Add a constant for Vulkan backend

diff --git a/source/core/backend.h b/source/core/backend.h
index 2d58d38731a71402595fc50c17650d2518328729..abdb4ccf4b27a72e6af5375f5a0ce0839816b928 100644 (file)
--- a/source/core/backend.h
+++ b/source/core/backend.h
@@ -9,7 +9,8 @@ namespace GL {
 enum GraphicsApi
 {
        OPENGL,
-       OPENGL_ES
+       OPENGL_ES,
+       VULKAN
 };
 
 struct Version