;bitmap functions
Global Dim QBColor(15)
Global Dim SortColor(15)
Global Dim Q256Color(256)
#Factor = 8.2258064516129
QBColor( 0 )=0
QBColor( 1 )=RGB(128,0,0)
QBColor( 2 )=RGB(0,255,0)
QBColor( 3 )=RGB(0,128,128)
QBColor( 4 )=RGB(0,0,128)
QBColor( 5 )=RGB(128,0,128)
QBColor( 6 )=RGB(0,128,128)
QBColor( 7 )=RGB(128,128,128)
QBColor( 8 )=RGB(192,192,192)
QBColor( 9 )=RGB(255,0,0)
QBColor( 10 )=RGB(0,255,0)
QBColor( 11 )=RGB(255,255,0)
QBColor( 12 )=RGB(0,0,255)
QBColor( 13 )=RGB(255,0,255)
QBColor( 14 )=RGB(0,255,255)
QBColor( 15 )=RGB(255,255,255)

;now to sort them
SortColor(0)=0
For sc.l=1 To 15
  ;find smallest QBColor
  LC.l=QBColor(SortColor(sc-1))
  small.l=0
  For QB=1 To 15
    If QBColor(QB)>LC
      If small
        If QBColor(QB)<QBColor(small)
          small=QB
        EndIf
      Else
        small=QB
      EndIf
    EndIf
  Next QB
  SortColor(sc)=small
Next sc

;load palet
#USeBuild=1
CompilerIf #USeBuild=0

  If InitSprite() And InitPalette()
    If OpenScreen(640,480,8,"dummy")
      P=LoadPalette(#PB_Any, #IncPath$+"C256.bmp")
      If P
        For C=0 To 255
          Q256Color(C)=GetPaletteColor(P,C)
        Next C
        FreePalette(P)
        CloseScreen()
        ;save palette in data file
        If CreateFile(1,#IncPath$+"P256.pbi")
          For C=0 To 255
            msg$="Q256Color("+Str(c)+")="+Str(Q256Color(C))
            WriteStringN(1,msg$)
          Next C
          CloseFile(1)
          MessageRequester("Bitmaps.PBI","P256.PBI created",0)
        Else
          MessageRequester("Bitmaps.PBI","Unable to create P256.PBI",0)
        EndIf
      Else
        CloseScreen()
        MessageRequester("Bitmaps.PBI","Unable to load palette",0)
      EndIf
    Else
      MessageRequester("Bitmaps.PBI","Unable to open screen",0)
    EndIf
  EndIf
CompilerEndIf
Procedure.l GetNearestColor(color.l)
  ;first check if is a color already
  For q=0 To 15
    If QBColor(q)=color
      ProcedureReturn q
    EndIf
  Next q
  For q.l=0 To 15
    If QBColor(SortColor(q))<color
      If q<15
        If QBColor(SortColor(q+1))>color
          small.l=color-QBColor(SortColor(q))
          big.l=QBColor(SortColor(q+1))-color
          If small>big
            ProcedureReturn SortColor(q+1)
          Else
            ProcedureReturn SortColor(q)
          EndIf
        EndIf
      EndIf
    EndIf
  Next q
  ProcedureReturn 15
EndProcedure
Procedure GetColor16(R,G,B)
   ;this converts RGB To a color
   ;For use in 16 bit mode
   ;this assumes 5 bits per color
   ;and bit 5 is not used
   ;If R<0 Or R>31 then R=0
   ;If G<0 Or G>31 then G=0
   ;If B<0 Or B>31 then B=0
  C=((R&$1F)<<11)+((G&$1F)<<6)+(B&$1F)
  ProcedureReturn C
EndProcedure
Procedure GetColor16R(C)
  ;R=Int(C/2048)
  R=(C>>11)&$1F
  ProcedureReturn R
EndProcedure
Procedure GetColor16G(C)
  ;R=Int(C/2048)
  ;R=C&($1F<<11)
  ;C=C-R
  ;G=Int(C/64)
  G=(C>>6)&$1F
  ProcedureReturn G
EndProcedure
Procedure GetColor16B(C)
  ;G=Int(C/32)
  ;G=C&($1F<<6)
  ;G=G*32
  ;B=(C-G)&$1F
  B=C&$1F
  ProcedureReturn B
EndProcedure
Procedure ConvertC16(C)
  ;determine RGB first
  R=((C>>11)&$1F)*#Factor
  G=((C>>6)&$1F)*#Factor
  B=(C&$1F)*#Factor
  ;then rescale values
  ;as a percent of 255
  ;factor.f=255/31
  ProcedureReturn RGB(R,G,B)
EndProcedure