Fixed running under KMSDRM video driver on Linux

SDL2 works fine without a window system, but it seems the DPI-querying
API will crash so let's not call that.

Should still add command line options to control the screen resolution,
i.e., overriding the window size.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/app.h b/src/app.h
index 5d1d42e1..55bec5a6 100644
--- a/src/app.h
+++ b/src/app.h
@@ -87,6 +87,8 @@ iBool               isLandscape_App     (void);
 iLocalDef iBool     isPortrait_App      (void) { return !isLandscape_App(); }
 enum iAppDeviceType deviceType_App      (void);
 iLocalDef iBool     isPortraitPhone_App (void) { return isPortrait_App() && deviceType_App() == phone_AppDeviceType; }
+iBool               isRunningUnderWindowSystem_App  (void);
+
 iGmCerts *          certs_App           (void);
 iVisited *          visited_App         (void);
 iBookmarks *        bookmarks_App       (void);