ofDocsexamples ios vboExample src ofApp.mm
#include "ofApp.h"

//--------------------------------------------------------------
void ofApp::setup(){	
	ofSetOrientation(OF_ORIENTATION_90_RIGHT);//Set iOS to Orientation Landscape Right
	
	bPause	   = false;
	restLength = 3.0;
	space      = 4;
	
	zoom	   = -500;	
	zoomTarget = 200;
	
	center.x   = ((GRID_WIDTH-1)  * space) / 2;
	center.y   = ((GRID_HEIGHT-1) * space) / 2;
	
	for (int i=0; i<GRID_WIDTH; i++) {
		for (int j=0; j<GRID_HEIGHT; j++) {
			
			int x	  = (i * space) - center.x;
			int y     = 0;
			int z     = (j * space) - center.y;
			int index = (j*GRID_WIDTH+i) * LENGTH;
			
			// now we are at each line
			for (int k=0; k<LENGTH; k++) {
				
				y = ofMap(k, 0, LENGTH, 0, 50);
				
				pos[index + k].x = x;
				pos[index + k].y = y;
				pos[index + k].z = z;
			}
			
			
		}
	}
	
	total = GRID_WIDTH*GRID_HEIGHT*LENGTH;
	vbo.setVertexData(pos, total, GL_DYNAMIC_DRAW);
	
}


//--------------------------------------------------------------
void ofApp::update(){
	
	
	if(!bPause) {
		glm::vec3 vec;
		float   r = 0.3;
		
		for (int i=0; i<GRID_WIDTH; i++) {
			for (int j=0; j<GRID_HEIGHT; j++) {
				
				int x	  = (i * space) - center.x;
				int y     = 0;
				int z     = (j * space) - center.y;
				int index = (j*GRID_WIDTH+i) * LENGTH;
				
				pos[index].set(x, y, z);
				pos[index+1].set(x+ofRandom(-r,r), y+ofRandom(-r,r), z+ofRandom(-r,r));
				pos[index+1].y -= 1.0;
				
				for (int k=2; k<LENGTH; k++) {
					vec		 =  pos[index + k] - pos[index + (k-2)];
					float d  = vec.length();
					if(d > 0.0) {
						pos[index + k] = pos[index + k-1] + (vec * restLength) /d;
					}	
				}
			}
		}
	}
	
	
	zoom += (zoomTarget-zoom) * 0.04;
	
}

//--------------------------------------------------------------
void ofApp::draw() {
	
	
	ofPushMatrix();
	ofTranslate(ofGetWidth()/2, ofGetHeight()/2, zoom);
	
	ofRotate(mouseX, 1, 0, 0);
	ofRotate(mouseY, 0, 1, 1);
	
	
	// the lines
	ofEnableAlphaBlending();
	ofSetColor(255, 255, 255);
	vbo.bind();
	vbo.updateVertexData(pos, total);
	
	for (int i=0; i<GRID_WIDTH; i++) {
		for (int j=0; j<GRID_HEIGHT; j++) {
			int index = (j*GRID_WIDTH+i) * LENGTH;
			vbo.draw(GL_LINE_STRIP, index, LENGTH);
		}
	}
	
	vbo.unbind();
	
	ofPopMatrix();
	
	
	ofSetColor(90, 90, 90);
	ofDrawBitmapString(ofToString(ofGetFrameRate(), 1), 5, 20);
}

//--------------------------------------------------------------
void ofApp::exit(){
    
}

//--------------------------------------------------------------
void ofApp::touchDown(ofTouchEventArgs & touch){
	if(touch.id == 2) bPause = !bPause;
}

//--------------------------------------------------------------
void ofApp::touchMoved(ofTouchEventArgs & touch){
	if(touch.id == 1) {
		zoomTarget = ofMap(touch.x, 0.0, ofGetWidth(), 100, 500);		
	}
}

//--------------------------------------------------------------
void ofApp::touchUp(ofTouchEventArgs & touch){
	
}

//--------------------------------------------------------------
void ofApp::touchDoubleTap(ofTouchEventArgs & touch){
	
}

//--------------------------------------------------------------
void ofApp::touchCancelled(ofTouchEventArgs & touch){
	
}

//--------------------------------------------------------------
void ofApp::lostFocus(){
    
}

//--------------------------------------------------------------
void ofApp::gotFocus(){
    
}

//--------------------------------------------------------------
void ofApp::gotMemoryWarning(){
    
}

//--------------------------------------------------------------
void ofApp::deviceOrientationChanged(int newOrientation){
    
}