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piline.c
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1993-12-06
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/**
** PILINE.C
**
** Copyright (C) 1992, Csaba Biegl
** 820 Stirrup Dr, Nashville, TN, 37221
** csaba@vuse.vanderbilt.edu
**
** This file is distributed under the terms listed in the document
** "copying.cb", available from the author at the address above.
** A copy of "copying.cb" should accompany this file; if not, a copy
** should be available from where this file was obtained. This file
** may not be distributed without a verbatim copy of "copying.cb".
** You should also have received a copy of the GNU General Public
** License along with this program (it is in the file "copying");
** if not, write to the Free Software Foundation, Inc., 675 Mass Ave,
** Cambridge, MA 02139, USA.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**/
#include "p8514a.h"
void _GrPIDrawLine(long addr,int color,int deltax,int deltay)
{
if(CURC->gc_onscreen) {
int oper = C_OPER(color);
int command = CMD_LINE | DRAW | PLANAR | WRTDATA | INC_X | INC_Y;
int majorAxis,minorAxis;
int twiceMinor;
if((_GrPIDrawTable[oper] ^ (color &= C_SIGNIF)) == 0) return;
WaitQueue(4);
outpw(FRGD_COLOR,color);
outpw(FRGD_MIX,_GrPIMixTable[oper]);
outpw(CUR_X,COORD_X(addr));
outpw(CUR_Y,COORD_Y(addr));
if(deltay < 0) {
deltay = (-deltay);
command &= ~INC_Y;
}
if(deltax < deltay) {
command |= YMAJAXIS;
majorAxis = deltay;
minorAxis = deltax;
}
else {
majorAxis = deltax;
minorAxis = deltay;
}
twiceMinor = minorAxis << 1;
WaitQueue(5);
outpw(ERR_TERM,twiceMinor - majorAxis - 1);
outpw(DESTY_AXSTP,twiceMinor);
outpw(DESTX_DIASTP,(twiceMinor - (majorAxis << 1)));
outpw(MAJ_AXIS_PCNT,majorAxis);
outpw(CMD,command);
return;
}
_GrP8DrawLine(addr,color,deltax,deltay);
}