rockbox/apps/plugins/snow.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 Itai Shaked
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 **************************************************************************/
#include "plugin.h"

#ifdef HAVE_LCD_BITMAP

#define NUM_PARTICLES (LCD_WIDTH * LCD_HEIGHT / 72)

static short particles[NUM_PARTICLES][2];
static struct plugin_api* rb;

static bool particle_exists(int particle)
{
    if (particles[particle][0]>=0 && particles[particle][1]>=0 && 
        particles[particle][0]<LCD_WIDTH && particles[particle][1]<LCD_HEIGHT)
        return true;
    else
        return false;
}

static int create_particle(void)
{
    int i;

    for (i=0; i<NUM_PARTICLES; i++) {
        if (!particle_exists(i)) {
            particles[i][0]=(rb->rand()%LCD_WIDTH);
            particles[i][1]=0;
            return i;
        }
    }
    return -1;
}

static void snow_move(void)
{
    int i;

    if (!(rb->rand()%2))
        create_particle();

    for (i=0; i<NUM_PARTICLES; i++) {
        if (particle_exists(i)) {
            rb->lcd_clearpixel(particles[i][0],particles[i][1]);
            switch ((rb->rand()%7)) {
                case 0:
                    particles[i][0]++;
                    break;

                case 1:
                    particles[i][0]--;
                    break;

                case 2:
                    break;

                default:
                    particles[i][1]++;
                    break;
            }
            if (particle_exists(i))
                rb->lcd_drawpixel(particles[i][0],particles[i][1]);
        }
    }
}

static void snow_init(void)
{
    int i;

    for (i=0; i<NUM_PARTICLES; i++) {
        particles[i][0]=-1;
        particles[i][1]=-1;
    }        
    rb->lcd_clear_display();
}

enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
{
    int button;
    TEST_PLUGIN_API(api);
    (void)(parameter);
    rb = api;

    snow_init();
    while (1) {
        snow_move();
        rb->lcd_update();
        rb->sleep(HZ/20);
        
        button = rb->button_get(false);

        if (button == BUTTON_OFF)
            return PLUGIN_OK;
        else
            if (rb->default_event_handler(button) == SYS_USB_CONNECTED)
                return PLUGIN_USB_CONNECTED;
    }
}

#endif