ofApp.cpp

#include "ofApp.h"

float ofApp::fade(float t){
    return (float)(t * t * t * ( t * ( t * 6 - 15) + 10));
}

//--------------------------------------------------------------
void ofApp::setup(){
    fog.allocate(ofGetWidth(),ofGetHeight(),1);
    grid.allocate(ofGetWidth(),ofGetHeight(),1);
    fogOut.allocate(ofGetWidth(), ofGetHeight(), OF_IMAGE_GRAYSCALE);
    gridOut.allocate(ofGetWidth(), ofGetHeight(), OF_IMAGE_GRAYSCALE);

    noise_gui.setup("Perlin Noise","",0,0);
    noise_gui.add(g_size.set("Grid Size",20,1,100));
}

//--------------------------------------------------------------
void ofApp::update(){
    float noise = ofNoise(0,0);

    grid.setColor(ofColor(0));
    fog.setColor(ofColor(0));

    for(int x = 0; x < grid.getWidth(); x++){
        if(x % g_size == 0){
            for(int y = 0; y < grid.getHeight(); y++){
                if(y % g_size == 0){
                    noise = ofNoise(x,y,ofGetElapsedTimef());
                    grid.setColor(x,y,ofFloatColor(noise));
                }
            }
        }
    }

    ofVec2f g1, g2, g3, g4;
    float f1, f2, f3, f4, u, v, t_1, t_2;

    for(int x = 0; x < grid.getWidth(); x++){
        for(int y = 0; y < grid.getHeight(); y++){
            //find neigboring grid points
            g1 = ofVec2f(x-(x % g_size),y-(y % g_size));
            g2 = ofVec2f(g1.x + g_size,g1.y);
            g3 = ofVec2f(g1.x,g1.y + g_size);
            g4 = g1 + g_size;

            //get noise values from the grid neighbors
            f1 = grid.getColor(g1.x,g1.y).r;
            f2 = grid.getColor(g2.x,g2.y).r;
            f3 = grid.getColor(g3.x,g3.y).r;
            f4 = grid.getColor(g4.x,g4.y).r;

            u = (float)(x % g_size)/g_size;
            v = (float)(y % g_size)/g_size;

//            u = fade(u);
//            v = fade(v);

            t_1 = ofLerp(f1,f2,u);
            t_2 = ofLerp(f3,f4,u);

            ofColor average = ofLerp(t_1,t_2,v);

            fog.setColor(x,y,average);
        }
    }

    fogOut.setFromPixels(fog.getData(), ofGetWidth(), ofGetHeight(), OF_IMAGE_GRAYSCALE);
    fogOut.update();
}

//--------------------------------------------------------------
void ofApp::draw(){
    fogOut.draw(0,0);
    noise_gui.draw();
}

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

}