Center position of an array of points that make up a Polygon

[breegeek]

Hello!

I am working on an app in OpenFrameworks that involves a bunch (an array) of amorphous blob-like shapes made of particles (using an addon that has some vector math and such built in). They are moving around. I am trying to be able to keep track of the center of these shapes at the base application level by trying to find and keep track of their center positions (will be using this for hit detection and such).

I know I need to find the average x position and y position of points that make up the vertices of my shapes, but I am a bit confused as to how.

Can anyone give me a bit of help figuring this out? That would be super helpful!!!

Sorry if that was inarticulate, maybe a look at the code will help:

void blob::draw(){

 for(int x=0; x<5; x++){

	if(!bEaten){
	    ofPushMatrix();
	    //ofScale(scale,scale);
        ofSetColor(r,g,b,80);
        ofBeginShape();
        ofFill();
        for (int i = 0; i < particles.size(); i++){
            ofVertex(particles[i]->pos.x,particles[i]->pos.y);


           //The following attempt at averaging didn't quite work...
            blobCenterX = particles[i]->pos.x / particles.size();
            blobCenterY = particles[i]->pos.y / particles.size();
		 }
		
 }
}

Thanks in advance!!! ^^

[ne555]

Average =( SUM(1->n) coordinates )/ n
Average = SUM(1->n) (coordinates/n)

[breegeek]

Awesome! Thanks!