Class BitRotator

java.lang.Object
com.twelvemonkeys.imageio.plugins.pcx.BitRotator

final class BitRotator extends Object
IFFUtil

Bit rotate methods based on Sue-Ken Yap, "A Fast 90-Degree Bitmap Rotator," in GRAPHICS GEMS II, James Arvo ed., Academic Press, 1991, ISBN 0-12-064480-0.

Version:
$Id: IFFUtil.java,v 1.0 06.mar.2006 13:31:35 haku Exp$
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private static final long[][]
     
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    (package private) static void
    bitRotateCW(byte[] pSrc, int pSrcPos, int pSrcStep, byte[] pDst, int pDstPos, int pDstStep)
    Rotate bits clockwise.
    private static long[]
    rtable(int n)
    Creates a rotation table

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • RTABLE

      private static final long[][] RTABLE
  • Constructor Details

    • BitRotator

      BitRotator()
  • Method Details

    • rtable

      private static long[] rtable(int n)
      Creates a rotation table
      Parameters:
      n - number of bits -1
      Returns:
      the rotation table
    • bitRotateCW

      static void bitRotateCW(byte[] pSrc, int pSrcPos, int pSrcStep, byte[] pDst, int pDstPos, int pDstStep)
      Rotate bits clockwise. The IFFImageReader uses this to convert pixel bits from planar to chunky. Bits from the source are rotated 90 degrees clockwise written to the destination.
      Parameters:
      pSrc - source pixel data
      pSrcPos - starting index of 8 x 8 bit source tile
      pSrcStep - byte offset between adjacent rows in source
      pDst - destination pixel data
      pDstPos - starting index of 8 x 8 bit destination tile
      pDstStep - byte offset between adjacent rows in destination