internal/graphicsdriver/direct: replace Get -> NewGraphics

Updates #2142

internal/graphicsdriver/directx/graphics_windows.go

@@ -20,7 +20,6 @@ import (
 	"os"
 	"reflect"
 	"strings"
-	"sync"
 	"unsafe"
 
 	"golang.org/x/sys/windows"
@@ -34,28 +33,22 @@ import (
 
 const frameCount = 2
 
-var (
+func NewGraphics() (graphicsdriver.Graphics, error) {
-	// isDirectXAvailable indicates whether DirectX is available or not.
+	const is64bit = uint64(^uintptr(0)) == ^uint64(0)
-	isDirectXAvailable     bool
-	isDirectXAvailableOnce sync.Once
-)
 
-var theGraphics Graphics
+	// In 32bit machines, DirectX is not used because
-
+	//   1) The functions syscall.Syscall cannot accept 64bit values as one argument
-func Get() *Graphics {
+	//   2) The struct layouts can be different
-	isDirectXAvailableOnce.Do(func() {
+	// TODO: Support DirectX for 32bit machines (#2088).
-		const is64bit = uint64(^uintptr(0)) == ^uint64(0)
+	if !is64bit {
-
+		return nil, fmt.Errorf("directx: DirectX is not available on a 32bit machine")
-		// In 32bit machines, DirectX is not used because
-		//   1) The functions syscall.Syscall cannot accept 64bit values as one argument
-		//   2) The struct layouts can be different
-		// TODO: Support DirectX for 32bit machines (#2088).
-		isDirectXAvailable = is64bit && theGraphics.initializeDevice() == nil
-	})
-	if !isDirectXAvailable {
-		return nil
 	}
-	return &theGraphics
+
+	g := &Graphics{}
+	if err := g.initializeDevice(); err != nil {
+		return nil, err
+	}
+	return g, nil
 }
 
 var inputElementDescs []_D3D12_INPUT_ELEMENT_DESC

internal/ui/graphics.go

@@ -24,7 +24,7 @@ import (
 type graphicsDriverCreator interface {
 	newAuto() (graphicsdriver.Graphics, error)
 	newOpenGL() (graphicsdriver.Graphics, error)
-	getDirectX() graphicsdriver.Graphics
+	newDirectX() (graphicsdriver.Graphics, error)
 	newMetal() (graphicsdriver.Graphics, error)
 }
 
@@ -51,10 +51,14 @@ func newGraphicsDriver(creator graphicsDriverCreator) (graphicsdriver.Graphics,
 		}
 		return g, nil
 	case "directx":
-		if g := creator.getDirectX(); g != nil {
+		g, err := creator.newDirectX()
-			return g, nil
+		if err != nil {
+			return nil, err
 		}
-		return nil, fmt.Errorf("ui: %s=%s is specified but DirectX is not available.", envName, env)
+		if g == nil {
+			return nil, fmt.Errorf("ui: %s=%s is specified but DirectX is not available.", envName, env)
+		}
+		return g, nil
 	case "metal":
 		g, err := creator.newMetal()
 		if err != nil {

internal/ui/ui_android.go

@@ -31,8 +31,8 @@ func (*graphicsDriverCreatorImpl) newOpenGL() (graphicsdriver.Graphics, error) {
 	return opengl.NewGraphics()
 }
 
-func (*graphicsDriverCreatorImpl) getDirectX() graphicsdriver.Graphics {
+func (*graphicsDriverCreatorImpl) newDirectX() (graphicsdriver.Graphics, error) {
-	return nil
+	return nil, nil
 }
 
 func (*graphicsDriverCreatorImpl) newMetal() (graphicsdriver.Graphics, error) {

internal/ui/ui_cbackend.go

@@ -35,8 +35,8 @@ func (*graphicsDriverCreatorImpl) newOpenGL() (graphicsdriver.Graphics, error) {
 	return opengl.NewGraphics()
 }
 
-func (*graphicsDriverCreatorImpl) getDirectX() graphicsdriver.Graphics {
+func (*graphicsDriverCreatorImpl) newDirectX() (graphicsdriver.Graphics, error) {
-	return nil
+	return nil, nil
 }
 
 func (*graphicsDriverCreatorImpl) newMetal() (graphicsdriver.Graphics, error) {

internal/ui/ui_glfw_darwin.go

@@ -276,8 +276,8 @@ func (*graphicsDriverCreatorImpl) newOpenGL() (graphicsdriver.Graphics, error) {
 	return opengl.NewGraphics()
 }
 
-func (*graphicsDriverCreatorImpl) getDirectX() graphicsdriver.Graphics {
+func (*graphicsDriverCreatorImpl) newDirectX() (graphicsdriver.Graphics, error) {
-	return nil
+	return nil, nil
 }
 
 func (*graphicsDriverCreatorImpl) newMetal() (graphicsdriver.Graphics, error) {

internal/ui/ui_glfw_unix.go

@@ -43,8 +43,8 @@ func (*graphicsDriverCreatorImpl) newOpenGL() (graphicsdriver.Graphics, error) {
 	return opengl.NewGraphics()
 }
 
-func (*graphicsDriverCreatorImpl) getDirectX() graphicsdriver.Graphics {
+func (*graphicsDriverCreatorImpl) newDirectX() (graphicsdriver.Graphics, error) {
-	return nil
+	return nil, nil
 }
 
 func (*graphicsDriverCreatorImpl) newMetal() (graphicsdriver.Graphics, error) {

internal/ui/ui_glfw_windows.go

@@ -36,24 +36,26 @@ type graphicsDriverCreatorImpl struct {
 }
 
 func (g *graphicsDriverCreatorImpl) newAuto() (graphicsdriver.Graphics, error) {
-	if d := g.getDirectX(); d != nil {
+	d, err1 := g.newDirectX()
+	if err1 == nil {
 		return d, nil
 	}
-	return g.newOpenGL()
+	o, err2 := g.newOpenGL()
+	if err2 == nil {
+		return o, nil
+	}
+	return nil, fmt.Errorf("ui: failed to choose graphics drivers: DirectX: %v, OpenGL: %v", err1, err2)
 }
 
 func (*graphicsDriverCreatorImpl) newOpenGL() (graphicsdriver.Graphics, error) {
 	return opengl.NewGraphics()
 }
 
-func (g *graphicsDriverCreatorImpl) getDirectX() graphicsdriver.Graphics {
+func (g *graphicsDriverCreatorImpl) newDirectX() (graphicsdriver.Graphics, error) {
 	if g.transparent {
-		return nil
+		return nil, fmt.Errorf("ui: DirectX is not available with a transparent window")
 	}
-	if d := directx.Get(); d != nil {
+	return directx.NewGraphics()
-		return d
-	}
-	return nil
 }
 
 func (*graphicsDriverCreatorImpl) newMetal() (graphicsdriver.Graphics, error) {

internal/ui/ui_ios.go

@@ -45,8 +45,8 @@ func (*graphicsDriverCreatorImpl) newOpenGL() (graphicsdriver.Graphics, error) {
 	return opengl.NewGraphics()
 }
 
-func (*graphicsDriverCreatorImpl) getDirectX() graphicsdriver.Graphics {
+func (*graphicsDriverCreatorImpl) newDirectX() (graphicsdriver.Graphics, error) {
-	return nil
+	return nil, nil
 }
 
 func (g *graphicsDriverCreatorImpl) newMetal() (graphicsdriver.Graphics, error) {

internal/ui/ui_js.go

@@ -35,8 +35,8 @@ func (*graphicsDriverCreatorImpl) newOpenGL() (graphicsdriver.Graphics, error) {
 	return opengl.NewGraphics()
 }
 
-func (*graphicsDriverCreatorImpl) getDirectX() graphicsdriver.Graphics {
+func (*graphicsDriverCreatorImpl) newDirectX() (graphicsdriver.Graphics, error) {
-	return nil
+	return nil, nil
 }
 
 func (*graphicsDriverCreatorImpl) newMetal() (graphicsdriver.Graphics, error) {