Update test: Show use of C's variadic functions

Author: Free-Pascal-meets-SDL-Website

tests/testver.pas

@@ -8,10 +8,12 @@
 
 { Test is based on testver.c }
 
+{$DEFINE C_VARIADIC_LOG} // !!! This define compiles Case 2. Comment out for Case 1 !!!
+
 program testver;
 
 uses
-  SDL3, SysUtils;
+  SDL3 {$IFNDEF C_VARIADIC_LOG}, SysUtils{$ENDIF};
 
 var
   version: Integer;
@@ -22,13 +24,39 @@
   else
     SDL_Log('Compiled with SDL older than 3.0');
 
+{ Case 1: Do NOT use C's variadic function:
+
+  Uses SDL_Log(fmt: PAnsiChar) with only the string parameter.
+  There is not variadic part in the SDL function itself.
+
+  The variadic part is provided by Pascal's Format() function
+  from SysUtils. }
+{$IFNDEF C_VARIADIC_LOG}
+  SDL_Log('Case 1: SDL_Log without variadic part.');
   SDL_Log(PChar(Format('Compiled version: %d.%d.%d (%s)',[
           SDL_MAJOR_VERSION, SDL_MINOR_VERSION, SDL_MICRO_VERSION,
           SDL_REVISION])));
   version := SDL_GetVersion();
   SDL_Log(PChar(Format('Runtime version: %d.%d.%d (%s)',
           [SDL_VERSIONNUM_MAJOR(version), SDL_VERSIONNUM_MINOR(version), SDL_VERSIONNUM_MICRO(version),
           SDL_GetRevision()])));
+  {$ENDIF}
+
+{ Case 2: Use C's variadic function:
+
+  Uses SDL_Log(fmt: PAnsiChar; Args: array of const). The variadic part
+  is provided directly by C's function. SysUtils is not needed. }
+{$IFDEF C_VARIADIC_LOG}
+  SDL_Log('Case 2: SDL_Log with variadic part.');
+  SDL_Log('Compiled version: %d.%d.%d (%s)', [
+          SDL_MAJOR_VERSION, SDL_MINOR_VERSION, SDL_MICRO_VERSION,
+          SDL_REVISION]);
+  version := SDL_GetVersion();
+  SDL_Log('Runtime version: %d.%d.%d (%s)',
+          [SDL_VERSIONNUM_MAJOR(version), SDL_VERSIONNUM_MINOR(version), SDL_VERSIONNUM_MICRO(version),
+          SDL_GetRevision()]);
+{$ENDIF}
+
   SDL_Quit();
 end.