direct-to-native-GL for GLX clients on Cygwin ("Windows-DRI")

Structurally, this is very similar to the existing Apple-DRI code, except I
have chosen to implement this using the __GLXDRIdisplay, etc. vtables (as
suggested originally in [1]), rather than a maze of ifdefs.  This also means
that LIBGL_ALWAYS_SOFTWARE and LIBGL_ALWAYS_INDIRECT work as expected.

[1] https://lists.freedesktop.org/archives/mesa-dev/2010-May/000756.html

This adds:

* the Windows-DRI extension protocol headers and the windowsdriproto.pc
file, for use in building the Windows-DRI extension for the X server

* a Windows-DRI extension helper client library

* a Windows-specific DRI implementation for GLX clients

The server is queried for Windows-DRI extension support on the screen before
using it (to detect the case where WGL is disabled or can't be activated).

The server is queried for fbconfigID to pixelformatindex mapping, which is
used to augment glx_config.

The server is queried for a native handle for the drawable (which is of a
different type for windows, pixmaps and pbuffers), which is used to augment
__GLXDRIdrawable.

Various GLX extensions are enabled depending on if the equivalent WGL
extension is available.

1 files changed, 237 insertions, 0 deletions

diff --git a/src/glx/windows/xwindowsdri.c b/src/glx/windows/xwindowsdri.c
new file mode 100644
index 00000000000..90884fa6a17
--- /dev/null
+++ b/src/glx/windows/xwindowsdri.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright © 2014 Jon Turney
+ *
+ * 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.
+ */
+
+/* THIS IS NOT AN X CONSORTIUM STANDARD */
+
+#include <X11/Xlibint.h>
+#include <X11/extensions/Xext.h>
+#include <X11/extensions/extutil.h>
+#include "windowsdristr.h"
+#include "xwindowsdri.h"
+#include <stdio.h>
+
+static XExtensionInfo _windowsdri_info_data;
+static XExtensionInfo *windowsdri_info = &_windowsdri_info_data;
+static char *windowsdri_extension_name = WINDOWSDRINAME;
+
+#define WindowsDRICheckExtension(dpy,i,val) \
+  XextCheckExtension (dpy, i, windowsdri_extension_name, val)
+
+/*****************************************************************************
+ *                                                                           *
+ *                         private utility routines                          *
+ *                                                                           *
+ *****************************************************************************/
+
+static int close_display(Display * dpy, XExtCodes * extCodes);
+
+static /* const */ XExtensionHooks windowsdri_extension_hooks = {
+   NULL,                        /* create_gc */
+   NULL,                        /* copy_gc */
+   NULL,                        /* flush_gc */
+   NULL,                        /* free_gc */
+   NULL,                        /* create_font */
+   NULL,                        /* free_font */
+   close_display,               /* close_display */
+   NULL,                        /* wire_to_event */
+   NULL,                        /* event_to_wire */
+   NULL,                        /* error */
+   NULL,                        /* error_string */
+};
+
+static
+XEXT_GENERATE_FIND_DISPLAY(find_display, windowsdri_info,
+                           windowsdri_extension_name,
+                           &windowsdri_extension_hooks,
+                           WindowsDRINumberEvents, NULL)
+
+static
+XEXT_GENERATE_CLOSE_DISPLAY(close_display, windowsdri_info)
+
+/*****************************************************************************
+ *                                                                           *
+ *                 public Windows-DRI Extension routines                     *
+ *                                                                           *
+ *****************************************************************************/
+
+#if 0
+#include <stdio.h>
+#define TRACE(msg, ...)  fprintf(stderr, "WindowsDRI" msg "\n", ##__VA_ARGS__);
+#else
+#define TRACE(msg, ...)
+#endif
+
+Bool
+XWindowsDRIQueryExtension(dpy, event_basep, error_basep)
+     Display *dpy;
+     int *event_basep, *error_basep;
+{
+   XExtDisplayInfo *info = find_display(dpy);
+
+   TRACE("QueryExtension:");
+   if (XextHasExtension(info)) {
+      *event_basep = info->codes->first_event;
+      *error_basep = info->codes->first_error;
+      TRACE("QueryExtension: return True");
+      return True;
+   }
+   else {
+      TRACE("QueryExtension: return False");
+      return False;
+   }
+}
+
+Bool
+XWindowsDRIQueryVersion(dpy, majorVersion, minorVersion, patchVersion)
+     Display *dpy;
+     int *majorVersion;
+     int *minorVersion;
+     int *patchVersion;
+{
+   XExtDisplayInfo *info = find_display(dpy);
+   xWindowsDRIQueryVersionReply rep;
+   xWindowsDRIQueryVersionReq *req;
+
+   TRACE("QueryVersion:");
+   WindowsDRICheckExtension(dpy, info, False);
+
+   LockDisplay(dpy);
+   GetReq(WindowsDRIQueryVersion, req);
+   req->reqType = info->codes->major_opcode;
+   req->driReqType = X_WindowsDRIQueryVersion;
+   if (!_XReply(dpy, (xReply *) & rep, 0, xFalse)) {
+      UnlockDisplay(dpy);
+      SyncHandle();
+      TRACE("QueryVersion: return False");
+      return False;
+   }
+   *majorVersion = rep.majorVersion;
+   *minorVersion = rep.minorVersion;
+   *patchVersion = rep.patchVersion;
+   UnlockDisplay(dpy);
+   SyncHandle();
+   TRACE("QueryVersion: %d.%d.%d", *majorVersion, *minorVersion, *patchVersion);
+   return True;
+}
+
+Bool
+XWindowsDRIQueryDirectRenderingCapable(dpy, screen, isCapable)
+     Display *dpy;
+     int screen;
+     Bool *isCapable;
+{
+   XExtDisplayInfo *info = find_display(dpy);
+   xWindowsDRIQueryDirectRenderingCapableReply rep;
+   xWindowsDRIQueryDirectRenderingCapableReq *req;
+
+   TRACE("QueryDirectRenderingCapable:");
+   WindowsDRICheckExtension(dpy, info, False);
+
+   LockDisplay(dpy);
+   GetReq(WindowsDRIQueryDirectRenderingCapable, req);
+   req->reqType = info->codes->major_opcode;
+   req->driReqType = X_WindowsDRIQueryDirectRenderingCapable;
+   req->screen = screen;
+   if (!_XReply(dpy, (xReply *) & rep, 0, xFalse)) {
+      UnlockDisplay(dpy);
+      SyncHandle();
+      TRACE("QueryDirectRenderingCapable: return False");
+      return False;
+   }
+   *isCapable = rep.isCapable;
+   UnlockDisplay(dpy);
+   SyncHandle();
+   TRACE("QueryDirectRenderingCapable:return True");
+   return True;
+}
+
+Bool
+XWindowsDRIQueryDrawable(Display *dpy, int screen, Drawable drawable,
+                        unsigned int * type, void ** handle)
+{
+   XExtDisplayInfo *info = find_display(dpy);
+   xWindowsDRIQueryDrawableReply rep;
+   xWindowsDRIQueryDrawableReq *req;
+
+   TRACE("QueryDrawable: XID %lx", drawable);
+   WindowsDRICheckExtension(dpy, info, False);
+
+   LockDisplay(dpy);
+   GetReq(WindowsDRIQueryDrawable, req);
+   req->reqType = info->codes->major_opcode;
+   req->driReqType = X_WindowsDRIQueryDrawable;
+   req->screen = screen;
+   req->drawable = drawable;
+
+   if (!_XReply(dpy, (xReply *) & rep, 0, xFalse)) {
+      UnlockDisplay(dpy);
+      SyncHandle();
+      TRACE("QueryDrawable: return False");
+      return False;
+   }
+
+   *type = rep.drawable_type;
+
+   // Note that despite being a derived type of void *, HANDLEs are defined to
+   // be a sign-extended 32 bit value (so they can be passed to 32-bit
+   // processes safely)
+   *handle = (void *)(intptr_t)rep.handle;
+
+   UnlockDisplay(dpy);
+   SyncHandle();
+   TRACE("QueryDrawable: type %d, handle %p", *type, *handle);
+   return True;
+}
+
+Bool
+XWindowsDRIFBConfigToPixelFormat(Display *dpy, int screen, int fbConfigID,
+                                int *pxfi)
+{
+   XExtDisplayInfo *info = find_display(dpy);
+   xWindowsDRIFBConfigToPixelFormatReply rep;
+   xWindowsDRIFBConfigToPixelFormatReq *req;
+
+   TRACE("FBConfigToPixelFormat: fbConfigID 0x%x", fbConfigID);
+   WindowsDRICheckExtension(dpy, info, False);
+
+   LockDisplay(dpy);
+   GetReq(WindowsDRIFBConfigToPixelFormat, req);
+   req->reqType = info->codes->major_opcode;
+   req->driReqType = X_WindowsDRIFBConfigToPixelFormat;
+   req->screen = screen;
+   req->fbConfigID = fbConfigID;
+
+   if (!_XReply(dpy, (xReply *) & rep, 0, xFalse)) {
+      UnlockDisplay(dpy);
+      SyncHandle();
+      TRACE("FBConfigToPixelFormat: return False");
+      return False;
+   }
+
+   *pxfi = rep.pixelFormatIndex;
+
+   UnlockDisplay(dpy);
+   SyncHandle();
+   TRACE("FBConfigToPixelFormat: pixelformatindex %d", *pxfi);
+   return True;
+}