bright1

#include "ofApp.h"

//--------------------------------------------------------------
void ofApp::setup(){
    dogImg.load("dog.jpg");
    threshold = 0;

    dogTex.allocate(dogImg.getWidth(),dogImg.getHeight(), GL_RGB);

}

//--------------------------------------------------------------
void ofApp::update(){

    // get a pointer to our image pixels

    //unsigned char * pixels = dogImg.getPixels();
    threshold = ofMap(mouseX, 0, ofGetWidth(),0,255);

    ofPixels dogPixels = dogImg.getPixels();

    for (int i=0; i<dogImg.getWidth()*dogImg.getHeight(); i++) {
        ofColor c = dogImg.getColor(i*3);
        float brightness = c.getBrightness();
        if (brightness < threshold) {
            //dogImg.setColor(i*3, ofColor(255,0,0));
            //pixels[i*3] = 255;
            //pixels[i*3+1] = 255;
            //pixels[i*3+2] = 255;
            dogPixels.setColor(i*3, ofColor(255,0,0));
        }
    }
    //dogImg.update();
    dogTex.loadData(dogPixels, dogImg.getWidth(), dogImg.getHeight(), GL_RGB);
}

//--------------------------------------------------------------
void ofApp::draw(){

    ofSetColor(255);
    dogImg.draw(0,0);

    // draw our texture with the changed pixel data

    dogTex.draw(dogImg.getWidth(),0);

}

//--------------------------------------------------------------
void ofApp::keyPressed(int key){

}

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

}