From ee11046d07622845dee3ab25a24426bbe80499b5 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sun, 24 Mar 2024 17:19:55 +0100
Subject: [PATCH] neopixel-square: The Game of Life

---
 test-neopixel-square/main.c | 83 +++++++++++++++++++++++++++++++++++--
 1 file changed, 79 insertions(+), 4 deletions(-)

diff --git a/test-neopixel-square/main.c b/test-neopixel-square/main.c
index 3aefaf4..05f44b2 100644
--- a/test-neopixel-square/main.c
+++ b/test-neopixel-square/main.c
@@ -154,6 +154,71 @@ static void neopixel_init(void)
 	timer_enable_counter(TIM4);
 }
 
+/*** Game of Life ***/
+
+#define LN 8
+
+byte life[LN+2][LN+2];
+byte lpred[LN+2][LN+2];
+
+static void life_init(void)
+{
+#if 1
+	// The R pentomino
+	life[3][4] = 1;
+	life[3][5] = 1;
+	life[4][3] = 1;
+	life[4][4] = 1;
+	life[5][4] = 1;
+#elif 0
+	// Blinker
+	life[3][2] = 1;
+	life[3][3] = 1;
+	life[3][4] = 1;
+#elif 0
+	// Glider
+	life[1][3] = 1;
+	life[2][1] = 1;
+	life[2][3] = 1;
+	life[3][2] = 1;
+	life[3][3] = 1;
+#endif
+}
+
+static void life_step(void)
+{
+	memcpy(lpred, life, sizeof(life));
+
+	for (uint i=1; i<=LN; i++)
+		for (uint j=1; j<=LN; j++) {
+			int neigh = 0;
+			for (uint ii=i-1; ii <= i+1; ii++)
+				for (uint jj=j-1; jj <= j+1; jj++)
+					neigh += lpred[ii][jj];
+			neigh -= life[i][j];
+			if (life[i][j]) {
+				if (neigh < 2 || neigh > 3)
+					life[i][j] = 0;
+			} else {
+				if (neigh == 3)
+					life[i][j] = 1;
+			}
+		}
+}
+
+static void life_show(void)
+{
+	uint led = 0;
+	for (uint i=1; i<=LN; i++)
+		for (uint j=1; j<=LN; j++) {
+			if (life[i][j])
+				neopixel_set(led, 0, 7, 0);
+			else
+				neopixel_set(led, 0, 0, 1);
+			led++;
+		}
+}
+
 /*** Main ***/
 
 int main(void)
@@ -166,19 +231,29 @@ int main(void)
 
 	debug_printf("Hello, world!\n");
 
-	uint i=63;
+	// uint i=63;
+	life_init();
+	life_show();
+	uint lsteps = 0;
 
 	for (;;) {
 		// wait_for_interrupt();
 		debug_led(1);
 		// neopixel_set(NPIX_NUM_LEDS-1, 0, 0x7f, 0);
-		neopixel_set(i, 0, 0, 7);
-		i = (i+1) % 64;
-		neopixel_set(i, 0, 63, 0);
+		// neopixel_set(i, 0, 0, 7);
+		// i = (i+1) % 64;
+		// neopixel_set(i, 0, 63, 0);
 		delay_ms(100);
 		debug_led(0);
 		// neopixel_set(NPIX_NUM_LEDS-1, 0, 0, 0x7f);
 		delay_ms(500);
+		if (lsteps++ < 30)
+			life_step();
+		else {
+			life_init();
+			lsteps = 0;
+		}
+		life_show();
 	}
 
 	return 0;
-- 
2.39.2