Refactoring: isRunning -> isImageAvailable

image.go

@@ -496,7 +496,7 @@ func (i *Image) ColorModel() color.Model {
 //
 // At can't be called outside the main loop (ebiten.Run's updating function) starts (as of version 1.4.0-alpha).
 func (i *Image) At(x, y int) color.Color {
-	if atomic.LoadInt32(&isRunning) == 0 {
+	if atomic.LoadInt32(&isImageAvailable) == 0 {
 		panic("ebiten: (*Image).At is not available outside the main loop so far")
 	}
 
@@ -519,7 +519,7 @@ func (i *Image) At(x, y int) color.Color {
 //
 // If the image is disposed, Set does nothing.
 func (img *Image) Set(x, y int, clr color.Color) {
-	if atomic.LoadInt32(&isRunning) == 0 {
+	if atomic.LoadInt32(&isImageAvailable) == 0 {
 		panic("ebiten: (*Image).Set is not available outside the main loop so far")
 	}
 

internal/web/js.go

@@ -22,10 +22,6 @@ import (
 	"syscall/js"
 )
 
-func IsGopherJS() bool {
-	return runtime.GOOS != "js"
-}
-
 func IsBrowser() bool {
 	return true
 }

internal/web/notjs.go

@@ -16,10 +16,6 @@
 
 package web
 
-func IsGopherJS() bool {
-	return false
-}
-
 func IsBrowser() bool {
 	return false
 }

run.go

@@ -22,7 +22,6 @@ import (
 	"github.com/hajimehoshi/ebiten/internal/driver"
 	"github.com/hajimehoshi/ebiten/internal/graphicsdriver"
 	"github.com/hajimehoshi/ebiten/internal/uidriver"
-	"github.com/hajimehoshi/ebiten/internal/web"
 )
 
 var _ = __EBITEN_REQUIRES_GO_VERSION_1_12_OR_LATER__
@@ -47,7 +46,7 @@ func CurrentFPS() float64 {
 var (
 	isDrawingSkipped = int32(0)
 	currentMaxTPS    = int32(DefaultTPS)
-	isRunning        = int32(0)
+	isImageAvailable = int32(0)
 )
 
 func setDrawingSkipped(skipped bool) {
@@ -133,12 +132,6 @@ func Run(f func(*Image) error, width, height int, scale float64, title string) e
 	c := newUIContext(f)
 	theUIContext.Store(c)
 
-	atomic.StoreInt32(&isRunning, 1)
-	// On GopherJS, run returns immediately.
-	if !web.IsGopherJS() {
-		defer atomic.StoreInt32(&isRunning, 0)
-	}
-
 	if err := uidriver.Get().Run(width, height, scale, title, c, graphicsdriver.Get()); err != nil {
 		if err == driver.RegularTermination {
 			return nil
@@ -160,7 +153,6 @@ func RunWithoutMainLoop(f func(*Image) error, width, height int, scale float64,
 	c := newUIContext(f)
 	theUIContext.Store(c)
 
-	atomic.StoreInt32(&isRunning, 1)
 	return uidriver.Get().RunWithoutMainLoop(width, height, scale, title, c, graphicsdriver.Get())
 }
 

uicontext.go

@@ -17,6 +17,7 @@ package ebiten
 import (
 	"fmt"
 	"math"
+	"sync/atomic"
 
 	"github.com/hajimehoshi/ebiten/internal/clock"
 	"github.com/hajimehoshi/ebiten/internal/driver"
@@ -96,6 +97,10 @@ func (c *uiContext) Update(afterFrameUpdate func()) error {
 	if err := shareable.BeginFrame(); err != nil {
 		return err
 	}
+
+	// Images are available after shareable is initialized.
+	atomic.StoreInt32(&isImageAvailable, 1)
+
 	for i := 0; i < updateCount; i++ {
 		c.offscreen.Clear()
 		// Mipmap images should be disposed by fill.