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>

.gitlab-ci/windows/piglit_run.ps1

@@ -1,6 +1,7 @@
 $env:PIGLIT_NO_FAST_SKIP = 1
 
 Copy-Item -Path _install\bin\opengl32.dll -Destination C:\Piglit\lib\piglit\bin\opengl32.dll
+Copy-Item -Path _install\bin\libgallium_wgl.dll -Destination C:\Piglit\lib\piglit\bin\libgallium_wgl.dll
 
 # Run this using VsDevCmd.bat to ensure DXIL.dll is in %PATH%
 cmd.exe /C "C:\BuildTools\Common7\Tools\VsDevCmd.bat -host_arch=amd64 -arch=amd64 && py -3 C:\Piglit\bin\piglit.py run `"$env:PIGLIT_PROFILE`" $env:PIGLIT_OPTIONS $env:PIGLIT_TESTS .\results"

src/gallium/meson.build

@@ -240,6 +240,7 @@ if with_platform_windows
   else
     winsys_d3d12_wgl = declare_dependency()
   endif
+  subdir('targets/wgl')
   subdir('targets/libgl-gdi')
 endif
 if with_tests

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

src/gallium/targets/wgl/gallium_wgl.def

@@ -0,0 +1,26 @@
+EXPORTS
+	DrvCopyContext
+	DrvCreateContext
+	DrvCreateLayerContext
+	DrvDeleteContext
+	DrvDescribeLayerPlane
+	DrvDescribePixelFormat
+	DrvGetLayerPaletteEntries
+	DrvGetProcAddress
+	DrvPresentBuffers
+	DrvRealizeLayerPalette
+	DrvReleaseContext
+	DrvSetCallbackProcs
+	DrvSetContext
+	DrvSetLayerPaletteEntries
+	DrvSetPixelFormat
+	DrvShareLists
+	DrvSwapBuffers
+	DrvSwapLayerBuffers
+	DrvValidateVersion
+
+	stw_get_current_context
+	stw_get_current_dc
+	stw_pixelformat_choose
+	stw_pixelformat_get
+	stw_override_opengl32_entry_points

src/gallium/targets/wgl/meson.build

@@ -0,0 +1,48 @@
+# Copyright © Microsoft 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 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.
+
+
+gallium_wgl_link_args = []
+if cc.get_id() == 'gcc' and host_machine.cpu_family() != 'x86_64'
+  gallium_wgl_link_args += ['-Wl,--enable-stdcall-fixup']
+endif
+
+wgldef = files('gallium_wgl.def')[0]
+
+libgallium_wgl = shared_library(
+  'gallium_wgl',
+  ['wgl.c'],
+  vs_module_defs : wgldef,
+  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,
+  ],
+  link_whole : [libwgl],
+  link_with : [
+    libgallium, libglsl, libmesa_gallium, libwsgdi, libglapi_static, libglapi
+  ],
+  dependencies : [
+    dep_ws2_32, idep_nir, idep_mesautil, driver_swrast, driver_swr,
+    driver_d3d12, driver_zink, winsys_d3d12_wgl
+  ],
+  link_args : gallium_wgl_link_args,
+  name_prefix : 'lib',
+  install : true,
+)
+libgallium_wgl_build_dir = meson.current_build_dir()

src/gallium/targets/wgl/wgl.c

@@ -83,7 +83,7 @@ static boolean use_zink = FALSE;
 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)
+wgl_screen_create_by_name(HDC hDC, const char* driver, struct sw_winsys *winsys)
 {
    struct pipe_screen* screen = NULL;
 
@@ -125,7 +125,7 @@ gdi_screen_create_by_name(HDC hDC, const char* driver, struct sw_winsys *winsys)
 }
 
 static struct pipe_screen *
-gdi_screen_create(HDC hDC)
+wgl_screen_create(HDC hDC)
 {
    struct sw_winsys *winsys;
    UNUSED bool sw_only = env_var_as_boolean("LIBGL_ALWAYS_SOFTWARE", false);
@@ -154,7 +154,7 @@ gdi_screen_create(HDC hDC)
     * 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);
+      struct pipe_screen* screen = wgl_screen_create_by_name(hDC, drivers[i], winsys);
       if (screen) {
          created_driver_name = drivers[i];
          return screen;
@@ -169,7 +169,7 @@ gdi_screen_create(HDC hDC)
 
 
 static void
-gdi_present(struct pipe_screen *screen,
+wgl_present(struct pipe_screen *screen,
             struct pipe_context *ctx,
             struct pipe_resource *res,
             HDC hDC)
@@ -227,7 +227,7 @@ gdi_present(struct pipe_screen *screen,
 
 #if WINVER >= 0xA00
 static boolean
-gdi_get_adapter_luid(struct pipe_screen* screen,
+wgl_get_adapter_luid(struct pipe_screen* screen,
    HDC hDC,
    LUID* adapter_luid)
 {
@@ -241,7 +241,7 @@ gdi_get_adapter_luid(struct pipe_screen* screen,
 
 
 static unsigned
-gdi_get_pfd_flags(struct pipe_screen *screen)
+wgl_get_pfd_flags(struct pipe_screen *screen)
 {
 #ifdef GALLIUM_D3D12
    if (use_d3d12)
@@ -252,7 +252,7 @@ gdi_get_pfd_flags(struct pipe_screen *screen)
 
 
 static struct stw_winsys_framebuffer *
-gdi_create_framebuffer(struct pipe_screen *screen,
+wgl_create_framebuffer(struct pipe_screen *screen,
                        HDC hDC,
                        int iPixelFormat)
 {
@@ -264,26 +264,26 @@ gdi_create_framebuffer(struct pipe_screen *screen,
 }
 
 static const char *
-gdi_get_name(void)
+wgl_get_name(void)
 {
    return created_driver_name;
 }
 
 
 static const struct stw_winsys stw_winsys = {
-   &gdi_screen_create,
-   &gdi_present,
+   &wgl_screen_create,
+   &wgl_present,
 #if WINVER >= 0xA00
-   &gdi_get_adapter_luid,
+   &wgl_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,
+   &wgl_get_pfd_flags,
+   &wgl_create_framebuffer,
+   &wgl_get_name,
 };