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/*

 * tkImgUtil.c --

 *

 *      This file contains image related utility functions.

 *

 * Copyright (c) 1995 Sun Microsystems, Inc.

 *

 * See the file "license.terms" for information on usage and redistribution

 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.

 *

 * RCS: @(#) $Id: tkImgUtil.c,v 1.1.1.1 2002-01-16 10:25:52 markom Exp $

 */

#include "tkInt.h"

#include "tkPort.h"

#include "xbytes.h"

/*

 *----------------------------------------------------------------------

 *

 * TkAlignImageData --

 *

 *      This function takes an image and copies the data into an

 *      aligned buffer, performing any necessary bit swapping.

 *

 * Results:

 *      Returns a newly allocated buffer that should be freed by the

 *      caller.

 *

 * Side effects:

 *      None.

 *

 *----------------------------------------------------------------------

 */

char *

TkAlignImageData(image, alignment, bitOrder)

    XImage *image;              /* Image to be aligned. */

    int alignment;              /* Number of bytes to which the data should

                                 * be aligned (e.g. 2 or 4) */

    int bitOrder;               /* Desired bit order: LSBFirst or MSBFirst. */

{

    long dataWidth;

    char *data, *srcPtr, *destPtr;

    int i, j;

    if (image->bits_per_pixel != 1) {

        panic("TkAlignImageData: Can't handle image depths greater than 1.");

    }

    /*

     * Compute line width for output data buffer.

     */

    dataWidth = image->bytes_per_line;

    if (dataWidth % alignment) {

        dataWidth += (alignment - (dataWidth % alignment));

    }

    data = ckalloc(dataWidth * image->height);

    destPtr = data;

    for (i = 0; i < image->height; i++) {

        srcPtr = &image->data[i * image->bytes_per_line];

        for (j = 0; j < dataWidth; j++) {

            if (j >= image->bytes_per_line) {

                *destPtr = 0;

            } else if (image->bitmap_bit_order != bitOrder) {

                *destPtr = xBitReverseTable[(unsigned char)(*(srcPtr++))];

            } else {

                *destPtr = *(srcPtr++);

            }

            destPtr++;

        }

    }

    return data;

}