) 
			
			Text 0,20, m
			
			If m < close Then
			
				close# = m
				rightcell = centroidcat
				
				
				VertexCoords surface, v1, p1c\x, p1c\y, p1c\z
				VertexCoords surface, v2, p2c\x, p2c\y, p2c\z
				VertexCoords surface, v3, p3c\x, p3c\y, p3c\z
				VertexCoords surface, v4, p4c\x, p4c\y, p4c\z
				
			EndIf
		EndIf
		

		
		UpdateNormals poscell
	
	Next	
	
	
End Function

I have already start to isolate where bogus data flowed, so the function catsphere() is not operational here, it's responsible for projecting the grid face toward sphere surface, so the result of this function should be a neatly align grid .... which I'm not having, I'm having a slanted grid for no reason. The responsible for enumerated the grid is PointTile(), which I visualize with the g(i) structure that hold some entity.

Function pointtile.point3d(i, offset#, division#, s#, axis=0);:Stop

		a# = offset + ( i Mod division )*s
		b# = offset + ( i  /  division )*s
		
		Select axis
			;__________________________________________
			Case 0;xz floor (top)
			x# = a
			z# = b
			y# = s
			;__________________________________________
			Case 1;xy forward wall (front)
			x# = a
			y# = b
			z# = s
			;__________________________________________
			Case 2;zy side1 wall 
			z# = a
			y# = b
			x# = s
			;__________________________________________
			Case 3;xz floor (bottom)
			x# = a
			z# = b
			y# = -s
			;__________________________________________
			Case 4;xy forward wall (back)
			x# = a
			y# = b
			z# = -s
			;__________________________________________
			Case 5;zy side2 wall 
			z# = a
			y# = b
			x# = -s
			;__________________________________________

		End Select
		
		p.point3d = New point3d
		p\x = x
		p\y = y
		p\z = z
		
		Return p
		;return x,y,z

End Function


The catch is that if I extract this function and throw it into it's own project, it works perfectly, WTF WHAT DID I MISS?:

division = 3
size = 10

	division = division +1
	d2# = division*division
	S# = size/(division-1);step size
	
	;center = 0 -> corner, center = 1 -> center offset
	center = 0
	offset# = 0:	If center = 1 Then offset = - (size) / 2

For i = 0 To d2-1
axis=1

		a# = offset + ( i Mod division )*s
		b# = offset + ( i  /  division )*s
		
		Select axis
			;__________________________________________
			Case 0;xz floor (top)
			x# = a
			z# = b
			y# = s
			;__________________________________________
			Case 1;xy forward wall (front)
			x# = a
			y# = b
			z# = s
			;__________________________________________
			Case 2;zy side1 wall 
			z# = a
			y# = b
			x# = s
			;__________________________________________
			Case 3;xz floor (bottom)
			x# = a
			z# = b
			y# = -s
			;__________________________________________
			Case 4;xy forward wall (back)
			x# = a
			y# = b
			z# = -s
			;__________________________________________
			Case 5;zy side2 wall 
			z# = a
			y# = b
			x# = -s
			;__________________________________________

		End Select
		
		Plot x+10,y+10

Next

WaitKey()



neoshaman(Posted 2016) [#2]
Hold on, trial and error win again, I had to turn division from float to int :/