/*************************************************************************** * __________ __ ___. * 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. * ****************************************************************************/ #ifndef SIMULATOR /* not for simulator by now */ #include "plugin.h" #ifdef HAVE_LCD_BITMAP /* and also not for the Player */ #include "gray.h" /******************************* Globals ***********************************/ static struct plugin_api* rb; /* global api struct pointer */ static unsigned char *gbuf; static unsigned int gbuf_size = 0; static unsigned char wave_array[256]; /* Pre calculated wave array */ static unsigned char colours[256]; /* Smooth transition of shades */ static unsigned char graybuffer[LCD_HEIGHT*LCD_WIDTH]; /* off screen buffer */ static unsigned char sp1, sp2, sp3, sp4; /* Speed of plasma */ static int plasma_frequency; /* Key assignement, all bitmapped models */ #define PLASMA_QUIT BUTTON_OFF #define PLASMA_INCREASE_FREQUENCY BUTTON_UP #define PLASMA_DECREASE_FREQUENCY BUTTON_DOWN #define WAV_AMP 90 /* Precalculated sine * 16384 (fixed point 18.14) */ static const short sin_table[91] = { 0, 285, 571, 857, 1142, 1427, 1712, 1996, 2280, 2563, 2845, 3126, 3406, 3685, 3963, 4240, 4516, 4790, 5062, 5334, 5603, 5871, 6137, 6401, 6663, 6924, 7182, 7438, 7691, 7943, 8191, 8438, 8682, 8923, 9161, 9397, 9630, 9860, 10086, 10310, 10531, 10748, 10963, 11173, 11381, 11585, 11785, 11982, 12175, 12365, 12550, 12732, 12910, 13084, 13254, 13420, 13582, 13740, 13894, 14043, 14188, 14329, 14466, 14598, 14725, 14848, 14967, 15081, 15190, 15295, 15395, 15491, 15582, 15668, 15749, 15825, 15897, 15964, 16025, 16082, 16135, 16182, 16224, 16261, 16294, 16321, 16344, 16361, 16374, 16381, 16384 }; static short sin(int val) { /* value should be between 0 and 360 degree for correct lookup*/ val%=360; if(val<0) val+=360; /* Speed improvement through successive lookup */ if (val < 181) { if (val < 91) { /* phase 0-90 degree */ return (short)sin_table[val]; } else { /* phase 91-180 degree */ return (short)sin_table[180-val]; } } else { if (val < 271) { /* phase 181-270 degree */ return -(short)sin_table[val-180]; } else { /* phase 270-359 degree */ return -(short)sin_table[360-val]; } } return 0; } /* * 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((i * 360 * plasma_frequency) / 256))) / 16384); } } /* * This function is to make a smooth shade from white into * black and back into white again. I thought this would be quicker * than calculating on the fly - am I wrong? */ static void shades_generate(void) { int i=1; int j=0; int nAdd=2; for(i=0; i < 256; ++i) { colours[i] = j; j += nAdd; if(j > 240 || j < 2) { nAdd = -nAdd; } } } void cleanup(void *parameter) { (void)parameter; gray_release(); rb->backlight_set_timeout(rb->global_settings->backlight_timeout); } /* * Main function that also contain the main plasma * algorithm. */ int main(void) { plasma_frequency = 1; int shades, button, x, y; unsigned char p1,p2,p3,p4,t1,t2,t3,t4, z; int n=0; /*Generate the neccesary pre calced stuff*/ wave_table_generate(); shades_generate(); /* get the remainder of the plugin buffer */ gbuf = (unsigned char *) rb->plugin_get_buffer(&gbuf_size); shades = gray_init(rb, gbuf, gbuf_size, false, LCD_WIDTH, LCD_HEIGHT/8, 32, NULL) + 1; /* switch on grayscale overlay */ gray_show(true); sp1 = 4; sp2 = 2; sp3 = 4; sp4 = 2; p1=p2=p3=p4=0; while (true) { t1=p1; t2=p2; n=0; 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]; graybuffer[n] = colours[z]; t3+=1; t4+=2; ++n; } t1+=2; t2+=1; rb->yield(); } p1+=sp1; p2-=sp2; p3+=sp3; p4-=sp4; gray_ub_gray_bitmap(graybuffer, 0, 0, LCD_WIDTH, LCD_HEIGHT); button = rb->button_get(false); switch(button) { 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; 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; /* * this macro should be called as the first thing you do in the plugin. * it test that the api version and model the plugin was compiled for * matches the machine it is running on */ TEST_PLUGIN_API(api); rb = api; // copy to global api pointer (void)parameter; if (rb->global_settings->backlight_timeout > 0) rb->backlight_set_timeout(1);/* keep the light on */ ret = main(); return ret; } #endif // #ifdef HAVE_LCD_BITMAP #endif // #ifndef SIMULATOR