/*
 * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistribution of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 * - Redistribution in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
 * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
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 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
 * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
 * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed or intended for use
 * in the design, construction, operation or maintenance of any nuclear
 * facility.
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 * Sun gratefully acknowledges that this software was originally authored
 * and developed by Kenneth Bradley Russell and Christopher John Kline.
 */

package org.j3d.opengl.swt.internal.ri.x11;

// External imports
import javax.media.opengl.GLContext;
import javax.media.opengl.GLException;

import com.sun.opengl.impl.GLContextShareSet;
import com.sun.opengl.impl.x11.GLX;
import com.sun.opengl.impl.x11.GLXFBConfig;

public class X11ExternalGLDrawable extends X11GLDrawable
{
    private int fbConfigID;
    private int renderType;
    private int screen;
    private long readDrawable;

    public X11ExternalGLDrawable()
    {
        super(null, null);

        display = GLX.glXGetCurrentDisplay();
        drawable = GLX.glXGetCurrentDrawable();
        readDrawable = GLX.glXGetCurrentReadDrawable();

        // Need GLXFBConfig ID in order to properly create new contexts
        // on this drawable
        long context = GLX.glXGetCurrentContext();
        int[] val = new int[1];
        GLX.glXQueryContext(display, context, GLX.GLX_FBCONFIG_ID, val, 0);
        fbConfigID = val[0];
        renderType = GLX.GLX_RGBA_TYPE;
        GLX.glXQueryContext(display, context, GLX.GLX_RENDER_TYPE, val, 0);
        GLX.glXQueryContext(display, context, GLX.GLX_SCREEN, val, 0);
        screen = val[0];
    }

    public GLContext createContext(GLContext shareWith)
    {
        return new Context(shareWith);
    }

    public void setSize(int newWidth, int newHeight)
    {
        throw new GLException("Should not call this");
    }

    public int getWidth()
    {
        throw new GLException("Should not call this");
    }

    public int getHeight()
    {
        throw new GLException("Should not call this");
    }

    public void destroy()
    {
    }

    class Context extends X11GLContext
    {
        Context(GLContext shareWith)
        {
            super(X11ExternalGLDrawable.this, shareWith);
            this.drawable = drawable;
        }

        protected int makeCurrentImpl() throws GLException
        {
            if(drawable.getDrawable() == 0)
            {
                // parent drawable not properly initialized
                // FIXME: signal error?
                return CONTEXT_NOT_CURRENT;
            }

            // Note that we have to completely override makeCurrentImpl
            // because the underlying makeCurrent call differs from the norm
            boolean created = false;
            if(context == 0)
            {
                create();
                created = true;
            }

            if(!GLX.glXMakeContextCurrent(drawable.getDisplay(),
                                          drawable.getDrawable(),
                                          readDrawable,
                                          context))
            {
                throw new GLException("Error making context current");
            }
            else
            {
                mostRecentDisplay = drawable.getDisplay();
            }

            if(created)
            {
                resetGLFunctionAvailability();
                return CONTEXT_CURRENT_NEW;
            }
            return CONTEXT_CURRENT;
        }

        protected void releaseImpl() throws GLException
        {
            if(!GLX.glXMakeContextCurrent(drawable.getDisplay(), 0, 0, 0))
                throw new GLException("Error freeing OpenGL context");
        }

        protected void create()
        {
            // We already have the GLXFBConfig ID for the context. All we
            // need to do is use it to choose the GLXFBConfig and then
            // create a context with it.
            int[] iattributes = new int[] {
                GLX.GLX_FBCONFIG_ID,
                fbConfigID,
                0,
                0
            };

            float[] fattributes = new float[0];
            int[] nelementsTmp = new int[1];
            GLXFBConfig[] fbConfigs = GLX.glXChooseFBConfig(display, screen, iattributes, 0, nelementsTmp, 0);
            int nelements = nelementsTmp[0];
            if(nelements <= 0)
                throw new GLException("context creation error: couldn't find a suitable frame buffer configuration");

            if(nelements != 1)
                throw new GLException("context creation error: shouldn't get more than one GLXFBConfig");


            // Note that we currently don't allow selection of anything but
            // the first GLXFBConfig in the returned list (there should be only one)
            GLXFBConfig fbConfig = fbConfigs[0];

            // Create a gl context for the drawable
            X11GLContext other = (X11GLContext) GLContextShareSet.getShareContext(this);
            long share = 0;

            if(other != null)
            {
                share = other.getContext();
                if(share == 0)
                    throw new GLException("GLContextShareSet returned an invalid OpenGL context");
            }

            // FIXME: how to determine "direct" bit?
            context = GLX.glXCreateNewContext(display, fbConfig, renderType, share, true);

            if(context == 0)
            {
                String detail = "    display=" + toHexString(display) +
                    " fbconfig=" + fbConfig +
                    " fbconfigID=" + toHexString(fbConfigID) +
                    " renderType=" + toHexString(renderType) +
                    " share=" + toHexString(share);
                throw new GLException("context creation error: glXCreateNewContext() failed: " + detail);
            }

            GLContextShareSet.contextCreated(this);

        }
    }
}