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

*/
// d_clear: clears a specified rectangle to the specified color

#include "quakedef.h"
#include "vid.h"

/*
================
D_FillRect
================
*/
void
D_FillRect(vrect_t *rect, int color)
{
    int rx, ry, rwidth, rheight;
    unsigned char *dest;
    unsigned *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 (rx + rwidth > vid.width)
	rwidth = vid.width - rx;
    if (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) && (((long)dest & 0x03) == 0)) {
	// faster aligned dword clear
	ldest = (unsigned *)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 *)((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;
	}
    }
}
