Hi,
i have a problem with the correct use of OpenGL-Syntax  ( glBegin(), glEnd();).

The Sketch is running, but the glRects are not drawing. Its simply a white Space.

At the start of the Sketch Processing prints out an error: OpenGL error 1282 at top endDraw(): invalid operation.

I hope you can help me with the correct OpenGl-Syntax.

1. import SimpleOpenNI.*;
   import processing.opengl.*;
   import javax.media.opengl.*;
   import processing.video.*;
   import ddf.minim.*;
   
   Minim minim;
   AudioInput in;
   MovieMaker mm;
   
   
   PImage handtracked;
   
   SimpleOpenNI context;
   
   float        soundin ;
   float        xoff = 0.0;
   float        zoomF =1.5f;
   float        rotX = radians(180);
   float        rotY = radians(0);
   
   boolean      handsTrackFlag = false;
   PVector      handVec = new PVector();
   ArrayList    handVecList = new ArrayList();
   int          handVecListSize = 30;
   String       lastGesture = "";
   boolean      freeze = false;
   int          freezetimer = 0;
   float        alphawert = 0.0;
   
   
   ArrayList    frameVecList = new ArrayList();
   ArrayList<Float> abgreifen_x = new ArrayList<Float>();
   ArrayList<Float> abgreifen_y = new ArrayList<Float>();
   ArrayList<Float> abgreifen_z = new ArrayList<Float>();
   
   //--------------------------------------------------------- SETUP
   
   void setup()
   {
   
     background(255);
     frameRate(30);
   
     size(640, 480, OPENGL);
     hint(DISABLE_OPENGL_2X_SMOOTH); 
   
     mm = new MovieMaker(this, width, height, "drawing###.mov", 8, MovieMaker.VIDEO, MovieMaker.HIGH);
     context = new SimpleOpenNI(this);
     context.enableDepth(); 
     context.enableRGB();
     context.alternativeViewPointDepthToImage();
   
     context.enableGesture();
     context.enableHands();
   
     context.addGesture("Wave");
     context.addGesture("Click");
     context.addGesture("RaiseHand");
   
     context.setMirror(true);
   
     if (context.enableDepth() == false)
     {
       println("Can't open the depthMap, maybe the camera is not connected!");
       exit();
       return;
     }
   
     smooth();
     perspective(radians(50),
     float(width)/float(height),
     10, 150000);
   
     minim = new Minim(this);
     minim.debugOn();
   
     in = minim.getLineIn(Minim.STEREO, 512);
   }
   
   
   //____________________________________________________ DRAW
   
   void draw()
   {
     PGraphicsOpenGL pgl = (PGraphicsOpenGL) g;
     GL gl = pgl.beginGL();
   
     int sekunde = second();
   
     for (int i = 0; i < in.bufferSize() - 1; i++)
     {
       soundin = in.left.get(i)*40;
     }
   
     background(255);
     context.update();
   
     PImage rgbImage = context.rgbImage();
     rgbImage.resize(1024, 768);
   
     translate(width/2, height/2, 0);
     rotateX(rotX);
     rotateY(rotY);
     scale(zoomF);
   
     int[]   depthMap = context.depthMap();
     int     steps   = 3;
     int     index;
     PVector realWorldPoint;
   
     translate(0, 0, -1000);
   
     PVector[] realWorldMap = context.depthMapRealWorld();
     for (int y=0;y < context.depthHeight();y+=steps)
     {
       for (int x=0;x < context.depthWidth();x+=steps)
       {
   
         index = x + y * context.depthWidth();
         noFill();
         realWorldPoint = realWorldMap[index];
         color c = rgbImage.pixels[index];
         int helligkeit = int(brightness(c));
   
         if (depthMap[index] > 1000 && depthMap[index] < 2250 )
         {
           frameVecList.add(realWorldPoint);
   
   
           //_______________________________________________________IF-Sound-Abfrage für Lines
   
   //        if (soundin >= 1) {
   //        }
          
   
           if (dist(realWorldPoint.x, realWorldPoint.y, realWorldPoint.z, handVec.x, handVec.y, handVec.z) < 200 ) {
   
             gl.glBegin(gl.GL_LINES);
             gl.glTranslatef(realWorldPoint.x, realWorldPoint.y-10, realWorldPoint.z);
             gl.glColor4f(map(helligkeit, 1, 255, 0.0, 1.0)*2, map(helligkeit, 1, 255, 0.0, 1.0)*4, map(helligkeit, 1, 255, 0.0, 1.0)*4, 1.0);
             gl.glRectf(0, 0, 3+(map(helligkeit, 1, 255, 1, 2.5)), 20+(map(helligkeit, 1, 255, 1, 2.5)));
             gl.glEnd();
           }
   
           //_____________________________________________________ Basis-Look + Sound-Effekt
   
           xoff=xoff+0.01;
           float n = (noise(xoff) * 250)*soundin;
           gl.glBegin(gl.GL_LINES);
           gl.glTranslatef(realWorldPoint.x+n/10, realWorldPoint.y+(n/2)/10, realWorldPoint.z);
           gl.glColor4f(map(helligkeit, 1, 255, 0.0, 1.0)*2, map(helligkeit, 1, 255, 0.0, 1.0)*2, map(helligkeit, 1, 255, 0.0, 1.0)*2, 1.0);
           gl.glRectf(0, 0, 1.5+(map(helligkeit, 1, 255, 1, 4.5))+random(2), 4+(map(helligkeit, 1, 255, 1, 2.5)));
           gl.glEnd();
   
   
           //__________________________________________________ Depth-Random-Effekt
   
           if (depthMap[index] > random(250, 1000)) {
             if (depthMap[index] % 4 <= 0) {
               gl.glBegin(gl.GL_LINES);      
               gl.glTranslatef(realWorldPoint.x, realWorldPoint.y-5, realWorldPoint.z);
               gl.glColor4f(map(helligkeit, 1, 255, 0.0, 1.0), map(helligkeit, 1, 255, 0.0, 1.0)*8, map(helligkeit, 1, 255, 0.0, 1.0)*5, 1.0);
               gl.glRectf(0, 0, 1.5+(map(helligkeit, 1, 255, 1, 2.5)), 10+(map(helligkeit, 1, 255, 1, 2.5)));
               gl.glEnd();
             }
           }
         }
       }
     }
   
   
     //______________________________________________________________ Freeze-Effekt
   
     if (frameCount%45==0) {
       freeze = true;
       for (int i = 0; i <= frameVecList.size()-1; i++) { 
         PVector f = (PVector) frameVecList.get(i); 
   
         abgreifen_x.add(f.x);
         abgreifen_y.add(f.y);
         abgreifen_z.add(f.z);
       }
     }
   
     if (freeze == true) {
       freezetimer++;
       alphawert = alphawert+0.025;
       for (int i = abgreifen_x.size()-1; i >= 0; i--) {
         stroke(0);
         strokeWeight(5);
         gl.glBegin(gl.GL_LINES); 
         gl.glTranslatef(abgreifen_x.get(i)+10, abgreifen_y.get(i)-10, abgreifen_z.get(i)-freezetimer*15);
         gl.glColor4f(0.0, 0.8, 0.65, 1.0-alphawert);
         gl.glRectf(0, 0, 1.5, 10);
         gl.glEnd();
       }
       if (freezetimer == 3) {
         for (int i = abgreifen_x.size()-1; i >= 0; i--) {
           gl.glBegin(gl.GL_LINES); 
           gl.glTranslatef(abgreifen_x.get(i)-10, abgreifen_y.get(i)+10, abgreifen_z.get(i)-freezetimer*25);
           gl.glColor4f(0.0, 0.65, 0.8, 1.0-alphawert);
           gl.glRectf(0, 0, 1.5, 10);
           gl.glEnd();
         }
       }
       if (freezetimer == 20) {
         abgreifen_x.clear();
         abgreifen_y.clear();
         abgreifen_z.clear();
         freezetimer = 0;
         alphawert = 0.0;
         freeze = false;
       }
     }
   
     //_______________________________________________________ Background-Rects
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(width), random(height), random(1800, 2250));
       gl.glColor4f(0.0, 0.8, 0.65, 1.0-random(0.85, 0.975));
       gl.glRectf(0, 0, 10+random(5, 10), 25+random(20, 25));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(-width), random(-height), random(1800, 2250));
       gl.glColor4f(0.0, 0.8, 0.65, 1.0-random(0.85, 0.975));
       gl.glRectf(0, 0, random(3, 9)+random(5, 10), random(25, 42)+random(20, 35));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(-width), random(height), random(1800, 2250));
       gl.glColor4f(0.0, 0.8, 0.65, 1.0-random(0.85, 0.975));
       gl.glRectf(0, 0, random(5, 12)+random(5, 10), random(20, 40)+random(20, 27));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(width), random(-height), random(1800, 2250));
       gl.glColor4f(0.0, 0.8, 0.65, 1.0-random(0.85, 0.975));
       gl.glRectf(0, 0, random(4, 10)+random(5, 10), random(20, 35)+random(10, 15));
       gl.glEnd();
     }
   
     //__________________________________________________________ Zweite Background-Rect Ebene (schwarz)
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(width), random(height), random(1800, 2250));
       gl.glColor4f(0.0, 0.0, 0.0, 1.0-random(0.05, 0.45));
       gl.glRectf(0, 0, random(1, 4), random(5, 10));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(-width), random(-height), random(1800, 2250));
       gl.glColor4f(0.0, 0.0, 0.0, 1.0-random(0.05, 0.45));
       gl.glRectf(0, 0, random(1, 4), random(5, 10));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(-width), random(height), random(1800, 2250));
       gl.glColor4f(0.0, 0.0, 0.0, 1.0-random(0.05, 0.45));
       gl.glRectf(0, 0, random(2, 4), random(5, 15));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(width), random(-height), random(1800, 2250));
       gl.glColor4f(0.0, 0.0, 0.0, 1.0-random(0.05, 0.45));
       gl.glRectf(0, 0, random(2, 4), random(5, 10));
       gl.glEnd();
     }
   
     frameVecList.clear();
     mm.addFrame();
     pgl.endGL();
   }
   

Hi,
we are working on a Kinect-Project.

Everthing worked fine until we started to "optimize" the OpenGL-Settings for glBegin and glEnd.
Now we don`t know what to fill in gl.glBegin(); function.

With gl.GL_LINES the sketch starts, but nothing is drawing.
(When the Sketch starts the following error is shown: OpenGL error 1282 at top endDraw(): invalid operation).

Any idea what to type in gl.glBegin(); and how we use the openGL-Structure right?

1. import SimpleOpenNI.*;
   import processing.opengl.*;
   import javax.media.opengl.*;
   import processing.video.*;
   import ddf.minim.*;
   
   Minim minim;
   AudioInput in;
   MovieMaker mm;
   
   
   PImage handtracked;
   
   SimpleOpenNI context;
   
   float        soundin ;
   float        xoff = 0.0;
   float        zoomF =1.5f;
   float        rotX = radians(180);
   float        rotY = radians(0);
   
   boolean      handsTrackFlag = false;
   PVector      handVec = new PVector();
   ArrayList    handVecList = new ArrayList();
   int          handVecListSize = 30;
   String       lastGesture = "";
   boolean      freeze = false;
   int          freezetimer = 0;
   float        alphawert = 0.0;
   
   
   ArrayList    frameVecList = new ArrayList();
   ArrayList<Float> abgreifen_x = new ArrayList<Float>();
   ArrayList<Float> abgreifen_y = new ArrayList<Float>();
   ArrayList<Float> abgreifen_z = new ArrayList<Float>();
   
   //--------------------------------------------------------- SETUP
   
   void setup()
   {
   
     background(255);
     frameRate(30);
   
     size(640, 480, OPENGL);
     hint(DISABLE_OPENGL_2X_SMOOTH); 
   
     mm = new MovieMaker(this, width, height, "drawing###.mov", 8, MovieMaker.VIDEO, MovieMaker.HIGH);
     context = new SimpleOpenNI(this);
     context.enableDepth(); 
     context.enableRGB();
     context.alternativeViewPointDepthToImage();
   
     context.enableGesture();
     context.enableHands();
   
     context.addGesture("Wave");
     context.addGesture("Click");
     context.addGesture("RaiseHand");
   
     context.setMirror(true);
   
     if (context.enableDepth() == false)
     {
       println("Can't open the depthMap, maybe the camera is not connected!");
       exit();
       return;
     }
   
     smooth();
     perspective(radians(50),
     float(width)/float(height),
     10, 150000);
   
     minim = new Minim(this);
     minim.debugOn();
   
     in = minim.getLineIn(Minim.STEREO, 512);
   }
   
   
   //____________________________________________________ DRAW
   
   void draw()
   {
     PGraphicsOpenGL pgl = (PGraphicsOpenGL) g;
     GL gl = pgl.beginGL();
   
     int sekunde = second();
   
     for (int i = 0; i < in.bufferSize() - 1; i++)
     {
       soundin = in.left.get(i)*40;
     }
   
     background(255);
     context.update();
   
     PImage rgbImage = context.rgbImage();
     rgbImage.resize(1024, 768);
   
     translate(width/2, height/2, 0);
     rotateX(rotX);
     rotateY(rotY);
     scale(zoomF);
   
     int[]   depthMap = context.depthMap();
     int     steps   = 3;
     int     index;
     PVector realWorldPoint;
   
     translate(0, 0, -1000);
   
     PVector[] realWorldMap = context.depthMapRealWorld();
     for (int y=0;y < context.depthHeight();y+=steps)
     {
       for (int x=0;x < context.depthWidth();x+=steps)
       {
   
         index = x + y * context.depthWidth();
         noFill();
         realWorldPoint = realWorldMap[index];
         color c = rgbImage.pixels[index];
         int helligkeit = int(brightness(c));
   
         if (depthMap[index] > 1000 && depthMap[index] < 2250 )
         {
           frameVecList.add(realWorldPoint);
   
   
           //_______________________________________________________IF-Sound-Abfrage für Lines
   
   //        if (soundin >= 1) {
   //        }
          
   
           if (dist(realWorldPoint.x, realWorldPoint.y, realWorldPoint.z, handVec.x, handVec.y, handVec.z) < 200 ) {
   
             gl.glBegin(gl.GL_LINES);
             gl.glTranslatef(realWorldPoint.x, realWorldPoint.y-10, realWorldPoint.z);
             gl.glColor4f(map(helligkeit, 1, 255, 0.0, 1.0)*2, map(helligkeit, 1, 255, 0.0, 1.0)*4, map(helligkeit, 1, 255, 0.0, 1.0)*4, 1.0);
             gl.glRectf(0, 0, 3+(map(helligkeit, 1, 255, 1, 2.5)), 20+(map(helligkeit, 1, 255, 1, 2.5)));
             gl.glEnd();
           }
   
           //_____________________________________________________ Basis-Look + Sound-Effekt
   
           xoff=xoff+0.01;
           float n = (noise(xoff) * 250)*soundin;
           gl.glBegin(gl.GL_LINES);
           gl.glTranslatef(realWorldPoint.x+n/10, realWorldPoint.y+(n/2)/10, realWorldPoint.z);
           gl.glColor4f(map(helligkeit, 1, 255, 0.0, 1.0)*2, map(helligkeit, 1, 255, 0.0, 1.0)*2, map(helligkeit, 1, 255, 0.0, 1.0)*2, 1.0);
           gl.glRectf(0, 0, 1.5+(map(helligkeit, 1, 255, 1, 4.5))+random(2), 4+(map(helligkeit, 1, 255, 1, 2.5)));
           gl.glEnd();
   
   
           //__________________________________________________ Depth-Random-Effekt
   
           if (depthMap[index] > random(250, 1000)) {
             if (depthMap[index] % 4 <= 0) {
               gl.glBegin(gl.GL_LINES);      
               gl.glTranslatef(realWorldPoint.x, realWorldPoint.y-5, realWorldPoint.z);
               gl.glColor4f(map(helligkeit, 1, 255, 0.0, 1.0), map(helligkeit, 1, 255, 0.0, 1.0)*8, map(helligkeit, 1, 255, 0.0, 1.0)*5, 1.0);
               gl.glRectf(0, 0, 1.5+(map(helligkeit, 1, 255, 1, 2.5)), 10+(map(helligkeit, 1, 255, 1, 2.5)));
               gl.glEnd();
             }
           }
         }
       }
     }
   
   
     //______________________________________________________________ Freeze-Effekt
   
     if (frameCount%45==0) {
       freeze = true;
       for (int i = 0; i <= frameVecList.size()-1; i++) { 
         PVector f = (PVector) frameVecList.get(i); 
   
         abgreifen_x.add(f.x);
         abgreifen_y.add(f.y);
         abgreifen_z.add(f.z);
       }
     }
   
     if (freeze == true) {
       freezetimer++;
       alphawert = alphawert+0.025;
       for (int i = abgreifen_x.size()-1; i >= 0; i--) {
         stroke(0);
         strokeWeight(5);
         gl.glBegin(gl.GL_LINES); 
         gl.glTranslatef(abgreifen_x.get(i)+10, abgreifen_y.get(i)-10, abgreifen_z.get(i)-freezetimer*15);
         gl.glColor4f(0.0, 0.8, 0.65, 1.0-alphawert);
         gl.glRectf(0, 0, 1.5, 10);
         gl.glEnd();
       }
       if (freezetimer == 3) {
         for (int i = abgreifen_x.size()-1; i >= 0; i--) {
           gl.glBegin(gl.GL_LINES); 
           gl.glTranslatef(abgreifen_x.get(i)-10, abgreifen_y.get(i)+10, abgreifen_z.get(i)-freezetimer*25);
           gl.glColor4f(0.0, 0.65, 0.8, 1.0-alphawert);
           gl.glRectf(0, 0, 1.5, 10);
           gl.glEnd();
         }
       }
       if (freezetimer == 20) {
         abgreifen_x.clear();
         abgreifen_y.clear();
         abgreifen_z.clear();
         freezetimer = 0;
         alphawert = 0.0;
         freeze = false;
       }
     }
   
     //_______________________________________________________ Background-Rects
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(width), random(height), random(1800, 2250));
       gl.glColor4f(0.0, 0.8, 0.65, 1.0-random(0.85, 0.975));
       gl.glRectf(0, 0, 10+random(5, 10), 25+random(20, 25));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(-width), random(-height), random(1800, 2250));
       gl.glColor4f(0.0, 0.8, 0.65, 1.0-random(0.85, 0.975));
       gl.glRectf(0, 0, random(3, 9)+random(5, 10), random(25, 42)+random(20, 35));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(-width), random(height), random(1800, 2250));
       gl.glColor4f(0.0, 0.8, 0.65, 1.0-random(0.85, 0.975));
       gl.glRectf(0, 0, random(5, 12)+random(5, 10), random(20, 40)+random(20, 27));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(width), random(-height), random(1800, 2250));
       gl.glColor4f(0.0, 0.8, 0.65, 1.0-random(0.85, 0.975));
       gl.glRectf(0, 0, random(4, 10)+random(5, 10), random(20, 35)+random(10, 15));
       gl.glEnd();
     }
   
     //__________________________________________________________ Zweite Background-Rect Ebene (schwarz)
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(width), random(height), random(1800, 2250));
       gl.glColor4f(0.0, 0.0, 0.0, 1.0-random(0.05, 0.45));
       gl.glRectf(0, 0, random(1, 4), random(5, 10));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(-width), random(-height), random(1800, 2250));
       gl.glColor4f(0.0, 0.0, 0.0, 1.0-random(0.05, 0.45));
       gl.glRectf(0, 0, random(1, 4), random(5, 10));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(-width), random(height), random(1800, 2250));
       gl.glColor4f(0.0, 0.0, 0.0, 1.0-random(0.05, 0.45));
       gl.glRectf(0, 0, random(2, 4), random(5, 15));
       gl.glEnd();
     }
   
     for (int i = 0; i <= random(10,50); i++) {
       gl.glBegin(gl.GL_LINES);
       gl.glTranslatef(random(width), random(-height), random(1800, 2250));
       gl.glColor4f(0.0, 0.0, 0.0, 1.0-random(0.05, 0.45));
       gl.glRectf(0, 0, random(2, 4), random(5, 10));
       gl.glEnd();
     }
   
     frameVecList.clear();
     mm.addFrame();
     pgl.endGL();
   }