Add Texture.Width, Height and RenderTarget.Width, Height

example/image/main.go

@@ -19,7 +19,6 @@ package main
 import (
 	"github.com/hajimehoshi/ebiten"
 	"github.com/hajimehoshi/ebiten/ebitenutil"
-	"image"
 	_ "image/jpeg"
 	"log"
 	"math"
@@ -33,31 +32,27 @@ const (
 type Game struct {
 	count          int
 	gophersTexture *ebiten.Texture
-	gophersTextureWidth  int
-	gophersTextureHeight int
 }
 
 func (g *Game) Update(gr ebiten.GraphicsContext) error {
 	g.count++
 
-	geo := ebiten.TranslateGeometry(-float64(g.gophersTextureWidth)/2, -float64(g.gophersTextureHeight)/2)
+	w, h := g.gophersTexture.Size()
+	geo := ebiten.TranslateGeometry(-float64(w)/2, -float64(h)/2)
 	geo.Concat(ebiten.ScaleGeometry(0.5, 0.5))
 	geo.Concat(ebiten.TranslateGeometry(screenWidth/2, screenHeight/2))
 	clr := ebiten.RotateHue(float64(g.count%180) * 2 * math.Pi / 180)
-	ebiten.DrawWhole(gr.Texture(g.gophersTexture), g.gophersTextureWidth, g.gophersTextureHeight, geo, clr)
+	ebiten.DrawWhole(gr.Texture(g.gophersTexture), w, h, geo, clr)
 	return nil
 }
 
 func main() {
 	g := new(Game)
-	var img image.Image
 	var err error
-	g.gophersTexture, img, err = ebitenutil.NewTextureFromFile("images/gophers.jpg", ebiten.FilterLinear)
+	g.gophersTexture, _, err = ebitenutil.NewTextureFromFile("images/gophers.jpg", ebiten.FilterLinear)
 	if err != nil {
 		log.Fatal(err)
 	}
-	g.gophersTextureWidth = img.Bounds().Size().X
-	g.gophersTextureHeight = img.Bounds().Size().Y
 	if err := ebiten.Run(g.Update, screenWidth, screenHeight, 2, "Image (Ebiten Demo)"); err != nil {
 		log.Fatal(err)
 	}

graphics.go

@@ -75,6 +75,11 @@ type Texture struct {
 	glTexture *opengl.Texture
 }
 
+// Size returns the size of the texture.
+func (t *Texture) Size() (width int, height int) {
+	return t.glTexture.Width(), t.glTexture.Height()
+}
+
 // RenderTarget represents a render target.
 // A render target is essentially same as a texture, but it is assumed that the
 // all alpha values of a render target is maximum.
@@ -83,6 +88,11 @@ type RenderTarget struct {
 	texture        *Texture
 }
 
+// Size returns the size of the render target.
+func (r *RenderTarget) Size() (width int, height int) {
+	return r.glRenderTarget.Width(), r.glRenderTarget.Height()
+}
+
 func u(x int, width int) float32 {
 	return float32(x) / float32(opengl.AdjustSizeForTexture(width))
 }

graphicscontext.go

@@ -32,7 +32,7 @@ func newGraphicsContext(screenWidth, screenHeight, screenScale int) (*graphicsCo
 
 	c := &graphicsContext{
 		currents:     make([]*RenderTarget, 1),
-		defaultR:     idsInstance.addRenderTarget(r),
+		defaultR:     &RenderTarget{r, nil},
 		screen:       screen,
 		screenWidth:  screenWidth,
 		screenHeight: screenHeight,
@@ -57,7 +57,12 @@ var _ GraphicsContext = new(graphicsContext)
 
 func (c *graphicsContext) dispose() {
 	// NOTE: Now this method is not used anywhere.
-	idsInstance.deleteRenderTarget(c.screen)
+	glRenderTarget := c.screen.glRenderTarget
+	texture := c.screen.texture
+	glTexture := texture.glTexture
+
+	glRenderTarget.Dispose()
+	glTexture.Dispose()
 }
 
 func (c *graphicsContext) Clear() error {
@@ -72,8 +77,8 @@ func (c *graphicsContext) Texture(texture *Texture) Drawer {
 	return &textureWithContext{texture, c}
 }
 
-func (c *graphicsContext) RenderTarget(id *RenderTarget) Drawer {
+func (c *graphicsContext) RenderTarget(renderTarget *RenderTarget) Drawer {
-	return &textureWithContext{idsInstance.toTexture(id), c}
+	return &textureWithContext{renderTarget.texture, c}
 }
 
 func (c *graphicsContext) PushRenderTarget(renderTarget *RenderTarget) {

ids.go

@@ -23,18 +23,16 @@ import (
 	"math"
 )
 
+// ids manages the current render target to be used.
+// TODO: Change this name. `ids` is not appropriate for now.
 type ids struct {
 	currentRenderTarget *RenderTarget
 }
 
 var idsInstance = &ids{}
 
-func (i *ids) toTexture(renderTarget *RenderTarget) *Texture {
-	return renderTarget.texture
-}
-
 func (i *ids) createRenderTarget(width, height int, filter int) (*RenderTarget, error) {
-	glTexture, err := opengl.CreateTexture(width, height, filter)
+	glTexture, err := opengl.NewTexture(width, height, filter)
 	if err != nil {
 		return nil, err
 	}
@@ -52,21 +50,6 @@ func (i *ids) createRenderTarget(width, height int, filter int) (*RenderTarget,
 	return renderTarget, nil
 }
 
-// NOTE: renderTarget can't be used as a texture.
-func (i *ids) addRenderTarget(glRenderTarget *opengl.RenderTarget) *RenderTarget {
-	return &RenderTarget{glRenderTarget, nil}
-}
-
-func (i *ids) deleteRenderTarget(renderTarget *RenderTarget) {
-
-	glRenderTarget := renderTarget.glRenderTarget
-	texture := renderTarget.texture
-	glTexture := texture.glTexture
-
-	glRenderTarget.Dispose()
-	glTexture.Dispose()
-}
-
 func (i *ids) fillRenderTarget(renderTarget *RenderTarget, r, g, b uint8) error {
 	if err := i.setViewportIfNeeded(renderTarget); err != nil {
 		return err

internal/opengl/texture.go

@@ -94,18 +94,19 @@ func createNativeTexture(textureWidth, textureHeight int, pixels []uint8, filter
 	return nativeTexture
 }
 
-func CreateTexture(width, height int, filter int) (*Texture, error) {
+func NewTexture(width, height int, filter int) (*Texture, error) {
 	w := AdjustSizeForTexture(width)
 	h := AdjustSizeForTexture(height)
 	native := createNativeTexture(w, h, nil, filter)
 	return &Texture{native, width, height}, nil
 }
 
-func CreateTextureFromImage(img image.Image, filter int) (*Texture, error) {
+func NewTextureFromImage(img image.Image, filter int) (*Texture, error) {
+	origSize := img.Bounds().Size()
 	adjustedImage := adjustImageForTexture(img)
 	size := adjustedImage.Bounds().Size()
 	native := createNativeTexture(size.X, size.Y, adjustedImage.Pix, filter)
-	return &Texture{native, size.X, size.Y}, nil
+	return &Texture{native, origSize.X, origSize.Y}, nil
 }
 
 func (t *Texture) Dispose() {

ui.go

@@ -132,7 +132,7 @@ func (u *ui) newTexture(img image.Image, filter int) (*Texture, error) {
 	var texture *Texture
 	var err error
 	u.use(func() {
-		glTexture, err := opengl.CreateTextureFromImage(img, filter)
+		glTexture, err := opengl.NewTextureFromImage(img, filter)
 		if err != nil {
 			return
 		}