So, Im trying to learn some OPENGL with the new GLGraphics library. I have written a simple brightness/contrast glsl shader to go along with the testing..
My main problem is binding a filtered texture back onto a quad (ie. sprite filtering);

How does one go about this. Here is my code.

import processing.xml.*;
import controlP5.*;
import processing.opengl.*;
import codeanticode.glgraphics.*;
import javax.media.opengl.*;
import com.sun.opengl.util.texture.*;  
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;

ControlP5 controlP5;
PImage tex,texAlpha;
PGraphicsOpenGL pgl;
GL gl;
GLGraphicsOffScreen         glMain;

float b;        //brightness
float c;        //contrast

Quad q1;
float [] cpos;

void setup() {
size(800, 400, GLConstants.GLGRAPHICS);
glMain = new GLGraphicsOffScreen(width, height, this);
pgl = (PGraphicsOpenGL) g;
gl = pgl.gl;
q1 = new Quad(this,width/2,-height/2);}

void draw() {
 colorMode(RGB,1.0);
    background(0);
q1.render();
}

class Quad {
GLTexture                   img;
GLTexture                   tex;
GLTextureFilter             pixelate,bc;
GLTextureFilterParameters   params, paramsa;
     PImage _image;

float x,y;
float b=.5;
float c=.5;
Quad (PApplet t, float _x, float _y){
this.x = _x; this.y=_y;
img = new GLTexture(t, "sprite.jpg");
tex = new GLTexture(t,img.width,img.height);
pixelate = new GLTextureFilter(t, "pixelate.xml");  
paramsa = new GLTextureFilterParameters(t);  
bc = new GLTextureFilter(t, "bc.xml");
params = new GLTextureFilterParameters(t);  

}  

void update(float _x,float _y){
this.x=_x; this.y=_y;
}  
void render() {
 float k = map(mouseX, 0, 640, -1, 1);
float k1 = map(mouseX, 0, 640, 10, 0);
//float k1 = -k*2.5
params.parFlt1 = k;
params.parFlt2 = (-k*5)-.1;
img.filter(bc, tex,params);
tex.render(0,0, 200, 200);

// Must copy the above from the framebuffer ? and render it onto the quad described below..

 gl.glPushMatrix();
 gl.glTranslatef(x, y,0);
 gl.glBegin(GL.GL_QUADS);
 gl.glEnable( GL.GL_TEXTURE_2D );
 gl.glBindTexture( GL.GL_TEXTURE_2D,tex);
 gl.glNormal3f(0.0f,0.0f,1.0f);
 gl.glTexCoord2f(0, 0); gl.glVertex2f(0, 200);
 gl.glTexCoord2f(1, 0); gl.glVertex2f(200,200);
 gl.glTexCoord2f(1, 1); gl.glVertex2f(200, 0);
 gl.glTexCoord2f(0, 1); gl.glVertex2f(0, 0);
 gl.glDisable( GL.GL_TEXTURE_2D );
 gl.glEnd();
 gl.glPopMatrix();

}}