src/video/x11/SDL_x11gl.c
author Sam Lantinga <slouken@libsdl.org>
Mon, 19 Aug 2002 17:58:08 +0000
changeset 450 8a43e0cbf02f
parent 297 f6ffac90895c
child 566 d6e7d7006062
permissions -rw-r--r--
Added SDL_GL_STEREO for stereoscopic OpenGL contexts
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/*
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    SDL - Simple DirectMedia Layer
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    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  Sam Lantinga
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    This library is free software; you can redistribute it and/or
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    modify it under the terms of the GNU Library General Public
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    License as published by the Free Software Foundation; either
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    version 2 of the License, or (at your option) any later version.
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    This library is distributed in the hope that it will be useful,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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    Library General Public License for more details.
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    You should have received a copy of the GNU Library General Public
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    License along with this library; if not, write to the Free
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    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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    Sam Lantinga
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    slouken@libsdl.org
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*/
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#ifdef SAVE_RCSID
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static char rcsid =
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 "@(#) $Id$";
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#endif
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#include <stdlib.h>	/* For getenv() prototype */
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#include <string.h>
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#include "SDL_events_c.h"
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#include "SDL_error.h"
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#include "SDL_x11video.h"
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#include "SDL_x11dga_c.h"
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#include "SDL_x11gl_c.h"
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#define DEFAULT_OPENGL	"libGL.so.1"
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/* return the preferred visual to use for openGL graphics */
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XVisualInfo *X11_GL_GetVisual(_THIS)
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{
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#ifdef HAVE_OPENGL
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	/* 64 seems nice. */
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	int attribs[64];
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	int i;
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	/* load the gl driver from a default path */
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	if ( ! this->gl_config.driver_loaded ) {
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	        /* no driver has been loaded, use default (ourselves) */
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	        if ( X11_GL_LoadLibrary(this, NULL) < 0 ) {
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		        return NULL;
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		}
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	}
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	/* See if we already have a window which we must use */
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	if ( SDL_windowid ) {
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		XWindowAttributes a;
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		XVisualInfo vi_in;
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		int out_count;
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		XGetWindowAttributes(SDL_Display, SDL_Window, &a);
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		vi_in.screen = SDL_Screen;
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		vi_in.visualid = XVisualIDFromVisual(a.visual);
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		glx_visualinfo = XGetVisualInfo(SDL_Display,
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	                     VisualScreenMask|VisualIDMask, &vi_in, &out_count);
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		return glx_visualinfo;
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	}
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        /* Setup our GLX attributes according to the gl_config. */
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	i = 0;
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	attribs[i++] = GLX_RGBA;
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	attribs[i++] = GLX_RED_SIZE;
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	attribs[i++] = this->gl_config.red_size;
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	attribs[i++] = GLX_GREEN_SIZE;
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	attribs[i++] = this->gl_config.green_size;
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	attribs[i++] = GLX_BLUE_SIZE;
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	attribs[i++] = this->gl_config.blue_size;
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	if( this->gl_config.alpha_size ) {
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		attribs[i++] = GLX_ALPHA_SIZE;
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		attribs[i++] = this->gl_config.alpha_size;
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	}
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	if( this->gl_config.buffer_size ) {
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		attribs[i++] = GLX_BUFFER_SIZE;
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		attribs[i++] = this->gl_config.buffer_size;
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	}
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	if( this->gl_config.double_buffer ) {
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		attribs[i++] = GLX_DOUBLEBUFFER;
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	}
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	attribs[i++] = GLX_DEPTH_SIZE;
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	attribs[i++] = this->gl_config.depth_size;
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	if( this->gl_config.stencil_size ) {
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		attribs[i++] = GLX_STENCIL_SIZE;
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		attribs[i++] = this->gl_config.stencil_size;
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	}
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	if( this->gl_config.accum_red_size ) {
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		attribs[i++] = GLX_ACCUM_RED_SIZE;
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		attribs[i++] = this->gl_config.accum_red_size;
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	}
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	if( this->gl_config.accum_green_size ) {
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		attribs[i++] = GLX_ACCUM_GREEN_SIZE;
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		attribs[i++] = this->gl_config.accum_green_size;
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	}
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	if( this->gl_config.accum_blue_size ) {
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		attribs[i++] = GLX_ACCUM_BLUE_SIZE;
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		attribs[i++] = this->gl_config.accum_blue_size;
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	}
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	if( this->gl_config.accum_alpha_size ) {
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		attribs[i++] = GLX_ACCUM_ALPHA_SIZE;
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		attribs[i++] = this->gl_config.accum_alpha_size;
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	}
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	if( this->gl_config.stereo ) {
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		attribs[i++] = GLX_STEREO;
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		attribs[i++] = this->gl_config.stereo;
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	}
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#ifdef GLX_DIRECT_COLOR /* Try for a DirectColor visual for gamma support */
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	attribs[i++] = GLX_X_VISUAL_TYPE;
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	attribs[i++] = GLX_DIRECT_COLOR;
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#endif
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	attribs[i++] = None;
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 	glx_visualinfo = this->gl_data->glXChooseVisual(GFX_Display, 
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						  SDL_Screen, attribs);
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#ifdef GLX_DIRECT_COLOR
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	if( !glx_visualinfo ) { /* No DirectColor visual?  Try again.. */
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		attribs[i-3] = None;
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 		glx_visualinfo = this->gl_data->glXChooseVisual(GFX_Display, 
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						  SDL_Screen, attribs);
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	}
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#endif
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	if( !glx_visualinfo ) {
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		SDL_SetError( "Couldn't find matching GLX visual");
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		return NULL;
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	}
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	return glx_visualinfo;
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#else
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	SDL_SetError("X11 driver not configured with OpenGL");
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	return NULL;
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#endif
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}
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int X11_GL_CreateWindow(_THIS, int w, int h)
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{
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	int retval;
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#ifdef HAVE_OPENGL
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	XSetWindowAttributes attributes;
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	unsigned long mask;
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	unsigned long black;
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	black = (glx_visualinfo->visual == DefaultVisual(SDL_Display,
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						 	SDL_Screen))
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	       	? BlackPixel(SDL_Display, SDL_Screen) : 0;
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	attributes.background_pixel = black;
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	attributes.border_pixel = black;
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	attributes.colormap = SDL_XColorMap;
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	mask = CWBackPixel | CWBorderPixel | CWColormap;
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	SDL_Window = XCreateWindow(SDL_Display, WMwindow,
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			0, 0, w, h, 0, glx_visualinfo->depth,
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			InputOutput, glx_visualinfo->visual,
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			mask, &attributes);
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	if ( !SDL_Window ) {
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		SDL_SetError("Could not create window");
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		return -1;
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	}
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	retval = 0;
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#else
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	SDL_SetError("X11 driver not configured with OpenGL");
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	retval = -1;
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#endif
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	return(retval);
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}
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int X11_GL_CreateContext(_THIS)
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{
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	int retval;
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#ifdef HAVE_OPENGL
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	/* We do this to create a clean separation between X and GLX errors. */
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	XSync( SDL_Display, False );
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	glx_context = this->gl_data->glXCreateContext(GFX_Display, 
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				     glx_visualinfo, NULL, True);
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	XSync( GFX_Display, False );
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	if (glx_context == NULL) {
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		SDL_SetError("Could not create GL context");
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		return -1;
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	}
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	gl_active = 1;
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#else
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	SDL_SetError("X11 driver not configured with OpenGL");
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#endif
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	if ( gl_active ) {
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		retval = 0;
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	} else {
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		retval = -1;
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	}
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	return(retval);
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}
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void X11_GL_Shutdown(_THIS)
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{
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#ifdef HAVE_OPENGL
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	/* Clean up OpenGL */
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	if( glx_context ) {
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		this->gl_data->glXMakeCurrent(GFX_Display, None, NULL);
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		if (glx_context != NULL)
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			this->gl_data->glXDestroyContext(GFX_Display, glx_context);
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		if( this->gl_data->glXReleaseBuffersMESA ) {
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		    this->gl_data->glXReleaseBuffersMESA(GFX_Display,SDL_Window);
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		}
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		glx_context = NULL;
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	}
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	gl_active = 0;
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#endif /* HAVE_OPENGL */
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}
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#ifdef HAVE_OPENGL
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/* Make the current context active */
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int X11_GL_MakeCurrent(_THIS)
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{
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	int retval;
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	retval = 0;
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	if ( ! this->gl_data->glXMakeCurrent(GFX_Display,
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	                                     SDL_Window, glx_context) ) {
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		SDL_SetError("Unable to make GL context current");
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		retval = -1;
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	}
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	XSync( GFX_Display, False );
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	/* More Voodoo X server workarounds... Grr... */
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	SDL_Lock_EventThread();
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	X11_CheckDGAMouse(this);
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	SDL_Unlock_EventThread();
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	return(retval);
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}
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/* Get attribute data from glX. */
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int X11_GL_GetAttribute(_THIS, SDL_GLattr attrib, int* value)
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{
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	int retval;
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	int glx_attrib = None;
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	switch( attrib ) {
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	    case SDL_GL_RED_SIZE:
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		glx_attrib = GLX_RED_SIZE;
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		break;
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	    case SDL_GL_GREEN_SIZE:
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		glx_attrib = GLX_GREEN_SIZE;
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		break;
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	    case SDL_GL_BLUE_SIZE:
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		glx_attrib = GLX_BLUE_SIZE;
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		break;
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	    case SDL_GL_ALPHA_SIZE:
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		glx_attrib = GLX_ALPHA_SIZE;
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		break;
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	    case SDL_GL_DOUBLEBUFFER:
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		glx_attrib = GLX_DOUBLEBUFFER;
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		break;
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	    case SDL_GL_BUFFER_SIZE:
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		glx_attrib = GLX_BUFFER_SIZE;
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		break;
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	    case SDL_GL_DEPTH_SIZE:
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		glx_attrib = GLX_DEPTH_SIZE;
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		break;
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	    case SDL_GL_STENCIL_SIZE:
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		glx_attrib = GLX_STENCIL_SIZE;
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		break;
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	    case SDL_GL_ACCUM_RED_SIZE:
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		glx_attrib = GLX_ACCUM_RED_SIZE;
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		break;
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	    case SDL_GL_ACCUM_GREEN_SIZE:
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		glx_attrib = GLX_ACCUM_GREEN_SIZE;
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		break;
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	    case SDL_GL_ACCUM_BLUE_SIZE:
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		glx_attrib = GLX_ACCUM_BLUE_SIZE;
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		break;
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	    case SDL_GL_ACCUM_ALPHA_SIZE:
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		glx_attrib = GLX_ACCUM_ALPHA_SIZE;
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		break;
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	    case SDL_GL_STEREO:
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		glx_attrib = GLX_STEREO;
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		break;
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	    default:
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		return(-1);
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	}
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	retval = this->gl_data->glXGetConfig(GFX_Display, glx_visualinfo, glx_attrib, value);
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	return retval;
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}
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void X11_GL_SwapBuffers(_THIS)
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{
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	this->gl_data->glXSwapBuffers(GFX_Display, SDL_Window);
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}
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#endif /* HAVE_OPENGL */
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void X11_GL_UnloadLibrary(_THIS)
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{
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#ifdef HAVE_OPENGL
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	if ( this->gl_config.driver_loaded ) {
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		dlclose(this->gl_config.dll_handle);
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		this->gl_data->glXGetProcAddress = NULL;
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		this->gl_data->glXChooseVisual = NULL;
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		this->gl_data->glXCreateContext = NULL;
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		this->gl_data->glXDestroyContext = NULL;
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		this->gl_data->glXMakeCurrent = NULL;
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		this->gl_data->glXSwapBuffers = NULL;
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		this->gl_config.dll_handle = NULL;
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		this->gl_config.driver_loaded = 0;
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	}
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#endif
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}
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#ifdef HAVE_OPENGL
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/* Passing a NULL path means load pointers from the application */
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int X11_GL_LoadLibrary(_THIS, const char* path) 
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{
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	void* handle;
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	int dlopen_flags;
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   341
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   342
 	if ( gl_active ) {
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 		SDL_SetError("OpenGL context already created");
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 		return -1;
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 	}
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#ifdef RTLD_GLOBAL
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	dlopen_flags = RTLD_LAZY | RTLD_GLOBAL;
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#else
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	dlopen_flags = RTLD_LAZY;
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#endif
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	handle = dlopen(path, dlopen_flags);
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	/* Catch the case where the application isn't linked with GL */
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   354
	if ( (dlsym(handle, "glXChooseVisual") == NULL) && (path == NULL) ) {
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   355
		dlclose(handle);
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   356
		path = getenv("SDL_VIDEO_GL_DRIVER");
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   357
		if ( path == NULL ) {
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			path = DEFAULT_OPENGL;
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   359
		}
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		handle = dlopen(path, dlopen_flags);
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   361
	}
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   362
	if ( handle == NULL ) {
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   363
		SDL_SetError("Could not load OpenGL library");
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   364
		return -1;
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   365
	}
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   366
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   367
	/* Unload the old driver and reset the pointers */
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	X11_GL_UnloadLibrary(this);
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   369
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   370
	/* Load new function pointers */
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	this->gl_data->glXGetProcAddress =
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		(void *(*)(const GLubyte *)) dlsym(handle, "glXGetProcAddressARB");
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   373
	this->gl_data->glXChooseVisual =
slouken@180
   374
		(XVisualInfo *(*)(Display *, int, int *)) dlsym(handle, "glXChooseVisual");
slouken@180
   375
	this->gl_data->glXCreateContext =
slouken@180
   376
		(GLXContext (*)(Display *, XVisualInfo *, GLXContext, int)) dlsym(handle, "glXCreateContext");
slouken@180
   377
	this->gl_data->glXDestroyContext =
slouken@180
   378
		(void (*)(Display *, GLXContext)) dlsym(handle, "glXDestroyContext");
slouken@180
   379
	this->gl_data->glXMakeCurrent =
slouken@180
   380
		(int (*)(Display *, GLXDrawable, GLXContext)) dlsym(handle, "glXMakeCurrent");
slouken@180
   381
	this->gl_data->glXSwapBuffers =
slouken@180
   382
		(void (*)(Display *, GLXDrawable)) dlsym(handle, "glXSwapBuffers");
slouken@180
   383
	this->gl_data->glXGetConfig =
slouken@180
   384
		(int (*)(Display *, XVisualInfo *, int, int *)) dlsym(handle, "glXGetConfig");
slouken@0
   385
	/* We don't compare below for this in case we're not using Mesa. */
slouken@180
   386
	this->gl_data->glXReleaseBuffersMESA =
slouken@180
   387
		(void (*)(Display *, GLXDrawable)) dlsym( handle, "glXReleaseBuffersMESA" );
slouken@0
   388
slouken@0
   389
	if ( (this->gl_data->glXChooseVisual == NULL) || 
slouken@0
   390
	     (this->gl_data->glXCreateContext == NULL) ||
slouken@0
   391
	     (this->gl_data->glXDestroyContext == NULL) ||
slouken@0
   392
	     (this->gl_data->glXMakeCurrent == NULL) ||
slouken@0
   393
	     (this->gl_data->glXSwapBuffers == NULL) ||
slouken@0
   394
	     (this->gl_data->glXGetConfig == NULL) ) {
slouken@0
   395
		SDL_SetError("Could not retrieve OpenGL functions");
slouken@0
   396
		return -1;
slouken@0
   397
	}
slouken@0
   398
slouken@0
   399
	this->gl_config.dll_handle = handle;
slouken@0
   400
	this->gl_config.driver_loaded = 1;
slouken@0
   401
	if ( path ) {
slouken@0
   402
		strncpy(this->gl_config.driver_path, path,
slouken@0
   403
			sizeof(this->gl_config.driver_path)-1);
slouken@0
   404
	} else {
slouken@0
   405
		strcpy(this->gl_config.driver_path, "");
slouken@0
   406
	}
slouken@0
   407
	return 0;
slouken@0
   408
}
slouken@0
   409
slouken@0
   410
void *X11_GL_GetProcAddress(_THIS, const char* proc)
slouken@0
   411
{
slouken@110
   412
	static char procname[1024];
slouken@0
   413
	void* handle;
slouken@110
   414
	void* retval;
slouken@0
   415
	
slouken@0
   416
	handle = this->gl_config.dll_handle;
slouken@0
   417
#if 0 /* This doesn't work correctly yet */
slouken@0
   418
	if ( this->gl_data->glXGetProcAddress ) {
slouken@0
   419
        void *func, *func2;
slouken@0
   420
		func = this->gl_data->glXGetProcAddress(proc);
slouken@0
   421
        func2 = dlsym(handle, proc);
slouken@0
   422
        if ( func != func2 ) {
slouken@0
   423
fprintf(stderr, "glXGetProcAddress returned %p and dlsym returned %p for %s\n", func, func2, proc);
slouken@0
   424
        }
slouken@0
   425
        return this->gl_data->glXGetProcAddress(proc);
slouken@0
   426
	}
slouken@0
   427
#endif
slouken@110
   428
#if defined(__OpenBSD__) && !defined(__ELF__)
slouken@110
   429
#undef dlsym(x,y);
slouken@110
   430
#endif
slouken@110
   431
	retval = dlsym(handle, proc);
slouken@110
   432
	if (!retval && strlen(proc) <= 1022) {
slouken@127
   433
		procname[0] = '_';
slouken@110
   434
		strcpy(procname + 1, proc);
slouken@110
   435
		retval = dlsym(handle, procname);
slouken@110
   436
	}
slouken@110
   437
	return retval;
slouken@0
   438
}
slouken@0
   439
slouken@0
   440
#endif /* HAVE_OPENGL */