Use nanoseconds to calculate fps

No need to round this earlier on.

Removes an unnecessary implicit float -> double conversion in the calculation also

src/hud_elements.cpp

@@ -463,7 +463,7 @@ void HudElements::frame_timing(){
         char hash[40];
         snprintf(hash, sizeof(hash), "##%s", overlay_param_names[OVERLAY_PARAM_ENABLED_frame_timing]);
         HUDElements.sw_stats->stat_selector = OVERLAY_PLOTS_frame_timing;
-        HUDElements.sw_stats->time_dividor = 1000.0f;
+        HUDElements.sw_stats->time_dividor = 1000000.0f; /* ns -> ms */
         ImGui::PushStyleColor(ImGuiCol_FrameBg, ImVec4(0.0f, 0.0f, 0.0f, 0.0f));
         double min_time = 0.0f;
         double max_time = 50.0f;

src/mesa/util/os_time.h

@@ -52,16 +52,6 @@ int64_t
 os_time_get_nano(void);
 
 
-/*
- * Get the current time in microseconds from an unknown base.
- */
-static inline int64_t
-os_time_get(void)
-{
-   return os_time_get_nano() / 1000;
-}
-
-
 /*
  * Sleep.
  */

src/overlay.cpp

@@ -72,9 +72,9 @@ void update_hw_info(struct swapchain_stats& sw_stats, struct overlay_params& par
 
 void update_hud_info(struct swapchain_stats& sw_stats, struct overlay_params& params, uint32_t vendorID){
    uint32_t f_idx = sw_stats.n_frames % ARRAY_SIZE(sw_stats.frames_stats);
-   uint64_t now = os_time_get(); /* us */
-   double elapsed = (double)(now - sw_stats.last_fps_update); /* us */
-   fps = 1000000.0f * sw_stats.n_frames_since_update / elapsed;
+   uint64_t now = os_time_get_nano(); /* ns */
+   double elapsed = (double)(now - sw_stats.last_fps_update); /* ns */
+   fps = 1000000000.0 * sw_stats.n_frames_since_update / elapsed;
    if (logger->is_active())
       benchmark.fps_data.push_back(fps);
 

src/overlay_params.cpp

@@ -147,7 +147,7 @@ parse_string_to_keysym_vec(const char *str)
 static uint32_t
 parse_fps_sampling_period(const char *str)
 {
-   return strtol(str, NULL, 0) * 1000;
+   return strtol(str, NULL, 0) * 1000000; /* ms to ns */
 }
 
 static std::vector<std::uint32_t>
@@ -575,7 +575,7 @@ parse_overlay_config(struct overlay_params *params,
    params->enabled[OVERLAY_PARAM_ENABLED_core_load_change] = false;
    params->enabled[OVERLAY_PARAM_ENABLED_legacy_layout] = true;
    params->enabled[OVERLAY_PARAM_ENABLED_frametime] = true;
-   params->fps_sampling_period = 500000; /* 500ms */
+   params->fps_sampling_period = 500000000; /* 500ms */
    params->width = 0;
    params->height = 140;
    params->control = -1;

src/overlay_params.h

@@ -187,7 +187,7 @@ struct overlay_params {
    bool enabled[OVERLAY_PARAM_ENABLED_MAX];
    enum overlay_param_position position;
    int control;
-   uint32_t fps_sampling_period; /* us */
+   uint32_t fps_sampling_period; /* ns */
    std::vector<std::uint32_t> fps_limit;
    bool help;
    bool no_display;