dxx-rebirth/common/2d/circle.cpp
2017-03-11 19:56:23 +00:00

73 lines
2.1 KiB
C++

/*
* Portions of this file are copyright Rebirth contributors and licensed as
* described in COPYING.txt.
* Portions of this file are copyright Parallax Software and licensed
* according to the Parallax license below.
* See COPYING.txt for license details.
THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING, AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
*/
#include "u_mem.h"
#include "gr.h"
#include "grdef.h"
namespace dcx {
#if !DXX_USE_OGL
int gr_ucircle(grs_canvas &canvas, const fix xc1, const fix yc1, const fix r1, const uint8_t color)
{
int p,x, y, xc, yc, r;
r = f2i(r1);
xc = f2i(xc1);
yc = f2i(yc1);
p=3-(r*2);
x=0;
y=r;
while(x<y)
{
// Draw the first octant
gr_upixel(canvas.cv_bitmap, xc - y, yc - x, color);
gr_upixel(canvas.cv_bitmap, xc + y, yc - x, color);
gr_upixel(canvas.cv_bitmap, xc - y, yc + x, color);
gr_upixel(canvas.cv_bitmap, xc + y, yc + x, color);
if (p<0)
p=p+(x<<2)+6;
else {
// Draw the second octant
gr_upixel(canvas.cv_bitmap, xc - x, yc - y, color);
gr_upixel(canvas.cv_bitmap, xc + x, yc - y, color);
gr_upixel(canvas.cv_bitmap, xc - x, yc + y, color);
gr_upixel(canvas.cv_bitmap, xc + x, yc + y, color);
p=p+((x-y)<<2)+10;
y--;
}
x++;
}
if(x==y) {
gr_upixel(canvas.cv_bitmap, xc - x, yc - y, color);
gr_upixel(canvas.cv_bitmap, xc + x, yc - y, color);
gr_upixel(canvas.cv_bitmap, xc - x, yc + y, color);
gr_upixel(canvas.cv_bitmap, xc + x, yc + y, color);
}
return 0;
}
#endif //!OGL
}