igl | Make sure we can completely eliminate OpenGL from our CMake builds

Summary:
Make sure we can completely eliminate OpenGL from our CMake builds.

Clean Vulkan-only builds are now possible with IGLU/Shell/Tests enabled.

Reviewed By: EricGriffith

Differential Revision: D50154469

fbshipit-source-id: cfd42b2140a3246f88dc48d5058e4f559d644ebe

CMakeLists.txt

@@ -94,10 +94,6 @@ else()
   endif()
 endif()
 
-if(IGL_WITH_IGLU AND (NOT IGL_WITH_OPENGL) AND (NOT IGL_WITH_OPENGLES))
-  message(FATAL_ERROR "IGL_WITH_IGLU requires enabling IGL_WITH_OPENGL OR IGL_WITH_OPENGLES.")
-endif()
-
 if(IGL_WITH_SHELL AND (NOT IGL_WITH_IGLU))
   message(FATAL_ERROR "IGL_WITH_SHELL requires enabling IGL_WITH_IGLU.")
 endif()

IGLU/CMakeLists.txt

@@ -10,6 +10,10 @@ set(PROJECT_NAME "IGLU")
 macro(ADD_IGLU_MODULE module)
   file(GLOB_RECURSE SRC_FILES LIST_DIRECTORIES false RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} ${module}/*.cpp)
   file(GLOB_RECURSE HEADER_FILES LIST_DIRECTORIES false RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} ${module}/*.h)
+  if((NOT IGL_WITH_OPENGL) AND (NOT IGL_WITH_OPENGLES))
+    list(REMOVE_ITEM SRC_FILES ${module}/OpenGLTextureAccessor.cpp)
+    list(REMOVE_ITEM HEADER_FILES ${module}/OpenGLTextureAccessor.h)
+  endif()
   add_library(IGLU${module} ${SRC_FILES} ${HEADER_FILES})
   igl_set_cxxstd(IGLU${module} 17)
   igl_set_folder(IGLU${module} "IGL/${PROJECT_NAME}")
@@ -49,7 +53,3 @@ target_sources(IGLUimgui PRIVATE "${IGL_ROOT_DIR}/third-party/deps/src/imgui/img
 target_sources(IGLUimgui PRIVATE "${IGL_ROOT_DIR}/third-party/deps/src/imgui/imgui_widgets.cpp")
 target_include_directories(IGLUimgui PUBLIC "${IGL_ROOT_DIR}/third-party/deps/src/imgui")
 target_include_directories(IGLUtexture_accessor PUBLIC "${IGL_ROOT_DIR}/third-party/deps/src/glew/include")
-
-if(WIN32)
-  target_include_directories(IGLUtexture_accessor PUBLIC "${IGL_ROOT_DIR}/third-party/deps/src/glew/include")
-endif()

IGLU/texture_accessor/TextureAccessorFactory.cpp

@@ -21,12 +21,14 @@ std::unique_ptr<ITextureAccessor> TextureAccessorFactory::createTextureAccessor(
     const std::shared_ptr<igl::ITexture>& texture,
     igl::IDevice& device) {
   switch (backendType) {
+#if IGL_BACKEND_OPENGL
   case igl::BackendType::OpenGL:
     return std::make_unique<OpenGLTextureAccessor>(texture, device);
+#endif // IGL_BACKEND_OPENGL
 #if IGL_PLATFORM_APPLE
   case igl::BackendType::Metal:
     return std::make_unique<MetalTextureAccessor>(texture, device);
-#endif
+#endif // IGL_PLATFORM_APPLE
   default:
     IGL_ASSERT_NOT_IMPLEMENTED();
     return nullptr;