RenderTargetClass

import org.lwjgl.opengl.ARBFramebufferObject;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GL14;


public class RenderTarget {

    int colorTextureID, framebufferID, depthRenderBufferID,
        width,height;

    public RenderTarget(int width, int height){
        this.width= width;
        this.height = height;
        // init our fbo
        framebufferID = ARBFramebufferObject.glGenFramebuffers();                                           // create a new framebuffer
        colorTextureID = GL11.glGenTextures();                                              // and a new texture used as a color buffer
        depthRenderBufferID = ARBFramebufferObject.glGenRenderbuffers();                                    // And finally a new depthbuffer

        ARBFramebufferObject.glBindFramebuffer(ARBFramebufferObject.GL_FRAMEBUFFER, framebufferID);                         // switch to the new framebuffer

        // initialize color texture
        GL11.glBindTexture(GL11.GL_TEXTURE_2D, colorTextureID);                                 // Bind the colorbuffer texture
        GL11.glTexParameterf(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);               // make it linear filterd
        GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGBA16, width, height, 0,GL11.GL_RGBA, GL11.GL_INT, (java.nio.ByteBuffer) null);   // Create the texture data
        ARBFramebufferObject.glFramebufferTexture2D(ARBFramebufferObject.GL_FRAMEBUFFER ,
                ARBFramebufferObject.GL_COLOR_ATTACHMENT0 ,GL11.GL_TEXTURE_2D, colorTextureID, 0); // attach it to the framebuffer



        // initialize depth renderbuffer
        ARBFramebufferObject.glBindRenderbuffer(ARBFramebufferObject.GL_RENDERBUFFER , depthRenderBufferID);                // bind the depth renderbuffer
        ARBFramebufferObject.glRenderbufferStorage(ARBFramebufferObject.GL_RENDERBUFFER , GL14.GL_DEPTH_COMPONENT24,  width, height);   // get the data space for it
        ARBFramebufferObject.glFramebufferRenderbuffer(ARBFramebufferObject.GL_FRAMEBUFFER ,
                ARBFramebufferObject.GL_DEPTH_ATTACHMENT ,
                ARBFramebufferObject.GL_RENDERBUFFER , depthRenderBufferID); // bind it to the renderbuffer

        ARBFramebufferObject.glBindFramebuffer(ARBFramebufferObject.GL_FRAMEBUFFER , 0);                                    // Swithch back to normal framebuffer rendering


        completenessCheck();
    }

    private void completenessCheck(){
        int framebuffer = ARBFramebufferObject.glCheckFramebufferStatus( ARBFramebufferObject.GL_FRAMEBUFFER  );
        switch ( framebuffer ) {
            case ARBFramebufferObject.GL_FRAMEBUFFER_COMPLETE :
                break;
            case ARBFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT :
                throw new RuntimeException( "FrameBuffer: " + framebufferID
                        + ", has caused a GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT  exception" );
            case ARBFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT :
                throw new RuntimeException( "FrameBuffer: " + framebufferID
                        + ", has caused a GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT  exception" );
            case ARBFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER :
                throw new RuntimeException( "FrameBuffer: " + framebufferID
                        + ", has caused a GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER  exception" );
            case ARBFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER :
                throw new RuntimeException( "FrameBuffer: " + framebufferID
                        + ", has caused a GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER  exception" );
            default:
                throw new RuntimeException( "Unexpected reply from glCheckFramebufferStatusEXT: " + framebuffer );
        }
    }

    public void bind(){
        ARBFramebufferObject.glBindFramebuffer(ARBFramebufferObject.GL_FRAMEBUFFER , framebufferID);
        GL11.glPushAttrib(GL11.GL_VIEWPORT_BIT);
        GL11.glViewport( 0, 0, width, height);
        GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);
    }

    public void unBind(){
        ARBFramebufferObject.glBindFramebuffer(ARBFramebufferObject.GL_FRAMEBUFFER , 0);
        GL11.glPopAttrib();
    }
}