Force fullscreen in case of KMS display

Change GL2, GL3 and Vulkan drivers to behave as fullscreen if context driver
(such as KMS/DRM or KHR) does not support windowed mode at all.
Take it into account also for refresh rate switch.

gfx/drivers/gl2.c

@@ -4258,6 +4258,7 @@ static void *gl2_init(const video_info_t *video,
    unsigned temp_width                  = 0;
    unsigned temp_height                 = 0;
    bool force_smooth                    = false;
+   bool force_fullscreen                = false;
    const char *vendor                   = NULL;
    const char *renderer                 = NULL;
    const char *version                  = NULL;
@@ -4281,6 +4282,13 @@ static void *gl2_init(const video_info_t *video,
       gl->ctx_driver->get_video_size(gl->ctx_data,
                &mode_width, &mode_height);
 
+   if (!video->fullscreen && !gl->ctx_driver->has_windowed)
+   {
+      RARCH_DBG("[GL]: Config requires windowed mode, but context driver does not support it. "
+                "Forcing fullscreen for this session.\n");
+      force_fullscreen = true;
+   }
+
 #if defined(DINGUX)
    mode_width  = 320;
    mode_height = 240;
@@ -4311,17 +4319,23 @@ static void *gl2_init(const video_info_t *video,
       win_width  = full_x;
       win_height = full_y;
    }
+   /* If fullscreen had to be forced, video->width/height is incorrect */
+   else if (force_fullscreen)
+   {
+      win_width  = settings->uints.video_fullscreen_x;
+      win_height = settings->uints.video_fullscreen_y;
+   }
 
    if (     !gl->ctx_driver->set_video_mode
          || !gl->ctx_driver->set_video_mode(gl->ctx_data,
-            win_width, win_height, video->fullscreen))
+            win_width, win_height, (video->fullscreen || force_fullscreen)))
       goto error;
 #if defined(__APPLE__) && !defined(IOS) && !defined(HAVE_COCOA_METAL)
    /* This is a hack for now to work around a very annoying
     * issue that currently eludes us. */
    if (     !gl->ctx_driver->set_video_mode
          || !gl->ctx_driver->set_video_mode(gl->ctx_data,
-            win_width, win_height, video->fullscreen))
+            win_width, win_height, (video->fullscreen || force_fullscreen)))
       goto error;
 #endif
 
@@ -4446,7 +4460,7 @@ static void *gl2_init(const video_info_t *video,
    gl2_begin_debug(gl);
 #endif
 
-   if (video->fullscreen)
+   if (video->fullscreen || force_fullscreen)
       gl->flags  |=  GL2_FLAG_FULLSCREEN;
 
    mode_width     = 0;

gfx/drivers/gl3.c

@@ -1770,6 +1770,7 @@ static void *gl3_init(const video_info_t *video,
    unsigned full_x, full_y;
    settings_t *settings                 = config_get_ptr();
    bool video_gpu_record                = settings->bools.video_gpu_record;
+   bool force_fullscreen                = false;
    int interval                         = 0;
    unsigned mode_width                  = 0;
    unsigned mode_height                 = 0;
@@ -1799,6 +1800,13 @@ static void *gl3_init(const video_info_t *video,
       gl->ctx_driver->get_video_size(gl->ctx_data,
                &mode_width, &mode_height);
 
+   if (!video->fullscreen && !gl->ctx_driver->has_windowed)
+   {
+      RARCH_DBG("[GLCore]: Config requires windowed mode, but context driver does not support it. "
+                "Forcing fullscreen for this session.\n");
+      force_fullscreen = true;
+   }
+
    full_x      = mode_width;
    full_y      = mode_height;
    mode_width  = 0;
@@ -1827,10 +1835,16 @@ static void *gl3_init(const video_info_t *video,
       win_width  = full_x;
       win_height = full_y;
    }
+   /* If fullscreen had to be forced, video->width/height is incorrect */
+   else if (force_fullscreen)
+   {
+      win_width  = settings->uints.video_fullscreen_x;
+      win_height = settings->uints.video_fullscreen_y;
+   }
 
    if (     !gl->ctx_driver->set_video_mode
          || !gl->ctx_driver->set_video_mode(gl->ctx_data,
-            win_width, win_height, video->fullscreen))
+            win_width, win_height, (video->fullscreen || force_fullscreen)))
       goto error;
 
    if (gl->flags & GL3_FLAG_USE_SHARED_CONTEXT)
@@ -1889,7 +1903,7 @@ static void *gl3_init(const video_info_t *video,
 
    if (video->vsync)
       gl->flags   |= GL3_FLAG_VSYNC;
-   if (video->fullscreen)
+   if (video->fullscreen || force_fullscreen)
       gl->flags   |= GL3_FLAG_FULLSCREEN;
    if (video->force_aspect)
       gl->flags   |= GL3_FLAG_KEEP_ASPECT;

gfx/drivers/vulkan.c

@@ -3318,6 +3318,7 @@ static void *vulkan_init(const video_info_t *video,
    int interval                       = 0;
    unsigned temp_width                = 0;
    unsigned temp_height               = 0;
+   bool force_fullscreen              = false;
    const gfx_ctx_driver_t *ctx_driver = NULL;
    settings_t *settings               = config_get_ptr();
 #ifdef VULKAN_HDR_SWAPCHAIN
@@ -3351,6 +3352,13 @@ static void *vulkan_init(const video_info_t *video,
       vk->ctx_driver->get_video_size(vk->ctx_data,
             &mode_width, &mode_height);
 
+   if (!video->fullscreen && !vk->ctx_driver->has_windowed)
+   {
+      RARCH_DBG("[Vulkan]: Config requires windowed mode, but context driver does not support it. "
+                "Forcing fullscreen for this session.\n");
+      force_fullscreen = true;
+   }
+
    full_x                             = mode_width;
    full_y                             = mode_height;
    mode_width                         = 0;
@@ -3376,10 +3384,16 @@ static void *vulkan_init(const video_info_t *video,
       win_width  = full_x;
       win_height = full_y;
    }
+   /* If fullscreen had to be forced, video->width/height is incorrect */
+   else if (force_fullscreen)
+   {
+      win_width  = settings->uints.video_fullscreen_x;
+      win_height = settings->uints.video_fullscreen_y;
+   }
 
    if (     !vk->ctx_driver->set_video_mode
          || !vk->ctx_driver->set_video_mode(vk->ctx_data,
-            win_width, win_height, video->fullscreen))
+            win_width, win_height, (video->fullscreen || force_fullscreen)))
    {
       RARCH_ERR("[Vulkan]: Failed to set video mode.\n");
       goto error;
@@ -3412,7 +3426,7 @@ static void *vulkan_init(const video_info_t *video,
       vk->flags         |=  VK_FLAG_VSYNC;
    else
       vk->flags         &= ~VK_FLAG_VSYNC;
-   if (video->fullscreen)
+   if (video->fullscreen || force_fullscreen)
       vk->flags         |=  VK_FLAG_FULLSCREEN;
    else
       vk->flags         &= ~VK_FLAG_FULLSCREEN;

gfx/video_driver.c

@@ -1243,7 +1243,8 @@ void video_switch_refresh_rate_maybe(
    unsigned video_bfi                 = settings->uints.video_black_frame_insertion;
    unsigned shader_subframes          = settings->uints.video_shader_subframes;
    bool vrr_runloop_enable            = settings->bools.vrr_runloop_enable;
-   bool exclusive_fullscreen          = settings->bools.video_fullscreen && !settings->bools.video_windowed_fullscreen;
+   bool exclusive_fullscreen          = (video_st->flags | VIDEO_FLAG_FORCE_FULLSCREEN) || (
+                                        settings->bools.video_fullscreen && !settings->bools.video_windowed_fullscreen);
    bool windowed_fullscreen           = settings->bools.video_fullscreen && settings->bools.video_windowed_fullscreen;
    bool all_fullscreen                = settings->bools.video_fullscreen || settings->bools.video_windowed_fullscreen;