Yesterday I started doing some code to practice a bit the concepts of OOP... I'm trying to make a simple Space Invaders alien generator... Basically I want to create a code that will create a 12x8 grid of square objects, and fill it randomly white or black. Then is the part I got stuck... I want to take that grid and just flip it so to create a symmetric shape.... I basically create the first half of the alien and flip horizontally to complete it.

I am using a 2d Array to create the first grid and push/pop Matrix for the symmetry... But the result is upside down as you can see from the code below... Any ideas?

2. Tile [][] grid;
3. 
   
4. //number of rows and columns
5. int cols;
6. int rows;
7. 
   
8. void setup() {  
9.   size(600, 600);
10.   background(255);
11.   //cols=width/6;
12.   // rows=height/6;
13.   cols=12;
14.   rows=8;
15.   grid = new Tile[cols][rows]; //the array dimensions are equal to n.of rows/columns
16. 
    
17.   //loop through cols and rows
18.   for (int i=0; i<cols; i++) {
19.     for (int j=0; j<rows; j++) {
20.       //start creating objects
21.       grid[i][j] = new Tile (i*5, j*5, 5);
22.     }
23.   }
24. 
    
25.   for (int i=0; i<cols; i++) {
26.     for (int j=0; j<rows; j++) {
27.       //show me them goodies
28.       pushMatrix();
29.       translate(180, 180);
30.       grid[i][j].display();
31.       popMatrix();
32.     }
33.   }
34. }
35. 
    
36. void draw() {
37. }

And here is the class

2. class Tile {
3.   float x, y;
4.   float side;
5.   int col;
6.   int chance;
7. 
   
8.   Tile (float tempX, float tempY, float tempSide) {
9.     x = tempX;
10.     y = tempY;
11.     side = tempSide;
12.     
13.     float fate = random(10);
14.     chance = int(fate * 1.4);
15.   }
16. 
    
17.   void display() {
18.     if (chance <= 5) {    
19.       fill(0);
20.       println('0');
21.     } 
22.     else {
23.       fill(255);
24.       println('1');
25.     }
26.     rect (x, y, side, side);
27.     pushMatrix();
28.     translate(60,15);
29.     rotate(radians(180));
30.     rect (x, y, side, side);
31.     popMatrix();
32.   }
33. }
34.