// COMP1405/1005 - Day09
// Functions example

// variables
float x,y;
int count;
float myFloat = 0.0;

// initialize
void setup(){
  // the setup() function has no input paramaters and 
  // does not return anything
  // We use it to initialize variables (and set up the 
  // output window, colors, etc)
  size(600,400); count = 0; textSize(40); fill(0);
  
  frameRate(2); // set frame rate to be 2 frames per second
                // so that we can see the colour changes easier
}

// getRandomColor : int -> color
// Purpose : function returns a random color 
//           with each R,G,B value bounded above by the
//           input value
// Example : color c = getRandomColor(100);
color getRandomColor(int max){ 
  // the function returns a "color"
  // all functions that have a output/return type must 
  // explicitly "return" a value of the correct type 
  return color( random(max), random(max), random(max));
}
  
// area : float , int -> float
// Purpose : computes the area of a rectangle
//           with length and width defined by
//           the input values
float area(float lengthIn, int widthIn){
  float answer;
  answer = lengthIn * widthIn;
  return answer ;
}

// main program
void draw(){

  if (count < 1){
    myFloat = area(0.5, 4);
  }
  color theColor = getRandomColor(225);
  
  // for fun, let's change the background colour 
  // depending on the RGB values of theColor
  color bgColor = color( 255-red(theColor), 
                         255-green(theColor), 
                         255-blue(theColor));
  background(bgColor);
  fill( theColor );
  text("answer = " + myFloat, 100,100);
  count += 1;
}