TestPjs

<processingjs> // All Examples Written by Casey Reas and Ben Fry

// unless otherwise stated.

// center point

float centerX = 0, centerY = 0;

float radius = 45, rotAngle = -90;

float accelX, accelY;

float springing = .0085, damping = .98;

//corner nodes

int nodes = 5;

float nodeStartX[] = new float[nodes];

float nodeStartY[] = new float[nodes];

float[]nodeX = new float[nodes];

float[]nodeY = new float[nodes];

float[]angle = new float[nodes];

float[]frequency = new float[nodes];

// soft-body dynamics

float organicConstant = 1;

void setup() {

 size(800, 600);

 //center shape in window

 centerX = width/2;

 centerY = height/2;

 // iniitalize frequencies for corner nodes

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

   frequency[i] = random(5, 12);

 }

 noStroke();

 smooth();

 frameRate(30);

}

void draw() {

 //fade background

 fill(0, 100);

 rect(0,0,width, height);

 drawShape();

 moveShape();

}

void drawShape() {

 //  calculate node  starting locations

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

   nodeStartX[i] = centerX+cos(radians(rotAngle))*radius;

   nodeStartY[i] = centerY+sin(radians(rotAngle))*radius;

   rotAngle += 360.0/nodes;

 }

 // draw polygon

 curveTightness(organicConstant);

 fill(255);

 beginShape();

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

   curveVertex(nodeX[i], nodeY[i]);

 }

 for (int i=0; i<nodes-1; i++){

   curveVertex(nodeX[i], nodeY[i]);

 }

 endShape(CLOSE);

}

void moveShape() {

 //move center point

 float deltaX = mouseX-centerX;

 float deltaY = mouseY-centerY;

 // create springing effect

 deltaX *= springing;

 deltaY *= springing;

 accelX += deltaX;

 accelY += deltaY;

 // move predator's center

 centerX += accelX;

 centerY += accelY;

 // slow down springing

 accelX *= damping;

 accelY *= damping;

 // change curve tightness

 organicConstant = 1-((abs(accelX)+abs(accelY))*.1);

 //move nodes

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

   nodeX[i] = nodeStartX[i]+sin(radians(angle[i]))*(accelX*2);

   nodeY[i] = nodeStartY[i]+sin(radians(angle[i]))*(accelY*2);

   angle[i]+=frequency[i];

 }

}

</processingjs>