From ace698b10e41ecf77e8155e72a8954f9ddacacc4 Mon Sep 17 00:00:00 2001
From: Diogo Cordeiro <diogo@fc.up.pt>
Date: Wed, 12 Feb 2020 17:36:02 +0000
Subject: [PATCH] Move snake with frontiers

---
 snake.ino | 73 ++++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 61 insertions(+), 12 deletions(-)

diff --git a/snake.ino b/snake.ino
index 5af5485..34a4c23 100644
--- a/snake.ino
+++ b/snake.ino
@@ -55,36 +55,85 @@ void setup() {
 
 void loop() {
   delay(300);
+  if (!move_snake(read_sensors())) {
+    switch(cur_dir)
+    {
+      case 0: // iddle
+        // Just don't
+      break;
+      case 1: // up
+        // Move
+        if (snake_y+1 <= 7) {
+          pixels[snake_x][++snake_y] = LOW;
+        }
+      break;
+      case 2: // right
+        // Move
+        if (snake_x+1 <= 7) {
+          pixels[++snake_x][snake_y] = LOW;
+        }
+      break;
+      case 3: // down
+        // Move
+        if (snake_y-1 >= 0) {
+          pixels[snake_x][--snake_y] = LOW;
+        }
+      break;
+      case 4: // left
+        // Move
+        if (snake_x-1 >= 0) {
+          pixels[--snake_x][snake_y] = LOW;
+        }
+      break;
+    }
+  }
+
+  // draw the screen:
+  refresh_screen();
+}
+
+// true if it has moved, false otherwise
+bool move_snake(int dir) {
   // read input:
-  // up: 1
-  // right: 2
-  // down: 3
-  // left: 4
-  switch(read_sensors())
+  switch(dir)
   {
     case 0: // iddle
       // Just don't
     break;
     case 1: // up
       // Move
-      pixels[snake_x][++snake_y] = LOW;
+      if (cur_dir != 3) {
+        pixels[snake_x][++snake_y] = LOW;
+        cur_dir = 1;
+        return true;
+      }
     break;
     case 2: // right
       // Move
-      pixels[++snake_x][snake_y] = LOW;
+      if (cur_dir != 4) {
+        pixels[++snake_x][snake_y] = LOW;
+        cur_dir = 2;
+        return true;
+      }
     break;
     case 3: // down
       // Move
-      pixels[snake_x][--snake_y] = LOW;
+      if (cur_dir != 1) {
+        pixels[snake_x][--snake_y] = LOW;
+        cur_dir = 3;
+        return true;
+      }
     break;
     case 4: // left
       // Move
-      pixels[--snake_x][snake_y] = LOW;
+      if (cur_dir != 2) {
+        pixels[--snake_x][snake_y] = LOW;
+        cur_dir = 4;
+        return true;
+      }
     break;
   }
-
-  // draw the screen:
-  refresh_screen();
+  return false;
 }
 
 // iddle: 0