quakeforge/libs/video/renderer/sw/d_fill.c

/*
	d_fill.c

	clears a specified rectangle to the specified color

	Copyright (C) 1996-1997  Id Software, Inc.

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	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.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "d_iface.h"
#include "r_internal.h"

void
D_FillRect (vrect_t *rect, int color)
{
	int rx, ry, rwidth, rheight;
	unsigned char *dest;
	unsigned int *ldest;

	rx = rect->x;
	ry = rect->y;
	rwidth = rect->width;
	rheight = rect->height;

	if (rx < 0) {
		rwidth += rx;
		rx = 0;
	}
	if (ry < 0) {
		rheight += ry;
		ry = 0;
	}
	if ((unsigned) (rx + rwidth) > vid.width)
		rwidth = vid.width - rx;
	if ((unsigned) (ry + rheight) > vid.height)
		rheight = vid.height - rx;

	if (rwidth < 1 || rheight < 1)
		return;

	dest = ((byte *) vid.buffer + ry * vid.rowbytes + rx);

	if (((rwidth & 0x03) == 0) && (((intptr_t) dest & 0x03) == 0)) {
		// faster aligned dword clear
		ldest = (unsigned int *) dest;
		color += color << 16;

		rwidth >>= 2;
		color += color << 8;

		for (ry = 0; ry < rheight; ry++) {
			for (rx = 0; rx < rwidth; rx++)
				ldest[rx] = color;
			ldest = (unsigned int *) ((byte *) ldest + vid.rowbytes);
		}
	} else {
		// slower byte-by-byte clear for unaligned cases
		for (ry = 0; ry < rheight; ry++) {
			for (rx = 0; rx < rwidth; rx++)
				dest[rx] = color;
			dest += vid.rowbytes;
		}
	}
}