noise

#include "ofApp.h"

//--------------------------------------------------------------
void ofApp::setup(){
    ofBackground(238);
    ofSetBackgroundAuto(false);
    fieldIntensity = 500; //ofRandom(2,10);
    noiseScale = 1000; //ofRandom(200,400);
    agentCount = 5000;
    stepSize = 5;
    edge = 50;
    for (int i=0; i<agentCount; i++) {
        Particle partTemp;
        partTemp.pos = ofPoint(ofRandom(ofGetWidth()+edge),ofRandom(ofGetHeight()+edge));
        partTemp.prevPos = ofPoint(0,0);
        locations.push_back(partTemp);
    }
}

//--------------------------------------------------------------
void ofApp::update(){
    for (auto &loc: locations) {
        float angle = ofNoise(loc.pos.x/noiseScale, loc.pos.y/noiseScale)*fieldIntensity;
        loc.prevPos.x = loc.pos.x;
        loc.prevPos.y = loc.pos.y;
        loc.pos.x += cos(angle)*stepSize;
        loc.pos.y += sin(angle)*stepSize;
        if (loc.pos.x < -edge || loc.pos.x > ofGetWidth()+edge || loc.pos.y < -edge || loc.pos.y > ofGetHeight()+edge) {
            loc.pos = ofPoint(ofRandom(ofGetWidth()),ofRandom(ofGetHeight()));
            loc.prevPos = loc.pos;
        }
    }
}

//--------------------------------------------------------------
void ofApp::draw(){
    for (auto loc: locations) {
        ofSetColor(34,25);
        ofDrawLine(loc.prevPos.x, loc.prevPos.y, loc.pos.x, loc.pos.y);
    }
}

//--------------------------------------------------------------
void ofApp::keyPressed(int key){
    if (key == 'n') {
        locations.clear();
        setup();
    }
    if (key == 'c') {
        setup();
    }
    if(key == 's'){
        img.grabScreen(0, 0 , ofGetWidth(), ofGetHeight());
        stringstream fileName;
        fileName << "screenshot" << ofRandom(1000) << ".png";
        img.save(fileName.str());
    }
}

//--------------------------------------------------------------
void ofApp::keyReleased(int key){
}

//--------------------------------------------------------------
void ofApp::mouseMoved(int x, int y ){

}

//--------------------------------------------------------------
void ofApp::mouseDragged(int x, int y, int button){

}

//--------------------------------------------------------------
void ofApp::mousePressed(int x, int y, int button){

}

//--------------------------------------------------------------
void ofApp::mouseReleased(int x, int y, int button){

}

//--------------------------------------------------------------
void ofApp::mouseEntered(int x, int y){

}

//--------------------------------------------------------------
void ofApp::mouseExited(int x, int y){

}

//--------------------------------------------------------------
void ofApp::windowResized(int w, int h){

}

//--------------------------------------------------------------
void ofApp::gotMessage(ofMessage msg){

}

//--------------------------------------------------------------
void ofApp::dragEvent(ofDragInfo dragInfo){

}