163 lines
5.7 KiB
C
163 lines
5.7 KiB
C
/* $XFree86: xc/programs/Xserver/hw/xfree86/xf4bpp/mfbbres.c,v 1.3 1999/06/06 08:48:54 dawes Exp $ */
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/* Combined Purdue/PurduePlus patches, level 2.0, 1/17/89 */
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/***********************************************************
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Copyright (c) 1987 X Consortium
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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Except as contained in this notice, the name of the X Consortium shall not be
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used in advertising or otherwise to promote the sale, use or other dealings
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in this Software without prior written authorization from the X Consortium.
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Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.
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All Rights Reserved
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Permission to use, copy, modify, and distribute this software and its
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documentation for any purpose and without fee is hereby granted,
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provided that the above copyright notice appear in all copies and that
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both that copyright notice and this permission notice appear in
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supporting documentation, and that the name of Digital not be
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used in advertising or publicity pertaining to distribution of the
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software without specific, written prior permission.
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DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
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ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
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DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
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ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
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WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
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ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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SOFTWARE.
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******************************************************************/
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/* GJA -- modified this file for vga16 */
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/* $XConsortium: mfbbres.c /main/5 1996/02/21 17:56:30 kaleb $ */
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#include "xf4bpp.h"
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#include "OScompiler.h"
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#include "mfbmap.h"
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#include "mfb.h"
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#include "maskbits.h"
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#include "miline.h"
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#include "wm3.h"
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/* Solid bresenham line */
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/* NOTES
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e2 is used less often than e1, so it's not in a register
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*/
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void
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xf4bppBresS(addrlbase, nlwidth, signdx, signdy, axis, x1, y1, e, e1, e2, len)
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PixelType *addrlbase; /* pointer to base of bitmap */
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int nlwidth; /* width in longwords of bitmap */
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int signdx, signdy; /* signs of directions */
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int axis; /* major axis (Y_AXIS or X_AXIS) */
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int x1, y1; /* initial point */
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register int e; /* error accumulator */
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register int e1; /* bresenham increments */
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int e2;
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int len; /* length of line */
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{
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register int yinc; /* increment to next scanline, in bytes */
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register PixelType *addrl; /* bitmask long pointer
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*dont* * cast to char pointer */
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register PixelType bit; /* current bit being set/cleared/etc. */
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PixelType leftbit = mask[0]; /* leftmost bit to process in new word */
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PixelType rightbit = mask[PPW-1]; /* rightmost bit to process in new word */
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register int e3 = e2-e1;
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/* point to longword containing first point */
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addrl = mfbScanline(addrlbase, x1, y1, nlwidth);
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yinc = signdy * nlwidth;
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e = e-e1; /* to make looping easier */
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bit = mask[x1 & PIM];
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if (!len)
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return;
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if (axis == X_AXIS)
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{
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if (signdx > 0)
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{
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while(len--)
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{
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UPDRW(addrl,bit);
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e += e1;
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if (e >= 0)
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{
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addrl += yinc;
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e += e3;
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}
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bit = SCRRIGHT(bit,1);
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if (!bit) { bit = leftbit; addrl++; }
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}
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}
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else
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{
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while(len--)
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{
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UPDRW(addrl,bit);
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e += e1;
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if (e >= 0)
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{
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addrl += yinc;
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e += e3;
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}
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bit = SCRLEFT(bit,1);
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if (!bit) { bit = rightbit; addrl--; }
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}
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}
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} /* if X_AXIS */
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else
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{
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if (signdx > 0)
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{
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while(len--)
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{
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UPDRW(addrl,bit);
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e += e1;
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if (e >= 0)
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{
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bit = SCRRIGHT(bit,1);
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if (!bit) { bit = leftbit; addrl++; }
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e += e3;
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}
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addrl += yinc;
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}
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}
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else
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{
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while(len--)
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{
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UPDRW(addrl,bit);
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e += e1;
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if (e >= 0)
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{
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bit = SCRLEFT(bit,1);
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if (!bit) { bit = rightbit; addrl--; }
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e += e3;
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}
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addrl += yinc;
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}
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}
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} /* else Y_AXIS */
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}
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