Separate input and render goroutines

gfx/gfx.go

@@ -17,7 +17,6 @@ import (
 )
 
 type RenderState struct {
-	Animating bool
 	Frames int
 	Frame  int
 }
@@ -87,9 +86,8 @@ func Render(rs RenderState, sOld, sNew game.State, w *pixelgl.Window, sb spriteB
 	renderSpawnPoints(sBatch, sNew.SpawnPoints, w.Bounds(), colors)
 	sBatch.Draw(w)
 
+	if rs.Frame < rs.Frames {
 		rs.Frame++
-	if rs.Frame > rs.Frames {
-		rs.Animating = false
 	}
 	return rs
 }

main.go

@@ -29,7 +29,6 @@ func run() error {
 	s := game.NewState()
 
 	rs := gfx.RenderState{
-		Animating: true,
 		Frames: 15,
 	}
 	sb, err := gfx.NewSpriteBank()
@@ -39,20 +38,30 @@ func run() error {
 	sOld := s
 	turn := 1
 
+	cmdC := make(chan []game.Command)
+	go func() { cmdC <- game.PollCommands(s) }()
+
+	stateCA := make(chan game.State)
+	stateCB := make(chan game.State)
+
+	go func(s game.State, sOld game.State, stateC <-chan game.State) {
 		var (
 			frames = 0
 			second = time.Tick(time.Second)
 		)
 
-	cmdC := make(chan []game.Command)
-	go func() { cmdC <- game.PollCommands(s) }()
-
 		for !w.Closed() {
-		if rs.Animating {
-			rs = gfx.Render(rs, sOld, s, w, *sb)
-			if !rs.Animating {
+			if rs.Frame == rs.Frames {
+				select {
+				case ss := <-stateCA:
 					sOld = s
+					s = ss
+					rs.Frame = 0
+				default:
 				}
+			}
+
+			rs = gfx.Render(rs, sOld, s, w, *sb)
 			w.Update()
 			frames++
 
@@ -62,15 +71,14 @@ func run() error {
 				frames = 0
 			default:
 			}
-		} else {
+		}
+	}(s, sOld, stateCA)
+
+	for !w.Closed() {
 		switch {
 		case w.Pressed(pixelgl.KeyQ):
 			return nil
-			case w.Pressed(pixelgl.KeySpace) || true:
-				//log.Printf("TURN %d", turn)
-				rs.Animating = true
-				rs.Frame = 0
-
+		case w.Pressed(pixelgl.KeySpace):
 			cmds := <-cmdC
 			s = game.UpdateState(s, sOld, cmds)
 			turn++
@@ -79,12 +87,16 @@ func run() error {
 				sOld = s
 				turn = 1
 			}
-				go func() { cmdC <- game.PollCommands(s) }()
+			go func() {
+				s := <-stateCB
+				cmdC <- game.PollCommands(s)
+			}()
+			stateCA <- s
+			stateCB <- s
 		}
 
 		w.UpdateInput()
 	}
-	}
 	return nil
 }