Graphics3D 640,480
SetBuffer BackBuffer()
piv=CreatePivot()
cam=CreateCamera(piv)

CameraRange cam,.1,40
PositionEntity cam,0,0,-2
tex=LoadTexture("tex0.bmp")
lit=CreateLight()

mesh=CreateSphere(80);LoadMesh("geosphere.3ds")
ScaleEntity mesh,1,1,1
ScaleTexture tex,0.2,0.2

EntityTexture mesh,tex

WireFrame True

While Not KeyDown(1)
   TurnEntity mesh,0,0.1,0
   If KeyHit(57) Then ok=do_Landscaping(mesh,1,.02)


   If KeyDown(203) TurnEntity piv,0,1,0
   If KeyDown(205) TurnEntity piv,0,-1,0
   If KeyDown(200) TurnEntity piv,1,0,0
   If KeyDown(208) TurnEntity piv,-1,0,0

   If KeyDown(44) MoveEntity cam,0,0,-0.1
   If KeyDown(30) MoveEntity cam,0,0,0.1
   UpdateWorld
   RenderWorld
   Text 320,0,ok,1,0
   Text 0,0,"Hit <space> to terraform..."
   Flip
Wend

FreeEntity lit
FreeEntity cam
FreeEntity piv
EndGraphics
End

Function do_Landscaping(mesh,iterate,scale#)
   surf=GetSurface(mesh,CountSurfaces(mesh))
   n.vector=New vector
   p.vector=New vector
   v.vector=New vector
   For a=0 To iterate
      e#=Rnd(-scale,scale)
      Random_Vector(n)   ;Create a random vector
      For b=0 To CountVertices(surf)-1
         v\x=VertexX(surf,b)
         v\y=VertexY(surf,b)
         v\z=VertexZ(surf,b)
         prod#=Vect_Product(n,v)
         If prod>0 Then
            VertexCoords surf,b,VertexX(surf,b)+(VertexNX(surf,b)*e),VertexY(surf,b)+(VertexNY(surf,b)*e),VertexZ(surf,b)+(VertexNZ(surf,b)*e)
         Else
            VertexCoords surf,b,VertexX(surf,b)-(VertexNX(surf,b)*e),VertexY(surf,b)-(VertexNY(surf,b)*e),VertexZ(surf,b)-(VertexNZ(surf,b)*e)
         End If      
      Next
      fst=False
   Next
   Delete n
   Delete p
   Delete v
   Return vcnt
End Function

Function Random_Vector(v.vector)
   v\x=Rnd(-1,1)
   v\y=Rnd(-1,1)
   v\z=Rnd(-1,1)
   Normalise(v)
End Function

Type vector
   Field x#
   Field y#
   Field z#
   Field u#
   Field v#
End Type
;
;   Globals
;
Global G_width
Global G_height
Global G_Depth

Global Bearing.vector=New vector
Global Normal.vector=New vector
Global CProd.vector=New vector
Global Tnorm.vector=New vector

Global DProd#
;
;Cross and DotProduct functions
Function CrossProduct(x1#,y1#,z1#,x2#,y2#,z2#)
   CProd\x=(y1*z2)-(z1*y2)
   CProd\y=(z1*x2)-(x1*z2)
   CProd\z=(x1*y2)-(y1*x2)
End Function
Function DotProduct#(x1#,y1#,z1#,x2#,y2#,z2#)
   DProd=((x1*x2)+(y1*y2)+(z1*z2))
   Return DProd
End Function
;Return Cross product answers
Function CproductX#()
   Return CProd\x
End Function
Function CproductY#()
   Return CProd\y
End Function
Function CproductZ#()
   Return CProd\z
End Function
;Return Dot product answers
Function DProduct#()
   Return DProd
End Function



Function Delete_Vectors()
   Delete Each vector
End Function

;
;   Math Functions
;
;Bearing between two entity's
Function GetBearingVector(ent1,ent2)
   Bearing\x#=EntityX(ent2)-EntityX(ent1)
   Bearing\y#=EntityY(ent2)-EntityY(ent1)
   Bearing\z#=EntityZ(ent2)-EntityZ(ent1)
   Normalise(Bearing)
End Function

;Return Bearing
Function BearingX#()
   Return Bearing\x
End Function
Function BearingY#()
   Return Bearing\y
End Function
Function BearingZ#()
   Return Bearing\z
End Function

Function Normalise(a.vector)
   l# = Mag(a\x,a\y,a\z)
   a\x=a\x/l
   a\y=a\y/l
   a\z=a\z/l
   Return
End Function


; Normalise x/y/z store answer in Normal.vector
Function Norm(x#,y#,z#)
   l# = Mag(x,y,z)
   Normal\x=x/l
   Normal\y=y/l
   Normal\z=z/l
End Function
Function NormX#()
   Return Normal\x
End Function
Function NormY#()
   Return Normal\y
End Function
Function NormZ#()
   Return Normal\z
End Function
; *********************************************


Function Mag#(x#,y#,z#)
   Return Sqr(x^2+y^2+z^2)
End Function

Function TurntoFace(ent1,ent2,tol#)
   GetBearingVector(ent1,ent2)
   dx#=BearingX()*360/tol
   dy#=BearingY()*360/tol
   dz#=BearingZ()*360/tol
   TurnEntity ent1,-dy,-dx,0
End Function

Function range#(ent1,ent2)
   x#=EntityX(ent2)-EntityX(ent1)
   y#=EntityY(ent2)-EntityY(ent1)
   z#=EntityZ(ent2)-EntityZ(ent1)
   Return Sqr(x^2+y^2+z^2)
End Function
Function range2d#(ent1,ent2)
   x#=EntityX(ent2)-EntityX(ent1)
   z#=EntityZ(ent2)-EntityZ(ent1)
   Return Sqr(x^2+z^2)
End Function
Function rangepoint#(x1#,y1#,z1#,x2#,y2#,z2#)
   x#=x1-x2
   y#=y1-y2
   z#=z1-z2
   Return Sqr(x^2+y^2+z^2)
End Function

Function SetGraphics(tag3d,targetwidth)
   ;tag3d - true to setup graphics mode, false for normal mode
   ;targetwidth - aim for width
   wid=0
   mode=0
   For a=1 To CountGfxModes()
      g_width=GfxModeWidth(a)
      g_height=GfxModeHeight(a)
      g_depth=GfxModeDepth(a)
      If g_width>wid And g_width<=targetwidth Then
         wid=g_width
         hig=g_height
         dep=g_depth
         mode=a
      End If
   Next
   If wid>0 Then
      If tag3d=True Then
         Graphics3D wid,hig
      Else
         Graphics wid,hig
      End If
      g_width=wid
      g_height=hig
      g_depth=dep
   End If
End Function

;
;   Get Normal of a picked point
;   On a terrain
;
Function Get_Terrain_Normal(terr,x#,z#)
   x1#=x:z1#=z:y1#=TerrainY(terr,x1,0,z1)
   x2#=x+.5:z2#=z:y2#=TerrainY(terr,x2,0,z2)
   x3#=x:z3#=z+.5:y3#=TerrainY(terr,x3,0,z3)
   
   xx1#=x2-x1:yy1#=y2-y1:zz1#=z2-z1
   xx2#=x3-x1:yy2#=y3-y1:zz2#=z3-z1
   Norm(xx1,yy1,zz1)
   xx1=NormX():yy1=normy():zz1=normz()
   Norm(xx2,yy2,zz2)
   xx2=NormX():yy2=normy():zz2=normz()
   CrossProduct(xx2,yy2,zz2,xx1,yy1,zz1)
   TNorm\x=CProductX()
   TNorm\y=CProductY()
   TNorm\z=CProductZ()
End Function

Function TNormalX#()
   Return Tnorm\x
End Function
Function TNormalY#()
   Return Tnorm\y
End Function
Function TNormalZ#()
   Return Tnorm\z
End Function
;
;
;

Function Vect_Product#(a.vector,b.vector)
   DProd=((a\x*b\x)+(a\y*b\y)+(a\z*b\z))
   Return DProd
End Function

Function distance_to_plane#(x1#,y1#,z1#,x2#,y2#,z2#,x3#,y3#,z3#)
   
End Function