add a config key for "exclusive" i.e. mode-changing fullscreen (#231)

prboom2/src/SDL/i_video.c

@@ -111,6 +111,7 @@ int gl_depthbuffer_bits=16;
 extern void M_QuitDOOM(int choice);
 int use_fullscreen;
 int desired_fullscreen;
+int exclusive_fullscreen;
 int render_vsync;
 int screen_multiply;
 int render_screen_multiply;
@@ -720,6 +721,10 @@ static void I_FillScreenResolutionsList(void)
       // make sure the canonical resolutions are always available
       if (i > count - 1)
       {
+        // no hard-coded resolutions for mode-changing fullscreen
+        if (exclusive_fullscreen)
+          continue;
+
         mode.w = canonicals[i - count].w;
         mode.h = canonicals[i - count].h;
       }
@@ -891,6 +896,10 @@ void I_CalculateRes(int width, int height)
     unsigned int count1, count2;
     int pitch1, pitch2;
 
+    if (desired_fullscreen && exclusive_fullscreen)
+    {
+      I_ClosestResolution(&width, &height);
+    }
     SCREENWIDTH = width;//(width+15) & ~15;
     SCREENHEIGHT = height;
 
@@ -1181,11 +1190,13 @@ void I_UpdateVideoMode(void)
   }
 
   // Fullscreen desktop for software renderer only - DTIED
-  if (desired_fullscreen && V_GetMode() != VID_MODEGL)
-    init_flags |= SDL_WINDOW_FULLSCREEN_DESKTOP;
-  else
-  if ( desired_fullscreen )
-    init_flags |= SDL_WINDOW_FULLSCREEN;
+  if (desired_fullscreen)
+  {
+    if (V_GetMode() == VID_MODEGL || exclusive_fullscreen)
+      init_flags |= SDL_WINDOW_FULLSCREEN;
+    else
+      init_flags |= SDL_WINDOW_FULLSCREEN_DESKTOP;
+  }
 
   // In windowed mode, the window can be resized while the game is
   // running.  This feature is disabled on OS X, as it adds an ugly
@@ -1260,7 +1271,7 @@ void I_UpdateVideoMode(void)
     }
 
     // [FG] apply screen_multiply to initial window size
-    if (!(init_flags & SDL_WINDOW_FULLSCREEN_DESKTOP))
+    if (!desired_fullscreen)
     {
       SDL_SetWindowSize(sdl_window, screen_multiply*SCREENWIDTH, screen_multiply*actualheight);
     }

prboom2/src/i_video.h

@@ -102,6 +102,7 @@ void I_StartFrame (void);
 
 extern int use_fullscreen;  /* proff 21/05/2000 */
 extern int desired_fullscreen; //e6y
+extern int exclusive_fullscreen;
 
 void I_UpdateRenderSize(void);	// Handle potential
 extern int renderW;		// resolution scaling

prboom2/src/m_misc.c

@@ -464,6 +464,8 @@ default_t defaults[] =
   {"screen_resolution",{NULL, &screen_resolution},{0,"640x480"},UL,UL,def_str,ss_none},
   {"use_fullscreen",{&use_fullscreen},{0},0,1, /* proff 21/05/2000 */
    def_bool,ss_none},
+  {"exclusive_fullscreen",{&exclusive_fullscreen},{0},0,1, // [FG] mode-changing fullscreen
+  def_bool,ss_none},
   {"render_vsync",{&render_vsync},{1},0,1,
    def_bool,ss_none},
   {"translucency",{&default_translucency},{1},0,1,   // phares
@@ -1065,7 +1067,7 @@ default_t defaults[] =
    def_bool,ss_stat},
   {"render_wipescreen", {&render_wipescreen},  {1},0,1,
    def_bool,ss_stat},
-  {"render_screen_multiply", {&render_screen_multiply},  {1},1,4,
+  {"render_screen_multiply", {&render_screen_multiply},  {1},1,5,
    def_int,ss_stat},
   {"integer_scaling", {&integer_scaling},  {0},0,1,
    def_bool,ss_stat},