lovr.headset.getDisplayFrequency;

src/api/l_headset.c

@@ -147,6 +147,16 @@ static int l_lovrHeadsetGetDisplayDimensions(lua_State* L) {
   return 2;
 }
 
+static int l_lovrHeadsetGetDisplayFrequency(lua_State* L) {
+  float frequency = lovrHeadsetDriver->getDisplayFrequency ? lovrHeadsetDriver->getDisplayFrequency() : 0.f;
+  if (frequency == 0.f) {
+    lua_pushnil(L);
+  } else {
+    lua_pushnumber(L, frequency);
+  }
+  return 1;
+}
+
 static int l_lovrHeadsetGetDisplayMask(lua_State* L) {
   uint32_t count;
   const float* points = lovrHeadsetDriver->getDisplayMask(&count);
@@ -537,6 +547,7 @@ static const luaL_Reg lovrHeadset[] = {
   { "getDisplayWidth", l_lovrHeadsetGetDisplayWidth },
   { "getDisplayHeight", l_lovrHeadsetGetDisplayHeight },
   { "getDisplayDimensions", l_lovrHeadsetGetDisplayDimensions },
+  { "getDisplayFrequency", l_lovrHeadsetGetDisplayFrequency },
   { "getDisplayMask", l_lovrHeadsetGetDisplayMask },
   { "getClipDistance", l_lovrHeadsetGetClipDistance },
   { "setClipDistance", l_lovrHeadsetSetClipDistance },

src/modules/headset/headset.h

@@ -59,6 +59,7 @@ typedef struct HeadsetInterface {
   bool (*getName)(char* name, size_t length);
   HeadsetOrigin (*getOriginType)(void);
   void (*getDisplayDimensions)(uint32_t* width, uint32_t* height);
+  float (*getDisplayFrequency)(void);
   const float* (*getDisplayMask)(uint32_t* count);
   double (*getDisplayTime)(void);
   void (*getClipDistance)(float* clipNear, float* clipFar);

src/modules/headset/openvr.c

@@ -207,6 +207,10 @@ static void openvr_getDisplayDimensions(uint32_t* width, uint32_t* height) {
   state.system->GetRecommendedRenderTargetSize(width, height);
 }
 
+static float openvr_getDisplayFrequency() {
+  return state.system->GetFloatTrackedDeviceProperty(HEADSET, ETrackedDeviceProperty_Prop_DisplayFrequency_Float, NULL);
+}
+
 static const float* openvr_getDisplayMask(uint32_t* count) {
   struct HiddenAreaMesh_t hiddenAreaMesh = state.system->GetHiddenAreaMesh(EVREye_Eye_Left, EHiddenAreaMeshType_k_eHiddenAreaMesh_Standard);
 
@@ -231,7 +235,7 @@ static double openvr_getDisplayTime(void) {
   float secondsSinceVsync;
   state.system->GetTimeSinceLastVsync(&secondsSinceVsync, NULL);
 
-  float frequency = state.system->GetFloatTrackedDeviceProperty(HEADSET, ETrackedDeviceProperty_Prop_DisplayFrequency_Float, NULL);
+  float frequency = openvr_getDisplayFrequency();
   float frameDuration = 1.f / frequency;
   float vsyncToPhotons = state.system->GetFloatTrackedDeviceProperty(HEADSET, ETrackedDeviceProperty_Prop_SecondsFromVsyncToPhotons_Float, NULL);
 
@@ -533,6 +537,7 @@ HeadsetInterface lovrHeadsetOpenVRDriver = {
   .getName = openvr_getName,
   .getOriginType = openvr_getOriginType,
   .getDisplayDimensions = openvr_getDisplayDimensions,
+  .getDisplayFrequency = openvr_getDisplayFrequency,
   .getDisplayMask = openvr_getDisplayMask,
   .getDisplayTime = openvr_getDisplayTime,
   .getClipDistance = openvr_getClipDistance,