/*
 * 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"

/*
 * 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;
        }
    }
}
