Add fps_limit param

src/overlay.cpp

@@ -2144,20 +2144,11 @@ static void overlay_DestroySwapchainKHR(
    destroy_swapchain_data(swapchain_data);
 }
 
-void getFpsLimit(){
-   const char *fpsLimit = std::getenv("FPS");
-   if (fpsLimit != nullptr && !string(fpsLimit).empty()) {
-      double fps = stod(fpsLimit);
-      targetFrameTime = double(1000000000.0f / fps);
-   }
-}
-
 void FpsLimiter(){
    int64_t now = os_time_get_nano();
    sleepTime = targetFrameTime - (now - frameEnd);
    this_thread::sleep_for(chrono::nanoseconds(sleepTime - frameOverhead));
    frameOverhead = (now - frameStart);
-   cout << frameOverhead << endl;
 }
 
 static VkResult overlay_QueuePresentKHR(
@@ -2576,8 +2567,6 @@ static VkResult overlay_CreateInstance(
    if (engineName == "vkd3d")
       engineName = "VKD3D";
 
-   getFpsLimit();
-   
    assert(chain_info->u.pLayerInfo);
    PFN_vkGetInstanceProcAddr fpGetInstanceProcAddr =
       chain_info->u.pLayerInfo->pfnNextGetInstanceProcAddr;
@@ -2600,7 +2589,9 @@ static VkResult overlay_CreateInstance(
    instance_data_map_physical_devices(instance_data, true);
 
    parse_overlay_env(&instance_data->params, getenv("MANGOHUD_CONFIG"));
-   
+   if (instance_data->params.fps_limit > 0)
+      targetFrameTime = double(1000000000.0f / instance_data->params.fps_limit);
+
    int font_size;
    instance_data->params.font_size > 0 ? font_size = instance_data->params.font_size : font_size = 24;
    instance_data->params.font_size > 0 ? font_size = instance_data->params.font_size : instance_data->params.font_size = 24;

src/overlay_params.c

@@ -79,6 +79,12 @@ parse_fps_sampling_period(const char *str)
    return strtol(str, NULL, 0) * 1000;
 }
 
+static uint32_t
+parse_fps_limit(const char *str)
+{
+   return strtol(str, NULL, 0);
+}
+
 static bool
 parse_no_display(const char *str)
 {
@@ -183,6 +189,7 @@ parse_overlay_env(struct overlay_params *params,
    params->width = 280;
    params->height = 140;
    params->control = -1;
+   params->fps_limit = 0;
 
    if (!env)
       return;

src/overlay_params.h

@@ -52,6 +52,7 @@ extern "C" {
    OVERLAY_PARAM_CUSTOM(height)                      \
    OVERLAY_PARAM_CUSTOM(no_display)                  \
    OVERLAY_PARAM_CUSTOM(control)                     \
+   OVERLAY_PARAM_CUSTOM(fps_limit)                   \
    OVERLAY_PARAM_CUSTOM(font_size)                   \
    OVERLAY_PARAM_CUSTOM(help)
 
@@ -77,6 +78,7 @@ struct overlay_params {
    FILE *output_file;
    int control;
    uint32_t fps_sampling_period; /* us */
+   uint32_t fps_limit;
    bool help;
    bool no_display;
    unsigned width;