Project 4: Flocks of Objects
Examples:
Creating our Own Objects
Step 1 - Making a basic 'bouncer' object class:// declare a new "Mover" object named "m1" Mover m1 = new Mover(100, 100, 10); void setup(){ // Runs once at start size(640, 480); // Set screen size background(0); // Make background black } void draw(){ // Runs every frame background(0); // Cover all with black background m1.display(); // This calls the function in "m1" to draw it on the screen } // Here is the code that sets up what a "Mover" is, // what values (variables) it has, and what // behaviors (functions) it has class Mover { //DATA: Here are the values we want every Mover to have int x; // x position of the Mover int y; // y position of the Mover int speed; // Speed of the Mover //CONSTRUCTOR: This is the "constructor." It's a special function //that is used to make a new Mover. We called it at the top //of this program. You can put "arguments" in the cosntructor //to set variables when each new object is made. //So "new Mover(100, 100, 10);" sets x to 100, y to 100, speed to 10. Mover(int _x, int _y, int _speed) { x = _x; y = _y; speed = _speed; } //This is a function for actually drawing the mover on the screen. //It uses the x, y , and speed values to draw the mover in the right position. //It also includes code for the "bouncing" behavior void display() { if(x<0 || x>width){ // If the Mover goes off the screen... speed = -1*speed; // Reverse the speed (multiply it by -1) } x = x+speed; // Add the 'speed' to the x value to make it move to another position. stroke(100, 50, 0); //Stroke color fill(200, 100, 0); //Fill color ellipse(x,y,13,13); //Draw the circle } }
Step 2 - Making multiple 'Movers' (new code highlighted in yellow):
// declare 4 "Mover" objects Mover m1 = new Mover(100, 100, 10); Mover m2 = new Mover(110, 110, 5); Mover m3 = new Mover(120, 120, 1); Mover m4 = new Mover(130, 130, 7); void setup(){ // Runs once at start size(640, 480); // Set screen size background(0); // Make background black } void draw(){// Runs every frame background(0); // Cover all with black background //Call the "display()" function in all the movers to draw them on screen m1.display(); m2.display(); m3.display(); m4.display(); } // Here is the code that sets up what a "Mover" is, // what values (variables) it has, and what // behaviors (functions) it has class Mover { //DATA: Here are the values we want every Mover to have int x; // x position of the Mover int y; // y position of the Mover int speed; // Speed of the Mover //CONSTRUCTOR: This is the "constructor." It's a special function //that is used to make a new Mover. We called it at the top //of this program. You can put "arguments" in the cosntructor //to set variables when each new object is made. //So "new Mover(100, 100, 10);" sets x to 100, y to 100, speed to 10. Mover(int _x, int _y, int _speed) { x = _x; y = _y; speed = _speed; } //This is a function for actually drawing the mover on the screen. //It uses the x, y , and speed values to draw the mover in the right position. //It also includes code for the "bouncing" behavior void display() { if(x<0 || x>width){ // If the Mover goes off the screen... speed = -1*speed; // Reverse the speed (multiply it by -1) } x = x+speed; // Add the 'speed' to the x value to make it move to another position. stroke(100, 50, 0); //Stroke color fill(200, 100, 0); //Fill color ellipse(x,y,13,13); //Draw the circle } }
Step 3 - Using arrays and loops to make hundreds of objects (new code highlighted in yellow):
Mover[] m = new Mover[100]; // Creates an ARRAY of 100 Mover objects void setup(){ // Runs once at start size(640, 480); // Set screen size background(0); // Make background black //This is a 'for' loop, which we can use to repeat code without typing it all //You give it variable with a starting value, a limit, and a change in //value which will happen each time it loops. //This 'for' loop starts when i=0, continues while i<100, and adds 1 to i each loop. //So it will run 100 times for (int i = 0; i < 100; i++) { //Every time this code loops, it creates a new 'Mover' in a slot in the array //In initialized the 'Mover' with random values for x, y ,and speed m[i] = new Mover(int(random(width)), int(random(height)), int(random(7)+1)); } } void draw(){ //Runs every frame background(0); // Cover all with black background //Another 'for' loop. This one calls 'display' for all the 'Movers' in //the array we made. for (int i = 0; i < 100; i++) { m[i].display(); } } //The 'Mover' class is mostly the same, however we've added some new behaviors //in the 'display' function class Mover { int x; int y; int speed; Mover(int _x, int _y, int _speed) { x = _x; y = _y; speed = _speed; } void display() { if(x<0 || x>width){ //If Mover goes off screen, reverse direction speed *= -1; } if (abs(y-mouseY)<100 && abs(x-mouseX)<100) // If Mover is close to mouse, jump down { y += 10; if (y >= height){ //If object jumps off of bottom of screen, jump back to top y=1; } } x = x+speed; stroke(100, 50, 0); fill(200, 100, 0); ellipse(x,y,13,13); } }
Step 4 - Adding different behaviors and variables to objects (new code highlighted in yellow):
//This code is mostly the same as the previous, but we've added //other behaviors to the Mover class's display() function Mover[] m1 = new Mover[100]; void setup(){ size(640, 480); background(0); for (int i = 0; i < 100; i++) { m1[i] = new Mover(int(random(width)), int(random(height)), int(random(7)+1)); } } void draw(){ background(0); for (int i = 0; i < 100; i++) { m1[i].display(); } } class Mover { int x; int y; int speed; int diameter = 13; // Added a new variable, 'diameter' to change size Mover(int _x, int _y, int _speed) { x = _x; y = _y; speed = _speed; } void display() { if(x<0 || x>width){ //If Mover goes off screen, reverse direction speed *= -1; } // If Mover is close to mouse, make its diameter increase if (abs(y-mouseY)<100 && abs(x-mouseX)<100) { diameter +=1; } else{ diameter = 13; } x = x + speed; stroke(100, 50, 0); // Random flicker fill fill(random(50, 255), random(50, 255), random(50, 255)); ellipse(x,y,diameter,diameter); } }