/**

  * $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;

 }