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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.
*/
#include "tkInt.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(
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) {
Tcl_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((unsigned) 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;
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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