replace GLEW with libepoxytemp-libepoxy

As discussed in https://developer.blender.org/D12034#412258, GLEW should be replaced by libepoxy to enable dynamic loading of OpenGL.

Build:
```sh
make lite debug ninja BUILD_CMAKE_ARGS="-DWITH_GHOST_X11=OFF -DWITH_GHOST_WAYLAND=ON -DWITH_GHOST_WAYLAND_LIBDECOR=ON -DPYTHON_VERSION=3.10" BUILD_DIR="../blender_build"
```

Verify that there are no X11 dependencies any more:
```sh
lddtree ./blender_build/bin/blender
```
and:
```sh
./blender_build/bin/blender
```

should then start a pure Wayland client.

This also works with GLX (`-DWITH_GHOST_X11=ON -DWITH_GHOST_WAYLAND=OFF`).

This has not been tested on other systems (Windows, macOS) as I do not have access to those systems and the build bot does not allow me to trigger experimental builds any more (I get "you need to have role 'any-control'").

Reviewed By: campbellbarton, brecht, jbakker

Differential Revision: https://developer.blender.org/D15291

12 files changed, 16 insertions, 29 deletions

diff --git a/intern/cycles/app/CMakeLists.txt b/intern/cycles/app/CMakeLists.txt
index 6aea962eab5..d46ece55256 100644
--- a/intern/cycles/app/CMakeLists.txt
+++ b/intern/cycles/app/CMakeLists.txt
@@ -44,8 +44,8 @@ endif()
 
 if(WITH_CYCLES_STANDALONE AND WITH_CYCLES_STANDALONE_GUI)
   add_definitions(${GL_DEFINITIONS})
-  list(APPEND INC_SYS ${GLEW_INCLUDE_DIR} ${SDL2_INCLUDE_DIRS})
-  list(APPEND LIB ${CYCLES_GL_LIBRARIES} ${CYCLES_GLEW_LIBRARIES} ${SDL2_LIBRARIES})
+  list(APPEND INC_SYS ${Epoxy_INCLUDE_DIRS} ${SDL2_INCLUDE_DIRS})
+  list(APPEND LIB ${CYCLES_GL_LIBRARIES} ${Epoxy_LIBRARIES} ${SDL2_LIBRARIES})
 endif()
 
 cycles_external_libraries_append(LIB)
diff --git a/intern/cycles/app/opengl/display_driver.cpp b/intern/cycles/app/opengl/display_driver.cpp
index 8b99f3b6feb..d9c72c07ae4 100644
--- a/intern/cycles/app/opengl/display_driver.cpp
+++ b/intern/cycles/app/opengl/display_driver.cpp
@@ -7,8 +7,8 @@
 #include "util/log.h"
 #include "util/string.h"
 
-#include <GL/glew.h>
 #include <SDL.h>
+#include <epoxy/gl.h>
 
 CCL_NAMESPACE_BEGIN
 
diff --git a/intern/cycles/app/opengl/shader.cpp b/intern/cycles/app/opengl/shader.cpp
index 9db9ea7fce9..4d22fc2b763 100644
--- a/intern/cycles/app/opengl/shader.cpp
+++ b/intern/cycles/app/opengl/shader.cpp
@@ -6,7 +6,7 @@
 #include "util/log.h"
 #include "util/string.h"
 
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 
 CCL_NAMESPACE_BEGIN
 
diff --git a/intern/cycles/app/opengl/window.cpp b/intern/cycles/app/opengl/window.cpp
index 7351ae3eecd..f3352decd08 100644
--- a/intern/cycles/app/opengl/window.cpp
+++ b/intern/cycles/app/opengl/window.cpp
@@ -11,8 +11,8 @@
 #include "util/time.h"
 #include "util/version.h"
 
-#include <GL/glew.h>
 #include <SDL.h>
+#include <epoxy/gl.h>
 
 CCL_NAMESPACE_BEGIN
 
@@ -294,7 +294,6 @@ void window_main_loop(const char *title,
   SDL_RaiseWindow(V.window);
 
   V.gl_context = SDL_GL_CreateContext(V.window);
-  glewInit();
   SDL_GL_MakeCurrent(V.window, nullptr);
 
   window_reshape(width, height);
diff --git a/intern/cycles/blender/CMakeLists.txt b/intern/cycles/blender/CMakeLists.txt
index 4919b99cfe0..c6f8fc39623 100644
--- a/intern/cycles/blender/CMakeLists.txt
+++ b/intern/cycles/blender/CMakeLists.txt
@@ -3,7 +3,6 @@
 
 set(INC
   ..
-  ../../glew-mx
   ../../guardedalloc
   ../../mikktspace
   ../../../source/blender/makesdna
@@ -13,8 +12,8 @@ set(INC
 )
 
 set(INC_SYS
+  ${Epoxy_INCLUDE_DIRS}
   ${PYTHON_INCLUDE_DIRS}
-  ${GLEW_INCLUDE_DIR}
 )
 
 set(SRC
@@ -64,6 +63,7 @@ set(LIB
   cycles_subd
   cycles_util
 
+  ${Epoxy_LIBRARIES}
   ${PYTHON_LINKFLAGS}
   ${PYTHON_LIBRARIES}
 )
diff --git a/intern/cycles/cmake/external_libs.cmake b/intern/cycles/cmake/external_libs.cmake
index 51830250f2e..bc859d830ba 100644
--- a/intern/cycles/cmake/external_libs.cmake
+++ b/intern/cycles/cmake/external_libs.cmake
@@ -505,26 +505,19 @@ if(CYCLES_STANDALONE_REPOSITORY)
 endif()
 
 ###########################################################################
-# GLEW
+# Epoxy
 ###########################################################################
 
 if(CYCLES_STANDALONE_REPOSITORY)
   if((WITH_CYCLES_STANDALONE AND WITH_CYCLES_STANDALONE_GUI) OR
      WITH_CYCLES_HYDRA_RENDER_DELEGATE)
     if(MSVC AND EXISTS ${_cycles_lib_dir})
-      set(GLEW_LIBRARY "${_cycles_lib_dir}/opengl/lib/glew.lib")
-      set(GLEW_INCLUDE_DIR "${_cycles_lib_dir}/opengl/include")
-      add_definitions(-DGLEW_STATIC)
+      set(Epoxy_LIBRARIES "${_cycles_lib_dir}/epoxy/lib/epoxy.lib")
+      set(Epoxy_INCLUDE_DIRS "${_cycles_lib_dir}/epoxy/include")
     else()
-      find_package(GLEW REQUIRED)
+      find_package(Epoxy REQUIRED)
     endif()
-
-    set(CYCLES_GLEW_LIBRARIES ${GLEW_LIBRARY})
   endif()
-else()
-  # Workaround for unconventional variable name use in Blender.
-  set(GLEW_INCLUDE_DIR "${GLEW_INCLUDE_PATH}")
-  set(CYCLES_GLEW_LIBRARIES bf_intern_glew_mx ${BLENDER_GLEW_LIBRARIES})
 endif()
 
 ###########################################################################
diff --git a/intern/cycles/device/CMakeLists.txt b/intern/cycles/device/CMakeLists.txt
index 6418801c572..71789a76406 100644
--- a/intern/cycles/device/CMakeLists.txt
+++ b/intern/cycles/device/CMakeLists.txt
@@ -3,12 +3,9 @@
 
 set(INC
   ..
-  ../../glew-mx
 )
 
-set(INC_SYS
-  ${GLEW_INCLUDE_DIR}
-)
+set(INC_SYS )
 
 if(WITH_CYCLES_DEVICE_OPTIX OR WITH_CYCLES_DEVICE_CUDA)
   if(WITH_CUDA_DYNLOAD)
diff --git a/intern/cycles/device/hip/device_impl.cpp b/intern/cycles/device/hip/device_impl.cpp
index 82db55ea715..a84f1edd70e 100644
--- a/intern/cycles/device/hip/device_impl.cpp
+++ b/intern/cycles/device/hip/device_impl.cpp
@@ -16,7 +16,6 @@
 #  include "util/log.h"
 #  include "util/map.h"
 #  include "util/md5.h"
-#  include "util/opengl.h"
 #  include "util/path.h"
 #  include "util/string.h"
 #  include "util/system.h"
diff --git a/intern/cycles/hydra/CMakeLists.txt b/intern/cycles/hydra/CMakeLists.txt
index aa194fb936e..60bb40a0d63 100644
--- a/intern/cycles/hydra/CMakeLists.txt
+++ b/intern/cycles/hydra/CMakeLists.txt
@@ -10,14 +10,14 @@ set(INC
 )
 set(INC_SYS
   ${USD_INCLUDE_DIRS}
-  ${GLEW_INCLUDE_DIR}
+  ${Epoxy_INCLUDE_DIRS}
 )
 
 set(LIB
   cycles_scene
   cycles_session
   cycles_graph
-  ${CYCLES_GLEW_LIBRARIES}
+  ${Epoxy_LIBRARIES}
 )
 cycles_external_libraries_append(LIB)
 
diff --git a/intern/cycles/hydra/display_driver.cpp b/intern/cycles/hydra/display_driver.cpp
index 0c0b577c358..1a989605335 100644
--- a/intern/cycles/hydra/display_driver.cpp
+++ b/intern/cycles/hydra/display_driver.cpp
@@ -11,7 +11,7 @@
 #include "hydra/render_buffer.h"
 #include "hydra/session.h"
 
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 #include <pxr/imaging/hgiGL/texture.h>
 
 HDCYCLES_NAMESPACE_OPEN_SCOPE
diff --git a/intern/cycles/util/CMakeLists.txt b/intern/cycles/util/CMakeLists.txt
index fddac1dbbcf..17161f2c37b 100644
--- a/intern/cycles/util/CMakeLists.txt
+++ b/intern/cycles/util/CMakeLists.txt
@@ -3,7 +3,6 @@
 
 set(INC
   ..
-  ../../glew-mx
 )
 
 set(INC_SYS
diff --git a/intern/cycles/util/opengl.h b/intern/cycles/util/opengl.h
index 090deb861c4..fefee4ec022 100644
--- a/intern/cycles/util/opengl.h
+++ b/intern/cycles/util/opengl.h
@@ -7,6 +7,6 @@
 /* OpenGL header includes, used everywhere we use OpenGL, to deal with
  * platform differences in one central place. */
 
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 
 #endif /* __UTIL_OPENGL_H__ */