apps/plugins/mandelbrot.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2004 Matthias Wientapper
  11  *
  12  *
  13  * All files in this archive are subject to the GNU General Public License.
  14  * See the file COPYING in the source tree root for full license agreement.
  15  *
  16  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  17  * KIND, either express or implied.
  18  *
  19  ****************************************************************************/
  20 #ifndef SIMULATOR
  21 #include "plugin.h"
  22
  23 #ifdef HAVE_LCD_BITMAP // this is not fun on the player
  24 # include "gray.h"
  25
  26 static struct plugin_api* rb;
  27 static char buff[32];
  28 static int lcd_aspect_ratio;
  29 static int x_min;
  30 static int x_max;
  31 static int y_min;
  32 static int y_max;
  33 static int delta;
  34 static int max_iter;
  35 static unsigned char *gbuf;
  36 static unsigned int gbuf_size = 0;
  37
  38
  39 void init_mandelbrot_set(void){
  40     x_min = -5<<25;  // -2.0<<26
  41     x_max =  1<<26;  //  1.0<<26
  42     y_min = -1<<26;  // -1.0<<26
  43     y_max =  1<<26;  //  1.0<<26
  44     delta = (x_max - x_min) >> 3;  // /8
  45     max_iter = 25;
  46 }
  47
  48 void calc_mandelbrot_set(void){
  49
  50     unsigned int start_tick;
  51     int n_iter;
  52     int x_pixel, y_pixel;
  53     int x, x2, y, y2, a, b;
  54     int x_fact, y_fact;
  55     int brightness;
  56
  57     start_tick = *rb->current_tick;
  58
  59 //    rb->lcd_clear_display();
  60 //    rb->lcd_update();
  61
  62     gray_clear_display();
  63
  64     x_fact = (x_max - x_min) / LCD_WIDTH;
  65     y_fact = (y_max - y_min) / LCD_HEIGHT;
  66
  67     for(y_pixel = LCD_HEIGHT-1; y_pixel>=0; y_pixel--){
  68         b = (y_pixel * y_fact) + y_min;
  69         for (x_pixel = LCD_WIDTH-1; x_pixel>=0; x_pixel--){
  70             a = (x_pixel * x_fact) + x_min;
  71             x = 0;
  72             y = 0;
  73             n_iter = 0;
  74
  75             while (++n_iter<=max_iter) {
  76                 x >>= 13;
  77                 y >>= 13;
  78                 x2 = x * x;
  79                 y2 = y * y;
  80
  81                 if (x2 + y2 > (4<<26)) break;
  82
  83                 y = 2 * x * y + b;
  84                 x = x2 - y2 + a;
  85             }
  86
  87             // "coloring"
  88             brightness = 0;
  89             if  (n_iter > max_iter){
  90                 brightness = 0; // black
  91             } else {
  92                 brightness = 255 - (31 * (n_iter & 7));
  93             }
  94
  95             gray_drawpixel( x_pixel, y_pixel, brightness);
  96         }
  97     }
  98 }
  99
 100
 101 enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
 102 {
 103     int grayscales;
 104     bool redraw = true;
 105
 106     TEST_PLUGIN_API(api);
 107     rb = api;
 108     (void)parameter;
 109
 110     /* This plugin uses the grayscale framework, so initialize */
 111     gray_init(api);
 112
 113     /* get the remainder of the plugin buffer */
 114     gbuf = (unsigned char *) rb->plugin_get_buffer(&gbuf_size);
 115
 116     /* initialize the grayscale buffer:
 117      * 112 pixels wide, 8 rows (64 pixels) high, (try to) reserve
 118      * 16 bitplanes for 17 shades of gray.*/
 119     grayscales = gray_init_buffer(gbuf, gbuf_size, 112, 8, 16, NULL) + 1;
 120     if (grayscales != 17){
 121         rb->snprintf(buff, sizeof(buff), "%d", grayscales);
 122         rb->lcd_puts(0, 1, buff);
 123         rb->lcd_update();
 124         rb->sleep(HZ*2);
 125         return(0);
 126     }
 127
 128     gray_show_display(true); /* switch on grayscale overlay */
 129
 130     init_mandelbrot_set();
 131     lcd_aspect_ratio = ((LCD_WIDTH<<13) / LCD_HEIGHT)<<13;
 132
 133     /* main loop */
 134     while (true){
 135         if(redraw)
 136             calc_mandelbrot_set();
 137
 138         redraw = false;
 139
 140         switch (rb->button_get(true)) {
 141         case BUTTON_OFF:
 142             gray_release_buffer();
 143             return PLUGIN_OK;
 144
 145         case BUTTON_ON:
 146             x_min -= ((delta>>13)*(lcd_aspect_ratio>>13));
 147             x_max += ((delta>>13)*(lcd_aspect_ratio>>13));
 148             y_min -= delta;
 149             y_max += delta;
 150             delta = (x_max - x_min) >> 3;
 151             redraw = true;
 152             break;
 153
 154
 155         case BUTTON_PLAY:
 156             x_min += ((delta>>13)*(lcd_aspect_ratio>>13));
 157             x_max -= ((delta>>13)*(lcd_aspect_ratio>>13));
 158             y_min += delta;
 159             y_max -= delta;
 160             delta = (x_max - x_min) >> 3;
 161             redraw = true;
 162             break;
 163
 164         case BUTTON_UP:
 165             y_min -= delta;
 166             y_max -= delta;
 167             redraw = true;
 168             break;
 169
 170         case BUTTON_DOWN:
 171             y_min += delta;
 172             y_max += delta;
 173             redraw = true;
 174             break;
 175
 176         case BUTTON_LEFT:
 177             x_min -= delta;
 178             x_max -= delta;
 179             redraw = true;
 180             break;
 181
 182         case BUTTON_RIGHT:
 183             x_min += delta;
 184             x_max += delta;
 185             redraw = true;
 186             break;
 187
 188         case BUTTON_F1:
 189             if (max_iter>5){
 190                 max_iter -= 5;
 191                 redraw = true;
 192             }
 193             break;
 194
 195         case BUTTON_F2:
 196             if (max_iter < 195){
 197                 max_iter += 5;
 198                 redraw = true;
 199             }
 200             break;
 201
 202         case BUTTON_F3:
 203             init_mandelbrot_set();
 204             redraw = true;
 205             break;
 206
 207         case SYS_USB_CONNECTED:
 208             gray_release_buffer();
 209             rb->usb_screen();
 210             return PLUGIN_USB_CONNECTED;
 211         }
 212     }
 213     gray_release_buffer();
 214     return false;
 215 }
 216 #endif
 217 #endif