119 lines
2.4 KiB
C
119 lines
2.4 KiB
C
/* $Id: circle.c,v 1.4 2002-10-10 18:55:32 btb Exp $ */
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/*
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THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
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SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO
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END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
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ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
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IN USING, DISPLAYING, AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
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SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
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FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
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CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS
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AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
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COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
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*/
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#ifdef HAVE_CONFIG_H
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#include <conf.h>
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#endif
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#ifdef RCS
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static char rcsid[] = "$Id: circle.c,v 1.4 2002-10-10 18:55:32 btb Exp $";
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#endif
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#include "u_mem.h"
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#include "gr.h"
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#include "grdef.h"
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#ifndef OGL
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int gr_circle(fix xc1,fix yc1,fix r1)
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{
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int p,x, y, xc, yc, r;
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r = f2i(r1);
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xc = f2i(xc1);
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yc = f2i(yc1);
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p=3-(r*2);
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x=0;
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y=r;
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// Big clip
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if ( (xc+r) < 0 ) return 1;
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if ( (xc-r) > GWIDTH ) return 1;
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if ( (yc+r) < 0 ) return 1;
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if ( (yc-r) > GHEIGHT ) return 1;
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while(x<y)
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{
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// Draw the first octant
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gr_pixel( xc-y, yc-x );
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gr_pixel( xc+y, yc-x );
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gr_pixel( xc-y, yc+x );
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gr_pixel( xc+y, yc+x );
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if (p<0)
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p=p+(x<<2)+6;
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else {
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// Draw the second octant
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gr_pixel( xc-x, yc-y );
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gr_pixel( xc+x, yc-y );
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gr_pixel( xc-x, yc+y );
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gr_pixel( xc+x, yc+y );
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p=p+((x-y)<<2)+10;
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y--;
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}
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x++;
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}
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if(x==y) {
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gr_pixel( xc-x, yc-y );
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gr_pixel( xc+x, yc-y );
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gr_pixel( xc-x, yc+y );
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gr_pixel( xc+x, yc+y );
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}
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return 0;
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}
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int gr_ucircle(fix xc1,fix yc1,fix r1)
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{
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int p,x, y, xc, yc, r;
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r = f2i(r1);
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xc = f2i(xc1);
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yc = f2i(yc1);
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p=3-(r*2);
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x=0;
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y=r;
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while(x<y)
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{
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// Draw the first octant
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gr_upixel( xc-y, yc-x );
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gr_upixel( xc+y, yc-x );
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gr_upixel( xc-y, yc+x );
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gr_upixel( xc+y, yc+x );
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if (p<0)
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p=p+(x<<2)+6;
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else {
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// Draw the second octant
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gr_upixel( xc-x, yc-y );
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gr_upixel( xc+x, yc-y );
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gr_upixel( xc-x, yc+y );
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gr_upixel( xc+x, yc+y );
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p=p+((x-y)<<2)+10;
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y--;
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}
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x++;
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}
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if(x==y) {
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gr_upixel( xc-x, yc-y );
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gr_upixel( xc+x, yc-y );
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gr_upixel( xc-x, yc+y );
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gr_upixel( xc+x, yc+y );
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}
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return 0;
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}
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#endif //!OGL
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