/**

 * $Id: gl_glx.c,v 1.2 2006-02-15 12:39:13 nkeynes Exp $

 *

 * GLX framebuffer support. Note depends on an X11 video driver 

 * (ie video_gtk) to maintain the X11 side of things.

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include "dream.h"

#include <X11/Xlib.h>

#include <GL/glx.h>

#include "video.h"

#include "drivers/video_x11.h"

GLXContext glx_context;

Window glx_window;

gboolean glx_open = FALSE;

gboolean gl_glx_create_window( uint32_t width, uint32_t height )

{

    int major, minor;

    const char *glxExts, *glxServer;

    int visual_attrs[] = { GLX_RGBA, GLX_RED_SIZE, 4, 

			   GLX_GREEN_SIZE, 4, 

			   GLX_BLUE_SIZE, 4,

			   GLX_ALPHA_SIZE, 4,

			   GLX_DEPTH_SIZE, 16,

			   GLX_DOUBLEBUFFER, 

			   None };

    int screen = XScreenNumberOfScreen(video_x11_screen);

    XSetWindowAttributes win_attrs;

    XVisualInfo *visual;

    if( glXQueryVersion( video_x11_display, &major, &minor ) == False ) {

	ERROR( "X Display lacks the GLX nature" );

	return FALSE;

    }

    if( major < 1 || minor < 2 ) {

	ERROR( "X display supports GLX %d.%d, but we need at least 1.2", major, minor );

	return FALSE;

    }

    glxExts = glXQueryExtensionsString( video_x11_display, screen );

    glxServer = glXQueryServerString( video_x11_display, screen, GLX_VENDOR );

    INFO( "GLX version %d.%d, %s. Supported exts: %s", major, minor,

	  glxServer, glxExts );

    /* Find ourselves a nice visual */

    visual = glXChooseVisual( video_x11_display, 

			      screen,

			      visual_attrs );

    if( visual == NULL ) {

	ERROR( "Unable to obtain a compatible visual" );

	return FALSE;

    }

    /* And a matching gl context */

    glx_context = glXCreateContext( video_x11_display, visual, None, True );

    if( glx_context == NULL ) {

	ERROR( "Unable to obtain a GLX Context. Possibly your system is broken in some small, undefineable way" );

	return FALSE;

    }

    /* Ok, all good so far. Unfortunately the visual we need to use will 

     * almost certainly be different from the one our frame is using. Which 

     * means we have to jump through the following hoops to create a 

     * child window with the appropriate settings.

     */

    win_attrs.event_mask = 0;

    win_attrs.colormap = XCreateColormap( video_x11_display, 

					  RootWindowOfScreen(video_x11_screen),

					  visual->visual, AllocNone );

    glx_window = XCreateWindow( video_x11_display, video_x11_window, 

				0, 0, width, height, 0, visual->depth, 

				InputOutput, visual->visual, 

				CWColormap | CWEventMask, 

				&win_attrs );

    if( glx_window == None ) {

	/* Hrm. Aww, no window? */

	ERROR( "Unable to create GLX window" );

	glXDestroyContext( video_x11_display, glx_context );

	if( win_attrs.colormap ) 

	    XFreeColormap( video_x11_display, win_attrs.colormap );

	return FALSE;

    }

    XMapRaised( video_x11_display, glx_window );

    /* And finally set the window to be the active drawing area */

    if( glXMakeCurrent( video_x11_display, glx_window, glx_context ) == False ) {

	/* Oh you have _GOT_ to be kidding me */

	ERROR( "Unable to prepare GLX window for drawing" );

	XDestroyWindow( video_x11_display, glx_window );

	XFreeColormap( video_x11_display, win_attrs.colormap );

	glXDestroyContext( video_x11_display, glx_context );

	return FALSE;

    }

    glx_open = TRUE;

    return TRUE;

}

gboolean gl_glx_set_output_format( uint32_t width, uint32_t height,

				   int colour_format )

{

    GLXFBConfig config;

    int screen = XScreenNumberOfScreen(video_x11_screen);

    int buffer_attrs[] = { GLX_PBUFFER_WIDTH, width, 

			   GLX_PBUFFER_HEIGHT, height,

			   GLX_PRESERVED_CONTENTS, True,

			   None };

    if( !glx_open ) {

	if( !gl_glx_create_window( width, height ) )

	    return FALSE;

    }

    return TRUE;

}

gboolean gl_glx_swap_frame( )

{

    return FALSE;

}