REM <<      AmigaBasic        >>  
REM << Find Ptrs to BitPlanes >>
REM << Carolyn Scheppner  CBM >>

depth = 5
x = 320
y = 200

SCREEN 2,x,y,depth,1
WINDOW 2,"Click Mouse to Exit",,7,2

GOSUB GetScrAddrs

PRINT
PRINT "STRUCTURE ADDRESSES:"
PRINT "Window -----"sWindow&
PRINT "Screen -----"sScreen&
PRINT "ViewPort ---"sViewPort&
PRINT "RastPort ---"sRastPort&
PRINT "BitMap -----"sBitMap&
PRINT "ColorMap ---"sColorMap&
PRINT "ColorTable -"colorTab&
PRINT
PRINT "OTHER VALUES:"
PRINT "Width ------"scrWidth%
PRINT "Height -----"scrHeight%
PRINT "Depth ------"scrDepth%
PRINT "Colors -----"nColors%
PRINT
PRINT "BITPLANE ADDRESSES:"
FOR k = 0 TO scrDepth%-1
   PRINT "BitPlane" k "---"bPlane&(k)
NEXT

LOCATE 2,1
PRINT TAB(26)"RGB VALUES:":PRINT
FOR k = 0 TO (nColors%/2)-1
   COLOR k: PRINT TAB(25)"* ";: COLOR 1
   PRINT HEX$(PEEKW(colorTab&+(2*k)))
NEXT
LOCATE 4,1
FOR k = (nColors%/2) TO nColors%-1 
   COLOR k: PRINT TAB(33)"* ";: COLOR 1
   PRINT HEX$(PEEKW(colorTab&+(2*k)))
NEXT

PRINT:PRINT:PRINT TAB(25)"Poking->"

REM << Test - Random Poke to the BitPlanes >>
bytesPerRow% = scrWidth% / 8
rowByte% =  33
FOR y = 178 TO 186
  FOR k = 0 TO depth-1
    POKE bPlane&(k)+(y*bytesPerRow%)+rowByte%, INT(255*RND)
  NEXT  
NEXT

WaitForClick:
SLEEP
IF MOUSE(0) = 0 THEN WaitForClick


Cleanup:
WINDOW CLOSE 2
SCREEN CLOSE 2
END

GetScrAddrs:
REM - Get addresses of screen structures
   sWindow&   = WINDOW(7)
   sScreen&   = PEEKL(sWindow& + 46)
   sViewPort& = sScreen& + 44
   sRastPort& = sScreen& + 84
   sColorMap& = PEEKL(sViewPort& + 4)
   colorTab&  = PEEKL(sColorMap& + 4)
   sBitMap&   = PEEKL(sRastPort& + 4)

   REM - Get screen parameters
   scrWidth%  = PEEKW(sScreen& + 12)
   scrHeight% = PEEKW(sScreen& + 14)
   scrDepth%  = PEEK(sBitMap& + 5)
   nColors%   = 2^scrDepth%

   REM - Get addresses of Bit Planes 
   FOR kk = 0 TO scrDepth% - 1
      bPlane&(kk) = PEEKL(sBitMap&+8+(kk*4))
   NEXT
RETURN