ui: Refactoring: Remove events

internal/loop/run.go

@@ -86,10 +86,17 @@ type GraphicsContext interface {
 	UpdateAndDraw(context *opengl.Context, updateCount int) error
 }
 
-type regularTermination struct{}
+type loopGraphicsContext struct {
+	runContext      *runContext
+	graphicsContext GraphicsContext
+}
 
-func (e regularTermination) Error() string {
-	return "regular termination"
+func (g *loopGraphicsContext) SetSize(width, height int, scale float64) error {
+	return g.graphicsContext.SetSize(width, height, scale)
+}
+
+func (g *loopGraphicsContext) Update() error {
+	return g.runContext.render(g.graphicsContext)
 }
 
 func Run(g GraphicsContext, width, height int, scale float64, title string, fps int) (err error) {
@@ -114,10 +121,8 @@ func Run(g GraphicsContext, width, height int, scale float64, title string, fps
 	currentRunContext.lastUpdated = n
 	currentRunContext.lastFPSUpdated = n
 
-	if err := ui.CurrentUI().AnimationFrameLoop(func() error {
-		return currentRunContext.update(g)
-	}); err != nil {
-		if err == (regularTermination{}) {
+	if err := ui.CurrentUI().AnimationFrameLoop(&loopGraphicsContext{currentRunContext, g}); err != nil {
+		if _, ok := err.(*ui.RegularTermination); ok {
 			return nil
 		}
 		return err
@@ -125,31 +130,6 @@ func Run(g GraphicsContext, width, height int, scale float64, title string, fps
 	return nil
 }
 
-func (c *runContext) update(g GraphicsContext) error {
-	e, err := ui.CurrentUI().Update()
-	if err != nil {
-		return err
-	}
-	switch e := e.(type) {
-	case ui.NopEvent:
-	case ui.ScreenSizeEvent:
-		if err := g.SetSize(e.Width, e.Height, e.ActualScale); err != nil {
-			return err
-		}
-		e.Done <- struct{}{}
-	case ui.CloseEvent:
-		return regularTermination{}
-	case ui.RenderEvent:
-		if err := currentRunContext.render(g); err != nil {
-			return err
-		}
-		e.Done <- struct{}{}
-	default:
-		panic("not reach")
-	}
-	return nil
-}
-
 func (c *runContext) render(g GraphicsContext) error {
 	fps := c.fps
 	n := now()

internal/ui/event.go

@@ -1,32 +0,0 @@
-// Copyright 2016 Hajime Hoshi
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package ui
-
-type NopEvent struct {
-}
-
-type CloseEvent struct {
-}
-
-type ScreenSizeEvent struct {
-	Width       int
-	Height      int
-	ActualScale float64
-	Done        chan struct{}
-}
-
-type RenderEvent struct {
-	Done chan struct{}
-}

internal/ui/ui.go

@@ -14,12 +14,23 @@
 
 package ui
 
+type GraphicsContext interface {
+	SetSize(width, height int, scale float64) error
+	Update() error
+}
+
 type UserInterface interface {
 	Start(width, height int, scale float64, title string) error
-	Update() (interface{}, error)
 	Terminate() error
-	AnimationFrameLoop(f func() error) error
+	AnimationFrameLoop(g GraphicsContext) error
 	ScreenScale() float64
 	SetScreenSize(width, height int) (bool, error)
 	SetScreenScale(scale float64) (bool, error)
 }
+
+type RegularTermination struct {
+}
+
+func (*RegularTermination) Error() string {
+	return "regular termination"
+}

internal/ui/ui_glfw.go

@@ -192,32 +192,29 @@ func (u *userInterface) pollEvents() error {
 	return currentInput.update(u.window, u.scale*glfwScale())
 }
 
-func (u *userInterface) Update() (interface{}, error) {
+func (u *userInterface) update(g GraphicsContext) error {
 	shouldClose := false
 	_ = u.runOnMainThread(func() error {
 		shouldClose = u.window.ShouldClose()
 		return nil
 	})
 	if shouldClose {
-		return CloseEvent{}, nil
+		return &RegularTermination{}
 	}
 
-	var screenSizeEvent *ScreenSizeEvent
+	actualScale := 0.0
 	_ = u.runOnMainThread(func() error {
 		if !u.sizeChanged {
 			return nil
 		}
 		u.sizeChanged = false
-		screenSizeEvent = &ScreenSizeEvent{
-			Width:       u.width,
-			Height:      u.height,
-			ActualScale: u.actualScreenScale(),
-			Done:        make(chan struct{}, 1),
-		}
+		actualScale = u.actualScreenScale()
 		return nil
 	})
-	if screenSizeEvent != nil {
-		return *screenSizeEvent, nil
+	if 0 < actualScale {
+		if err := g.SetSize(u.width, u.height, actualScale); err != nil {
+			return err
+		}
 	}
 
 	if err := u.runOnMainThread(func() error {
@@ -236,11 +233,12 @@ func (u *userInterface) Update() (interface{}, error) {
 		}
 		return nil
 	}); err != nil {
-		return nil, err
+		return err
 	}
-	// Dummy channel
-	ch := make(chan struct{}, 1)
-	return RenderEvent{ch}, nil
+	if err := g.Update(); err != nil {
+		return err
+	}
+	return nil
 }
 
 func (u *userInterface) Terminate() error {
@@ -251,9 +249,9 @@ func (u *userInterface) Terminate() error {
 	return nil
 }
 
-func (u *userInterface) AnimationFrameLoop(f func() error) error {
+func (u *userInterface) AnimationFrameLoop(g GraphicsContext) error {
 	for {
-		if err := f(); err != nil {
+		if err := u.update(g); err != nil {
 			return err
 		}
 		// The bound framebuffer must be the default one (0) before swapping buffers.

internal/ui/ui_js.go

@@ -65,28 +65,26 @@ func (u *userInterface) ActualScreenScale() float64 {
 	return u.scale * u.deviceScale
 }
 
-func (u *userInterface) Update() (interface{}, error) {
+func (u *userInterface) update(g GraphicsContext) error {
 	if !u.windowFocus {
-		return NopEvent{}, nil
+		return nil
 	}
 	if !u.contextRestored {
-		return NopEvent{}, nil
+		return nil
 	}
 	currentInput.updateGamepads()
 	if u.sizeChanged {
 		u.sizeChanged = false
 		w, h := u.size()
-		e := ScreenSizeEvent{
-			Width:       w,
-			Height:      h,
-			ActualScale: u.ActualScreenScale(),
-			Done:        make(chan struct{}, 1),
+		if err := g.SetSize(w, h, u.ActualScreenScale()); err != nil {
+			return err
 		}
-		return e, nil
+		return nil
 	}
-	// Dummy channel
-	ch := make(chan struct{}, 1)
-	return RenderEvent{ch}, nil
+	if err := g.Update(); err != nil {
+		return err
+	}
+	return nil
 }
 
 func (u *userInterface) Terminate() error {
@@ -94,18 +92,18 @@ func (u *userInterface) Terminate() error {
 	return nil
 }
 
-func (u *userInterface) AnimationFrameLoop(f func() error) error {
+func (u *userInterface) AnimationFrameLoop(g GraphicsContext) error {
 	ch := make(chan error)
-	var ff func()
-	ff = func() {
-		if err := f(); err != nil {
+	var f func()
+	f = func() {
+		if err := u.update(g); err != nil {
 			ch <- err
 			close(ch)
 			return
 		}
-		js.Global.Get("window").Call("requestAnimationFrame", ff)
+		js.Global.Get("window").Call("requestAnimationFrame", f)
 	}
-	ff()
+	f()
 	return <-ch
 }
 

internal/ui/ui_mobile.go

@@ -81,28 +81,23 @@ func (u *userInterface) Terminate() error {
 	return nil
 }
 
-func (u *userInterface) Update() (interface{}, error) {
+func (u *userInterface) AnimationFrameLoop(g GraphicsContext) error {
+	for {
 		if u.sizeChanged {
 			// Sizing also calls GL functions
 			<-chRender
 			u.sizeChanged = false
-		e := ScreenSizeEvent{
-			Width:       u.width,
-			Height:      u.height,
-			ActualScale: u.actualScreenScale(),
-			Done:        chRenderEnd,
-		}
-		return e, nil
-	}
-	<-chRender
-	return RenderEvent{chRenderEnd}, nil
-}
-
-func (u *userInterface) AnimationFrameLoop(f func() error) error {
-	for {
-		if err := f(); err != nil {
+			if err := g.SetSize(u.width, u.height, u.actualScreenScale()); err != nil {
 				return err
 			}
+			chRenderEnd <- struct{}{}
+			continue
+		}
+		<-chRender
+		if err := g.Update(); err != nil {
+			return err
+		}
+		chRenderEnd <- struct{}{}
 	}
 }