From 8f857daf3e4f2af460352a06b71ab412911d079d Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Thu, 9 Sep 2021 03:58:58 +0900
Subject: [PATCH] internal/restorable: Bug fix: Forbid NewImage before the
 graphics driver is ready

---
 internal/restorable/image.go       | 4 ++++
 internal/restorable/images.go      | 3 +++
 internal/restorable/shader_test.go | 5 +++--
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/internal/restorable/image.go b/internal/restorable/image.go
index 8570ef8c5..505a54c05 100644
--- a/internal/restorable/image.go
+++ b/internal/restorable/image.go
@@ -141,6 +141,10 @@ func ensureEmptyImage() *Image {
 //
 // Note that Dispose is not called automatically.
 func NewImage(width, height int) *Image {
+	if !graphicsDriverInitialized {
+		panic("restorable: graphics driver must be ready at NewImage but not")
+	}
+
 	i := &Image{
 		image:  graphicscommand.NewImage(width, height),
 		width:  width,
diff --git a/internal/restorable/images.go b/internal/restorable/images.go
index e1f6db211..b877a4830 100644
--- a/internal/restorable/images.go
+++ b/internal/restorable/images.go
@@ -281,8 +281,11 @@ func (i *images) restore() error {
 	return nil
 }
 
+var graphicsDriverInitialized bool
+
 // InitializeGraphicsDriverState initializes the graphics driver state.
 func InitializeGraphicsDriverState() error {
+	graphicsDriverInitialized = true
 	return graphicscommand.InitializeGraphicsDriverState()
 }
 
diff --git a/internal/restorable/shader_test.go b/internal/restorable/shader_test.go
index 7167347be..6fca3bccb 100644
--- a/internal/restorable/shader_test.go
+++ b/internal/restorable/shader_test.go
@@ -25,9 +25,10 @@ import (
 	etesting "github.com/hajimehoshi/ebiten/v2/internal/testing"
 )
 
-var emptyImage = NewImage(3, 3)
-
 func clearImage(img *Image, w, h int) {
+	emptyImage := NewImage(3, 3)
+	defer emptyImage.Dispose()
+
 	dx0 := float32(0)
 	dy0 := float32(0)
 	dx1 := float32(w)