hw/xwin/glx: Rewrite WGL wrappers after Xserver conversion to direct GL dispatch

v1: Rewrite by Marc Haesen of the WGL wrapper function generation script to use
Khronos group XML.

v2: Remove -dispatchheader option, since dispatch.h doesn't exist anymore, use
the private glapi interface to construct the GL dispatch table for the native
WGL thunks.

v3:
Rewrite to generate shims for the OpenGL 1.2.1 (GL 1.2 + GL_ARB_imaging
+GL_ARB_multitexture + GL_ARB_texture_compression(?)) functions the server links
directly with rather than libGL.

These shims dispatch to either the mesa GL DLL, or a thunking DLL containing
cdecl-to-stcall wrapper functions for the native GL DLL.

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Reviewed-by: Adam Jackson <ajax@redhat.com>

8 files changed, 653 insertions, 399 deletions

diff --git a/configure.ac b/configure.ac
index 3855d721f..045dfbe46 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2109,7 +2109,7 @@ if test "x$XWIN" = xyes; then
 	esac
 
 	XWIN_LIBS="$FB_LIB $MI_LIB $FIXES_LIB $XEXT_LIB $RANDR_LIB $RENDER_LIB $DBE_LIB $RECORD_LIB $GLX_LIBS $XKB_LIB $XKB_STUB_LIB $COMPOSITE_LIB $DAMAGE_LIB $PRESENT_LIB $MIEXT_SYNC_LIB $MIEXT_DAMAGE_LIB $MIEXT_SHADOW_LIB $XI_LIB $OS_LIB"
-	XWIN_SYS_LIBS="$XWIN_SYS_LIBS $XWINMODULES_LIBS $GLX_SYS_LIBS"
+	XWIN_SYS_LIBS="$XWIN_SYS_LIBS $XWINMODULES_LIBS"
 	AC_SUBST(XWIN_LIBS)
 	AC_SUBST(XWIN_SERVER_NAME)
 	AC_SUBST(XWIN_SYS_LIBS)
@@ -2125,10 +2125,16 @@ if test "x$XWIN" = xyes; then
 
 dnl XWin with AIGLX requires OpenGL spec files in order to generate wrapper code for native GL functions
 	if [test "x$XWIN" = xyes && test "x$AIGLX" = xyes] ; then
-           AC_CHECK_PROG(PYTHON, python, python)
-           if test -z "$PYTHON"; then
-                AC_MSG_ERROR([python not found])
+           AC_CHECK_PROG(PYTHON3, python3, python3)
+           if test -z "$PYTHON3"; then
+                AC_MSG_ERROR([python3 not found])
            fi
+           AC_MSG_CHECKING(for python module lxml)
+           $PYTHON3 -c "import lxml;"
+           if test $? -ne 0 ; then
+                AC_MSG_ERROR([not found])
+           fi
+           AC_MSG_RESULT(yes)
            if test "x$KHRONOS_SPEC_DIR" = "xauto" ; then
 		PKG_CHECK_MODULES([KHRONOS_OPENGL_REGISTRY], [khronos-opengl-registry])
 		KHRONOS_SPEC_DIR=`pkg-config khronos-opengl-registry --variable=specdir`
diff --git a/hw/xwin/Makefile.am b/hw/xwin/Makefile.am
index c7006959c..7f0eaf097 100644
--- a/hw/xwin/Makefile.am
+++ b/hw/xwin/Makefile.am
@@ -157,7 +157,7 @@ XWIN_LIBS += 	$(top_builddir)/pseudoramiX/libPseudoramiX.la
 
 XWin_DEPENDENCIES = $(MULTIWINDOWEXTWM_LIBS) $(XWIN_GLX_LIBS) $(XWIN_LIBS) $(XSERVER_LIBS)
 XWin_LDADD = $(MULTIWINDOW_LIBS) $(MULTIWINDOWEXTWM_LIBS) $(XWIN_GLX_LIBS) $(XWIN_GLX_LINK_FLAGS) $(XWIN_LIBS) $(MAIN_LIB) $(XSERVER_LIBS) $(XSERVER_SYS_LIBS) $(XWIN_SYS_LIBS)
-XWin_LDFLAGS = -mwindows -static
+XWin_LDFLAGS = -mwindows -static -Wl,--disable-stdcall-fixup
 
 .rc.o:
 	$(AM_V_GEN)$(WINDRES) --use-temp-file -i $< --input-format=rc -o $@ -O coff -I $(top_builddir)/include
diff --git a/hw/xwin/glx/Makefile.am b/hw/xwin/glx/Makefile.am
index 067ee5b3c..f2dffbffb 100644
--- a/hw/xwin/glx/Makefile.am
+++ b/hw/xwin/glx/Makefile.am
@@ -1,14 +1,18 @@
 noinst_LTLIBRARIES = libXwinGLX.la
+lib_LTLIBRARIES = libnativeGLthunk.la
 
 libXwinGLX_la_SOURCES = \
 	winpriv.c \
 	winpriv.h \
 	glwindows.h \
-	glwrap.c \
+	glshim.c \
 	indirect.c \
 	wgl_ext_api.c \
 	wgl_ext_api.h
 
+libnativeGLthunk_la_SOURCES = \
+	glthunk.c
+
 if XWIN_MULTIWINDOW
 DEFS_MULTIWINDOW = -DXWIN_MULTIWINDOW
 endif
@@ -30,16 +34,32 @@ AM_CFLAGS = -DHAVE_XWIN_CONFIG_H $(DIX_CFLAGS) \
             -I$(top_srcdir) \
             -I$(top_srcdir)/hw/xwin/
 
+libnativeGLthunk_la_CFLAGS = $(AM_CFLAGS) -Wno-unused-function -Wno-missing-prototypes -Wno-missing-declarations
+libnativeGLthunk_la_LDFLAGS = -shared -no-undefined -avoid-version -lopengl32 -export-symbols generated_gl_thunks.def
+EXTRA_libnativeGLthunk_la_DEPENDENCIES = generated_gl_thunks.def
+
 if XWIN_GLX_WINDOWS
 
-generated_gl_wrappers.c: gen_gl_wrappers.py $(KHRONOS_SPEC_DIR)/gl.spec $(KHRONOS_SPEC_DIR)/gl.tm
-	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_gl_wrappers.py --spec=$(KHRONOS_SPEC_DIR)/gl.spec --typemap=$(KHRONOS_SPEC_DIR)/gl.tm --dispatch-header=$(top_srcdir)/glx/dispatch.h --staticwrappers >generated_gl_wrappers.c
+if DEBUG
+GENGLWRAPPERSOPTS=""
+else
+GENGLWRAPPERSOPTS="-nodebug"
+endif
+
+generated_wgl_wrappers.c: $(srcdir)/gen_gl_wrappers.py $(KHRONOS_SPEC_DIR)/wgl.xml $(KHRONOS_SPEC_DIR)/reg.py
+	$(AM_V_GEN)PYTHONPATH=$(KHRONOS_SPEC_DIR) $(PYTHON3) $(srcdir)/gen_gl_wrappers.py -registry $(KHRONOS_SPEC_DIR)/wgl.xml -prefix wgl -wrapper -preresolve $(GENGLWRAPPERSOPTS) -outfile $@
+
+generated_gl_shim.c: $(srcdir)/gen_gl_wrappers.py $(KHRONOS_SPEC_DIR)/gl.xml $(KHRONOS_SPEC_DIR)/reg.py
+	$(AM_V_GEN)PYTHONPATH=$(KHRONOS_SPEC_DIR) $(PYTHON3) $(srcdir)/gen_gl_wrappers.py -registry $(KHRONOS_SPEC_DIR)/gl.xml -shim $(GENGLWRAPPERSOPTS) -outfile $@
+
+generated_gl_thunks.c: $(srcdir)/gen_gl_wrappers.py $(KHRONOS_SPEC_DIR)/gl.xml $(KHRONOS_SPEC_DIR)/reg.py
+	$(AM_V_GEN)PYTHONPATH=$(KHRONOS_SPEC_DIR) $(PYTHON3) $(srcdir)/gen_gl_wrappers.py -registry $(KHRONOS_SPEC_DIR)/gl.xml -thunk $(GENGLWRAPPERSOPTS) -outfile $@
 
-generated_wgl_wrappers.c: gen_gl_wrappers.py $(KHRONOS_SPEC_DIR)/wglext.spec $(KHRONOS_SPEC_DIR)/wgl.tm
-	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_gl_wrappers.py --spec=$(KHRONOS_SPEC_DIR)/wglext.spec --typemap=$(KHRONOS_SPEC_DIR)/wgl.tm --prefix=wgl --preresolve >generated_wgl_wrappers.c
+generated_gl_thunks.def: $(srcdir)/gen_gl_wrappers.py $(KHRONOS_SPEC_DIR)/gl.xml $(KHRONOS_SPEC_DIR)/reg.py
+	$(AM_V_GEN)PYTHONPATH=$(KHRONOS_SPEC_DIR) $(PYTHON3) $(srcdir)/gen_gl_wrappers.py -registry $(KHRONOS_SPEC_DIR)/gl.xml -thunkdefs $(GENGLWRAPPERSOPTS) -outfile $@
 endif
 
-BUILT_SOURCES = generated_gl_wrappers.c generated_wgl_wrappers.c
+BUILT_SOURCES = generated_gl_shim.c generated_gl_thunks.c generated_gl_thunks.def generated_wgl_wrappers.c
 CLEANFILES = $(BUILT_SOURCES)
 
 EXTRA_DIST = gen_gl_wrappers.py
diff --git a/hw/xwin/glx/gen_gl_wrappers.py b/hw/xwin/glx/gen_gl_wrappers.py
index 2273589c9..683b9d903 100755
--- a/hw/xwin/glx/gen_gl_wrappers.py
+++ b/hw/xwin/glx/gen_gl_wrappers.py
@@ -1,325 +1,485 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 #
-# Comedy python script to generate cdecl to stdcall wrappers for GL functions
+# python script to generate cdecl to stdcall wrappers for GL functions
+# adapted from genheaders.py
 #
-# This is designed to operate on OpenGL spec files from
-# http://www.opengl.org/registry/api/
-#
-#
-# Copyright (c) Jon TURNEY 2009
+# Copyright (c) 2013 The Khronos Group Inc.
 #
 # Permission is hereby granted, free of charge, to any person obtaining a
-# copy of this software and associated documentation files (the "Software"),
-# to deal in the Software without restriction, including without limitation
-# the rights to use, copy, modify, merge, publish, distribute, sublicense,
-# and/or sell copies of the Software, and to permit persons to whom the
-# Software is furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
-# THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
-# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
-# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-# DEALINGS IN THE SOFTWARE.
-#
-# Except as contained in this notice, the name(s) of the above copyright
-# holders shall not be used in advertising or otherwise to promote the sale,
-# use or other dealings in this Software without prior written authorization.
-#
-
-import sys
-import re
-import getopt
-
-dispatchheader = ''
-prefix = 'gl'
-preresolve = False
-staticwrappers = False
-
-opts, args = getopt.getopt(sys.argv[1:], "", ['spec=', 'typemap=', 'dispatch-header=', 'prefix=', 'preresolve', 'staticwrappers' ])
-
-for o,a in opts:
-        if o == '--typemap' :
-                typemapfile = a
-        elif o == '--dispatch-header' :
-                dispatchheader = a
-        elif o == '--spec' :
-                specfile = a
-        elif o == '--prefix' :
-                prefix = a
-        elif o == '--preresolve' :
-                preresolve = True
-        elif o == '--staticwrappers' :
-                staticwrappers = True
-
+# copy of this software and/or associated documentation files (the
+# "Materials"), to deal in the Materials without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Materials, and to
+# permit persons to whom the Materials are furnished to do so, subject to
+# the following conditions:
 #
-# look for all the SET_ macros in dispatch.h, this is the set of functions
-# we need to generate
-#
-
-dispatch = {}
-
-if dispatchheader :
-        fh = open(dispatchheader)
-        dispatchh = fh.readlines()
-
-        dispatch_regex = re.compile(r'^SET_(\S*)\(')
-
-        for line in dispatchh :
-                line = line.strip()
-                m1 = dispatch_regex.search(line)
-
-                if m1 :
-                        dispatch[m1.group(1)] = 1
-
-        del dispatch['by_offset']
-
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Materials.
 #
-# read the typemap .tm file
-#
-
-typemap = {}
-
-fh = open(typemapfile)
-tm = fh.readlines()
-
-typemap_regex = re.compile(r'#define\sSET_(\S*)\(')
-
-for line in tm :
-        # ignore everything after a '#' as a comment
-        hash = line.find('#')
-        if hash != -1 :
-                line = line[:hash-1]
-
-        # ignore blank lines
-        if line.startswith('#') or len(line) == 0 :
-                continue
-
-        l = line.split(',')
-        typemap[l[0]] = l[3].strip()
-
-# interestingly, * is not a C type
-if typemap['void'] == '*' :
-        typemap['void'] = 'void'
-
-#
-# crudely parse the .spec file
-#
-
-r1 = re.compile(r'\t(\S*)\s+(\S*.*)')
-r2 = re.compile(r'(.*)\((.*)\)')
-r3 = re.compile(r'glWindowPos.*MESA')
-r4 = re.compile(r'gl.*Program(s|)NV')
-r5 = re.compile(r'glGetVertexAttribfvNV')
-
-wrappers = {}
-
-fh = open(specfile)
-glspec = fh.readlines()
-param_count = 0
-
-for line in glspec :
-        line = line.rstrip()
-
-        # ignore everything after a '#' as a comment
-        hash = line.find('#')
-        if hash != -1 :
-                line = line[:hash-1]
-
-        # ignore blank lines
-        if line.startswith('#') or len(line) == 0 :
-                continue
-
-        # lines containing ':' aren't intersting to us
-        if line.count(':') != 0 :
-                continue
-
-        # attributes of each function follow the name, indented by a tab
-        if not line.startswith('\t') :
-                m1 = r2.search(line)
-                if m1 :
-                        function = m1.group(1)
-                        arglist_use = m1.group(2)
-                        wrappers[function] = {}
-
-                        # ensure formal parameter names don't collide with reserved names or shadow global declarations
-                        arglist_use = ',' .join([i.rstrip() + '_' for i in arglist_use.split(",")])
-
-                        wrappers[function]['arglist_use'] = arglist_use
-                        param_count = 0
-        else :
-                m1 = r1.search(line)
-                if m1 :
-                        attribute = m1.group(1)
-                        value = m1.group(2)
-
-                        # make param attributes unique and ordered
-                        if attribute == 'param' :
-                                attribute = 'param' + '%02d' % param_count
-                                param_count += 1
-
-                        wrappers[function][attribute] = value
-
-#
-# now emit code
-#
-
-print '/* Automatically generated by ' + sys.argv[0] + ' DO NOT EDIT */'
-print '/* from ' + specfile + ' and typemap ' + typemapfile + ' */'
-print ''
-
-#
-# if required, emit code for non-lazy function resolving
-#
-
-if preresolve :
-        for w in sorted(wrappers.keys()) :
-                funcname = prefix + w
-                print 'RESOLVE_DECL(PFN' + funcname.upper() + 'PROC);'
-
-        print ''
-        print 'void ' + prefix + 'ResolveExtensionProcs(void)'
-        print '{'
-
-        for w in sorted(wrappers.keys()) :
-                funcname = prefix + w
-                print '  PRERESOLVE(PFN' + funcname.upper() + 'PROC, "' + funcname + '");'
-
-        print '}\n'
+# THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+# MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+
+import sys, time, pdb, string, cProfile
+from reg import *
+
+# Default input / log files
+errFilename = None
+diagFilename = 'diag.txt'
+regFilename = 'gl.xml'
+outFilename = 'gen_gl_wrappers.c'
+
+protect=True
+prefix="gl"
+preresolve=False
+wrapper=False
+shim=False
+thunk=False
+thunkdefs=False
+staticwrappers=False
+nodebug=False
+
+#exclude base WGL API
+WinGDI={key: 1 for key in [
+     "wglCopyContext"
+    ,"wglCreateContext"
+    ,"wglCreateLayerContext"
+    ,"wglDeleteContext"
+    ,"wglGetCurrentContext"
+    ,"wglGetCurrentDC"
+    ,"wglGetProcAddress"
+    ,"wglMakeCurrent"
+    ,"wglShareLists"
+    ,"wglUseFontBitmapsA"
+    ,"wglUseFontBitmapsW"
+    ,"wglUseFontBitmaps"
+    ,"SwapBuffers"
+    ,"wglUseFontOutlinesA"
+    ,"wglUseFontOutlinesW"
+    ,"wglUseFontOutlines"
+    ,"wglDescribeLayerPlane"
+    ,"wglSetLayerPaletteEntries"
+    ,"wglGetLayerPaletteEntries"
+    ,"wglRealizeLayerPalette"
+    ,"wglSwapLayerBuffers"
+    ,"wglSwapMultipleBuffers"
+    ,"ChoosePixelFormat"
+    ,"DescribePixelFormat"
+    ,"GetEnhMetaFilePixelFormat"
+    ,"GetPixelFormat"
+    ,"SetPixelFormat"
+]}
+
+if __name__ == '__main__':
+    i = 1
+    while (i < len(sys.argv)):
+        arg = sys.argv[i]
+        i = i + 1
+        if (arg == '-noprotect'):
+            print('Disabling inclusion protection in output headers', file=sys.stderr)
+            protect = False
+        elif (arg == '-registry'):
+            regFilename = sys.argv[i]
+            i = i+1
+            print('Using registry', regFilename, file=sys.stderr)
+        elif (arg == '-outfile'):
+            outFilename = sys.argv[i]
+            i = i+1
+        elif (arg == '-preresolve'):
+            preresolve=True
+        elif (arg == '-wrapper'):
+            wrapper=True
+        elif (arg == '-shim'):
+            shim=True
+        elif (arg == '-thunk'):
+            thunk=True
+        elif (arg == '-thunkdefs'):
+            thunkdefs=True
+        elif (arg == '-staticwrappers'):
+            staticwrappers=True
+        elif (arg == '-prefix'):
+            prefix = sys.argv[i]
+            i = i+1
+        elif (arg == '-nodebug'):
+            nodebug = True
+        elif (arg[0:1] == '-'):
+            print('Unrecognized argument:', arg, file=sys.stderr)
+            exit(1)
+
+print('Generating', outFilename, file=sys.stderr)
+
+# Load & parse registry
+reg = Registry()
+tree = etree.parse(regFilename)
+reg.loadElementTree(tree)
+
+allVersions = '.*'
+
+genOpts = CGeneratorOptions(
+        apiname           = prefix,
+        profile           = 'compatibility',
+        versions          = allVersions,
+        emitversions      = allVersions,
+        defaultExtensions = prefix,                   # Default extensions for GL
+        protectFile       = protect,
+        protectFeature    = protect,
+        protectProto      = protect,
+        )
+
+# create error/warning & diagnostic files
+if (errFilename):
+    errWarn = open(errFilename,'w')
+else:
+    errWarn = sys.stderr
+diag = open(diagFilename, 'w')
+
+class PreResolveOutputGenerator(OutputGenerator):
+    def __init__(self,
+                 errFile = sys.stderr,
+                 warnFile = sys.stderr,
+                 diagFile = sys.stdout):
+        OutputGenerator.__init__(self, errFile, warnFile, diagFile)
+        self.wrappers={}
+    def beginFile(self, genOpts):
+        self.outFile.write('/* Automatically generated from %s - DO NOT EDIT */\n\n'%regFilename)
+    def endFile(self):
+        self.outFile.write('\nvoid ' + prefix + 'ResolveExtensionProcs(void)\n{\n')
+        for funcname in self.wrappers.keys():
+            self.outFile.write( '  PRERESOLVE(PFN' + funcname.upper() + 'PROC, "' + funcname + '");\n')
+        self.outFile.write('}\n\n')
+    def beginFeature(self, interface, emit):
+        OutputGenerator.beginFeature(self, interface, emit)
+    def endFeature(self):
+        OutputGenerator.endFeature(self)
+    def genType(self, typeinfo, name):
+        OutputGenerator.genType(self, typeinfo, name)
+    def genEnum(self, enuminfo, name):
+        OutputGenerator.genEnum(self, enuminfo, name)
+    def genCmd(self, cmd, name):
+        OutputGenerator.genCmd(self, cmd, name)
+
+        if name in WinGDI:
+            return
+
+        self.outFile.write('RESOLVE_DECL(PFN' + name.upper() + 'PROC);\n')
+        self.wrappers[name]=1
+
+class WrapperOutputGenerator(OutputGenerator):
+    def __init__(self,
+                 errFile = sys.stderr,
+                 warnFile = sys.stderr,
+                 diagFile = sys.stdout):
+        OutputGenerator.__init__(self, errFile, warnFile, diagFile)
+    def beginFile(self, genOpts):
+        self.outFile.write('/* Automatically generated from %s - DO NOT EDIT */\n\n'%regFilename)
+    def endFile(self):
+        pass
+    def beginFeature(self, interface, emit):
+        OutputGenerator.beginFeature(self, interface, emit)
+        self.OldVersion = self.featureName.startswith('GL_VERSION_1_0') or self.featureName.startswith('GL_VERSION_1_1')
+    def endFeature(self):
+        OutputGenerator.endFeature(self)
+    def genType(self, typeinfo, name):
+        OutputGenerator.genType(self, typeinfo, name)
+    def genEnum(self, enuminfo, name):
+        OutputGenerator.genEnum(self, enuminfo, name)
+    def genCmd(self, cmd, name):
+        OutputGenerator.genCmd(self, cmd, name)
+
+        if name in WinGDI:
+            return
+
+        proto=noneStr(cmd.elem.find('proto'))
+        rettype=noneStr(proto.text)
+        if rettype.lower()!="void ":
+            plist = ([t for t in proto.itertext()])
+            rettype = ''.join(plist[:-1])
+        rettype=rettype.strip()
+        if staticwrappers: self.outFile.write("static ")
+        self.outFile.write("%s %sWrapper("%(rettype, name))
+        params = cmd.elem.findall('param')
+        plist=[]
+        for param in params:
+            paramlist = ([t for t in param.itertext()])
+            paramtype = ''.join(paramlist[:-1])
+            paramname = paramlist[-1]
+            plist.append((paramtype, paramname))
+        Comma=""
+        if len(plist):
+            for ptype, pname in plist:
+                self.outFile.write("%s%s%s_"%(Comma, ptype, pname))
+                Comma=", "
+        else:
+            self.outFile.write("void")
 
-#
-# now emit the wrappers
-# for GL 1.0 and 1.1 functions, generate stdcall wrappers which call the function directly
-# for GL 1.2+ functions, generate wrappers which use wglGetProcAddress()
-#
+        self.outFile.write(")\n{\n")
 
-for w in sorted(wrappers.keys()) :
+        # for GL 1.0 and 1.1 functions, generate stdcall wrappers which call the function directly
+        if self.OldVersion:
+            if not nodebug:
+                self.outFile.write('  if (glxWinDebugSettings.enable%scallTrace) ErrorF("%s\\n");\n'%(prefix.upper(), name))
+                self.outFile.write("  glWinDirectProcCalls++;\n")
+                self.outFile.write("\n")
 
-        funcname = prefix + w
-        returntype = wrappers[w]['return']
-        if returntype != 'void' :
-                returntype = typemap[returntype]
+            if rettype.lower()=="void":
+                self.outFile.write("  %s( "%(name))
+            else:
+                self.outFile.write("  return %s( "%(name))
 
-        # Avoid generating wrappers which aren't referenced by the dispatch table
-        if dispatchheader and not dispatch.has_key(w) :
-                print '/* No wrapper for ' + funcname + ', not in dispatch table */'
-                continue
+            Comma=""
+            for ptype, pname in plist:
+                self.outFile.write("%s%s_"%(Comma, pname))
+                Comma=", "
 
-        # manufacture arglist
-        # if no param attributes were found, it should be 'void'
-        al = []
-        for k in sorted(wrappers[w].keys()) :
-                if k.startswith('param') :
-                        l = wrappers[w][k].split()
+        # for GL 1.2+ functions, generate stdcall wrappers which use wglGetProcAddress()
+        else:
+            if rettype.lower()=="void":
+                self.outFile.write('  RESOLVE(PFN%sPROC, "%s");\n'%(name.upper(), name))
+
+                if not nodebug:
+                    self.outFile.write("\n")
+                    self.outFile.write('  if (glxWinDebugSettings.enable%scallTrace) ErrorF("%s\\n");\n'%(prefix.upper(), name))
+                    self.outFile.write("\n")
+
+                self.outFile.write("  RESOLVED_PROC(PFN%sPROC)( """%(name.upper()))
+            else:
+                self.outFile.write('  RESOLVE_RET(PFN%sPROC, "%s", FALSE);\n'%(name.upper(), name))
+
+                if not nodebug:
+                    self.outFile.write("\n")
+                    self.outFile.write('  if (glxWinDebugSettings.enable%scallTrace) ErrorF("%s\\n");\n'%(prefix.upper(), name))
+                    self.outFile.write("\n")
+
+                self.outFile.write("  return RESOLVED_PROC(PFN%sPROC)("%(name.upper()))
+
+            Comma=""
+            for ptype, pname in plist:
+                self.outFile.write("%s%s_"%(Comma, pname))
+                Comma=", "
+        self.outFile.write(" );\n}\n\n")
+
+class ThunkOutputGenerator(OutputGenerator):
+    def __init__(self,
+                 errFile = sys.stderr,
+                 warnFile = sys.stderr,
+                 diagFile = sys.stdout):
+        OutputGenerator.__init__(self, errFile, warnFile, diagFile)
+    def beginFile(self, genOpts):
+        self.outFile.write('/* Automatically generated from %s - DO NOT EDIT */\n\n'%regFilename)
+    def endFile(self):
+        pass
+    def beginFeature(self, interface, emit):
+        OutputGenerator.beginFeature(self, interface, emit)
+        self.OldVersion = self.featureName.startswith('GL_VERSION_1_0') or self.featureName.startswith('GL_VERSION_1_1')
+    def endFeature(self):
+        OutputGenerator.endFeature(self)
+    def genType(self, typeinfo, name):
+        OutputGenerator.genType(self, typeinfo, name)
+    def genEnum(self, enuminfo, name):
+        OutputGenerator.genEnum(self, enuminfo, name)
+    def genCmd(self, cmd, name):
+        OutputGenerator.genCmd(self, cmd, name)
+
+        proto=noneStr(cmd.elem.find('proto'))
+        rettype=noneStr(proto.text)
+        if rettype.lower()!="void ":
+            plist = ([t for t in proto.itertext()])
+            rettype = ''.join(plist[:-1])
+        rettype=rettype.strip()
+        self.outFile.write("%s %sWrapper("%(rettype, name))
+        params = cmd.elem.findall('param')
+        plist=[]
+        for param in params:
+            paramlist = ([t for t in param.itertext()])
+            paramtype = ''.join(paramlist[:-1])
+            paramname = paramlist[-1]
+            plist.append((paramtype, paramname))
+        Comma=""
+        if len(plist):
+            for ptype, pname in plist:
+                self.outFile.write("%s%s%s_"%(Comma, ptype, pname))
+                Comma=", "
+        else:
+            self.outFile.write("void")
 
-                        # ensure formal parameter names don't collide with reserved names or shadow global declarations
-                        l[0] = l[0] + '_'
+        self.outFile.write(")\n{\n")
 
-                        if l[2] == 'in' :
-                                if l[3] == 'array' :
-                                        arg = 'const ' + typemap[l[1]] + ' *' + l[0]
-                                else :
-                                        arg = typemap[l[1]] + ' ' + l[0]
-                        elif l[2] == 'out' :
-                                arg = typemap[l[1]] + ' *' + l[0]
+        # for GL 1.0 and 1.1 functions, generate stdcall thunk wrappers which call the function directly
+        if self.OldVersion:
+            if rettype.lower()=="void":
+                self.outFile.write("  %s( "%(name))
+            else:
+                self.outFile.write("  return %s( "%(name))
 
-                        al.append(arg)
+            Comma=""
+            for ptype, pname in plist:
+                self.outFile.write("%s%s_"%(Comma, pname))
+                Comma=", "
 
-        if len(al) == 0 :
-                arglist = 'void'
+        # for GL 1.2+ functions, generate wrappers which use wglGetProcAddress()
         else:
-                arglist  = ', '.join(al)
-
-        if wrappers[w]['category'].startswith('VERSION_1_0') or wrappers[w]['category'].startswith('VERSION_1_1') :
-                if staticwrappers :
-                        print 'static',
-                print returntype + ' ' + funcname + 'Wrapper(' + arglist + ')'
-                print '{'
-                print '  if (glxWinDebugSettings.enable' + prefix.upper() + 'callTrace) ErrorF("'+ funcname + '\\n");'
-                print '  glWinDirectProcCalls++;'
-                if returntype.lower() == 'void' :
-                        print '  ' +  funcname + '(',
-                else :
-                        print ' /* returntype was ' + returntype.lower() + '*/'
-                        print '  return ' +  funcname + '(',
-
-                if arglist != 'void' :
-                        print wrappers[w]['arglist_use'],
-
-                print ');'
-                print "}\n"
+            if rettype.lower()=="void":
+                self.outFile.write('  RESOLVE(PFN%sPROC, "%s");\n'%(name.upper(), name))
+                self.outFile.write("  RESOLVED_PROC(PFN%sPROC)( """%(name.upper()))
+            else:
+                self.outFile.write('  RESOLVE_RET(PFN%sPROC, "%s", FALSE);\n'%(name.upper(), name))
+                self.outFile.write("  return RESOLVED_PROC(PFN%sPROC)("%(name.upper()))
+
+            Comma=""
+            for ptype, pname in plist:
+                self.outFile.write("%s%s_"%(Comma, pname))
+                Comma=", "
+        self.outFile.write(" );\n}\n\n")
+
+class ThunkDefsOutputGenerator(OutputGenerator):
+    def __init__(self,
+                 errFile = sys.stderr,
+                 warnFile = sys.stderr,
+                 diagFile = sys.stdout):
+        OutputGenerator.__init__(self, errFile, warnFile, diagFile)
+    def beginFile(self, genOpts):
+        self.outFile.write("EXPORTS\n"); # this must be the first line for libtool to realize this is a .def file
+        self.outFile.write('; Automatically generated from %s - DO NOT EDIT\n\n'%regFilename)
+    def endFile(self):
+        pass
+    def beginFeature(self, interface, emit):
+        OutputGenerator.beginFeature(self, interface, emit)
+    def endFeature(self):
+        OutputGenerator.endFeature(self)
+    def genType(self, typeinfo, name):
+        OutputGenerator.genType(self, typeinfo, name)
+    def genEnum(self, enuminfo, name):
+        OutputGenerator.genEnum(self, enuminfo, name)
+    def genCmd(self, cmd, name):
+        OutputGenerator.genCmd(self, cmd, name)
+
+        # export the wrapper function with the name of the function it wraps
+        self.outFile.write("%s = %sWrapper\n"%(name, name))
+
+class ShimOutputGenerator(OutputGenerator):
+    def __init__(self,
+                 errFile = sys.stderr,
+                 warnFile = sys.stderr,
+                 diagFile = sys.stdout):
+        OutputGenerator.__init__(self, errFile, warnFile, diagFile)
+    def beginFile(self, genOpts):
+        self.outFile.write('/* Automatically generated from %s - DO NOT EDIT */\n\n'%regFilename)
+    def endFile(self):
+        pass
+    def beginFeature(self, interface, emit):
+        OutputGenerator.beginFeature(self, interface, emit)
+        self.OldVersion = self.featureName.startswith('GL_VERSION_1_0') or self.featureName.startswith('GL_VERSION_1_1') or self.featureName.startswith('GL_VERSION_1_2') or self.featureName.startswith('GL_ARB_imaging') or self.featureName.startswith('GL_ARB_multitexture') or self.featureName.startswith('GL_ARB_texture_compression')
+    def endFeature(self):
+        OutputGenerator.endFeature(self)
+    def genType(self, typeinfo, name):
+        OutputGenerator.genType(self, typeinfo, name)
+    def genEnum(self, enuminfo, name):
+        OutputGenerator.genEnum(self, enuminfo, name)
+    def genCmd(self, cmd, name):
+        OutputGenerator.genCmd(self, cmd, name)
+
+        if not self.OldVersion:
+            return
+
+        # for GL functions which are in the ABI, generate a shim which calls the function via GetProcAddress
+        proto=noneStr(cmd.elem.find('proto'))
+        rettype=noneStr(proto.text)
+        if rettype.lower()!="void ":
+            plist = ([t for t in proto.itertext()])
+            rettype = ''.join(plist[:-1])
+        rettype=rettype.strip()
+        self.outFile.write("%s %s("%(rettype, name))
+        params = cmd.elem.findall('param')
+        plist=[]
+        for param in params:
+            paramlist = ([t for t in param.itertext()])
+            paramtype = ''.join(paramlist[:-1])
+            paramname = paramlist[-1]
+            plist.append((paramtype, paramname))
+        Comma=""
+        if len(plist):
+            for ptype, pname in plist:
+                self.outFile.write("%s%s%s_"%(Comma, ptype, pname))
+                Comma=", "
         else:
-                if staticwrappers :
-                        print 'static',
-                print returntype + ' ' + funcname + 'Wrapper(' + arglist + ')'
-                print '{'
+            self.outFile.write("void")
 
-                stringname = funcname
+        self.outFile.write(")\n{\n")
 
-#
-# special case: Windows OpenGL implementations are far more likely to have GL_ARB_window_pos than GL_MESA_window_pos,
-# so arrange for the wrapper to use the ARB strings to find functions...
-#
+        self.outFile.write('  typedef %s (* PFN%sPROC)(' % (rettype, name.upper()))
 
-                m2 = r3.search(funcname)
-                if m2 :
-                        stringname = stringname.replace('MESA','ARB')
+        if len(plist):
+            Comma=""
+            for ptype, pname in plist:
+                self.outFile.write("%s %s %s_"%(Comma, ptype, pname))
+                Comma=", "
+        else:
+            self.outFile.write("void")
 
-#
-# special case: likewise, implementations are more likely to have GL_ARB_vertex_program than GL_NV_vertex_program,
-# especially if they are not NV implementations, so arrange for the wrapper to use ARB strings to find functions
-#
+        self.outFile.write(');\n')
 
-                m3 = r4.search(funcname)
-                if m3 :
-                        stringname = stringname.replace('NV','ARB')
-                m4 = r5.search(funcname)
-                if m4 :
-                        stringname = stringname.replace('NV','ARB')
-
-                pfntypename = 'PFN' + funcname.upper() + 'PROC'
-
-                if returntype.lower() == 'void' :
-                        print '  RESOLVE(' + pfntypename + ', "' + stringname + '");'
-                        print '  if (glxWinDebugSettings.enable' + prefix.upper() + 'callTrace) ErrorF("'+ funcname + '\\n");'
-                        print '  RESOLVED_PROC(' + pfntypename + ')(',
-                else :
-                        print '  RESOLVE_RET(' + pfntypename + ', "' + stringname + '", FALSE);'
-                        print '  if (glxWinDebugSettings.enable' + prefix.upper() + 'callTrace) ErrorF("'+ funcname + '\\n");'
-                        print '  return RESOLVED_PROC(' + pfntypename + ')(',
-
-                if arglist != 'void' :
-                        print wrappers[w]['arglist_use'],
-
-                print ');'
-                print "}\n"
-
-
-# generate function to setup the dispatch table, which sets each
-# dispatch table entry to point to it's wrapper function
-# (assuming we were able to make one)
-
-if dispatchheader :
-        print 'void glWinSetupDispatchTable(void)'
-        print '{'
-        print '  static struct _glapi_table *disp = NULL;'
-        print ''
-        print '  if (!disp)'
-        print '    {'
-        print '      disp = calloc(sizeof(void *), _glapi_get_dispatch_table_size());'
-        print '      assert(disp);'
-
-        for d in sorted(dispatch.keys()) :
-                if wrappers.has_key(d) :
-                        print '      SET_'+ d + '(disp, (void *)' + prefix + d + 'Wrapper);'
-                else :
-                        print '#warning  No wrapper for ' + prefix + d + ' !'
-
-        print '    }'
-        print ''
-        print '  _glapi_set_dispatch(disp);'
-        print '}'
+        if rettype.lower()=="void":
+            self.outFile.write('  RESOLVE(PFN%sPROC, "%s");\n'%(name.upper(), name))
+            self.outFile.write('  RESOLVED_PROC(')
+        else:
+            self.outFile.write('  RESOLVE_RET(PFN%sPROC, "%s", 0);\n'%(name.upper(), name))
+            self.outFile.write('  return RESOLVED_PROC(')
+
+        Comma=""
+        for ptype, pname in plist:
+            self.outFile.write("%s%s_"%(Comma, pname))
+            Comma=", "
+
+        self.outFile.write(" );\n}\n\n")
+
+def genHeaders():
+    outFile = open(outFilename,"w")
+
+    if preresolve:
+        gen = PreResolveOutputGenerator(errFile=errWarn,
+                                        warnFile=errWarn,
+                                        diagFile=diag)
+        gen.outFile=outFile
+        reg.setGenerator(gen)
+        reg.apiGen(genOpts)
+
+    if wrapper:
+        gen = WrapperOutputGenerator(errFile=errWarn,
+                                     warnFile=errWarn,
+                                     diagFile=diag)
+        gen.outFile=outFile
+        reg.setGenerator(gen)
+        reg.apiGen(genOpts)
+
+    if shim:
+        gen = ShimOutputGenerator(errFile=errWarn,
+                                  warnFile=errWarn,
+                                  diagFile=diag)
+        gen.outFile=outFile
+        reg.setGenerator(gen)
+        reg.apiGen(genOpts)
+
+    if thunk:
+        gen = ThunkOutputGenerator(errFile=errWarn,
+                                   warnFile=errWarn,
+                                   diagFile=diag)
+        gen.outFile=outFile
+        reg.setGenerator(gen)
+        reg.apiGen(genOpts)
+
+
+    if thunkdefs:
+        gen = ThunkDefsOutputGenerator(errFile=errWarn,
+                                       warnFile=errWarn,
+                                       diagFile=diag)
+        gen.outFile=outFile
+        reg.setGenerator(gen)
+        reg.apiGen(genOpts)
+
+    outFile.close()
+
+genHeaders()
diff --git a/hw/xwin/glx/glshim.c b/hw/xwin/glx/glshim.c
new file mode 100644
index 000000000..7109196c0
--- /dev/null
+++ b/hw/xwin/glx/glshim.c
@@ -0,0 +1,124 @@
+/*
+ * File: glshim.c
+ * Purpose: GL shim which redirects to a specified DLL
+ *
+ * Copyright (c) Jon TURNEY 2013
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+   A GL shim which redirects to a specified DLL
+
+   XWin is statically linked with this, rather than the system libGL, so that
+   GL calls can be directed to mesa cygGL-1.dll, or cygnativeGLthunk.dll
+   (which contains cdecl-to-stdcall thunks to the native openGL32.dll)
+*/
+
+#ifdef HAVE_XWIN_CONFIG_H
+#include <xwin-config.h>
+#endif
+
+#define GL_GLEXT_LEGACY
+#include <GL/gl.h>
+#undef GL_ARB_imaging
+#undef GL_VERSION_1_3
+#include <GL/glext.h>
+
+#include <X11/Xwindows.h>
+#include <os.h>
+#include "glwindows.h"
+#include <glx/glxserver.h>
+
+static HMODULE hMod = NULL;
+
+/*
+  Implement the __glGetProcAddress function by just using GetProcAddress() on the selected DLL
+*/
+void *glXGetProcAddressARB(const char *symbol)
+{
+    void *proc;
+
+    /* Default to the mesa GL implementation if one hasn't been selected yet */
+    if (!hMod)
+        glWinSelectImplementation(0);
+
+    proc = GetProcAddress(hMod, symbol);
+
+    if (glxWinDebugSettings.enableGLcallTrace)
+        ErrorF("glXGetProcAddressARB: Resolved '%s' in %p to %p\n", symbol, hMod, proc);
+
+    return proc;
+}
+
+/*
+  Select a GL implementation DLL
+*/
+int glWinSelectImplementation(int native)
+{
+    const char *dllname;
+
+    if (native) {
+        dllname = "cygnativeGLthunk.dll";
+    }
+    else {
+        dllname = "cygGL-1.dll";
+    }
+
+    hMod = LoadLibraryEx(dllname, NULL, 0);
+    if (hMod == NULL) {
+        ErrorF("glWinSelectGLimplementation: Could not load '%s'\n", dllname);
+        return -1;
+    }
+
+    ErrorF("glWinSelectGLimplementation: Loaded '%s'\n", dllname);
+
+    /* Connect __glGetProcAddress() to our implementation of glXGetProcAddressARB() above */
+    __glXsetGetProcAddress((glx_gpa_proc)glXGetProcAddressARB);
+
+    return 0;
+}
+
+#define RESOLVE_RET(proctype, symbol, retval) \
+    proctype proc = (proctype)glXGetProcAddressARB(symbol);   \
+    if (proc == NULL) return retval;
+
+#define RESOLVE(proctype, symbol) RESOLVE_RET(proctype, symbol,)
+#define RESOLVED_PROC proc
+
+/* Include generated shims for direct linkage to GL functions which are in the ABI */
+#include "generated_gl_shim.c"
+
+/*
+  Special wrapper for glAddSwapHintRectWIN for copySubBuffers
+
+  Only used with native GL if the GL_WIN_swap_hint extension is present, so we enable
+  GLX_MESA_copy_sub_buffer
+*/
+typedef void (__stdcall * PFNGLADDSWAPHINTRECTWIN) (GLint x, GLint y,
+                                                    GLsizei width,
+                                                    GLsizei height);
+
+void
+glAddSwapHintRectWINWrapper(GLint x, GLint y, GLsizei width,
+                            GLsizei height)
+{
+    RESOLVE(PFNGLADDSWAPHINTRECTWIN, "glAddSwapHintRectWIN");
+    RESOLVED_PROC(x, y, width, height);
+}
diff --git a/hw/xwin/glx/glwrap.c b/hw/xwin/glx/glthunk.c
index 73cff3cc1..d49fe487c 100644
--- a/hw/xwin/glx/glwrap.c
+++ b/hw/xwin/glx/glthunk.c
@@ -1,13 +1,8 @@
 /*
- * File: glwrap.c
- * Purpose: Wrapper functions for Win32 OpenGL functions
- *
- * Authors: Alexander Gottwald
- *          Jon TURNEY
- *
- * Copyright (c) Jon TURNEY 2009
- * Copyright (c) Alexander Gottwald 2004
+ * File: glthunk.c
+ * Purpose: cdecl thunk wrapper library for Win32 stdcall OpenGL library
  *
+ * Copyright (c) Jon TURNEY 2009,2013
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -37,34 +32,12 @@
 #endif
 
 #include <X11/Xwindows.h>
+
+#define GL_GLEXT_LEGACY
 #include <GL/gl.h>
+#undef GL_ARB_imaging
+#undef GL_VERSION_1_3
 #include <GL/glext.h>
-#include <glx/glxserver.h>
-#include <glx/glxext.h>
-#include <glx/glapi.h>
-#include <glx/dispatch.h>
-#include <glwindows.h>
-
-static unsigned int glWinIndirectProcCalls = 0;
-static unsigned int glWinDirectProcCalls = 0;
-
-void
-glWinCallDelta(void)
-{
-    static unsigned int glWinIndirectProcCallsLast = 0;
-    static unsigned int glWinDirectProcCallsLast = 0;
-
-    if ((glWinIndirectProcCalls != glWinIndirectProcCallsLast) ||
-        (glWinDirectProcCalls != glWinDirectProcCallsLast)) {
-        if (glxWinDebugSettings.enableTrace) {
-            ErrorF("after %d direct and %d indirect GL calls\n",
-                   glWinDirectProcCalls - glWinDirectProcCallsLast,
-                   glWinIndirectProcCalls - glWinIndirectProcCallsLast);
-        }
-        glWinDirectProcCallsLast = glWinDirectProcCalls;
-        glWinIndirectProcCallsLast = glWinIndirectProcCalls;
-    }
-}
 
 static PROC
 glWinResolveHelper(PROC * cache, const char *symbol)
@@ -75,11 +48,9 @@ glWinResolveHelper(PROC * cache, const char *symbol)
     if ((*cache) == NULL) {
         proc = wglGetProcAddress(symbol);
         if (proc == NULL) {
-            ErrorF("glwrap: Can't resolve \"%s\"\n", symbol);
             (*cache) = (PROC) - 1;
         }
         else {
-            ErrorF("glwrap: Resolved \"%s\"\n", symbol);
             (*cache) = proc;
         }
     }
@@ -99,10 +70,8 @@ glWinResolveHelper(PROC * cache, const char *symbol)
     static PROC cache = NULL; \
     __stdcall proctype proc = (proctype)glWinResolveHelper(&cache, symbol); \
     if (proc == NULL) { \
-        __glXErrorCallBack(0); \
         return retval; \
-    } \
-    glWinIndirectProcCalls++;
+    }
 
 #define RESOLVE(proctype, symbol) RESOLVE_RET(proctype, symbol,)
 
@@ -113,34 +82,6 @@ glWinResolveHelper(PROC * cache, const char *symbol)
 
   OpenGL 1.2 and upward is treated as extensions, function address must
   found using wglGetProcAddress(), but also stdcall so still need wrappers...
-
-  Include generated dispatch table setup function
 */
 
-#include "generated_gl_wrappers.c"
-
-/*
-  Special non-static wrapper for glGetString for debug output
-*/
-
-const GLubyte *
-glGetStringWrapperNonstatic(GLenum name)
-{
-    return glGetString(name);
-}
-
-/*
-  Special non-static wrapper for glAddSwapHintRectWIN for copySubBuffers
-*/
-
-typedef void (__stdcall * PFNGLADDSWAPHINTRECTWIN) (GLint x, GLint y,
-                                                    GLsizei width,
-                                                    GLsizei height);
-
-void
-glAddSwapHintRectWINWrapperNonstatic(GLint x, GLint y, GLsizei width,
-                                     GLsizei height)
-{
-    RESOLVE(PFNGLADDSWAPHINTRECTWIN, "glAddSwapHintRectWIN");
-    proc(x, y, width, height);
-}
+#include "generated_gl_thunks.c"
diff --git a/hw/xwin/glx/glwindows.h b/hw/xwin/glx/glwindows.h
index ec1d1f51b..4f859b498 100644
--- a/hw/xwin/glx/glwindows.h
+++ b/hw/xwin/glx/glwindows.h
@@ -42,12 +42,9 @@ typedef struct {
 
 extern glxWinDebugSettingsRec glxWinDebugSettings;
 
-void glWinCallDelta(void);
 void glxWinPushNativeProvider(void);
-const GLubyte *glGetStringWrapperNonstatic(GLenum name);
-void glAddSwapHintRectWINWrapperNonstatic(GLint x, GLint y, GLsizei width,
-                                          GLsizei height);
-void glWinSetupDispatchTable(void);
+void glAddSwapHintRectWINWrapper(GLint x, GLint y, GLsizei width, GLsizei height);
+int glWinSelectImplementation(int native);
 
 #if 1
 #define GLWIN_TRACE_MSG(msg, args...) if (glxWinDebugSettings.enableTrace) ErrorF(msg " [%s:%d]\n" , ##args , __FUNCTION__, __LINE__ )
diff --git a/hw/xwin/glx/indirect.c b/hw/xwin/glx/indirect.c
index 4f09652f0..3d01bed39 100644
--- a/hw/xwin/glx/indirect.c
+++ b/hw/xwin/glx/indirect.c
@@ -550,7 +550,9 @@ glxWinScreenProbe(ScreenPtr pScreen)
     if (NULL == screen)
         return NULL;
 
-    /* Dump out some useful information about the native renderer */
+    // Select the native GL implementation (WGL)
+    if (glWinSelectImplementation(1))
+        return NULL;
 
     // create window class
 #define WIN_GL_TEST_WINDOW_CLASS "XWinGLTest"
@@ -597,11 +599,12 @@ glxWinScreenProbe(ScreenPtr pScreen)
     // (but we need to have a current context for them to be resolvable)
     wglResolveExtensionProcs();
 
-    ErrorF("GL_VERSION:     %s\n", glGetStringWrapperNonstatic(GL_VERSION));
-    ErrorF("GL_VENDOR:      %s\n", glGetStringWrapperNonstatic(GL_VENDOR));
-    gl_renderer = (const char *) glGetStringWrapperNonstatic(GL_RENDERER);
+    /* Dump out some useful information about the native renderer */
+    ErrorF("GL_VERSION:     %s\n", glGetString(GL_VERSION));
+    ErrorF("GL_VENDOR:      %s\n", glGetString(GL_VENDOR));
+    gl_renderer = (const char *) glGetString(GL_RENDERER);
     ErrorF("GL_RENDERER:    %s\n", gl_renderer);
-    gl_extensions = (const char *) glGetStringWrapperNonstatic(GL_EXTENSIONS);
+    gl_extensions = (const char *) glGetString(GL_EXTENSIONS);
     wgl_extensions = wglGetExtensionsStringARBWrapper(hdc);
     if (!wgl_extensions)
         wgl_extensions = "";
@@ -615,7 +618,7 @@ glxWinScreenProbe(ScreenPtr pScreen)
         free(screen);
         LogMessage(X_ERROR,
                    "AIGLX: Won't use generic native renderer as it is not accelerated\n");
-        return NULL;
+        goto error;
     }
 
     // Can you see the problem here?  The extensions string is DC specific
@@ -726,7 +729,7 @@ glxWinScreenProbe(ScreenPtr pScreen)
             free(screen);
             LogMessage(X_ERROR,
                        "AIGLX: No fbConfigs could be made from native OpenGL pixel formats\n");
-            return NULL;
+            goto error;
         }
 
         /* These will be set by __glXScreenInit */
@@ -789,6 +792,13 @@ glxWinScreenProbe(ScreenPtr pScreen)
     pScreen->CopyWindow = glxWinCopyWindow;
 
     return &screen->base;
+
+ error:
+    // Something went wrong and we can't use the native GL implementation
+    // so make sure the mesa GL implementation is selected instead
+    glWinSelectImplementation(0);
+
+    return NULL;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -910,7 +920,7 @@ static void
 glxWinDrawableCopySubBuffer(__GLXdrawable * drawable,
                             int x, int y, int w, int h)
 {
-    glAddSwapHintRectWINWrapperNonstatic(x, y, w, h);
+    glAddSwapHintRectWINWrapper(x, y, w, h);
     glxWinDrawableSwapBuffers(NULL, drawable);
 }
 
@@ -1458,7 +1468,6 @@ glxWinContextMakeCurrent(__GLXcontext * base)
 
     GLWIN_TRACE_MSG("glxWinContextMakeCurrent context %p (native ctx %p)", gc,
                     gc->ctx);
-    glWinCallDelta();
 
     /* Keep a note of the last active context in the drawable */
     drawPriv = gc->base.drawPriv;
@@ -1528,7 +1537,6 @@ glxWinContextLoseCurrent(__GLXcontext * base)
 
     GLWIN_TRACE_MSG("glxWinContextLoseCurrent context %p (native ctx %p)", gc,
                     gc->ctx);
-    glWinCallDelta();
 
     /*
        An error seems to be reported if we try to make no context current
@@ -1623,8 +1631,6 @@ glxWinCreateContext(__GLXscreen * screen,
     context->ctx = NULL;
     context->shareContext = shareContext;
 
-    glWinSetupDispatchTable();
-
     GLWIN_DEBUG_MSG("GLXcontext %p created", context);
 
     return &(context->base);