/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1999 Brad Forschinger
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification, immediately at the beginning of the file.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * brad forschinger, 19990504 <retch@flag.blackened.net>
 * 
 * written with much help from warp_saver.c
 * 
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/syslog.h>
#include <sys/consio.h>
#include <sys/malloc.h>
#include <sys/fbio.h>

#include <dev/fb/fbreg.h>
#include <dev/fb/splashreg.h>
#include <dev/syscons/syscons.h>

#define SAVER_NAME       "fire_saver"

#define RED(n)           ((n) * 3 + 0)
#define GREEN(n)         ((n) * 3 + 1)
#define BLUE(n)          ((n) * 3 + 2)

#define SET_ORIGIN(adp, o) do {                         \
        int oo = o;                                     \
        if (oo != last_origin)                          \
            vidd_set_win_org(adp, last_origin = oo);    \
        } while (0)

static u_char           *buf;
static u_char           *vid;
static int               banksize, scrmode, bpsl, scrw, scrh;
static u_char            fire_pal[768];
static int               blanked;

static void
fire_update(video_adapter_t *adp)
{
        int x, y;
        int o, p;
        int last_origin = -1;

        /* make a new bottom line */
        for (x = 0, y = scrh; x < scrw; x++)
                buf[x + (y * bpsl)] = random() % 160 + 96;

        /* fade the flames out */
        for (y = 0; y < scrh; y++) {
                for (x = 0; x < scrw; x++) {
                        buf[x + (y * scrw)] =
                            (buf[(x + 0) + ((y + 0) * scrw)] +
                             buf[(x - 1) + ((y + 1) * scrw)] +
                             buf[(x + 0) + ((y + 1) * scrw)] +
                             buf[(x + 1) + ((y + 1) * scrw)]) / 4;
                        if (buf[x + (y * scrw)] > 0)
                                buf[x + (y * scrw)]--;
                }
        }

        /* blit our buffer into video ram */
        for (y = 0, p = 0, o = 0; y < scrh; y++, p += bpsl) {
                while (p > banksize) {
                        p -= banksize;
                        o += banksize;
                }
                SET_ORIGIN(adp, o);
                if (p + scrw < banksize) {
                        bcopy(buf + y * scrw, vid + p, scrw);
                } else {
                        bcopy(buf + y * scrw, vid + p, banksize - p);
                        SET_ORIGIN(adp, o + banksize);
                        bcopy(buf + y * scrw + (banksize - p), vid,
                              scrw - (banksize - p));
                        p -= banksize;
                        o += banksize;
                }
        }

}

static int
fire_saver(video_adapter_t *adp, int blank)
{
        int pl;

        if (blank) {
                /* switch to graphics mode */
                if (blanked <= 0) {
                        pl = splhigh();
                        vidd_set_mode(adp, scrmode);
                        vidd_load_palette(adp, fire_pal);
                        blanked++;
                        vid = (u_char *)adp->va_window;
                        banksize = adp->va_window_size;
                        bpsl = adp->va_line_width;
                        splx(pl);
                        vidd_clear(adp);
                }
                fire_update(adp);
        } else {
                blanked = 0;
        }

    return 0;
}

static int
fire_init(video_adapter_t *adp)
{
        video_info_t info;
        int i, red, green, blue;

        if (!vidd_get_info(adp, M_VGA_CG320, &info)) {
                scrmode = M_VGA_CG320;
        } else {
                log(LOG_NOTICE,
                    "%s: the console does not support M_VGA_CG320\n",
                    SAVER_NAME);
                return (ENODEV);
        }
    
        scrw = info.vi_width;
        scrh = info.vi_height;

        buf = (u_char *)malloc(scrw * (scrh + 1), M_DEVBUF, M_NOWAIT);
        if (buf) {
                bzero(buf, scrw * (scrh + 1));
        } else {
                log(LOG_NOTICE,
                    "%s: buffer allocation is failed\n",
                    SAVER_NAME);
                return (ENODEV);
        }

        /* intialize the palette */
        red = green = blue = 0;
        for (i = 0; i < 256; i++) {
                red++;
                if (red > 128)
                        green += 2;
                fire_pal[RED(i)] = red;
                fire_pal[GREEN(i)] = green;
                fire_pal[BLUE(i)] = blue;
        }

        return (0);
}

static int
fire_term(video_adapter_t *adp)
{
        free(buf, M_DEVBUF);
        return (0);
}

static scrn_saver_t fire_module = {
        SAVER_NAME,
        fire_init,
        fire_term,
        fire_saver,
        NULL
};

SAVER_MODULE(fire_saver, fire_module);