vulkan_sdl3: use common func for FPS pretty printout

A common way would be to use generic FPS indicator. But a slight problem
is that _putf return value isn't entirely reliable for this module,
since the frame may be dropped later doe to insufficient performance.

Because of the above, do not use the generic indicator, at least
for now. But use the common function to make the output "prettier"
(bold/color and if not performing well also use a color for FPS).

Author: MartinPulec

src/video_display.c

@@ -345,6 +345,26 @@ struct video_frame *display_get_frame(struct display *d)
         }
 }
 
+/**
+ * print display FPS
+ *
+ * Usually called from display_frame_helper for displays that use generic FPS
+ * indicator but externally linked for those that do not, like vulkan_sdl3.
+ */
+void
+display_print_fps(const char *prefix, double seconds, int frames,
+                  double nominal_fps)
+{
+        const double      fps     = frames / seconds;
+        const char *const fps_col = get_stat_color(fps / nominal_fps);
+
+        log_msg(LOG_LEVEL_INFO,
+                TERM_BOLD TERM_FG_MAGENTA "%s" TERM_RESET
+                                          "%d frames in %g seconds = " TERM_BOLD
+                                          "%s%g FPS" TERM_RESET "\n",
+                prefix, frames, seconds, fps_col, fps);
+}
+
 static bool display_frame_helper(struct display *d, struct video_frame *frame, long long timeout_ns)
 {
         enum {
@@ -364,15 +384,9 @@ static bool display_frame_helper(struct display *d, struct video_frame *frame, l
         long long seconds_ns = t - d->t0;
         if (seconds_ns > 5 * NS_IN_SEC) {
                 const double seconds = (double) seconds_ns / NS_IN_SEC;
-                const double fps      = d->frames / seconds;
-                const char *const fps_col  = get_stat_color(fps / frame_fps);
-
-                log_msg(LOG_LEVEL_INFO,
-                        TERM_BOLD TERM_FG_MAGENTA
-                        "%s" TERM_RESET "%d frames in %g seconds = " TERM_BOLD
-                        "%s%g FPS" TERM_RESET "\n",
-                        d->funcs->generic_fps_indicator_prefix, d->frames,
-                        seconds, fps_col, fps);
+                display_print_fps(d->funcs->generic_fps_indicator_prefix,
+                                  seconds, d->frames, frame_fps);
+
                 d->frames = 0;
                 d->t0 = t;
         }

src/video_display.h

@@ -13,7 +13,7 @@
  * @ingroup display
  */
 /* Copyright (c) 2001-2003 University of Southern California
- * Copyright (c) 2005-2023 CESNET z.s.p.o.
+ * Copyright (c) 2005-2025 CESNET, zájmové sdružení právnických osob
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, is permitted provided that the following conditions
@@ -211,6 +211,9 @@ bool                     display_reconfigure_audio(struct display *d, int quant_
 struct video_frame *get_splashscreen(void);
 const char         *get_audio_conn_flag_name(int audio_init_flag);
 
+void display_print_fps(const char *prefix, double seconds, int frames,
+                       double nominal_fps);
+
 #ifdef __cplusplus
 }
 #endif // __cplusplus

src/video_display/vulkan/vulkan_sdl3.cpp

@@ -394,9 +394,9 @@ void display_vulkan_run(void* state) {
                 auto now = chrono::steady_clock::now();
                 double seconds = chrono::duration<double>{ now - s->time }.count();
                 if (seconds > 5) {
-                        double fps = s->frames / seconds;
-                        log_msg(LOG_LEVEL_INFO, MOD_NAME "%llu frames in %g seconds = %g FPS\n",
-                                static_cast<long long unsigned>(s->frames), seconds, fps);
+                        display_print_fps(MOD_NAME, seconds, (int) s->frames,
+                                          s->current_desc.fps);
+
                         s->time = now;
                         s->frames = 0;
                 }