New functionality: QuakeForge now has a general OpenGL extension-loading

interface. To detect an extension, call QFGL_ExtensionPresent(). To get the address of an extension function, call QFGL_ExtensionAddress(). This function uses the preferred method for finding a function, based on whatever OS and windowing system you use.
2025-05-30 16:50:48 +00:00 · 2000-11-29 04:55:24 +00:00 · 2000-11-29 04:55:24 +00:00 · 732dc94090
commit 732dc94090
parent ba1b5f8974
2 changed files with 289 additions and 0 deletions
--- a/source/qfgl_ext.c
+++ b/source/qfgl_ext.c
@ -0,0 +1,180 @@
+/*
+	qfgl_ext.c
+
+	QuakeForge OpenGL extension interface definitions
+
+	Copyright (C) 2000 Jeff Teunissen <deek@dusknet.dhs.org>
+
+	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.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to:
+
+		Free Software Foundation, Inc.
+		59 Temple Place - Suite 330
+		Boston, MA  02111-1307, USA
+
+	$Id$
+*/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#ifdef HAVE_DLFCN_H
+# include <dlfcn.h>
+#endif
+#ifndef RTLD_LAZY
+# ifdef DL_LAZY
+#  define RTLD_LAZY     DL_LAZY
+# else
+#  define RTLD_LAZY     0
+# endif
+#endif
+
+#include <GL/gl.h>
+
+#ifdef HAVE_GL_GLX_H
+# include <GL/glx.h>
+#endif
+#ifdef HAVE_GL_GLEXT_H
+# include <GL/glext.h>
+#endif
+#ifdef HAVE_WINDOWS_H
+# include <windows.h>
+#endif
+
+#include <string.h>
+
+#include "qfgl_ext.h"
+#include "qtypes.h"
+
+/*
+	ParseExtensionList
+
+	It takes a bit of care to be fool-proof about parsing an OpenGL extensions
+	string. Don't be fooled by sub-strings, etc.
+*/
+qboolean
+QFGL_ParseExtensionList (const GLubyte *list, const char *name)
+{
+	const char	*start;
+	char		*where, *terminator;
+
+	// Extension names must not have spaces.
+	where = (GLubyte *) strchr (name, ' ');
+	if (where || *name == '\0')
+		return 0;
+
+	start = list;
+	for (;;) {
+		where = strstr (start, name);
+		if (!where)
+			break;
+		terminator = where + strlen (name);
+		if (where == start || *(where - 1) == ' ')
+			if (*terminator == ' ' || *terminator == '\0')
+				return 1;
+		start = terminator;
+	}
+	return 0;
+}
+
+qboolean
+QFGL_ExtensionPresent (const char *name)
+{
+	static const GLubyte	*gl_extensions = NULL;
+#ifdef _WIN32
+	static const GLubyte	*wgl_extensions = NULL;
+
+	static qboolean 					extensionFunc_present = true;
+	static QF_wglGetExtensionsStringEXT	extensionFunc = NULL;
+#endif
+
+	if (!gl_extensions) {	// get and save GL extension list
+		gl_extensions = glGetString (GL_EXTENSIONS);
+	}
+
+#ifdef _WIN32
+	if (!wgl_extensions) {	// get and save WGL extension list
+		if (extensionFunc_present && !extensionFunc) {
+			if (!(QFGL_ParseExtensionList (gl_extensions, "WGL_EXT_extensions_string"))) {
+				extensionFunc_present = false;
+			} else {
+				extensionFunc = QFGL_ExtensionAddress ("WGL_EXT_extension_string");
+			}
+		}
+
+		if (extensionFunc_present)
+			wgl_extensions = extensionFunc ();
+		else
+			wgl_extensions = "";
+	}
+
+	if (QFGL_ParseExtensionList (gl_extensions, name))
+		return true;
+	if (QFGL_ParseExtensionList (wgl_extensions, name))
+		return true;
+
+	return false;
+#else
+	return QFGL_ParseExtensionList (gl_extensions, name);
+#endif
+}
+
+
+void *
+QFGL_ExtensionAddress (const char *name)
+{
+#if defined(HAVE_GLX) && defined(HAVE_DLOPEN)
+	void	*dlhand = NULL;
+
+	static qboolean 				glProcAddress_present = true;
+	static QF_glXGetProcAddressARB	qfglXGetProcAddress = NULL;
+
+	if (glProcAddress_present && !qfglXGetProcAddress) {
+		if (QFGL_ExtensionPresent ("GLX_ARB_get_proc_address")) {
+			if ((dlhand = dlopen (NULL, RTLD_LAZY))) {
+				qfglXGetProcAddress = dlsym (dlhand, "glXGetProcAddressARB");
+				dlclose (dlhand);
+			} else {
+				glProcAddress_present = false;
+			}
+		} else {
+			glProcAddress_present = false;
+		}
+	}
+#endif
+
+	if (name) {
+#if defined(HAVE_GLX) && defined(HAVE_DLOPEN)
+		if (glProcAddress_present) {
+			return qfglXGetProcAddress ((const GLubyte *) name);
+		} else {
+			if ((dlhand = dlopen (NULL, RTLD_LAZY))) {
+				void *handle;
+				handle = dlsym (dlhand, name);
+				dlclose (dlhand);
+				return handle;
+			}
+			return NULL;
+		}
+#else
+# ifdef _WIN32
+		return wglGetProcAddress (name);
+# else
+		return NULL;
+# endif
+#endif
+	}
+	return NULL;
+}