Diff: main.cpp

Revision:

3:0e3179c452c5

Parent:

2:663b9aadf00c

Child:

4:3ceebacef5f1

--- a/main.cpp	Tue Apr 05 19:39:22 2016 +0000
+++ b/main.cpp	Wed Apr 06 11:52:25 2016 +0000
@@ -74,10 +74,17 @@
 int randomXoddEven = randomX%2; // find out whether odd or even
 int randomYoddEven = randomY%2;
 
+int snakeTailX[100];
+int snakeTailY[100];
+int snakeTailLength;
+
 // function prototypes
 void calibrateJoystick();
 void updateJoystick();
+void joystickDirection();
 void generateFood();
+void newFruitValues();
+
  
 int main()
 {
@@ -88,6 +95,11 @@
     
     int i = 41; // snake head origin x
     int j = 23; // snake head origin y
+    int prev_i;
+    int prev_j;
+    int prev2_i;
+    int prev2_j;
+
     
     srand(time(NULL));
       
@@ -101,21 +113,8 @@
         
         if (printFlag) {  // if flag set, clear flag and print joystick values to serial port
             printFlag = 0;
-            serial.printf("x = %f y = %f button = %d ",joystick.x,joystick.y,joystick.button);
- 
-            // check joystick direction
-            if (joystick.direction == UP)
-                serial.printf(" UP\n");
-            if (joystick.direction == DOWN)
-                serial.printf(" DOWN\n");
-            if (joystick.direction == LEFT)
-                serial.printf(" LEFT\n");
-            if (joystick.direction == RIGHT)
-                serial.printf(" RIGHT\n");
-            if (joystick.direction == CENTRE)
-                serial.printf(" CENTRE\n");
-            if (joystick.direction == UNKNOWN)
-                serial.printf(" Unsupported direction\n");
+            
+            joystickDirection();
                 
             if (joystick.direction == LEFT) {
                 if (currentDirection != right) { // user can't turn opposite way
@@ -123,14 +122,18 @@
                 }
                 while (currentDirection == left) { // enters left movement loop
                 lcd.clear();
+                prev2_i = prev_i;
+                prev2_j = prev_j;
+                prev_i = i;
+                prev_j = j;
                 i -= 2; // shifts two pixels (snake thickness)
                 lcd.drawRect(i,j,1,1,1); // snake head
+                lcd.drawRect(prev_i,prev_j,1,1,1);
+                lcd.drawRect(prev2_i,prev2_j,1,1,1);
                 lcd.drawRect(randomX,randomY,1,1,1); // food
-                if (i == randomX && j == randomY) {
-                    randomX =  rand() % 83 + 1;     // randomX in the range 1 to 81
-                    randomY =  rand() % 47 + 1;     // randomY in the range 1 to 47
-                    randomXoddEven = randomX%2; // find out whether odd or even
-                    randomYoddEven = randomY%2;
+                if (i == randomX && j == randomY) { // if fruit is eaten
+                    snakeTailLength++;
+                    newFruitValues();
                     generateFood();  
                     }
                 wait(1.0);
@@ -148,14 +151,18 @@
                 }
                 while (currentDirection == right) {
                 lcd.clear();
+                prev2_i = prev_i;
+                prev2_j = prev_j;
+                prev_i = i;
+                prev_j = j;
                 i += 2;
                 lcd.drawRect(i,j,1,1,1); // snake head
+                lcd.drawRect(prev_i,prev_j,1,1,1);
+                lcd.drawRect(prev2_i,prev2_j,1,1,1);
                 lcd.drawRect(randomX,randomY,1,1,1); // food
-                if (i == randomX && j == randomY) {
-                    randomX =  rand() % 83 + 1;     // randomX in the range 1 to 81
-                    randomY =  rand() % 47 + 1;     // randomY in the range 1 to 47
-                    randomXoddEven = randomX%2; // find out whether odd or even
-                    randomYoddEven = randomY%2;
+                if (i == randomX && j == randomY) { // if fruit is eaten
+                    snakeTailLength++;
+                    newFruitValues();
                     generateFood();  
                     }
                 wait(1.0);
@@ -173,14 +180,18 @@
                 }
                 while (currentDirection == up) {
                 lcd.clear();
+                prev2_i = prev_i;
+                prev2_j = prev_j;
+                prev_i = i;
+                prev_j = j;
                 j -= 2;
                 lcd.drawRect(i,j,1,1,1); // snake head
+                lcd.drawRect(prev_i,prev_j,1,1,1);
+                lcd.drawRect(prev2_i,prev2_j,1,1,1);
                 lcd.drawRect(randomX,randomY,1,1,1); // food
-                if (i == randomX && j == randomY) {
-                    randomX =  rand() % 83 + 1;     // randomX in the range 1 to 81
-                    randomY =  rand() % 47 + 1;     // randomY in the range 1 to 47
-                    randomXoddEven = randomX%2; // find out whether odd or even
-                    randomYoddEven = randomY%2;
+                if (i == randomX && j == randomY) { // if fruit is eaten
+                    snakeTailLength++;
+                    newFruitValues();
                     generateFood();  
                     }
                 wait(1.0);
@@ -198,14 +209,21 @@
                 }
                 while (currentDirection == down) { 
                 lcd.clear();
+                prev2_i = snakeTailX[];
+                prev2_j = snakeTailY[];
+                snakeTailX[] = prev_i;
+                snakeTailY[] = prev_j;
+                prev_i = i;
+                prev_j = j;
                 j += 2;
                 lcd.drawRect(i,j,1,1,1); // snake head
+                for (k=0; k<snakeTailLength; k++) {
+                    lcd.drawRect(prev_i,prev_j,1,1,1);
+                    }
                 lcd.drawRect(randomX,randomY,1,1,1); // food
-                if (i == randomX && j == randomY) {
-                    randomX =  rand() % 83 + 1;     // randomX in the range 1 to 81
-                    randomY =  rand() % 47 + 1;     // randomY in the range 1 to 47
-                    randomXoddEven = randomX%2; // find out whether odd or even
-                    randomYoddEven = randomY%2;
+                if (i == randomX && j == randomY) { // if fruit is eaten
+                    snakeTailLength++;
+                    newFruitValues();
                     generateFood();  
                     }
                 wait(1.0);
@@ -269,8 +287,8 @@
         randomX =  rand() % 83 + 1;     // randomX in the range 1 to 81
         randomY =  rand() % 47 + 1;     // randomY in the range 1 to 47
    
-        serial.printf("X = %i\n",randomX); // debug
-        serial.printf("Y = %i\n\n",randomY);
+    // serial.printf("X = %i\n",randomX); // debug
+    // serial.printf("Y = %i\n\n",randomY);
         
         randomXoddEven = randomX%2; // find out whether odd or even
         randomYoddEven = randomY%2;  
@@ -279,6 +297,35 @@
         lcd.drawRect(randomX,randomY,1,1,1);
 
 }
+
+void newFruitValues()
+{
+        // new fruit coordinate values are given before it is passed to the generateFood function
+                
+        randomX =  rand() % 83 + 1;     // randomX in the range 1 to 81
+        randomY =  rand() % 47 + 1;     // randomY in the range 1 to 47
+        randomXoddEven = randomX%2; // find out whether odd or even
+        randomYoddEven = randomY%2;
  
+}
+
+void joystickDirection() {
+ 
+ serial.printf("x = %f y = %f button = %d ",joystick.x,joystick.y,joystick.button);
  
-            
\ No newline at end of file
+            // check joystick direction
+            if (joystick.direction == UP)
+                serial.printf(" UP\n");
+            if (joystick.direction == DOWN)
+                serial.printf(" DOWN\n");
+            if (joystick.direction == LEFT)
+                serial.printf(" LEFT\n");
+            if (joystick.direction == RIGHT)
+                serial.printf(" RIGHT\n");
+            if (joystick.direction == CENTRE)
+                serial.printf(" CENTRE\n");
+            if (joystick.direction == UNKNOWN)
+                serial.printf(" Unsupported direction\n");
+
+ }
+             
\ No newline at end of file