From 52e71bfb639b2d53a3ea8e15577206ad79f20894 Mon Sep 17 00:00:00 2001
From: Chris Knight <cdknight@hotcat.org>
Date: Thu, 10 Sep 2020 20:34:38 -0700
Subject: [PATCH] draft proposal for community-contributed programs

---
 .../claud9999-life/life.ino                   | 121 ++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 examples/4. Community Contributions/claud9999-life/life.ino

diff --git a/examples/4. Community Contributions/claud9999-life/life.ino b/examples/4. Community Contributions/claud9999-life/life.ino
new file mode 100644
index 0000000..4b93de0
--- /dev/null
+++ b/examples/4. Community Contributions/claud9999-life/life.ino	
@@ -0,0 +1,121 @@
+/** Example "Game of Life" program for the InkPlate 6 by Chris Knight
+ *  https://github.com/claud9999
+ */
+
+#include <Inkplate.h>
+
+Inkplate display(INKPLATE_1BIT);
+
+#define SCREEN_WIDTH 800
+#define SCREEN_HEIGHT 600
+
+#define MIN_CELLSZ 8
+#define MAX_CELLSZ 40
+
+// initialize dimensions to the minimum size cell, maximum size arrays
+int cell_size = 0, cols = 0, rows = 0,
+    cell_maxage = 0, offset_x = 0, offset_y = 0;
+  
+char grid_a[(SCREEN_WIDTH / MIN_CELLSZ) * (SCREEN_HEIGHT / MIN_CELLSZ)],
+  grid_b[(SCREEN_WIDTH / MIN_CELLSZ) * (SCREEN_HEIGHT / MIN_CELLSZ)];
+char *grid_curr = grid_a, *grid_next = grid_b, *grid_tmp = NULL,
+    cell_curr, cell_next;
+int x = 0, y = 0, dx = 0, dy = 0, nx = 0, ny = 0,
+    neighbors = 0, cell_delta = 0, frame_count = 0;
+
+void randomize() {
+  cell_size = random(MIN_CELLSZ, MAX_CELLSZ + 1);
+
+  // compute the (rounded-down) number of rows and columns
+  cols = SCREEN_WIDTH / cell_size;
+  rows = SCREEN_HEIGHT / cell_size;
+
+  cell_maxage = (cell_size / 2) - 1;
+  // compute the "extra" space not covered by this grid, offset by half
+  offset_x = (SCREEN_WIDTH - cols * cell_size) / 2;
+  offset_y = (SCREEN_HEIGHT - rows * cell_size) / 2;
+
+  display.clean();
+  display.display();
+  
+  display.clearDisplay();
+
+  // compute a random density...
+  int density = random(5,15);
+
+  // and for that density, populate the initial grid
+  for(x = 0; x < cols; x++) {
+    for (y = 0; y < rows; y++) grid_curr[x + y * cols] = random(density) == 0;
+  }
+
+  frame_count = 0;
+}
+
+void setup() {
+  Serial.begin(115200);
+  display.begin();
+  randomize();
+}
+
+void loop() {
+  cell_delta = 0;
+  for(x = 0; x < cols; x++) {
+    for(y = 0; y < rows; y++) {
+      // count neighboring cells
+      neighbors = 0;
+      for(dx = -1; dx < 2; dx++) {
+        for(dy = -1; dy < 2; dy++) {
+          if(dx == 0 && dy == 0) continue; // skip "me"
+
+          nx = x + dx; if(nx < 0) nx = cols - 1; else if(nx >= cols) nx = 0;
+          ny = y + dy; if(ny < 0) ny = rows - 1; else if(ny >= rows) ny = 0;
+
+          if(grid_curr[nx + ny * cols]) neighbors++;
+        }// end for(dy)
+      }// end for(dx)
+
+      cell_curr = grid_curr[x + y * cols];
+      cell_next = 0;
+      switch(neighbors) {
+        case 2: // alive with 2 neighbors remains alive
+          if(!cell_curr) break;
+          // else cell is alive drop through
+        case 3: // 3 neighbors == alive
+          cell_next = cell_curr + 1;
+          if(cell_next > cell_maxage) cell_next = cell_maxage;
+      }
+
+      if(cell_next != 0 && cell_curr == 0
+          || cell_next == 0 && cell_curr != 0)
+        cell_delta++;
+      
+      if(cell_next) {
+        // if this is a new cell, paint it black
+        if(cell_next == 1)
+          display.fillRect(x * cell_size + offset_x, y * cell_size + offset_y,
+            cell_size, cell_size, 1);
+        // otherwise paint the inside white depending on how old it is
+        else display.fillRect(
+          x * cell_size + cell_size / 2 - cell_next + offset_x,
+          y * cell_size + cell_size / 2 - cell_next + offset_y,
+          cell_next * 2, cell_next * 2, 0);
+      } else if (cell_curr) {
+        // otherwise it's died, paint the whole cell white
+        display.fillRect(x * cell_size + offset_x, y * cell_size + offset_y,
+          cell_size, cell_size, 0);
+      }
+
+      grid_next[x + y * cols] = cell_next;
+    }//end for(y)
+  }//end for(x)
+
+  // swap which grid is current
+  grid_tmp = grid_next; grid_next = grid_curr; grid_curr = grid_tmp;
+
+  // the longer this goes, the more cells this has,
+  //   the more change is required or we reset
+  if(cell_delta * cell_size < frame_count) randomize();
+  else frame_count++;
+
+  display.partialUpdate();
+}