Show Ebiten

ebiten.go

@@ -0,0 +1,37 @@
+package ebiten
+
+import (
+	"time"
+	"github.com/hajimehoshi/go-ebiten/graphics"
+	"github.com/hajimehoshi/go-ebiten/ui"
+)
+
+type Game interface {
+	Update()
+	Draw(g *graphics.GraphicsContext, offscreen *graphics.Texture)
+}
+
+func Run(game Game, u ui.UI) {
+	ch := make(chan bool, 1)
+	device := graphics.NewDevice(
+		u.ScreenWidth(), u.ScreenHeight(), u.ScreenScale(),
+		func(g *graphics.GraphicsContext, offscreen *graphics.Texture) {
+			ticket := <-ch
+			game.Draw(g, offscreen)
+			ch<- ticket
+		})
+
+	go func() {
+		const frameTime = time.Second / 60
+		tick := time.Tick(frameTime)
+		for {
+			<-tick
+			ticket := <-ch
+			game.Update()
+			ch<- ticket
+		}
+	}()
+	ch<- true
+
+	u.Run(device)
+}

examples/glut/main.go

@@ -15,28 +15,27 @@ package main
 //
 import "C"
 import (
+	"image"
 	"image/color"
+	_ "image/png"
 	"os"
-	"time"
 	"unsafe"
+	"github.com/hajimehoshi/go-ebiten"
 	"github.com/hajimehoshi/go-ebiten/graphics"
 )
 
-var device *graphics.Device
-
-type DemoGame struct {
+type GlutUI struct{
+	screenWidth int
+	screenHeight int
+	screenScale int
+	device *graphics.Device
 }
 
-func (game *DemoGame) Update() {
-}
-
-func (game *DemoGame) Draw(g *graphics.GraphicsContext, offscreen *graphics.Texture) {
-	g.Fill(&color.RGBA{R: 128, G: 128, B: 255, A: 255})
-}
+var currentUI *GlutUI
 
 //export display
 func display() {
-	device.Update()
+	currentUI.device.Update()
 	C.glutSwapBuffers()
 }
 
@@ -45,7 +44,7 @@ func idle() {
 	C.glutPostRedisplay()
 }
 
-func main() {
+func (ui *GlutUI) Init() {
 	cargs := []*C.char{}
 	for _, arg := range os.Args {
 		cargs = append(cargs, C.CString(arg))
@@ -57,41 +56,76 @@ func main() {
 	}()
 	cargc := C.int(len(cargs))
 
-	screenWidth  := 256
-	screenHeight := 240
-	screenScale  := 2
+	ui.screenWidth  = 256
+	ui.screenHeight = 240
+	ui.screenScale  = 2
 
 	C.glutInit(&cargc, &cargs[0])
 	C.glutInitDisplayMode(C.GLUT_RGBA);
-	C.glutInitWindowSize(C.int(screenWidth * screenScale),
-		C.int(screenHeight * screenScale))
+	C.glutInitWindowSize(
+		C.int(ui.screenWidth  * ui.screenScale),
+		C.int(ui.screenHeight * ui.screenScale))
 
 	title := C.CString("Ebiten Demo")
 	defer C.free(unsafe.Pointer(title))
 	C.glutCreateWindow(title)
 
 	C.setGlutFuncs()
-
-	ch := make(chan bool, 1)
-	game := &DemoGame{}
-	device = graphics.NewDevice(screenWidth, screenHeight, screenScale,
-		func(g *graphics.GraphicsContext, offscreen *graphics.Texture) {
-			ticket := <-ch
-			game.Draw(g, offscreen)
-			ch<- ticket
-		})
-
-	go func() {
-		const frameTime = time.Second / 60
-		tick := time.Tick(frameTime)
-		for {
-			<-tick
-			ticket := <-ch
-			game.Update()
-			ch<- ticket
 }
-	}()
-	ch<- true
 
+func (ui *GlutUI) ScreenWidth() int {
+	return ui.screenWidth
+}
+
+func (ui *GlutUI) ScreenHeight() int {
+	return ui.screenHeight
+}
+
+func (ui *GlutUI) ScreenScale() int {
+	return ui.screenScale
+}
+
+func (ui *GlutUI) Run(device *graphics.Device) {
+	ui.device = device
 	C.glutMainLoop()
 }
+
+type DemoGame struct {
+	ebitenTexture *graphics.Texture
+}
+
+func (game *DemoGame) Update() {
+	if game.ebitenTexture == nil {
+		file, err := os.Open("ebiten.png")
+		if err != nil {
+			panic(err)
+		}
+		defer file.Close()
+		
+		img, _, err := image.Decode(file)
+		if err != nil {
+			panic(err)
+		}
+
+		game.ebitenTexture = currentUI.device.NewTextureFromImage(img)
+	}
+}
+
+func (game *DemoGame) Draw(g *graphics.GraphicsContext, offscreen *graphics.Texture) {
+	g.Fill(&color.RGBA{R: 128, G: 128, B: 255, A: 255})
+	if game.ebitenTexture == nil {
+		return
+	}
+	g.DrawTexture(game.ebitenTexture,
+		0, 0, game.ebitenTexture.Width, game.ebitenTexture.Height,
+		graphics.IdentityGeometryMatrix(),
+		graphics.IdentityColorMatrix())
+}
+
+func main() {
+	game := &DemoGame{}
+	currentUI = &GlutUI{}
+	currentUI.Init()
+
+	ebiten.Run(game, currentUI)
+}

game/game.go

@@ -1,10 +0,0 @@
-package game
-
-import (
-	_ "../graphics"
-)
-
-type Game interface {
-	Update()
-	Draw()
-}

graphics/device.go

@@ -5,6 +5,9 @@ package graphics
 // #include <OpenGL/gl.h>
 // #include <stdlib.h>
 import "C"
+import (
+	"image"
+)
 
 type Device struct {
 	screenWidth int
@@ -13,6 +16,7 @@ type Device struct {
 	graphicsContext *GraphicsContext
 	offscreenTexture *Texture
 	drawFunc func(*GraphicsContext, *Texture)
+	funcs []func()
 }
 
 func NewDevice(screenWidth, screenHeight, screenScale int,
@@ -22,13 +26,19 @@ func NewDevice(screenWidth, screenHeight, screenScale int,
 		screenHeight: screenHeight,
 		screenScale: screenScale,
 		graphicsContext: newGraphicsContext(screenWidth, screenHeight, screenScale),
-		offscreenTexture: NewTexture(screenWidth, screenHeight),
 		drawFunc: drawFunc,
+		funcs: []func(){},
 	}
+	device.offscreenTexture = device.NewTexture(screenWidth, screenHeight)
 	return device
 }
 
 func (device *Device) Update() {
+	for _, f := range device.funcs {
+		f()
+	}
+	device.funcs = []func(){}
+
 	g := device.graphicsContext
 	C.glEnable(C.GL_TEXTURE_2D)
 	C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MIN_FILTER, C.GL_NEAREST)
@@ -50,3 +60,25 @@ func (device *Device) Update() {
 		geometryMatrix, IdentityColorMatrix())
 	g.flush()
 }
+
+func (device *Device) NewTexture(width, height int) *Texture {
+	return createTexture(device, width, height, nil)
+}
+
+func (device *Device) NewTextureFromImage(img image.Image) *Texture {
+	var pix []uint8
+	switch img.(type) {
+	case *image.RGBA:
+		pix = img.(*image.RGBA).Pix
+	case *image.NRGBA:
+		pix = img.(*image.NRGBA).Pix
+	default:
+		panic("image should be RGBA or NRGBA")
+	}
+	size := img.Bounds().Size()
+	return createTexture(device, size.X, size.Y, pix)
+}
+
+func (device *Device) executeWhenDrawing(f func()) {
+	device.funcs = append(device.funcs, f)
+}

graphics/graphics_context.go

@@ -6,6 +6,7 @@ package graphics
 // #include <OpenGL/gl.h>
 import "C"
 import (
+	"fmt"
 	"image/color"
 	"math"
 	"unsafe"
@@ -117,8 +118,8 @@ func (context *GraphicsContext) SetOffscreen(texture *Texture) {
 		framebuffer = context.mainFramebuffer
 	}
 	C.glBindFramebuffer(C.GL_FRAMEBUFFER, framebuffer)
-	if C.glCheckFramebufferStatus(C.GL_FRAMEBUFFER) != C.GL_FRAMEBUFFER_COMPLETE {
-		panic("glBindFramebuffer failed")
+	if err := C.glCheckFramebufferStatus(C.GL_FRAMEBUFFER); err != C.GL_FRAMEBUFFER_COMPLETE {
+		panic(fmt.Sprintf("glBindFramebuffer failed: %d", err))
 	}
 	C.glEnable(C.GL_BLEND)
 	C.glBlendFunc(C.GL_SRC_ALPHA, C.GL_ONE_MINUS_SRC_ALPHA)

graphics/texture.go

@@ -5,9 +5,7 @@ package graphics
 // #include <OpenGL/gl.h>
 import "C"
 import (
-	"image"
 	"unsafe"
-	"github.com/hajimehoshi/go-ebiten/ui"
 )
 
 func Clp2(x uint64) uint64 {
@@ -29,7 +27,7 @@ type Texture struct {
 	TextureHeight int
 }
 
-func createTexture(width, height int, pixels []uint8) *Texture{
+func createTexture(device *Device, width, height int, pixels []uint8) *Texture{
 	textureWidth := int(Clp2(uint64(width)))
 	textureHeight := int(Clp2(uint64(height)))
 	if pixels != nil {
@@ -48,12 +46,7 @@ func createTexture(width, height int, pixels []uint8) *Texture{
 		TextureHeight: textureHeight,
 	}
 
-	ch := make(chan C.GLuint)
-	// TODO: should wait?
-	go func() {
-		texture.id = <-ch
-	}()
-	ui.ExecuteOnUIThread(func() {
+	device.executeWhenDrawing(func() {
 		textureID := C.GLuint(0)
 		C.glGenTextures(1, (*C.GLuint)(&textureID))
 		if textureID == 0 {
@@ -74,21 +67,13 @@ func createTexture(width, height int, pixels []uint8) *Texture{
 		C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MIN_FILTER, C.GL_LINEAR)
 		C.glBindTexture(C.GL_TEXTURE_2D, 0)
 
-		ch<- textureID
-		close(ch)
+		// TODO: lock?
+		texture.id = textureID
 	})
 
 	return texture
 }
 
-func NewTexture(width, height int) *Texture {
-	return createTexture(width, height, nil)
-}
-
-func NewTextureFromRGBA(image *image.RGBA) *Texture {
-	return createTexture(image.Rect.Size().X, image.Rect.Size().Y, image.Pix)
-}
-
 func (texture *Texture) IsAvailable() bool {
 	return texture.id != 0
 }

ui/ui.go

@@ -1,5 +1,16 @@
 package ui
 
+import (
+	"github.com/hajimehoshi/go-ebiten/graphics"
+)
+
+type UI interface {
+	ScreenWidth() int
+	ScreenHeight() int
+	ScreenScale() int
+	Run(device *graphics.Device)
+}
+
 func ExecuteOnUIThread(f func()) {
 	// TODO: implement!
 	f()