Text Snow, Open Frameworks

#include "ofApp.h"

#define RAIN_COUNT 50

void ofApp::setup(){
    grabber.setup(320, 240);
    image.allocate(320, 240, OF_IMAGE_COLOR);
    gui.setup();
    gui.add(thresh.setup("Threshold", 80, 0, 255));
    gui.add(showVideo.setup("Show Video"));
    ofSetFullscreen(true);

    for(int i = 0; i < RAIN_COUNT; i++){
        ofPoint point = ofPoint(ofRandom(ofGetWidth()),
                                ofRandom(ofGetHeight()) );
        rain.push_back(point);
        velocity.push_back(0.1);
        text.push_back(ofRandom('A', 'Z'));
    }
}

void ofApp::update(){
    // image
    grabber.update();
    unsigned char *imgPixels = image.getPixels().getData();
    unsigned char *vidPixels = grabber.getPixels().getData();
    for(int i = 0; i < 320*240; i++){
        unsigned char gray = (vidPixels[i*3+0] + vidPixels[i*3+1] + vidPixels[i*3+2])/3.0;
        if(gray < thresh){
            imgPixels[i*3+0] = imgPixels[i*3+1] = imgPixels[i*3+2] = 0;
        }else{
            imgPixels[i*3+0] = imgPixels[i*3+1] = imgPixels[i*3+2] = 255;
        }
    }
    image.update();

    // rain
    for(int i = 0; i < RAIN_COUNT; i++){

        int smW = rain[i].x / ofGetWidth() * 320;
        int smH = rain[i].y / ofGetHeight() * 240;
        int p = (smW + smH*320)*3;
        if(imgPixels[p] > thresh){
            rain[i].y += velocity[i];
            velocity[i] += 0.1;
        }
        else{
            rain[i].x = ofRandom(ofGetWidth());
            rain[i].y = 0;
            velocity[i] = 0;
            text[i] = ofRandom('A', 'Z');
        }
    }
}

void ofApp::draw(){
    ofBackground(0);
    ofSetColor(255, 255);
    if(showVideo){
        grabber.draw(0, 0, ofGetWidth(), ofGetHeight());
    } else{
        image.draw(0, 0, ofGetWidth(), ofGetHeight());
    }

//  ofSetColor(50, 50, 255, 255);
    for(int i = 0; i < RAIN_COUNT; i++){
//      ofDrawCircle(rain[i], 5);
        ofDrawBitmapString(text[i], rain[i]);
    }

    if(showGui){
        gui.draw();
    }
}

//--------------------------------------------------------------
void ofApp::keyPressed(int key){
    if(key == ' '){
        showGui = !showGui;
    }
}

//--------------------------------------------------------------
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){

}