wgl: Refactor drivers to a libgallium_wgl.dll

I'd like to support EGL on Windows, using the same architecture as Linux.
On Linux, libgallium_dri.so is a "megadriver," containing the Mesa Gallium
state tracker, plus the actual driver implementations.

Now, on Windows, libgallium_wgl.dll is a proper OpenGL ICD, and OpenGL32.dll
is just a stub DLL which implements the wgl* APIs in terms of that ICD.

This is the more "architecturally clean" way to share the state tracker
between EGL and WGL.

Reviewed By: Bill Kristiansen <billkris@microsoft.com>

Reviewed-by: Charmaine Lee >charmainel@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12677>

2 files changed, 5 insertions, 338 deletions

diff --git a/src/gallium/targets/libgl-gdi/libgl_gdi.c b/src/gallium/targets/libgl-gdi/libgl_gdi.c
deleted file mode 100644
index f7898eeebc9..00000000000
--- a/src/gallium/targets/libgl-gdi/libgl_gdi.c
+++ /dev/null
@@ -1,332 +0,0 @@
-/**************************************************************************
- *
- * Copyright 2009-2010 VMware, Inc.
- * All Rights Reserved.
- *
- * 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, sub license, 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
- * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
- *
- * The above copyright notice and this permission notice (including the
- * next paragraph) shall be included in all copies or substantial portions
- * of the Software.
- *
- *
- **************************************************************************/
-
-/**
- * @file
- * Softpipe/LLVMpipe support.
- *
- * @author Jose Fonseca <jfonseca@vmware.com>
- */
-
-
-#include <windows.h>
-
-#include "util/u_debug.h"
-#include "util/debug.h"
-#include "stw_winsys.h"
-#include "stw_device.h"
-#include "gdi/gdi_sw_winsys.h"
-#include "pipe/p_screen.h"
-#include "pipe/p_context.h"
-
-#ifdef GALLIUM_SOFTPIPE
-#include "softpipe/sp_texture.h"
-#include "softpipe/sp_screen.h"
-#include "softpipe/sp_public.h"
-#endif
-
-#ifdef GALLIUM_LLVMPIPE
-#include "llvmpipe/lp_texture.h"
-#include "llvmpipe/lp_screen.h"
-#include "llvmpipe/lp_public.h"
-#endif
-
-#ifdef GALLIUM_SWR
-#include "swr/swr_public.h"
-#endif
-#ifdef GALLIUM_D3D12
-#include "d3d12/wgl/d3d12_wgl_public.h"
-#endif
-
-#ifdef GALLIUM_ZINK
-#include "zink/zink_public.h"
-#endif
-
-#ifdef GALLIUM_LLVMPIPE
-static boolean use_llvmpipe = FALSE;
-#endif
-#ifdef GALLIUM_SWR
-static boolean use_swr = FALSE;
-#endif
-#ifdef GALLIUM_D3D12
-static boolean use_d3d12 = FALSE;
-#endif
-#ifdef GALLIUM_ZINK
-static boolean use_zink = FALSE;
-#endif
-
-static const char *created_driver_name = NULL;
-
-static struct pipe_screen *
-gdi_screen_create_by_name(HDC hDC, const char* driver, struct sw_winsys *winsys)
-{
-   struct pipe_screen* screen = NULL;
-
-#ifdef GALLIUM_LLVMPIPE
-   if (strcmp(driver, "llvmpipe") == 0) {
-      screen = llvmpipe_create_screen(winsys);
-      if (screen)
-         use_llvmpipe = TRUE;
-   }
-#endif
-#ifdef GALLIUM_SWR
-   if (strcmp(driver, "swr") == 0) {
-      screen = swr_create_screen(winsys);
-      if (screen)
-         use_swr = TRUE;
-   }
-#endif
-#ifdef GALLIUM_D3D12
-   if (strcmp(driver, "d3d12") == 0) {
-      screen = d3d12_wgl_create_screen(winsys, hDC);
-      if (screen)
-         use_d3d12 = TRUE;
-   }
-#endif
-#ifdef GALLIUM_ZINK
-   if (strcmp(driver, "zink") == 0) {
-      screen = zink_create_screen(winsys);
-      if (screen)
-         use_zink = TRUE;
-   }
-#endif
-#ifdef GALLIUM_SOFTPIPE
-   if (strcmp(driver, "softpipe") == 0) {
-      screen = softpipe_create_screen(winsys);
-   }
-#endif
-
-   return screen;
-}
-
-static struct pipe_screen *
-gdi_screen_create(HDC hDC)
-{
-   struct sw_winsys *winsys;
-   UNUSED bool sw_only = env_var_as_boolean("LIBGL_ALWAYS_SOFTWARE", false);
-
-   winsys = gdi_create_sw_winsys();
-   if (!winsys)
-      return NULL;
-
-   const char *const drivers[] = {
-      debug_get_option("GALLIUM_DRIVER", ""),
-#ifdef GALLIUM_D3D12
-      sw_only ? "" : "d3d12",
-#endif
-#if defined(GALLIUM_LLVMPIPE)
-      "llvmpipe",
-#endif
-#if GALLIUM_SWR
-      "swr",
-#endif
-#if defined(GALLIUM_SOFTPIPE)
-      "softpipe",
-#endif
-   };
-   
-   /* If the default driver screen creation fails, fall back to the next option in the
-    * sorted list. Don't do this if GALLIUM_DRIVER is specified.
-    */
-   for (unsigned i = 0; i < ARRAY_SIZE(drivers); ++i) {
-      struct pipe_screen* screen = gdi_screen_create_by_name(hDC, drivers[i], winsys);
-      if (screen) {
-         created_driver_name = drivers[i];
-         return screen;
-      }
-      if (i == 0 && drivers[i][0] != '\0')
-         break;
-   }
-
-   winsys->destroy(winsys);
-   return NULL;
-}
-
-
-static void
-gdi_present(struct pipe_screen *screen,
-            struct pipe_context *ctx,
-            struct pipe_resource *res,
-            HDC hDC)
-{
-   /* This will fail if any interposing layer (trace, debug, etc) has
-    * been introduced between the gallium frontends and the pipe driver.
-    *
-    * Ideally this would get replaced with a call to
-    * pipe_screen::flush_frontbuffer().
-    *
-    * Failing that, it may be necessary for intervening layers to wrap
-    * other structs such as this stw_winsys as well...
-    */
-
-   struct sw_winsys *winsys = NULL;
-   struct sw_displaytarget *dt = NULL;
-
-#ifdef GALLIUM_LLVMPIPE
-   if (use_llvmpipe) {
-      winsys = llvmpipe_screen(screen)->winsys;
-      dt = llvmpipe_resource(res)->dt;
-      gdi_sw_display(winsys, dt, hDC);
-      return;
-   }
-#endif
-
-#ifdef GALLIUM_SWR
-   if (use_swr) {
-      swr_gdi_swap(screen, ctx, res, hDC);
-      return;
-   }
-#endif
-
-#ifdef GALLIUM_D3D12
-   if (use_d3d12) {
-      d3d12_wgl_present(screen, ctx, res, hDC);
-      return;
-   }
-#endif
-
-#ifdef GALLIUM_ZINK
-   if (use_zink) {
-      screen->flush_frontbuffer(screen, ctx, res, 0, 0, hDC, NULL);
-      return;
-   }
-#endif
-
-#ifdef GALLIUM_SOFTPIPE
-   winsys = softpipe_screen(screen)->winsys,
-   dt = softpipe_resource(res)->dt,
-   gdi_sw_display(winsys, dt, hDC);
-#endif
-}
-
-
-#if WINVER >= 0xA00
-static boolean
-gdi_get_adapter_luid(struct pipe_screen* screen,
-   HDC hDC,
-   LUID* adapter_luid)
-{
-   if (!stw_dev || !stw_dev->callbacks.pfnGetAdapterLuid)
-      return false;
-
-   stw_dev->callbacks.pfnGetAdapterLuid(hDC, adapter_luid);
-   return true;
-}
-#endif
-
-
-static unsigned
-gdi_get_pfd_flags(struct pipe_screen *screen)
-{
-#ifdef GALLIUM_D3D12
-   if (use_d3d12)
-      return d3d12_wgl_get_pfd_flags(screen);
-#endif
-   return stw_pfd_gdi_support;
-}
-
-
-static struct stw_winsys_framebuffer *
-gdi_create_framebuffer(struct pipe_screen *screen,
-                       HDC hDC,
-                       int iPixelFormat)
-{
-#ifdef GALLIUM_D3D12
-   if (use_d3d12)
-      return d3d12_wgl_create_framebuffer(screen, hDC, iPixelFormat);
-#endif
-   return NULL;
-}
-
-static const char *
-gdi_get_name(void)
-{
-   return created_driver_name;
-}
-
-
-static const struct stw_winsys stw_winsys = {
-   &gdi_screen_create,
-   &gdi_present,
-#if WINVER >= 0xA00
-   &gdi_get_adapter_luid,
-#else
-   NULL, /* get_adapter_luid */
-#endif
-   NULL, /* shared_surface_open */
-   NULL, /* shared_surface_close */
-   NULL, /* compose */
-   &gdi_get_pfd_flags,
-   &gdi_create_framebuffer,
-   &gdi_get_name,
-};
-
-
-EXTERN_C BOOL WINAPI
-DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved);
-
-
-BOOL WINAPI
-DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
-{
-   switch (fdwReason) {
-   case DLL_PROCESS_ATTACH:
-      stw_init(&stw_winsys);
-      stw_init_thread();
-      break;
-
-   case DLL_THREAD_ATTACH:
-      stw_init_thread();
-      break;
-
-   case DLL_THREAD_DETACH:
-      stw_cleanup_thread();
-      break;
-
-   case DLL_PROCESS_DETACH:
-      if (lpvReserved == NULL) {
-         // We're being unloaded from the process.
-         stw_cleanup_thread();
-         stw_cleanup();
-      } else {
-         // Process itself is terminating, and all threads and modules are
-         // being detached.
-         //
-         // The order threads (including llvmpipe rasterizer threads) are
-         // destroyed can not be relied up, so it's not safe to cleanup.
-         //
-         // However global destructors (e.g., LLVM's) will still be called, and
-         // if Microsoft OPENGL32.DLL's DllMain is called after us, it will
-         // still try to invoke DrvDeleteContext to destroys all outstanding,
-         // so set stw_dev to NULL to return immediately if that happens.
-         stw_dev = NULL;
-      }
-      break;
-   }
-   return TRUE;
-}
diff --git a/src/gallium/targets/libgl-gdi/meson.build b/src/gallium/targets/libgl-gdi/meson.build
index 588749aa639..d0a21d0742e 100644
--- a/src/gallium/targets/libgl-gdi/meson.build
+++ b/src/gallium/targets/libgl-gdi/meson.build
@@ -28,18 +28,16 @@ ogldef = files('opengl32.def')[0]
 
 libopengl32 = shared_library(
   'opengl32',
-  ['libgl_gdi.c', 'stw_wgl.c'],
+  ['stw_wgl.c'],
   vs_module_defs : ogldef,
   include_directories : [
-    inc_include, inc_src, inc_mapi, inc_mesa, inc_gallium, inc_gallium_aux, inc_wgl, inc_gallium_winsys, inc_gallium_winsys_sw, inc_gallium_drivers,
+    inc_include, inc_wgl, inc_src,
   ],
-  link_whole : [libwgl],
   link_with : [
-    libgallium, libglsl, libmesa_gallium, libwsgdi, libglapi_static, libglapi
+    libgallium_wgl, libglapi_static, libglapi
   ],
   dependencies : [
-    dep_ws2_32, idep_nir, idep_mesautil, driver_swrast, driver_swr,
-    driver_d3d12, driver_zink, winsys_d3d12_wgl
+    idep_mesautil
   ],
   c_args : ['-D_GDI32_'],
   link_args : opengl32_link_args,
@@ -69,6 +67,7 @@ if with_tests
   # The CI pipeline for MinGW doesn't support creating a window, so don't run these tests there
   if with_tests and cc.get_id() != 'gcc'
     wgl_test_env = environment()
+    wgl_test_env.append('PATH', libgallium_wgl_build_dir)
     if with_shared_glapi
       wgl_test_env.append('PATH', libglapi_build_dir)
     endif