mobile: Accept gomobile build (#249)

internal/opengl/context_mobile.go

@@ -82,7 +82,16 @@ func Init() {
 	theContext = c
 }
 
+func InitWithContext(context mgl.Context) {
+	c := &Context{}
+	c.gl = context
+	theContext = c
+}
+
 func (c *Context) DoWork(chError <-chan error, chDone <-chan struct{}) error {
+	if c.worker == nil {
+		panic("not reached")
+	}
 	// TODO: Check this is called on the rendering thread
 loop:
 	for {

internal/ui/input_mobile.go

@@ -40,14 +40,14 @@ func (i *Input) IsMouseButtonPressed(key MouseButton) bool {
 	return false
 }
 
-func (i *Input) updateTouches(touches []Touch) {
+func (i *Input) updateTouches(touches []Touch, dx, dy int) {
 	i.m.Lock()
-	defer i.m.Unlock()
 	ts := make([]touch, len(touches))
 	for i := 0; i < len(ts); i++ {
 		ts[i].id = touches[i].ID()
 		x, y := touches[i].Position()
-		ts[i].x, ts[i].y = x, y
+		ts[i].x, ts[i].y = x+dx, y+dy
 	}
 	i.touches = ts
+	i.m.Unlock()
 }

internal/ui/mainloop_gomobilebuild.go

@@ -0,0 +1,95 @@
+// Copyright 2018 The Ebiten Authors
+//
+// 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.
+
+// +build android ios
+// +build gomobilebuild
+
+package ui
+
+import (
+	"golang.org/x/mobile/app"
+	"golang.org/x/mobile/event/lifecycle"
+	"golang.org/x/mobile/event/paint"
+	"golang.org/x/mobile/event/size"
+	mtouch "golang.org/x/mobile/event/touch"
+	"golang.org/x/mobile/gl"
+
+	"github.com/hajimehoshi/ebiten/internal/opengl"
+)
+
+var (
+	glContextCh chan gl.Context
+)
+
+func appMain(a app.App) {
+	var glctx gl.Context
+	touches := map[mtouch.Sequence]*touch{}
+	for e := range a.Events() {
+		switch e := a.Filter(e).(type) {
+		case lifecycle.Event:
+			switch e.Crosses(lifecycle.StageVisible) {
+			case lifecycle.CrossOn:
+				glctx, _ = e.DrawContext.(gl.Context)
+				// Assume that glctx is always a same instance.
+				// Then, only once initializing should be enough.
+				if glContextCh != nil {
+					glContextCh <- glctx
+					glContextCh = nil
+				}
+				a.Send(paint.Event{})
+			case lifecycle.CrossOff:
+				glctx = nil
+			}
+		case size.Event:
+			setFullscreen(e.WidthPx, e.HeightPx)
+		case paint.Event:
+			if glctx == nil || e.External {
+				continue
+			}
+			chRender <- struct{}{}
+			<-chRenderEnd
+			a.Publish()
+			a.Send(paint.Event{})
+		case mtouch.Event:
+			switch e.Type {
+			case mtouch.TypeBegin, mtouch.TypeMove:
+				s := float32(actualScale())
+				t := &touch{
+					id: int(e.Sequence), // TODO: Is it ok to cast from int64 to int here?
+					x:  int(e.X / s),
+					y:  int(e.Y / s),
+				}
+				touches[e.Sequence] = t
+			case mtouch.TypeEnd:
+				delete(touches, e.Sequence)
+			}
+			ts := []Touch{}
+			for _, t := range touches {
+				ts = append(ts, t)
+			}
+			UpdateTouches(ts)
+		}
+	}
+}
+
+func RunMainThreadLoop(ch <-chan error) error {
+	glContextCh = make(chan gl.Context)
+	app.Main(appMain)
+	return nil
+}
+
+func initOpenGL() {
+	ctx := <-glContextCh
+	opengl.InitWithContext(ctx)
+}

internal/ui/mainloop_notgomobilebuild.go

@@ -0,0 +1,32 @@
+// Copyright 2018 The Ebiten Authors
+//
+// 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.
+
+// +build android ios
+// +build !gomobilebuild
+
+package ui
+
+import (
+	"errors"
+
+	"github.com/hajimehoshi/ebiten/internal/opengl"
+)
+
+func RunMainThreadLoop(ch <-chan error) error {
+	return errors.New("ui: don't call this: use RunWithoutMainLoop instead of Run")
+}
+
+func initOpenGL() {
+	opengl.Init()
+}

internal/ui/ui_mobile.go

@@ -27,10 +27,6 @@ import (
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 )
 
-func RunMainThreadLoop(ch <-chan error) error {
-	return errors.New("ui: don't call this: use RunWithoutMainLoop instead of Run")
-}
-
 func Render(chError <-chan error) error {
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
@@ -54,6 +50,11 @@ type userInterface struct {
 	scale       float64
 	sizeChanged bool
 
+	// Used for gomobile-build
+	fullscreenScale    float64
+	fullscreenWidthPx  int
+	fullscreenHeightPx int
+
 	m sync.RWMutex
 }
 
@@ -72,9 +73,10 @@ func Run(width, height int, scale float64, title string, g GraphicsContext) erro
 	u.scale = scale
 	u.sizeChanged = true
 	u.m.Unlock()
-
 	// title is ignored?
-	opengl.Init()
+
+	initOpenGL()
+
 	for {
 		if err := u.update(g); err != nil {
 			return err
@@ -92,7 +94,7 @@ func (u *userInterface) updateGraphicsContext(g GraphicsContext) {
 	if sizeChanged {
 		width = u.width
 		height = u.height
-		actualScale = u.scale * devicescale.DeviceScale()
+		actualScale = u.actualScaleImpl()
 	}
 	u.sizeChanged = false
 	u.m.Unlock()
@@ -103,6 +105,25 @@ func (u *userInterface) updateGraphicsContext(g GraphicsContext) {
 	}
 }
 
+func actualScale() float64 {
+	return currentUI.actualScale()
+}
+
+func (u *userInterface) actualScale() float64 {
+	u.m.Lock()
+	s := u.actualScaleImpl()
+	u.m.Unlock()
+	return s
+}
+
+func (u *userInterface) actualScaleImpl() float64 {
+	scale := u.scale
+	if u.fullscreenScale != 0 {
+		scale = u.fullscreenScale
+	}
+	return scale * devicescale.DeviceScale()
+}
+
 func (u *userInterface) update(g GraphicsContext) error {
 	<-chRender
 	defer func() {
@@ -119,6 +140,17 @@ func (u *userInterface) update(g GraphicsContext) error {
 	return nil
 }
 
+func screenSize() (int, int) {
+	return currentUI.screenSize()
+}
+
+func (u *userInterface) screenSize() (int, int) {
+	u.m.Lock()
+	w, h := u.width, u.height
+	u.m.Unlock()
+	return w, h
+}
+
 func SetScreenSize(width, height int) bool {
 	currentUI.setScreenSize(width, height)
 	return true
@@ -129,6 +161,7 @@ func (u *userInterface) setScreenSize(width, height int) {
 	if u.width != width || u.height != height {
 		u.width = width
 		u.height = height
+		u.updateFullscreenScaleIfNeeded()
 		u.sizeChanged = true
 	}
 	u.m.Unlock()
@@ -156,12 +189,64 @@ func ScreenScale() float64 {
 	return s
 }
 
+func setFullscreen(widthPx, heightPx int) {
+	currentUI.setFullscreen(widthPx, heightPx)
+}
+
+func (u *userInterface) setFullscreen(widthPx, heightPx int) {
+	u.m.Lock()
+	u.fullscreenWidthPx = widthPx
+	u.fullscreenHeightPx = heightPx
+	u.updateFullscreenScaleIfNeeded()
+	u.sizeChanged = true
+	u.m.Unlock()
+}
+
+func (u *userInterface) updateFullscreenScaleIfNeeded() {
+	if u.fullscreenWidthPx == 0 || u.fullscreenHeightPx == 0 {
+		return
+	}
+	w, h := u.width, u.height
+	scaleX := float64(u.fullscreenWidthPx) / float64(w)
+	scaleY := float64(u.fullscreenHeightPx) / float64(h)
+	scale := scaleX
+	if scale > scaleY {
+		scale = scaleY
+	}
+	u.fullscreenScale = scale / devicescale.DeviceScale()
+}
+
 func ScreenPadding() (x0, y0, x1, y1 float64) {
-	return 0, 0, 0, 0
+	return currentUI.screenPadding()
+}
+
+func (u *userInterface) screenPadding() (x0, y0, x1, y1 float64) {
+	u.m.Lock()
+	x0, y0, x1, y1 = u.screenPaddingImpl()
+	u.m.Unlock()
+	return
+}
+
+func (u *userInterface) screenPaddingImpl() (x0, y0, x1, y1 float64) {
+	if u.fullscreenScale == 0 {
+		return 0, 0, 0, 0
+	}
+	s := u.fullscreenScale * devicescale.DeviceScale()
+	ox := (float64(u.fullscreenWidthPx) - float64(u.width)*s) / 2
+	oy := (float64(u.fullscreenHeightPx) - float64(u.height)*s) / 2
+	return ox, oy, ox, oy
 }
 
 func adjustCursorPosition(x, y int) (int, int) {
-	return x, y
+	return currentUI.adjustCursorPosition(x, y)
+}
+
+func (u *userInterface) adjustCursorPosition(x, y int) (int, int) {
+	u.m.Lock()
+	ox, oy, _, _ := u.screenPaddingImpl()
+	s := u.actualScaleImpl()
+	u.m.Unlock()
+	return x - int(ox/s), y - int(oy/s)
 }
 
 func IsCursorVisible() bool {
@@ -201,5 +286,9 @@ func SetWindowDecorated(decorated bool) {
 }
 
 func UpdateTouches(touches []Touch) {
-	currentInput.updateTouches(touches)
+	currentUI.m.Lock()
+	ox, oy, _, _ := currentUI.screenPaddingImpl()
+	s := currentUI.actualScaleImpl()
+	currentUI.m.Unlock()
+	currentInput.updateTouches(touches, -int(ox/s), -int(oy/s))
 }

mobile/mobile.go

@@ -14,6 +14,9 @@
 
 // Package mobile provides functions for mobile platforms (Android and iOS).
 //
+// This package is used when you use `gomobile bind`.
+// For `gomobile build`, you don't have to use this package.
+//
 // For usage, see https://github.com/hajimehoshi/ebiten/wiki/Mobile, https://github.com/hajimehoshi/ebiten/wiki/Android and https://github.com/hajimehoshi/ebiten/wiki/iOS.
 package mobile
 

run.go

@@ -109,7 +109,7 @@ func run(width, height int, scale float64, title string, g *graphicsContext) err
 // f is not called when the window is in background by default.
 // This setting is configurable with SetRunnableInBackground.
 //
-// The given scale is ignored on fullscreen mode.
+// The given scale is ignored on fullscreen mode or gomobile-build mode.
 //
 // Run returns error when 1) OpenGL error happens, 2) audio error happens or 3) f returns error.
 // In the case of 3), Run returns the same error.
@@ -139,8 +139,8 @@ func Run(f func(*Image) error, width, height int, scale float64, title string) e
 // RunWithoutMainLoop runs the game, but don't call the loop on the main (UI) thread.
 // Different from Run, this function returns immediately.
 //
-// Typically, Ebiten users don't have to call this directly.
+// Ebiten users should NOT call this function.
-// Instead, functions in github.com/hajimehoshi/ebiten/mobile module call this.
+// Instead, functions in github.com/hajimehoshi/ebiten/mobile package calls this.
 func RunWithoutMainLoop(f func(*Image) error, width, height int, scale float64, title string) <-chan error {
 	ch := make(chan error)
 	go func() {