Fix OpenGL3 driver to compile standalone

also test this configuration in CI

.github/workflows/build.yml

@@ -97,7 +97,7 @@ jobs:
 
       - name: Build
         run: |
-          cmake . -DBUILD_EXAMPLES=1 -DUSE_SDL2=ON -DENABLE_OPENGL3=ON
+          cmake . -DBUILD_EXAMPLES=1 -DUSE_SDL2=ON -DENABLE_OPENGL=OFF -DENABLE_OPENGL3=ON
           make -j2
 
       - name: Test (headless)
@@ -124,7 +124,7 @@ jobs:
 
       - name: Build
         run: |
-          cmake . -DBUILD_EXAMPLES=1 -DUSE_SDL2=ON -DENABLE_GLES2=ON
+          cmake . -DBUILD_EXAMPLES=1 -DUSE_SDL2=ON -DENABLE_OPENGL=OFF -DENABLE_GLES2=ON
           make -j2
 
       - name: Test (headless)
@@ -135,7 +135,7 @@ jobs:
       - name: Test (Xvfb)
         run: |
           cd bin/Linux
-          LIBGL_ALWAYS_SOFTWARE=true xvfb-run ./AutomatedTest gles2
+          LIBGL_ALWAYS_SOFTWARE=true xvfb-run ./AutomatedTest ogles2
 
   win32:
     runs-on: ubuntu-20.04

source/Irrlicht/CMakeLists.txt

@@ -260,7 +260,7 @@ endif()
 if(ENABLE_GLES2)
 	find_package(OpenGLES2 REQUIRED)
 endif()
-if(ENABLE_OPENGL)
+if(ENABLE_OPENGL OR ENABLE_OPENGL3)
 	set(OpenGL_GL_PREFERENCE "LEGACY")
 	find_package(OpenGL REQUIRED)
 endif()

source/Irrlicht/COpenGLCoreCacheHandler.h

@@ -6,8 +6,6 @@
 #define __C_OGLCORE_CACHE_HANDLER_H_INCLUDED__
 
 
-#if defined(_IRR_COMPILE_WITH_OPENGL_) || defined(_IRR_COMPILE_WITH_OGLES1_) || defined(_IRR_COMPILE_WITH_OGLES2_)
-
 #include "SMaterial.h"
 #include "ITexture.h"
 
@@ -643,4 +641,3 @@ protected:
 }
 
 #endif
-#endif

source/Irrlicht/COpenGLCoreFeature.h

@@ -6,8 +6,6 @@
 #define __C_OGLCORE_FEATURE_H_INCLUDED__
 
 
-#if defined(_IRR_COMPILE_WITH_OPENGL_) || defined(_IRR_COMPILE_WITH_OGLES1_) || defined(_IRR_COMPILE_WITH_OGLES2_)
-
 #include "irrTypes.h"
 
 namespace irr
@@ -37,4 +35,3 @@ public:
 }
 
 #endif
-#endif

source/Irrlicht/COpenGLCoreRenderTarget.h

@@ -6,8 +6,6 @@
 #define __C_OGLCORE_RENDER_TARGET_H_INCLUDED__
 
 
-#if defined(_IRR_COMPILE_WITH_OPENGL_) || defined(_IRR_COMPILE_WITH_OGLES1_) || defined(_IRR_COMPILE_WITH_OGLES2_)
-
 #include "IRenderTarget.h"
 
 #ifndef GL_FRAMEBUFFER_INCOMPLETE_FORMATS
@@ -400,4 +398,3 @@ protected:
 }
 
 #endif
-#endif

source/Irrlicht/COpenGLCoreTexture.h

@@ -6,8 +6,6 @@
 #define __C_OGLCORE_TEXTURE_H_INCLUDED__
 
 
-#if defined(_IRR_COMPILE_WITH_OPENGL_) || defined(_IRR_COMPILE_WITH_OGLES1_) || defined(_IRR_COMPILE_WITH_OGLES2_)
-
 #include "irrArray.h"
 #include "SMaterialLayer.h"
 #include "ITexture.h"
@@ -666,4 +664,3 @@ protected:
 }
 
 #endif
-#endif

source/Irrlicht/CSDLManager.cpp

@@ -4,7 +4,7 @@
 
 #include "CSDLManager.h"
 
-#if defined(_IRR_COMPILE_WITH_SDL_DEVICE_) && defined(_IRR_COMPILE_WITH_OPENGL_)
+#if defined(_IRR_COMPILE_WITH_SDL_DEVICE_)
 
 #include "CIrrDeviceSDL.h"
 #include "COpenGLCommon.h"
@@ -34,8 +34,6 @@ const SExposedVideoData& CSDLManager::getContext() const
 
 bool CSDLManager::activateContext(const SExposedVideoData& videoData, bool restorePrimaryOnZero)
 {
-	// unclear if this is still needed:
-	glFrontFace(GL_CW);
 	return true;
 }
 

source/Irrlicht/CSDLManager.h

@@ -6,7 +6,7 @@
 #define __C_SDL_MANAGER_H_INCLUDED__
 
 
-#if defined(_IRR_COMPILE_WITH_SDL_DEVICE_) && defined(_IRR_COMPILE_WITH_OPENGL_)
+#if defined(_IRR_COMPILE_WITH_SDL_DEVICE_)
 
 #include "IContextManager.h"