Clean up boot.lua;

A lot of clean up can happen now that C doesn't push delayed errors to
Lua.  This was happening for Pico and WebVR, neither of which are used
anymore.

Also default vsync to true but force it off if VR is active.

etc/boot.lua

@@ -24,7 +24,7 @@ function lovr.boot()
     },
     graphics = {
       debug = false,
-      vsync = false,
+      vsync = true,
       stencil = false,
       antialias = true,
       shadercache = true
@@ -219,59 +219,39 @@ function lovr.threaderror(thread, err)
 end
 
 function lovr.log(message, level, tag)
-  message = message:gsub('\n$', '')
-  print(message)
+  print(message:gsub('\n$', ''))
 end
 
--- This splits up the string returned by luax_getstack so it looks like the error message plus the string from
--- debug.traceback(). This includes splitting on the newline before 'stack traceback:' and appending a newline
-local function splitOnLabelLine(s, t)
-  local at = s:reverse():find(t:reverse())
-  if at then
-    local slen = #s
-    at = (#s - at - #t + 2)
-    return s:sub(1, at-2), s:sub(at,slen) .. '\n'
-  else
-    return s, ''
-  end
-end
-
--- lovr will run this function in its own coroutine
 return function()
-  local errored = false -- lovr.errhand may only be called once
-  local function onerror(e, tb) -- wrapper for errhand to ensure it is only called once
-    local function abortclean()
-      return 1
-    end
+  local errored = false
+
+  local function onerror(...)
     if not errored then
-      errored = true
-      return lovr.errhand(e, tb) or abortclean
+      errored = true -- Ensure errhand is only called once
+      return lovr.errhand(...) or function() return 1 end
     else
-      print('Error occurred while trying to display another error:\n' ..
-        tostring(e) .. formatTraceback(tb or debug.traceback('', 2)))
-      return abortclean
+      local message = tostring(...) .. formatTraceback(debug.traceback('', 2))
+      print('Error occurred while trying to display another error:\n' .. message)
+      return function() return 1 end
     end
   end
 
-  -- Executes lovr.boot and lovr.run.
-  -- continuation, afterward, will be either lovr.run's per-frame function, or the result of errhand.
-  local _, continuation = xpcall(lovr.boot, onerror)
+  -- thread will be either lovr.run's step function, or the result of errhand
+  local _, thread = xpcall(lovr.boot, onerror)
 
   while true do
-    if type(continuation) == 'string' then -- LuaJIT returns a fixed string if an error occurs in an xpcall error handler
-      print('Error occurred while trying to display another error: ' .. continuation)
-      return 1
+    local ok, result, cookie = xpcall(thread, onerror)
+
+    if result and ok then -- If step function returned something, exit coroutine and return to C
+      return result, cookie
+    elseif not ok then -- Switch to errhand loop
+      thread = result
+      if type(thread) ~= 'function' then
+        print('Error occurred while trying to display another error:\n' .. tostring(result))
+        return 1
+      end
     end
 
-    local ok, result, extra = xpcall(continuation, onerror)
-    if result and ok then return result, extra -- Result is value returned by function. Return it.
-    elseif not ok then continuation = result end -- Result is value returned by error handler. Make it the new error handler.
-
-    local externerror = coroutine.yield() -- Return control to C code
-
-    if externerror then -- A must-report error occurred in the C code
-      local errorpart, tracepart = splitOnLabelLine(externerror, 'stack traceback:')
-      continuation = onerror(errorpart, tracepart) -- Switch continuation to lovr.errhand
-    end
+    coroutine.yield()
   end
 end

src/api/api.h

@@ -106,9 +106,6 @@ typedef struct {
 #define luax_checkfloat(L, i) (float) luaL_checknumber(L, i)
 #define luax_optfloat(L, i, x) (float) luaL_optnumber(L, i, x)
 #define luax_tofloat(L, i) (float) lua_tonumber(L, i)
-#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)
 
 void luax_preload(struct lua_State* L);
 void _luax_registertype(struct lua_State* L, const char* name, const struct luaL_Reg* functions, void (*destructor)(void*));

src/modules/graphics/graphics.c

@@ -447,6 +447,9 @@ bool lovrGraphicsInit(GraphicsConfig* config) {
     gpu.vk.getPhysicalDevice = lovrHeadsetInterface->getVulkanPhysicalDevice;
     gpu.vk.createInstance = lovrHeadsetInterface->createVulkanInstance;
     gpu.vk.createDevice = lovrHeadsetInterface->createVulkanDevice;
+    if (lovrHeadsetInterface->driverType != DRIVER_DESKTOP) {
+      gpu.vk.vsync = false;
+    }
   }
 #endif