Arrays

In this assignment, you will create a game that lets the player “pop” balloons by moving the mouse over them.

Part 1:

Balloon

You do not need to add any further instance variables. You already have all the ones you need (center x and y, width and height, color, and x- and y-speed).

Add the following methods to the Balloon class:

void draw()

Modify this function so that you no longer draw the string on the balloon.

boolean hit(int pX, int pY)

This function returns true if the point (pX, pY) is inside the balloon, false otherwise. This requires a bit of math, so I am giving you the code:

boolean hit(int pX, int pY)
{
  float a = w / 2.0;
  float b = h / 2.0;
  float ex = pX - x; // calculate relative to center of ellipse
  float ey = pY - y;
  float r = (ex * ex) / (a * a) + (ey * ey) / (b * b);
  return (r < 1);
}

void pop()

This function “pops” the balloon by setting its center x and y coordinates to -1000 (thus moving it off-screen) and its x- and y- speed to zero (so it won’t move any more).

Putting it Together

Your main program makes a sketch that is 400 by 400 dots, and sets the frame rate to 20. The program will create an array of 30 Balloon objects of different sizes and colors and speeds. For each balloon:

• The balloon width must be between 20-45 pixels.
• The balloon height must be from 5-10 pixels greater than the width.
• The color must have a translucency from 128-200.
• The horizontal and vertical speeds must be between 3 and 7.

Your draw() function will have a loop that does the following for each of the balloons in the array:

• if the mouse has hit the balloon, pop it
• otherwise:
  • draw the balloon
  • move the balloon

When You Finish

Zip up the sketch into a zip file named game.zip and upload it.