fixes to viewport, config tuning

engine/types/gamestate.go

@@ -0,0 +1,20 @@
+package types
+
+type GameState struct {
+	Mainfunc     chan func()
+	Exit         chan struct{}
+	Input        chan string
+	RawInput     chan int
+	FovRecompute chan struct{}
+	Redraw		 chan struct{}
+}
+
+// do runs f on the main thread.
+func (g *GameState) Do(f func()) {
+	done := make(chan struct{}, 1)
+	g.Mainfunc <- func() {
+		f()
+		done <- struct{}{}
+	}
+	<-done
+}