Merge pull request #116 from bjornbytes/headset-render-error

Refactor asynchronous headset render errors;

src/api/headset.c

@@ -78,17 +78,16 @@ static void renderHelper(void* userdata) {
   HeadsetRenderData* renderData = userdata;
   lua_State* L = renderData->L;
 #ifdef LOVR_HEADSET_HELPER_USES_REGISTRY
-  lua_getglobal(L, "_lovrHeadsetRenderError");
-  bool noError = lua_isnil(L, -1);
-  lua_pop(L, 1);
-  if (noError) { // Skip if there's already an error waiting to show
+  luax_geterror(L);
+  if (lua_isnil(L, -1)) {
     lua_pushcfunction(L, luax_getstack);
     lua_rawgeti(L, LUA_REGISTRYINDEX, renderData->ref);
     if (lua_pcall(L, 0, 0, -2)) {
-      lua_setglobal(L, "_lovrHeadsetRenderError");
+      luax_seterror(L);
     }
     lua_pop(L, 1); // pop luax_getstack
   }
+  lua_pop(L, 1);
 #else
   lua_call(L, 0, 0);
 #endif

src/headset/oculus_mobile.c

@@ -262,7 +262,7 @@ bool lovrPlatformHasWindow() {
 extern unsigned char boot_lua[];
 extern unsigned int boot_lua_len;
 
-static lua_State *L, *Lcoroutine;
+static lua_State *L, *T;
 static int coroutineRef = LUA_NOREF;
 static int coroutineStartFunctionRef = LUA_NOREF;
 
@@ -358,8 +358,8 @@ static void bridgeLovrInitState() {
   }
 
   coroutineStartFunctionRef = luaL_ref(L, LUA_REGISTRYINDEX); // Value returned by boot.lua
-  Lcoroutine = lua_newthread(L); // Leave L clear to be used by the draw function
-  lua_atpanic(Lcoroutine, luax_custom_atpanic);
+  T = lua_newthread(L); // Leave L clear to be used by the draw function
+  lua_atpanic(T, luax_custom_atpanic);
   coroutineRef = luaL_ref(L, LUA_REGISTRYINDEX); // Hold on to the Lua-side coroutine object so it isn't GC'd
 
   lovrLog("\n STATE INIT COMPLETE\n");
@@ -401,13 +401,15 @@ void bridgeLovrUpdate(BridgeLovrUpdateData *updateData) {
 
   // Go
   if (coroutineStartFunctionRef != LUA_NOREF) {
-    lua_rawgeti(Lcoroutine, LUA_REGISTRYINDEX, coroutineStartFunctionRef);
-    luaL_unref (Lcoroutine, LUA_REGISTRYINDEX, coroutineStartFunctionRef);
+    lua_rawgeti(T, LUA_REGISTRYINDEX, coroutineStartFunctionRef);
+    luaL_unref (T, LUA_REGISTRYINDEX, coroutineStartFunctionRef);
     coroutineStartFunctionRef = LUA_NOREF; // No longer needed
   }
-  int coroutineArgs = luax_pushLovrHeadsetRenderError(Lcoroutine);
-  if (lua_resume(Lcoroutine, coroutineArgs) != LUA_YIELD) {
-    if (lua_type(Lcoroutine, -1) == LUA_TSTRING && !strcmp(lua_tostring(Lcoroutine, -1), "restart")) {
+
+  luax_geterror(T);
+  luax_clearerror(T);
+  if (lua_resume(T, 1) != LUA_YIELD) {
+    if (lua_type(T, -1) == LUA_TSTRING && !strcmp(lua_tostring(T, -1), "restart")) {
       lua_close(L);
       bridgeLovrInitState();
     } else {

src/luax.c

@@ -289,18 +289,6 @@ Color luax_checkcolor(lua_State* L, int index) {
   return color;
 }
 
-int luax_pushLovrHeadsetRenderError(lua_State *L) {
-  lua_getglobal(L, "_lovrHeadsetRenderError"); // renderCallback failed
-  bool haveRenderError = !lua_isnil(L, -1);
-  if (haveRenderError) {
-    lua_pushnil(L); // Now the error is on the stack remove it from globals
-    lua_setglobal(L, "_lovrHeadsetRenderError");
-  } else {
-    lua_pop(L, 1); // pop stray nil
-  }
-  return haveRenderError;
-}
-
 #if LUA_VERSION_NUM < 502
 void luax_setmainthread(lua_State *L) {
   lua_pushthread(L);

src/luax.h

@@ -10,6 +10,9 @@
 #define luax_checktype(L, i, T) ((T*) _luax_checktype(L, i, #T))
 #define luax_checkfloat(L, i) (float) luaL_checknumber(L, i)
 #define luax_optfloat(L, i, x) (float) luaL_optnumber(L, i, x)
+#define luax_geterror(L) lua_getfield(L, LUA_REGISTRYINDEX, "_lovrerror")
+#define luax_seterror(L) lua_setfield(L, LUA_REGISTRYINDEX, "_lovrerror")
+#define luax_clearerror(L) lua_pushnil(L), luax_seterror(L)
 typedef void (*luax_destructor)(void);
 
 int luax_print(lua_State* L);
@@ -27,7 +30,6 @@ int luax_getstack_panic(lua_State *L);
 void luax_pushconf(lua_State* L);
 int luax_setconf(lua_State* L);
 Color luax_checkcolor(lua_State* L, int index);
-int luax_pushLovrHeadsetRenderError(lua_State *L);
 
 #if LUA_VERSION_NUM < 502
 #define LUA_RIDX_MAINTHREAD 1

src/main.c

@@ -34,17 +34,13 @@ void lovrDestroy(void* arg) {
 
 static void emscriptenLoop(void* arg) {
   lovrEmscriptenContext* context = arg;
-  lua_getglobal(context->L, "_lovrHeadsetRenderError"); // webvr.c renderCallback failed
-  bool haveRenderError = !lua_isnil(context->L, -1);
-  if (!haveRenderError) {
-    lua_pop(context->L, 1);
-  }
+  lua_State* T = context->T;
 
-  int coroutineArgs = luax_pushLovrHeadsetRenderError(context->T);
-
-  if (lua_resume(context->T, coroutineArgs) != LUA_YIELD) {
-    bool restart = lua_type(context->T, -1) == LUA_TSTRING && !strcmp(lua_tostring(context->T, -1), "restart");
-    int status = lua_tonumber(context->T, -1);
+  luax_geterror(T);
+  luax_clearerror(T);
+  if (lua_resume(T, 1) != LUA_YIELD) {
+    bool restart = lua_type(T, -1) == LUA_TSTRING && !strcmp(lua_tostring(T, -1), "restart");
+    int status = lua_tonumber(T, -1);
 
     lua_close(context->L);
     emscripten_cancel_main_loop();