Add dispatch generation for wgl.

This is very poorly tested at this point, but survives a simple testcase.

.gitignore

@@ -93,3 +93,7 @@ glx_generated_vtable_defines.h
 egl_generated_dispatch.c
 egl_generated.h
 egl_generated_vtable_defines.h
+
+wgl_generated_dispatch.c
+wgl_generated.h
+wgl_generated_vtable_defines.h

configure.ac

@@ -52,6 +52,7 @@ case $host_os in
     mingw*)
         build_egl=no
         build_glx=no
+        build_wgl=yes
         # On windows, the DLL has to have all of its functions
         # resolved at link time, so we have to link directly aginst
         # opengl32.dll.  But that's the only GL provider, anyway.
@@ -66,6 +67,7 @@ case $host_os in
     *)
         build_egl=yes
         build_glx=yes
+        build_wgl=no
         # On platforms with dlopen, we load everything dynamically and
         # don't link against a specific window system or GL implementation.
         EPOXY_LINK_LIBS=""
@@ -84,6 +86,11 @@ if test x$build_glx = xyes; then
     AC_DEFINE([BUILD_GLX], [1], [build GLX tests])
 fi
 
+AM_CONDITIONAL(BUILD_WGL, test x$build_wgl = xyes)
+if test x$build_wgl = xyes; then
+    AC_DEFINE([BUILD_WGL], [1], [build WGL tests])
+fi
+
 
 case $host_os in
     mingw*)
@@ -123,4 +130,5 @@ AC_OUTPUT
 
 echo "           EGL:         $build_egl"
 echo "           GLX:         $build_glx"
+echo "           WGL:         $build_wgl"
 echo "        PYTHON:         $PYTHON"

include/epoxy/wgl.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * 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 (including the next
+ * paragraph) 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 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 SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+/** @file wgl.h
+ *
+ * Provides an implementation of a WGL dispatch layer using a hidden
+ * vtable.
+ */
+
+#ifndef __EPOXY_WGL_H
+#define __EPOXY_WGL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdbool.h>
+#include <windows.h>
+
+#undef wglUseFontBitmaps
+#undef wglUseFontOutlines
+
+#if defined(__wglxext_h_)
+#error epoxy/wgl.h must be included before (or in place of) wgl.h
+#else
+#define __wglxext_h_
+#endif
+
+#pragma once
+
+#include "epoxy/wgl_generated.h"
+#include "epoxy/wgl_generated_vtable_defines.h"
+
+bool epoxy_has_wgl_extension(HDC hdc, const char *extension);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* __EPOXY_WGL_H */

src/Makefile.am

@@ -42,6 +42,10 @@ if BUILD_GLX
 INSTALL_GLX_INCLUDES = $(GENERATED_GLX_INCLUDES)
 endif
 
+if BUILD_WGL
+INSTALL_WGL_INCLUDES = $(GENERATED_WGL_INCLUDES)
+endif
+
 GENERATED_GL_INCLUDES = \
 	$(builddir)/../include/epoxy/gl_generated.h \
 	$(builddir)/../include/epoxy/gl_generated_vtable_defines.h \
@@ -57,6 +61,11 @@ GENERATED_EGL_INCLUDES = \
 	$(builddir)/../include/epoxy/egl_generated_vtable_defines.h \
 	$()
 
+GENERATED_WGL_INCLUDES = \
+	$(tuilddir)/../include/epoxy/wgl_generated.h \
+	$(builddir)/../include/epoxy/wgl_generated_vtable_defines.h \
+	$()
+
 GENERATED_GL_SOURCE = gl_generated_dispatch.c
 
 GENERATED_GL = \
@@ -78,10 +87,18 @@ GENERATED_EGL = \
 	$(GENERATED_EGL_INCLUDES) \
 	$()
 
+GENERATED_WGL_SOURCE = wgl_generated_dispatch.c
+
+GENERATED_WGL = \
+	$(GENERATED_WGL_SOURCE) \
+	$(GENERATED_WGL_INCLUDES) \
+	$()
+
 BUILT_SOURCES = \
 	$(GENERATED_GL) \
 	$(GENERATED_GLX) \
 	$(GENERATED_EGL) \
+	$(GENERATED_WGL) \
 	$()
 CLEANFILES = $(BUILT_SOURCES)
 
@@ -91,6 +108,7 @@ libepoxy_la_SOURCES = \
 	$(GENERATED_GL) \
 	$(BUILD_EGL_CODE) \
 	$(BUILD_GLX_CODE) \
+	$(BUILD_WGL_CODE) \
 	$()
 
 libepoxy_la_LDFLAGS = \
@@ -112,10 +130,18 @@ BUILD_GLX_CODE = \
 	$()
 endif
 
+if BUILD_WGL
+BUILD_WGL_CODE = \
+	$(GENERATED_WGL) \
+	dispatch_wgl.c \
+	$()
+endif
+
 # These are generated alongside the .c file.
 $(GENERATED_GL_INCLUDES): $(GENERATED_GL_SOURCE)
 $(GENERATED_GLX_INCLUDES): $(GENERATED_GLX_SOURCE)
 $(GENERATED_EGL_INCLUDES): $(GENERATED_EGL_SOURCE)
+$(GENERATED_WGL_INCLUDES): $(GENERATED_WGL_SOURCE)
 
 $(GENERATED_GL_SOURCE): $(srcdir)/gen_dispatch.py $(top_srcdir)/registry/gl.xml
 	$(MKDIR_P) $(top_builddir)/include/epoxy
@@ -126,3 +152,6 @@ $(GENERATED_GLX_SOURCE): $(srcdir)/gen_dispatch.py $(top_srcdir)/registry/glx.xm
 
 $(GENERATED_EGL_SOURCE): $(srcdir)/gen_dispatch.py $(top_srcdir)/registry/egl.xml
 	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py --dir $(top_builddir) $(top_srcdir)/registry/egl.xml
+
+$(GENERATED_WGL_SOURCE): $(srcdir)/gen_dispatch.py $(top_srcdir)/registry/wgl.xml
+	$(AM_V_GEN)$(PYTHON) $(srcdir)/gen_dispatch.py --dir $(top_builddir) $(top_srcdir)/registry/wgl.xml

src/dispatch_common.c

@@ -322,8 +322,12 @@ epoxy_glx_dlsym(const char *name)
 void *
 epoxy_gl_dlsym(const char *name)
 {
+#ifdef _WIN32
+    return GetProcAddress(LoadLibraryA("OPENGL32"), name);
+#else
     /* There's no library for desktop GL support independent of GLX. */
     return epoxy_glx_dlsym(name);
+#endif
 }
 
 void *
@@ -341,7 +345,13 @@ epoxy_gles2_dlsym(const char *name)
 void *
 epoxy_get_core_proc_address(const char *name, int core_version)
 {
-    if (core_version <= 12) {
+#ifdef _WIN32
+    int core_symbol_support = 10;
+#else
+    int core_symbol_support = 12;
+#endif
+
+    if (core_version <= core_symbol_support) {
         return epoxy_gl_dlsym(name);
     } else {
         return epoxy_get_proc_address(name);

src/dispatch_common.h

@@ -26,9 +26,11 @@
 #ifdef _WIN32
 #define PLATFORM_HAS_EGL 0
 #define PLATFORM_HAS_GLX 0
+#define PLATFORM_HAS_WGL 1
 #else
 #define PLATFORM_HAS_EGL 1
 #define PLATFORM_HAS_GLX 1
+#define PLATFORM_HAS_WGL 0
 #endif
 
 #include "epoxy/gl.h"
@@ -38,6 +40,9 @@
 #if PLATFORM_HAS_EGL
 #include "epoxy/egl.h"
 #endif
+#if PLATFORM_HAS_WGL
+#include "epoxy/wgl.h"
+#endif
 
 #ifndef PUBLIC
 #  ifdef _WIN32
@@ -63,6 +68,7 @@ int epoxy_conservative_glx_version(void);
 bool epoxy_conservative_has_glx_extension(const char *name);
 int epoxy_conservative_egl_version(void);
 bool epoxy_conservative_has_egl_extension(const char *name);
+bool epoxy_conservative_has_wgl_extension(const char *name);
 void epoxy_print_failure_reasons(const char *name,
                                  const char **provider_names,
                                  const int *providers);

src/dispatch_wgl.c

@@ -0,0 +1,60 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * 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 (including the next
+ * paragraph) 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 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 SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "dispatch_common.h"
+
+/**
+ * If we can determine the WGL extension support from the current
+ * context, then return that, otherwise give the answer that will just
+ * send us on to get_proc_address().
+ */
+bool
+epoxy_conservative_has_wgl_extension(const char *ext)
+{
+    HDC hdc = wglGetCurrentDC();
+
+    if (!hdc)
+        return true;
+
+    return epoxy_has_wgl_extension(hdc, ext);
+}
+
+PUBLIC bool
+epoxy_has_wgl_extension(HDC hdc, const char *ext)
+ {
+     PFNWGLGETEXTENSIONSSTRINGARBPROC getext;
+
+     getext = (void *)wglGetProcAddress("wglGetExtensionsStringARB");
+     if (!getext) {
+         fprintf(stderr,
+                 "Implementation unexpectedly missing "
+                 "WGL_ARB_extensions_string.  Probably a libepoxy bug.\n");
+         return false;
+     }
+
+    return epoxy_extension_in_string(getext(hdc), ext);
+}

src/gen_dispatch.py

@@ -85,6 +85,13 @@ class GLFunction(object):
         self.alias_exts = []
 
     def add_arg(self, type, name):
+        # Reword glDepthRange() arguments to avoid clashing with the
+        # "near" and "far" keywords on win32.
+        if name == "near":
+            name = "hither"
+        elif name == "far":
+            name = "yon"
+
         self.args.append((type, name))
         if self.args_decl == 'void':
             self.args_list = name
@@ -192,6 +199,14 @@ class Generator(object):
     def parse_enums(self, reg):
         for enum in reg.findall('enums/enum'):
             name = enum.get('name')
+
+            # wgl.xml's 0xwhatever definitions end up colliding with
+            # wingdi.h's decimal definitions of these.
+            if ('WGL_SWAP_OVERLAY' in name or
+                'WGL_SWAP_UNDERLAY' in name or
+                'WGL_SWAP_MAIN_PLANE' in name):
+                continue
+
             self.max_enum_name_len = max(self.max_enum_name_len, len(name))
             self.enums[name] = enum.get('value')
 
@@ -270,6 +285,11 @@ class Generator(object):
             func = self.functions[name]
             func.add_provider(condition, loader, human_name)
 
+    def delete_require_statements(self, feature):
+        for command in feature.findall('require/command'):
+            name = command.get('name')
+            del self.functions[name]
+
     def parse_function_providers(self, reg):
         for feature in reg.findall('feature'):
             api = feature.get('api') # string gl, gles1, gles2, glx
@@ -316,6 +336,15 @@ class Generator(object):
                 else:
                     condition = 'true'
                     loader = 'epoxy_egl_dlsym({0})'
+            elif api == 'wgl':
+                # There's no reason for us to interpose the
+                # non-extension WGL symbols, which we know are always
+                # available.  The registry lists WGL 1.0 symbols both
+                # from opengl32.dll and gdi32.dll, so our dlsym()
+                # would have to know which came from where, if we were
+                # to interpose.
+                self.delete_require_statements(feature)
+                continue
             else:
                 sys.exit('unknown API: "{0}"'.format(api))
 
@@ -339,6 +368,11 @@ class Generator(object):
                 condition = 'epoxy_conservative_has_egl_extension("{0}")'.format(extname)
                 loader = 'eglGetProcAddress({0})'
                 self.process_require_statements(extension, condition, loader, human_name)
+            if 'wgl' in apis:
+                human_name = 'WGL extension \\"{0}\\"'.format(extname)
+                condition = 'epoxy_conservative_has_wgl_extension("{0}")'.format(extname)
+                loader = 'wglGetProcAddress({0})'
+                self.process_require_statements(extension, condition, loader, human_name)
             if {'gl', 'gles1', 'gles2'}.intersection(apis):
                 human_name = 'GL extension \\"{0}\\"'.format(extname)
                 condition = 'epoxy_conservative_has_gl_extension("{0}")'.format(extname)