opengl: Unexport NewTexture

internal/graphicscommand/command.go

@@ -19,7 +19,6 @@ import (
 
 	"github.com/hajimehoshi/ebiten/internal/affine"
 	"github.com/hajimehoshi/ebiten/internal/graphics"
-	emath "github.com/hajimehoshi/ebiten/internal/math"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 )
 
@@ -407,36 +406,17 @@ type newImageCommand struct {
 	height int
 }
 
-func checkSize(width, height int) {
-	if width < 1 {
-		panic(fmt.Sprintf("graphics: width (%d) must be equal or more than 1.", width))
-	}
-	if height < 1 {
-		panic(fmt.Sprintf("graphics: height (%d) must be equal or more than 1.", height))
-	}
-	m := MaxImageSize()
-	if width > m {
-		panic(fmt.Sprintf("graphics: width (%d) must be less than or equal to %d", width, m))
-	}
-	if height > m {
-		panic(fmt.Sprintf("graphics: height (%d) must be less than or equal to %d", height, m))
-	}
-}
-
 func (c *newImageCommand) String() string {
 	return fmt.Sprintf("new-image: result: %p, width: %d, height: %d", c.result, c.width, c.height)
 }
 
 // Exec executes a newImageCommand.
 func (c *newImageCommand) Exec(indexOffsetInBytes int) error {
-	w := emath.NextPowerOf2Int(c.width)
-	h := emath.NextPowerOf2Int(c.height)
-	checkSize(w, h)
-	t, err := opengl.GetContext().NewTexture(w, h)
+	i, err := opengl.NewImage(c.width, c.height)
 	if err != nil {
 		return err
 	}
-	c.result.image.Texture = t
+	c.result.image = i
 	return nil
 }
 
@@ -471,11 +451,7 @@ func (c *newScreenFramebufferImageCommand) String() string {
 
 // Exec executes a newScreenFramebufferImageCommand.
 func (c *newScreenFramebufferImageCommand) Exec(indexOffsetInBytes int) error {
-	checkSize(c.width, c.height)
-	// The (default) framebuffer size can't be converted to a power of 2.
-	// On browsers, c.width and c.height are used as viewport size and
-	// Edge can't treat a bigger viewport than the drawing area (#71).
-	c.result.image.Framebuffer = opengl.NewScreenFramebuffer(c.width, c.height)
+	c.result.image = opengl.NewScreenFramebufferImage(c.width, c.height)
 	return nil
 }
 

internal/graphicscommand/image.go

@@ -41,12 +41,15 @@ func MaxImageSize() int {
 
 // Image represents an image that is implemented with OpenGL.
 type Image struct {
-	image *opengl.Image
+	image  *opengl.Image
+	width  int
+	height int
 }
 
 func NewImage(width, height int) *Image {
 	i := &Image{
-		image: opengl.NewImage(width, height),
+		width:  width,
+		height: height,
 	}
 	c := &newImageCommand{
 		result: i,
@@ -59,7 +62,8 @@ func NewImage(width, height int) *Image {
 
 func NewScreenFramebufferImage(width, height int) *Image {
 	i := &Image{
-		image: opengl.NewImage(width, height),
+		width:  width,
+		height: height,
 	}
 	c := &newScreenFramebufferImageCommand{
 		result: i,
@@ -78,7 +82,8 @@ func (i *Image) Dispose() {
 }
 
 func (i *Image) Size() (int, int) {
-	return i.image.Size()
+	// i.image can be nil before initializing.
+	return i.width, i.height
 }
 
 func (i *Image) DrawImage(src *Image, vertices []float32, indices []uint16, clr *affine.ColorM, mode graphics.CompositeMode, filter graphics.Filter) {
@@ -112,5 +117,9 @@ func (i *Image) ReplacePixels(p []byte, x, y, width, height int) {
 }
 
 func (i *Image) IsInvalidated() bool {
+	// i.image can be nil before initializing.
+	if i.image == nil {
+		return false
+	}
 	return i.image.IsInvalidated()
 }

internal/opengl/context_desktop.go

@@ -135,7 +135,7 @@ func (c *Context) BlendFunc(mode graphics.CompositeMode) {
 	})
 }
 
-func (c *Context) NewTexture(width, height int) (Texture, error) {
+func (c *Context) newTexture(width, height int) (Texture, error) {
 	var texture Texture
 	if err := c.runOnContextThread(func() error {
 		var t uint32

internal/opengl/context_js.go

@@ -173,7 +173,7 @@ func (c *Context) BlendFunc(mode graphics.CompositeMode) {
 	gl.Call("blendFunc", int(s2), int(d2))
 }
 
-func (c *Context) NewTexture(width, height int) (Texture, error) {
+func (c *Context) newTexture(width, height int) (Texture, error) {
 	gl := c.gl
 	t := gl.Call("createTexture")
 	if t == js.Null() {

internal/opengl/context_mobile.go

@@ -133,7 +133,7 @@ func (c *Context) BlendFunc(mode graphics.CompositeMode) {
 	gl.BlendFunc(mgl.Enum(s2), mgl.Enum(d2))
 }
 
-func (c *Context) NewTexture(width, height int) (Texture, error) {
+func (c *Context) newTexture(width, height int) (Texture, error) {
 	gl := c.gl
 	t := gl.CreateTexture()
 	if t.Value <= 0 {

internal/opengl/framebuffer.go

@@ -37,8 +37,8 @@ func newFramebufferFromTexture(texture Texture, width, height int) (*Framebuffer
 	}, nil
 }
 
-// NewScreenFramebuffer creates a framebuffer for the screen.
-func NewScreenFramebuffer(width, height int) *Framebuffer {
+// newScreenFramebuffer creates a framebuffer for the screen.
+func newScreenFramebuffer(width, height int) *Framebuffer {
 	return &Framebuffer{
 		native: theContext.getScreenFramebuffer(),
 		width:  width,

internal/opengl/image.go

@@ -15,9 +15,27 @@
 package opengl
 
 import (
+	"fmt"
+
 	"github.com/hajimehoshi/ebiten/internal/math"
 )
 
+func checkSize(width, height int) {
+	if width < 1 {
+		panic(fmt.Sprintf("opengl: width (%d) must be equal or more than 1.", width))
+	}
+	if height < 1 {
+		panic(fmt.Sprintf("opengl: height (%d) must be equal or more than 1.", height))
+	}
+	m := theContext.MaxTextureSize()
+	if width > m {
+		panic(fmt.Sprintf("opengl: width (%d) must be less than or equal to %d", width, m))
+	}
+	if height > m {
+		panic(fmt.Sprintf("opengl: height (%d) must be less than or equal to %d", height, m))
+	}
+}
+
 type Image struct {
 	Texture     Texture
 	Framebuffer *Framebuffer
@@ -25,11 +43,33 @@ type Image struct {
 	height      int
 }
 
-func NewImage(width, height int) *Image {
-	return &Image{
+func NewImage(width, height int) (*Image, error) {
+	i := &Image{
 		width:  width,
 		height: height,
 	}
+	w := math.NextPowerOf2Int(width)
+	h := math.NextPowerOf2Int(height)
+	checkSize(w, h)
+	t, err := theContext.newTexture(w, h)
+	if err != nil {
+		return nil, err
+	}
+	i.Texture = t
+	return i, nil
+}
+
+func NewScreenFramebufferImage(width, height int) *Image {
+	checkSize(width, height)
+	i := &Image{
+		width:  width,
+		height: height,
+	}
+	// The (default) framebuffer size can't be converted to a power of 2.
+	// On browsers, c.width and c.height are used as viewport size and
+	// Edge can't treat a bigger viewport than the drawing area (#71).
+	i.Framebuffer = newScreenFramebuffer(width, height)
+	return i
 }
 
 func (i *Image) Size() (int, int) {