Index: apps/plugins/rocklife.c
===================================================================
--- apps/plugins/rocklife.c	(revision 0)
+++ apps/plugins/rocklife.c	(revision 0)
@@ -0,0 +1,489 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id: helloworld.c 8349 2006-01-15 18:20:18Z amiconn $
+ *
+ * Copyright (C) 2007 Matthias Wientapper
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/*
+ * This is an implementatino of Conway's Game of Life
+ *
+ * from http://en.wikipedia.org/wiki/Conway's_Game_of_Life:
+ *
+ * Rules
+ *
+ * The universe of the Game of Life is an infinite two-dimensional
+ * orthogonal grid of square cells, each of which is in one of two
+ * possible states, live or dead. Every cell interacts with its eight
+ * neighbours, which are the cells that are directly horizontally,
+ * vertically, or diagonally adjacent. At each step in time, the
+ * following transitions occur:
+ *
+ * 1. Any live cell with fewer than two live neighbours dies, as if by
+ *    loneliness.
+ *
+ * 2. Any live cell with more than three live neighbours dies, as if
+ *    by overcrowding.
+ *
+ * 3. Any live cell with two or three live neighbours lives,
+ *    unchanged, to the next generation.
+ *
+ * 4. Any dead cell with exactly three live neighbours comes to life.
+ *
+ * The initial pattern constitutes the first generation of the
+ * system. The second generation is created by applying the above
+ * rules simultaneously to every cell in the first generation --
+ * births and deaths happen simultaneously, and the discrete moment at
+ * which this happens is sometimes called a tick. (In other words,
+ * each generation is based entirely on the one before.) The rules
+ * continue to be applied repeatedly to create further generations.
+ *
+ *
+ *
+ * TODO:
+ *       - nicer colours for pixels with respect to age
+ *       - editor for start patterns
+ *       - probably tons of speed-up opportunities
+ */
+
+#include "plugin.h"
+#include "pluginlib_actions.h"
+
+PLUGIN_HEADER
+
+#define ROCKLIFE_PLAY_PAUSE PLA_FIRE
+#define ROCKLIFE_INIT       PLA_DOWN
+#define ROCKLIFE_NEXT       PLA_RIGHT
+#define ROCKLIFE_NEXT_REP   PLA_RIGHT_REPEAT
+#define ROCKLIFE_QUIT       PLA_QUIT
+#define ROCKLIFE_STATUS     PLA_LEFT
+
+#define PATTERN_RANDOM     0
+#define PATTERN_GROWTH_1   1
+#define PATTERN_GROWTH_2   2
+#define PATTERN_ACORN      3
+#define PATTERN_GLIDER_GUN 4 /* not yet implemented */
+
+static struct plugin_api* rb;
+const struct button_mapping *plugin_contexts[]
+= {generic_directions, generic_actions};
+
+
+unsigned char grid_a[LCD_WIDTH][LCD_HEIGHT];
+unsigned char grid_b[LCD_WIDTH][LCD_HEIGHT];
+int generation = 0;
+int population = 0;
+int status_line = 0;
+char buf[30];
+
+static inline void set_cell(int x, int y, char *pgrid){
+    pgrid[x+y*LCD_WIDTH]=1;
+}
+
+/* clear grid */
+void init_grid(char *pgrid){
+    int x, y;
+  
+    for(y=0; y<LCD_HEIGHT; y++){
+        for(x=0; x<LCD_WIDTH; x++){
+            pgrid[x+y*LCD_WIDTH] = 0;
+        }
+    }
+}
+
+/* fill grid with initial pattern */
+static void setup_grid(char *pgrid, int pattern){
+    int n, max;
+    int xmid, ymid;
+
+    max = LCD_HEIGHT*LCD_WIDTH;
+
+    switch(pattern){
+    case PATTERN_RANDOM:
+        rb->splash(HZ, true, "Random");
+#if 0 /* two oscilators, debug pattern */
+        set_cell( 0,  1 , pgrid);
+        set_cell( 1,  1 , pgrid);
+        set_cell( 2,  1 , pgrid);
+
+        set_cell( 6,  7 , pgrid);
+        set_cell( 7,  7 , pgrid);
+        set_cell( 8,  7 , pgrid);
+#endif   
+
+        /* fill screen randomly */
+        for(n=0; n<(max>>2); n++)
+            pgrid[rb->rand()%max] = 1;
+
+        break;
+
+    case PATTERN_GROWTH_1:
+        rb->splash(HZ, true, "Growth");
+        xmid = (LCD_WIDTH>>1) - 2;
+        ymid = (LCD_HEIGHT>>1) - 2;
+        set_cell(xmid + 6, ymid + 0 , pgrid);
+        set_cell(xmid + 4, ymid + 1 , pgrid);
+        set_cell(xmid + 6, ymid + 1 , pgrid);
+        set_cell(xmid + 7, ymid + 1 , pgrid);
+        set_cell(xmid + 4, ymid + 2 , pgrid);
+        set_cell(xmid + 6, ymid + 2 , pgrid);
+        set_cell(xmid + 4, ymid + 3 , pgrid);
+        set_cell(xmid + 2, ymid + 4 , pgrid);
+        set_cell(xmid + 0, ymid + 5 , pgrid);
+        set_cell(xmid + 2, ymid + 5 , pgrid);
+        break;
+    case PATTERN_ACORN:
+        rb->splash(HZ, true, "Acorn");
+        xmid = (LCD_WIDTH>>1) - 3;
+        ymid = (LCD_HEIGHT>>1) - 1;
+        set_cell(xmid + 1, ymid + 0 , pgrid);
+        set_cell(xmid + 3, ymid + 1 , pgrid);
+        set_cell(xmid + 0, ymid + 2 , pgrid);
+        set_cell(xmid + 1, ymid + 2 , pgrid);
+        set_cell(xmid + 4, ymid + 2 , pgrid);
+        set_cell(xmid + 5, ymid + 2 , pgrid);
+        set_cell(xmid + 6, ymid + 2 , pgrid);
+        break;
+    case PATTERN_GROWTH_2:
+        rb->splash(HZ, true, "Growth 2");
+        xmid = (LCD_WIDTH>>1) - 4;
+        ymid = (LCD_HEIGHT>>1) - 1;
+        set_cell(xmid + 0, ymid + 0 , pgrid);
+        set_cell(xmid + 1, ymid + 0 , pgrid);
+        set_cell(xmid + 2, ymid + 0 , pgrid);
+        set_cell(xmid + 4, ymid + 0 , pgrid);
+        set_cell(xmid + 0, ymid + 1 , pgrid);
+        set_cell(xmid + 3, ymid + 2 , pgrid);
+        set_cell(xmid + 4, ymid + 2 , pgrid);
+        set_cell(xmid + 1, ymid + 3 , pgrid);
+        set_cell(xmid + 2, ymid + 3 , pgrid);
+        set_cell(xmid + 4, ymid + 3 , pgrid);
+        set_cell(xmid + 0, ymid + 4 , pgrid);
+        set_cell(xmid + 2, ymid + 4 , pgrid);
+        set_cell(xmid + 4, ymid + 4 , pgrid);
+        break;
+    case PATTERN_GLIDER_GUN:
+        rb->splash(HZ, true, "Glider Gun");
+        set_cell( 24, 0, pgrid);
+        set_cell( 22, 1, pgrid);
+        set_cell( 24, 1, pgrid);
+        set_cell( 12, 2, pgrid);
+        set_cell( 13, 2, pgrid);
+        set_cell( 20, 2, pgrid);
+        set_cell( 21, 2, pgrid);
+        set_cell( 34, 2, pgrid);
+        set_cell( 35, 2, pgrid);
+        set_cell( 11, 3, pgrid);
+        set_cell( 15, 3, pgrid);
+        set_cell( 20, 3, pgrid);
+        set_cell( 21, 3, pgrid);
+        set_cell( 34, 3, pgrid);
+        set_cell( 35, 3, pgrid);
+        set_cell(  0, 4, pgrid);
+        set_cell(  1, 4, pgrid);
+        set_cell( 10, 4, pgrid);
+        set_cell( 16, 4, pgrid);
+        set_cell( 20, 4, pgrid);
+        set_cell( 21, 4, pgrid);
+        set_cell(  0, 5, pgrid);
+        set_cell(  1, 5, pgrid);
+        set_cell( 10, 5, pgrid);
+        set_cell( 14, 5, pgrid);
+        set_cell( 16, 5, pgrid);
+        set_cell( 17, 5, pgrid);
+        set_cell( 22, 5, pgrid);
+        set_cell( 24, 5, pgrid);
+        set_cell( 10, 6, pgrid);
+        set_cell( 16, 6, pgrid);
+        set_cell( 24, 6, pgrid);
+        set_cell( 11, 7, pgrid);
+        set_cell( 15, 7, pgrid);
+        set_cell( 12, 8, pgrid);
+        set_cell( 13, 8, pgrid);
+        break;
+    }
+}
+
+/* display grid */
+static void show_grid(char *pgrid){
+    int x, y;
+    int m;
+    unsigned char age;
+
+    rb->lcd_clear_display();
+    for(y=0; y<LCD_HEIGHT; y++){
+        for(x=0; x<LCD_WIDTH; x++){
+            m = y*LCD_WIDTH+x;
+            age = pgrid[m];
+            if(age){
+#if LCD_DEPTH >= 16
+                rb->lcd_set_foreground( LCD_RGBPACK( age, age, age ));
+#elif LCD_DEPTH == 2
+                rb->lcd_set_foreground(age>>7);
+#endif
+                rb->lcd_drawpixel(x, y);
+            }
+        }
+    }
+    if(status_line){
+        rb->snprintf(buf, sizeof(buf), "g:%d p:%d", generation, population);
+#if LCD_DEPTH > 1
+        rb->lcd_set_foreground( LCD_BLACK );
+#endif
+        rb->lcd_puts(0, 0, buf);
+    }
+    rb->lcd_update();
+}
+
+
+/* check state of cell depending on the number of neighbours */
+static inline int check_cell(unsigned char *n){
+    int sum; 
+    int empty_cells = 0;
+    unsigned char live = 0;
+
+    /* count empty neighbour cells */
+    if(n[0]==0) empty_cells++;
+    if(n[1]==0) empty_cells++;
+    if(n[2]==0) empty_cells++;
+    if(n[3]==0) empty_cells++;
+    if(n[5]==0) empty_cells++;
+    if(n[6]==0) empty_cells++;
+    if(n[7]==0) empty_cells++;
+    if(n[8]==0) empty_cells++;
+
+    /* now we build the number of non-zero neighbours :-P */
+    sum = 8 - empty_cells;
+
+    /* 1st and 2nd rule*/
+    if (n[4]  && (sum<2 || sum>3))
+        live = false;
+  
+    /* 3rd rule */
+    if (n[4] && (sum==2 || sum==3))
+        live = true;
+
+    /* 4rd rule */
+    if (!n[4] && sum==3)
+        live = true;
+
+    return live;
+}
+ 
+/* Calculate the next generation of cells 
+ *
+ * The borders of the grid are connected to their opposite sides.
+ *
+ *
+ * To avoid multiplications while accessing data in the 2-d grid
+ * (pgrid) we try to re-use previously accessed neighbourhood
+ * information which is stored in an 3x3 array.
+ *
+ */   
+static void next_generation(char *pgrid, char *pnext_grid){
+    int x, y;
+    unsigned char cell;
+    int age;
+    int m;
+    unsigned char n[9];
+
+    rb->memset(n, 0, sizeof(n));
+
+    /*
+     * cell is (4) with 8 neighbours
+     * 
+     *   0|1|2
+     *   -----
+     *   3|4|5
+     *   -----
+     *   6|7|8
+     */
+
+    population = 0;
+
+    /* go through the grid */
+    for(y=0; y<LCD_HEIGHT; y++){
+        for(x=0; x<LCD_WIDTH; x++){
+            if(y==0 && x==0){
+                /* first cell in first row, we have to load all neighbours */
+                n[0] = pgrid[((x+LCD_WIDTH-1)%LCD_WIDTH)+((y+LCD_HEIGHT-1)%LCD_HEIGHT)*LCD_WIDTH];
+                n[1] = pgrid[((x            )%LCD_WIDTH)+((y+LCD_HEIGHT-1)%LCD_HEIGHT)*LCD_WIDTH];
+                n[2] = pgrid[((x          +1)%LCD_WIDTH)+((y+LCD_HEIGHT-1)%LCD_HEIGHT)*LCD_WIDTH];
+                n[3] = pgrid[((x+LCD_WIDTH-1)%LCD_WIDTH)+((y             )%LCD_HEIGHT)*LCD_WIDTH];  
+                n[5] = pgrid[((x          +1)%LCD_WIDTH)+((y             )%LCD_HEIGHT)*LCD_WIDTH];
+                n[6] = pgrid[((x+LCD_WIDTH-1)%LCD_WIDTH)+((y           +1)%LCD_HEIGHT)*LCD_WIDTH];
+                n[7] = pgrid[((x            )%LCD_WIDTH)+((y           +1)%LCD_HEIGHT)*LCD_WIDTH];
+                n[8] = pgrid[((x          +1)%LCD_WIDTH)+((y           +1)%LCD_HEIGHT)*LCD_WIDTH];
+            } else {
+                if(x==0){
+                    /* beginning of a row, copy what we know about our predecessor, 
+                       0, 1, 3 are known, 2, 5, 6, 7, 8 have to be loaded
+                    */
+                    n[0] = n[4];
+                    n[1] = n[5];
+                    n[2] = pgrid[((x          +1)%LCD_WIDTH)+((y+LCD_HEIGHT-1)%LCD_HEIGHT)*LCD_WIDTH];
+                    n[3] = n[7];
+                    n[5] = pgrid[((x          +1)%LCD_WIDTH)+((y             )%LCD_HEIGHT)*LCD_WIDTH];
+                    n[6] = pgrid[((x+LCD_WIDTH-1)%LCD_WIDTH)+((y           +1)%LCD_HEIGHT)*LCD_WIDTH];
+                    n[7] = pgrid[((x            )%LCD_WIDTH)+((y           +1)%LCD_HEIGHT)*LCD_WIDTH];
+                    n[8] = pgrid[((x          +1)%LCD_WIDTH)+((y           +1)%LCD_HEIGHT)*LCD_WIDTH];
+                } else {
+                    /* we are moving right in a row, 
+                     * copy what we know about the neighbours on our left side,
+                     * 2, 5, 8 have to be loaded
+                     */
+                    n[0] = n[1];
+                    n[1] = n[2];
+                    n[2] = pgrid[((x          +1)%LCD_WIDTH)+((y+LCD_HEIGHT-1)%LCD_HEIGHT)*LCD_WIDTH];
+                    n[3] = n[4];
+                    n[5] = pgrid[((x          +1)%LCD_WIDTH)+((y             )%LCD_HEIGHT)*LCD_WIDTH];
+                    n[6] = n[7];
+                    n[7] = n[8];
+                    n[8] = pgrid[((x          +1)%LCD_WIDTH)+((y           +1)%LCD_HEIGHT)*LCD_WIDTH];
+                }
+            }
+
+            m = x+y*LCD_WIDTH;
+
+            /* how old is our cell? */
+            n[4] = pgrid[m];
+            age  = n[4];
+
+            /* calculate the cell based on given neighbour information */
+            cell = check_cell(n);
+
+            /* is the actual cell alive? */
+            if(cell){
+                population++;
+                /* prevent overflow */
+                if(age>252){
+                    pnext_grid[m] = 252;
+                } else {
+                    pnext_grid[m] = age + 1;
+                }
+            }
+            else
+                pnext_grid[m] = 0;
+#if 0
+            DEBUGF("x=%d,y=%d\n", x, y);
+            DEBUGF("cell: %d\n", cell);
+            DEBUGF("%d %d %d\n", n[0],n[1],n[2]);
+            DEBUGF("%d %d %d\n", n[3],n[4],n[5]);
+            DEBUGF("%d %d %d\n", n[6],n[7],n[8]);
+            DEBUGF("----------------\n");
+#endif
+        }
+    }
+    generation++;
+}
+ 
+/**********************************/
+/* this is the plugin entry point */
+/**********************************/
+enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
+{
+    int button = 0;
+    int quit = 0;
+    int stop = 0;
+    int pattern = 0;
+    char *pgrid;
+    char *pnext_grid;
+    char *ptemp;
+
+    (void)parameter;
+    rb = api;
+ 
+    rb->backlight_set_timeout(1);
+#if LCD_DEPTH > 1
+    rb->lcd_set_backdrop(NULL);
+    rb->lcd_set_background(LCD_DEFAULT_BG);
+#endif
+
+    /* link pointers to grids */
+    pgrid      = (char *)grid_a;
+    pnext_grid = (char *)grid_b;
+
+    init_grid(pgrid);
+    setup_grid(pgrid, pattern++);
+    show_grid(pgrid);
+ 
+    while(!quit) {
+        button = pluginlib_getaction(rb, TIMEOUT_BLOCK, plugin_contexts, 2);
+        switch(button) {
+        case ROCKLIFE_NEXT:
+        case ROCKLIFE_NEXT_REP:
+            /* calculate next generation */
+            next_generation(pgrid, pnext_grid);
+            /* swap buffers, grid is the new generation */
+            ptemp = pgrid;
+            pgrid = pnext_grid;
+            pnext_grid = ptemp;
+            /* show new generation */
+            show_grid(pgrid);
+            break;
+        case ROCKLIFE_PLAY_PAUSE:
+            stop = 0;
+            while(!stop){
+                /* calculate next generation */
+                next_generation(pgrid, pnext_grid);
+                /* swap buffers, grid is the new generation */
+                ptemp = pgrid;
+                pgrid = pnext_grid;
+                pnext_grid = ptemp;
+                /* show new generation */
+                rb->yield();
+                show_grid(pgrid);
+                button = pluginlib_getaction(rb, 0, plugin_contexts, 2);
+                switch(button) {
+                case ROCKLIFE_PLAY_PAUSE:
+                case ROCKLIFE_QUIT:
+                    stop = 1;
+                    break;
+                default:
+                    break;
+                }
+                rb->yield();
+            }
+            break;
+        case ROCKLIFE_INIT:
+            init_grid(pgrid);
+            setup_grid(pgrid, pattern);
+            show_grid(pgrid);
+            pattern++;
+            pattern%=5;
+            break;
+        case ROCKLIFE_STATUS:
+            status_line = !status_line;
+            show_grid(pgrid);
+            break;
+        case ROCKLIFE_QUIT:
+            /* quit plugin */
+            quit=true;
+            return PLUGIN_OK;
+            break;
+        default:
+            if (rb->default_event_handler(button) == SYS_USB_CONNECTED) {
+                return PLUGIN_USB_CONNECTED;
+            }
+            break;
+        }
+        rb->yield();
+    }
+
+    rb->backlight_set_timeout(rb->global_settings->backlight_timeout);
+    return PLUGIN_OK;
+}
+
+