snakeandarray

/* 

 Arrays - Snake

 Using regular arrays means that we can only store the defined # of items.

 You know how we do things like numCircles = 50? That means the array will

 only store 50 pieces of information. We can bump that up if we want more,

 of course--but sometimes it's nice to have less info being stored and

 displayed rather than more. 

 This is a slightly altered example from Daniel Shiffman's Processing book 

 that lets you draw a snake with a tail that follows your mouse.

 */

​

float angle;

​

​

int numPos = 25; // the number of positions we're holding

int[] xPos = new int[numPos]; // array of x positions

int[] yPos = new int[numPos]; // array of y positions

​

void setup() {

  size(500, 500,P3D); // define the size of your sketch

  smooth(); // when dealing with circles, it's nice to use smooth();

​

  // now let's initialize our array by setting all the elements to zero.

  for (int i = 0; i < numPos; i++) {

    xPos[i] = 0; 

    yPos[i] = 0;

​

  }

}

​

​

void draw() {

  background(255);

  angle+=5;

  smooth();

​

  // Shift the array elements down one spot via a for-loop.

  for (int i = 0; i < numPos-1; i++) { // Note: this will stop at the 2nd to last element!

    xPos[i] = xPos[i+1]; // so if i = 1, xPos at index 1 will = xPos at index 2, and so on.

    yPos[i] = yPos[i+1]; // same here

  }

​

  // We do the above so we can stick new information in the slot we just

  // opened up.

  xPos[numPos-1] = mouseX;

  yPos[numPos-1] = mouseY;

​

  // With all this information, you draw ellipses at all those points.

  for (int i = 0; i < numPos; i++) {

    noStroke();

    fill(255, random(255), random(255),70);

    // color is tied to i, and the rest is set random

    ellipse(xPos[i], yPos[i], i, i); // size also tied to i

​

​

}

}

​

  void mouseDragged(){

    if (keyPressed== true){

    }

    if (key=='z'){

  pushMatrix();

  translate(mouseX+1,mouseY+1);

  rotateZ(angle);

  fill(random(255),random(255),random(255),90);

  ellipse(20,20,100,45);

  popMatrix();  

    }

  }

​

​