rockbox/apps/plugins/plasma.c

/***************************************************************************
*             __________               __   ___.
*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
*                     \/            \/     \/    \/            \/
* $Id$
*
* Plasma demo plugin
*
* My crack at making a 80's style retro plasma effect for the fantastic
* rockbox! 
* Okay, I could've hard-coded the sine wave values, I just wanted the 
* challange of calculating them! silly: maybe, fun: yes!
*
* 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"
#include "helper.h"

#ifdef HAVE_LCD_BITMAP

#ifndef HAVE_LCD_COLOR
#include "gray.h"
#endif
#include "fixedpoint.h"

PLUGIN_HEADER

/******************************* Globals ***********************************/

static struct plugin_api* rb; /* global api struct pointer */
static unsigned char wave_array[256];  /* Pre calculated wave array */
#ifdef HAVE_LCD_COLOR
static fb_data colours[256]; /* Smooth transition of shades */
static int redfactor = 1, greenfactor = 2, bluefactor = 3;
static int redphase = 0, greenphase = 50, bluephase = 100;
           /* lower chance of gray at regular intervals */
#else
static unsigned char colours[256]; /* Smooth transition of shades */
static unsigned char graybuffer[LCD_HEIGHT*LCD_WIDTH]; /* off screen buffer */
static unsigned char *gbuf;
static size_t        gbuf_size = 0;
#endif
static unsigned char sp1, sp2, sp3, sp4; /* Speed of plasma */
static int plasma_frequency;

/* Key assignement, all bitmapped models */
#if (CONFIG_KEYPAD == IPOD_4G_PAD) || (CONFIG_KEYPAD == IPOD_3G_PAD) || \
    (CONFIG_KEYPAD == IPOD_1G2G_PAD)
#define PLASMA_QUIT BUTTON_MENU
#define PLASMA_INCREASE_FREQUENCY BUTTON_SCROLL_FWD
#define PLASMA_DECREASE_FREQUENCY BUTTON_SCROLL_BACK
#elif (CONFIG_KEYPAD == GIGABEAT_PAD)
#define PLASMA_QUIT BUTTON_A
#define PLASMA_INCREASE_FREQUENCY BUTTON_UP
#define PLASMA_DECREASE_FREQUENCY BUTTON_DOWN

#elif (CONFIG_KEYPAD == SANSA_E200_PAD) || \
(CONFIG_KEYPAD == SANSA_C200_PAD)
#define PLASMA_QUIT BUTTON_POWER
#define PLASMA_INCREASE_FREQUENCY BUTTON_UP
#define PLASMA_DECREASE_FREQUENCY BUTTON_DOWN

#elif (CONFIG_KEYPAD == IAUDIO_X5M5_PAD)
#define PLASMA_QUIT BUTTON_POWER
#define PLASMA_INCREASE_FREQUENCY BUTTON_UP
#define PLASMA_DECREASE_FREQUENCY BUTTON_DOWN
#elif (CONFIG_KEYPAD == IRIVER_H10_PAD)
#define PLASMA_QUIT BUTTON_POWER
#define PLASMA_INCREASE_FREQUENCY BUTTON_SCROLL_UP
#define PLASMA_DECREASE_FREQUENCY BUTTON_SCROLL_DOWN
#else
#define PLASMA_QUIT BUTTON_OFF
#define PLASMA_INCREASE_FREQUENCY BUTTON_UP
#define PLASMA_DECREASE_FREQUENCY BUTTON_DOWN
#if (CONFIG_KEYPAD == IRIVER_H100_PAD) || (CONFIG_KEYPAD == IRIVER_H300_PAD)
#define PLASMA_RC_QUIT            BUTTON_RC_STOP
#endif
#endif

#ifdef HAVE_LCD_COLOR
#if CONFIG_KEYPAD == IAUDIO_X5M5_PAD
#define PLASMA_REGEN_COLORS BUTTON_PLAY
#elif CONFIG_KEYPAD == IRIVER_H10_PAD
#define PLASMA_REGEN_COLORS BUTTON_PLAY
#elif (CONFIG_KEYPAD == SANSA_E200_PAD) || \
(CONFIG_KEYPAD == SANSA_C200_PAD)
#define PLASMA_REGEN_COLORS BUTTON_SELECT
#elif CONFIG_KEYPAD == IPOD_4G_PAD
#define PLASMA_REGEN_COLORS BUTTON_SELECT
#elif CONFIG_KEYPAD == IRIVER_H300_PAD
#define PLASMA_REGEN_COLORS BUTTON_SELECT
#elif CONFIG_KEYPAD == GIGABEAT_PAD
#define PLASMA_REGEN_COLORS BUTTON_SELECT
#endif
#endif

#define WAV_AMP 90

/*
 * Main wave function so we don't have to re-calc the sine 
 * curve every time. Mess around WAV_AMP and FREQ to make slighlty
 * weirder looking plasmas!
 */

static void wave_table_generate(void)
{
    int i;
    for (i=0;i<256;++i)
    {
        wave_array[i] = (unsigned char)((WAV_AMP
                      * (sin_int((i * 360 * plasma_frequency) / 256))) / 16384);
    }
}

#ifdef HAVE_LCD_COLOR
/* Make a smooth colour cycle. */
void shades_generate(int time)
{
    int i;
    unsigned red, green, blue;
    unsigned r = time * redfactor + redphase;
    unsigned g = time * greenfactor + greenphase;
    unsigned b = time * bluefactor + bluephase;

    for(i=0; i < 256; ++i)
    {
        r &= 0xFF; g &= 0xFF; b &= 0xFF;

        red = 2 * r;
        if (red > 255)
            red = 510 - red;
        green = 2 * g;
        if (green > 255)
            green = 510 - green;
        blue = 2 * b;
        if (blue > 255)
            blue= 510 - blue;

        colours[i] = LCD_RGBPACK(red, green, blue);

        r++; g++; b++;
    }
}
#else
/* Make a smooth shade from black into white and back into black again. */
static void shades_generate(void)
{
    int i, y;

    for(i=0; i < 256; ++i)
    {
        y = 2 * i;
        if (y > 255)
            y = 510 - y;
        colours[i] = y;
    }
}
#endif

void cleanup(void *parameter)
{
    (void)parameter;
    
#ifndef HAVE_LCD_COLOR
    gray_release();
#endif
    /* Turn on backlight timeout (revert to settings) */
    backlight_use_settings(rb); /* backlight control in lib/helper.c */
}

/*
 * Main function that also contain the main plasma
 * algorithm.
 */

int main(void)
{
    plasma_frequency = 1;
    int button, x, y;
    unsigned char p1,p2,p3,p4,t1,t2,t3,t4, z;
#ifdef HAVE_LCD_COLOR
    fb_data *ptr;
    int time=0;
#else
    unsigned char *ptr;
#endif

    /*Generate the neccesary pre calced stuff*/
    wave_table_generate();

#ifndef HAVE_LCD_COLOR
    shades_generate();  /* statically */

    /* get the remainder of the plugin buffer */
    gbuf = (unsigned char *) rb->plugin_get_buffer(&gbuf_size);

    gray_init(rb, gbuf, gbuf_size, false, LCD_WIDTH, LCD_HEIGHT, 32, 2<<8, NULL);
    /* switch on grayscale overlay */
    gray_show(true);
#endif
    sp1 = 4;
    sp2 = 2;
    sp3 = 4;
    sp4 = 2;
    p1=p2=p3=p4=0;
    while (true)
    {
#ifdef HAVE_LCD_COLOR
        shades_generate(time++); /* dynamically */
        ptr = rb->lcd_framebuffer;
#else
        ptr = graybuffer;
#endif
        t1=p1;
        t2=p2;
        for(y = 0; y < LCD_HEIGHT; ++y)
        {
            t3=p3;
            t4=p4;
            for(x = 0; x < LCD_WIDTH; ++x)
            {
                z = wave_array[t1] + wave_array[t2] + wave_array[t3]
                  + wave_array[t4];  
                *ptr++ = colours[z];
                t3+=1;
                t4+=2;
            }
            t1+=2;
            t2+=1;
            rb->yield();
        }
        p1+=sp1;
        p2-=sp2;
        p3+=sp3;
        p4-=sp4;
#ifdef HAVE_LCD_COLOR
        rb->lcd_update();
#else
        gray_ub_gray_bitmap(graybuffer, 0, 0, LCD_WIDTH, LCD_HEIGHT);
#endif

        button = rb->button_get(false);

        switch(button)
        {
#ifdef PLASMA_RC_QUIT
            case PLASMA_RC_QUIT:
#endif
            case(PLASMA_QUIT):
                cleanup(NULL);
                return PLUGIN_OK;
                break;

            case (PLASMA_INCREASE_FREQUENCY):
                ++plasma_frequency;
                wave_table_generate();
                break;

            case (PLASMA_DECREASE_FREQUENCY):
                if(plasma_frequency>1)
                {
                    --plasma_frequency;
                    wave_table_generate();
                }
                break;
#ifdef HAVE_LCD_COLOR
            case (PLASMA_REGEN_COLORS):
                redfactor=rb->rand()%4;
                greenfactor=rb->rand()%4;
                bluefactor=rb->rand()%4;
                redphase=rb->rand()%256;
                greenphase=rb->rand()%256;
                bluephase=rb->rand()%256;
                break;
#endif
                
            default:
                if (rb->default_event_handler_ex(button, cleanup, NULL)
                    == SYS_USB_CONNECTED)
                    return PLUGIN_USB_CONNECTED;
                break;
        }
    }
}

/*************************** Plugin entry point ****************************/

enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
{
    int ret;

    rb = api; /* copy to global api pointer */
    (void)parameter;
#if LCD_DEPTH > 1
    rb->lcd_set_backdrop(NULL);
#endif
    /* Turn off backlight timeout */
    backlight_force_on(rb); /* backlight control in lib/helper.c */

    ret = main();

    return ret;
}

#endif /* HAVE_LCD_BITMAP */