Drop stale OpenGL renderer cvars and misleading fallback hints

Vulkan-only clients no longer register r_allowSoftwareGL or r_glDriver
(USE_OPENGL_API). SDL GLimp only touches those cvars when OpenGL is
compiled in. Replace obsolete "+set cl_renderer opengl" help text with
Vulkan/SDL guidance and update the demo features cfg comment.

Co-authored-by: Tim Fox <timfox@outlook.com>

Author: cursoragent

examples/demo_game/mod/demo_features.cfg

@@ -14,8 +14,7 @@ set r_fontConsoleAlign 1
 
 // Optional SDF (pre-generated BMFont + distance atlas in pk3): set r_sdfEnable 1; set r_sdfFont "fonts/demo_console_sdf"; tune r_sdfSmoothing
 
-// --- Renderer backend (user often sets on command line) ---
-// +set cl_renderer vulkan   or   opengl
+// --- Renderer backend: Vulkan only (+set cl_renderer vulkan is the default) ---
 
 // --- PBR / materials (Vulkan path) ---
 set r_pbr 1

src/client/cl_main.c

@@ -869,9 +869,11 @@ cvar_t	*vid_xpos;			// X coordinate of window position
 cvar_t	*vid_ypos;			// Y coordinate of window position
 cvar_t	*r_noborder;
 
-cvar_t *r_allowSoftwareGL;	// don't abort out if the pixelformat claims software
 cvar_t *r_swapInterval;
+#ifdef USE_OPENGL_API
+cvar_t *r_allowSoftwareGL;	// don't abort out if the pixelformat claims software
 cvar_t *r_glDriver;
+#endif
 cvar_t *r_displayRefresh;
 cvar_t *r_fullscreen;
 cvar_t *r_mode;
@@ -3986,13 +3988,15 @@ static void CL_ToggleImgui_f( void )
 
 static void CL_InitGLimp_Cvars( void )
 {
-	// shared with GLimp
-	r_allowSoftwareGL = Cvar_Get( "r_allowSoftwareGL", "0", CVAR_LATCH );
-	Cvar_SetDescription( r_allowSoftwareGL, "Toggle the use of the default software OpenGL driver supplied by the Operating System." );
+	// shared with GLimp / VKimp
 	r_swapInterval = Cvar_Get( "r_swapInterval", "0", CVAR_ARCHIVE_ND );
 	Cvar_SetDescription( r_swapInterval, "V-blanks to wait before swapping buffers.\n 0: No V-Sync\n 1: Synced to the monitor's refresh rate." );
+#ifdef USE_OPENGL_API
+	r_allowSoftwareGL = Cvar_Get( "r_allowSoftwareGL", "0", CVAR_LATCH );
+	Cvar_SetDescription( r_allowSoftwareGL, "Toggle the use of the default software OpenGL driver supplied by the Operating System." );
 	r_glDriver = Cvar_Get( "r_glDriver", OPENGL_DRIVER_NAME, CVAR_ARCHIVE_ND | CVAR_LATCH );
 	Cvar_SetDescription( r_glDriver, "Specifies the OpenGL driver to use, will revert back to default if driver name set is invalid." );
+#endif
 
 	r_displayRefresh = Cvar_Get( "r_displayRefresh", "0", CVAR_LATCH );
 	Cvar_CheckRange( r_displayRefresh, "0", "500", CV_INTEGER );

src/client/client.h

@@ -428,9 +428,11 @@ extern	cvar_t	*vid_xpos;
 extern	cvar_t	*vid_ypos;
 extern	cvar_t	*r_noborder;
 
-extern	cvar_t	*r_allowSoftwareGL;
 extern	cvar_t	*r_swapInterval;
+#ifdef USE_OPENGL_API
+extern	cvar_t	*r_allowSoftwareGL;
 extern	cvar_t	*r_glDriver;
+#endif
 
 extern	cvar_t	*r_displayRefresh;
 extern	cvar_t	*r_fullscreen;
@@ -624,7 +626,7 @@ void	GLimp_Minimize( void );
 void	GLimp_LogComment( const char *comment );
 void	GLW_RestoreGamma( void );
 
-// OpenGL (needed for static OpenGL build, or Vulkan build with dlopen so OpenGL renderer can load)
+// Window / swapchain (SDL GLimp for OpenGL; VKimp for Vulkan)
 #if defined(USE_OPENGL_API) || defined(USE_VULKAN_API)
 void	GLimp_Init( glconfig_t *config );
 void	GLimp_Shutdown( qboolean unloadDLL );

src/platform/sdl/sdl_glimp.c

@@ -412,9 +412,10 @@ static int GLW_SetMode( int mode, const char *modeFS, qboolean fullscreen, qbool
 		else
 			perChannelColorBits = 4;
 
-#ifdef USE_VULKAN_API
+#if defined(USE_OPENGL_API)
+# ifdef USE_VULKAN_API
 		if ( !vulkan )
-#endif
+# endif
 		{
 
 #ifdef __sgi /* Fix for SGIs grabbing too many bits of color */
@@ -450,6 +451,7 @@ static int GLW_SetMode( int mode, const char *modeFS, qboolean fullscreen, qbool
 			if ( !r_allowSoftwareGL->integer )
 				SDL_GL_SetAttribute( SDL_GL_ACCELERATED_VISUAL, 1 );
 		}
+#endif /* USE_OPENGL_API */
 
 		if ( ( SDL_window = SDL_CreateWindow( cl_title, x, y, config->vidWidth, config->vidHeight, flags ) ) == NULL )
 		{
@@ -559,7 +561,7 @@ static int GLW_SetMode( int mode, const char *modeFS, qboolean fullscreen, qbool
 		Com_Printf( "[VK] Couldn't get a visual: %s\n", ( sdl_err && sdl_err[0] ) ? sdl_err : "(no SDL error string)" );
 		Com_Printf( "[VK] SDL video driver: %s\n", SDL_GetCurrentVideoDriver() ? SDL_GetCurrentVideoDriver() : "(none)" );
 #if defined(__arm__) || defined(__aarch64__)
-		Com_Printf( S_COLOR_YELLOW "[VK] On ARM, Vulkan may be unavailable. Try: ./idtech3.aarch64 +set cl_renderer opengl\n" );
+		Com_Printf( S_COLOR_YELLOW "[VK] On ARM, Vulkan may be unavailable. Ensure SDL was built with Vulkan support (see docs/ARM_RASPBERRY_PI.md).\n" );
 #endif
 		/* SDL built without Vulkan: no point retrying modes/drivers */
 		if ( vulkan && sdl_err && strstr( sdl_err, "Vulkan support" ) != NULL )
@@ -692,7 +694,9 @@ void GLimp_Init( glconfig_t *config )
 	in_nograb = Cvar_Get( "in_nograb", "0", 0 );
 	Cvar_SetDescription( in_nograb, "Do not capture mouse in game, may be useful during online streaming." );
 
+#ifdef USE_OPENGL_API
 	r_allowSoftwareGL = Cvar_Get( "r_allowSoftwareGL", "0", CVAR_LATCH );
+#endif
 
 	r_swapInterval = Cvar_Get( "r_swapInterval", "0", CVAR_ARCHIVE | CVAR_LATCH );
 	r_stereoEnabled = Cvar_Get( "r_stereoEnabled", "0", CVAR_ARCHIVE | CVAR_LATCH );
@@ -976,7 +980,7 @@ void VKimp_Init( glconfig_t *config )
 #if defined(__arm__) || defined(__aarch64__)
 			Com_Printf( S_COLOR_YELLOW "Vulkan failed on ARM. SDL needs Vulkan support.\n" );
 			Com_Printf( "  Build SDL with Vulkan: ./scripts/build_sdl_vulkan_rpi.sh\n" );
-			Com_Printf( "  Or use OpenGL: +set cl_renderer opengl\n" );
+			Com_Printf( "  Vulkan is required; rebuild SDL with Vulkan enabled.\n" );
 #endif
 			Com_Error( ERR_FATAL, "VKimp_Init() - could not load Vulkan subsystem: %s", SDL_GetError() );
 			return;
@@ -986,7 +990,7 @@ void VKimp_Init( glconfig_t *config )
 #if defined(__arm__) || defined(__aarch64__)
 			Com_Printf( S_COLOR_YELLOW "Vulkan failed on ARM. SDL may lack Vulkan support.\n" );
 			Com_Printf( "  Build SDL with Vulkan: ./scripts/build_sdl_vulkan_rpi.sh\n" );
-			Com_Printf( "  Or use OpenGL: +set cl_renderer opengl\n" );
+			Com_Printf( "  Vulkan is required; rebuild SDL with Vulkan enabled.\n" );
 #endif
 			Com_Error( ERR_FATAL, "VKimp_Init() - could not load Vulkan subsystem: %s", SDL_GetError() );
 			return;

src/platform/unix/linux_signals.c

@@ -84,7 +84,7 @@ static void signal_handler( int sig )
 		fprintf( stderr, "\n" );
 		fprintf( stderr, " Try these workarounds:\n" );
 		fprintf( stderr, "   1. Clear shader cache:  rm -rf ~/.nv/GLCache/\n" );
-		fprintf( stderr, "   2. Use OpenGL renderer: +set cl_renderer opengl\n" );
+		fprintf( stderr, "   2. Ensure Vulkan/SDL are built correctly (see docs/DEVELOPMENT_SETUP.md)\n" );
 		fprintf( stderr, "   3. Disable post-process: +set r_bloom 0 +set r_ssao 0\n" );
 		fprintf( stderr, "   4. Update GPU driver to the latest version\n" );
 		fprintf( stderr, "   5. Set r_volumetricFog 0 to disable volumetric fog\n" );