Add cull mode for both sides of a face

Signed-off-by: Tobias Frisch <tfrisch@uni-koblenz.de>

include/vkcv/GraphicsPipelineConfig.hpp

@@ -16,7 +16,7 @@
 namespace vkcv {
 
     enum class PrimitiveTopology{PointList, LineList, TriangleList, PatchList };
-	enum class CullMode{ None, Front, Back };
+	enum class CullMode{ None, Front, Back, Both };
     enum class DepthTest { None, Less, LessEqual, Greater, GreatherEqual, Equal };
 
     // add more as needed

src/vkcv/GraphicsPipelineManager.cpp

@@ -263,6 +263,9 @@ namespace vkcv
 			case CullMode::Back:
 				cullMode = vk::CullModeFlagBits::eBack;
 				break;
+			case CullMode::Both:
+				cullMode = vk::CullModeFlagBits::eFrontAndBack;
+				break;
 			default:
 			vkcv_log(LogLevel::ERROR, "Unknown CullMode");
 				cullMode = vk::CullModeFlagBits::eNone;