Add examples/glut/main.go

examples/glut/main.go

@@ -0,0 +1,73 @@
+package main
+
+// #cgo LDFLAGS: -framework GLUT -framework OpenGL
+//
+// #include <stdlib.h>
+// #include <GLUT/glut.h>
+//
+// void display(void);
+//
+// static void setDisplayFunc(void) {
+//   glutDisplayFunc(display);
+// }
+//
+import "C"
+import (
+	"image/color"
+	"os"
+	"unsafe"
+	"github.com/hajimehoshi/go-ebiten/graphics"
+)
+
+var device *graphics.Device
+
+type DemoGame struct {
+}
+
+func (game *DemoGame) Update() {
+}
+
+func (game *DemoGame) Draw(g *graphics.GraphicsContext, offscreen *graphics.Texture) {
+	g.Fill(&color.RGBA{R: 0, G: 0, B: 255, A: 255})
+}
+
+//export display
+func display() {
+	device.Update()
+}
+
+func main() {
+	cargs := []*C.char{}
+	for _, arg := range os.Args {
+		cargs = append(cargs, C.CString(arg))
+	}
+	defer func() {
+		for _, carg := range cargs {
+			C.free(unsafe.Pointer(carg))
+		}
+	}()
+	cargc := C.int(len(cargs))
+
+	screenWidth  := 256
+	screenHeight := 256
+	screenScale  := 1
+
+	C.glutInit(&cargc, &cargs[0])
+	C.glutInitDisplayMode(C.GLUT_RGBA);
+	C.glutInitWindowSize(C.int(screenWidth * screenScale),
+		C.int(screenHeight * screenScale))
+
+	title := C.CString("Ebiten Demo")
+	defer C.free(unsafe.Pointer(title))
+	C.glutCreateWindow(title)
+
+	C.setDisplayFunc()
+
+	game := &DemoGame{}
+	device = graphics.NewDevice(screenWidth, screenHeight, screenScale,
+		func(g *graphics.GraphicsContext, offscreen *graphics.Texture) {
+			game.Draw(g, offscreen)
+		})
+
+	C.glutMainLoop()
+}

graphics/device.go

@@ -6,7 +6,7 @@ package graphics
 // #include <stdlib.h>
 import "C"
 
-type device struct {
+type Device struct {
 	screenWidth int
 	screenHeight int
 	screenScale int
@@ -15,9 +15,9 @@ type device struct {
 	drawFunc func(*GraphicsContext, *Texture)
 }
 
-// This method should be called on the UI thread??
-func newDevice(screenWidth, screenHeight, screenScale int, drawFunc func(*GraphicsContext, *Texture)) *device {
-	return &device{
+func NewDevice(screenWidth, screenHeight, screenScale int,
+	drawFunc func(*GraphicsContext, *Texture)) *Device {
+	device := &Device{
 		screenWidth: screenWidth,
 		screenHeight: screenHeight,
 		screenScale: screenScale,
@@ -25,29 +25,29 @@ func newDevice(screenWidth, screenHeight, screenScale int, drawFunc func(*Graphi
 		offscreenTexture: NewTexture(screenWidth, screenHeight),
 		drawFunc: drawFunc,
 	}
+	return device
 }
 
-// This method should be called on the UI thread??
-func (d *device) Update() {
-	g := d.graphicsContext
-	// g.initialize()
+func (device *Device) Update() {
+	g := device.graphicsContext
 	C.glEnable(C.GL_TEXTURE_2D)
 	C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MIN_FILTER, C.GL_NEAREST)
 	C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MAG_FILTER, C.GL_NEAREST)
-	g.SetOffscreen(d.offscreenTexture)
+	g.SetOffscreen(device.offscreenTexture)
 	g.Clear()
-	d.drawFunc(g, d.offscreenTexture)
+	// TODO: lock this!
+	device.drawFunc(g, device.offscreenTexture)
 	g.flush()
+	
 	C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MIN_FILTER, C.GL_LINEAR)
 	C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MAG_FILTER, C.GL_LINEAR)
 	g.resetOffscreen()
 	g.Clear()
-
 	geometryMatrix := IdentityGeometryMatrix()
 	geometryMatrix.SetA(AffineMatrixElement(g.screenScale))
 	geometryMatrix.SetD(AffineMatrixElement(g.screenScale))
-	g.DrawTexture(d.offscreenTexture,
-		0, 0, d.screenWidth, d.screenHeight,
+	g.DrawTexture(device.offscreenTexture,
+		0, 0, device.screenWidth, device.screenHeight,
 		geometryMatrix, IdentityColorMatrix())
 	g.flush()
 }

graphics/graphics_context.go

@@ -2,14 +2,13 @@ package graphics
 
 // #cgo LDFLAGS: -framework OpenGL
 //
-// #include <OpenGL/gl.h>
 // #include <stdlib.h>
+// #include <OpenGL/gl.h>
 import "C"
 import (
 	"image/color"
 	"math"
 	"unsafe"
-	"../ui"
 )
 
 type GraphicsContext struct {
@@ -35,19 +34,19 @@ func newGraphicsContext(screenWidth, screenHeight, screenScale int) *GraphicsCon
 	mainFramebuffer := C.GLint(0)
 	C.glGetIntegerv(C.GL_FRAMEBUFFER_BINDING, &mainFramebuffer)
 	context.mainFramebuffer = C.GLuint(mainFramebuffer)
+
+	initializeShaders()
+
 	return context
 }
 
 func (context *GraphicsContext) Clear() {
-	ui.ExecuteOnUIThread(func() {
 	C.glClearColor(0, 0, 0, 1)
 	C.glClear(C.GL_COLOR_BUFFER_BIT)
-	})
 }
 
 func (context *GraphicsContext) Fill(color color.Color) {
 	r, g, b, a := color.RGBA()
-	ui.ExecuteOnUIThread(func() {
 	max := 65535.0
 	C.glClearColor(
 		C.GLclampf(float64(r) / max),
@@ -55,10 +54,10 @@ func (context *GraphicsContext) Fill(color color.Color) {
 		C.GLclampf(float64(b) / max),
 		C.GLclampf(float64(a) / max))
 	C.glClear(C.GL_COLOR_BUFFER_BIT)
-	})
 }
 
 func (context *GraphicsContext) DrawRect(x, y, width, height int, color color.Color) {
+	// TODO: implement!
 }
 
 func (context *GraphicsContext) DrawTexture(texture *Texture,
@@ -67,7 +66,6 @@ func (context *GraphicsContext) DrawTexture(texture *Texture,
 	geometryMatrix = geometryMatrix.Clone()
 	colorMatrix    = colorMatrix.Clone()
 
-	ui.ExecuteOnUIThread(func() {
 	context.setShaderProgram(geometryMatrix, colorMatrix)
 	C.glBindTexture(C.GL_TEXTURE_2D, texture.id)
 
@@ -109,11 +107,9 @@ func (context *GraphicsContext) DrawTexture(texture *Texture,
 	C.glDisableVertexAttribArray(C.GLuint(vertexAttrLocation))
 	C.glDisableClientState(C.GL_TEXTURE_COORD_ARRAY)
 	C.glDisableClientState(C.GL_VERTEX_ARRAY)
-	})
 }
 
 func (context *GraphicsContext) SetOffscreen(texture *Texture) {
-	ui.ExecuteOnUIThread(func() {
 	framebuffer := C.GLuint(0)
 	if texture != nil {
 		framebuffer = context.getFramebuffer(texture)
@@ -121,7 +117,9 @@ func (context *GraphicsContext) SetOffscreen(texture *Texture) {
 		framebuffer = context.mainFramebuffer
 	}
 	C.glBindFramebuffer(C.GL_FRAMEBUFFER, framebuffer)
-		// TODO: assert glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE
+	if C.glCheckFramebufferStatus(C.GL_FRAMEBUFFER) != C.GL_FRAMEBUFFER_COMPLETE {
+		panic("glBindFramebuffer failed")
+	}
 	C.glEnable(C.GL_BLEND)
 	C.glBlendFunc(C.GL_SRC_ALPHA, C.GL_ONE_MINUS_SRC_ALPHA)
 
@@ -140,8 +138,8 @@ func (context *GraphicsContext) SetOffscreen(texture *Texture) {
 	C.glViewport(0, 0,
 		C.GLsizei(math.Abs(float64(width))),
 		C.GLsizei(math.Abs(float64(height))))
-		e11 := float32(2.0 / width)
-		e22 := float32(2.0 / height)
+	e11 := float32(2.0) / float32(width)
+	e22 := float32(2.0) / float32(height)
 	e41 := float32(tx)
 	e42 := float32(ty)
 	context.projectionMatrix = [...]float32{
@@ -150,7 +148,6 @@ func (context *GraphicsContext) SetOffscreen(texture *Texture) {
 		0,   0,   1, 0,
 		e41, e42, 0, 1,
 	}
-	})
 }
 
 func (context *GraphicsContext) resetOffscreen() {

graphics/texture.go

@@ -7,7 +7,7 @@ import "C"
 import (
 	"image"
 	"unsafe"
-	"../ui"
+	"github.com/hajimehoshi/go-ebiten/ui"
 )
 
 func Clp2(x uint64) uint64 {
@@ -47,14 +47,18 @@ func createTexture(width, height int, pixels []uint8) *Texture{
 	}
 
 	ch := make(chan C.GLuint)
+	// TODO: should wait?
+	go func() {
+		texture.id = <-ch
+	}()
 	ui.ExecuteOnUIThread(func() {
 		textureID := C.GLuint(0)
 		C.glGenTextures(1, (*C.GLuint)(&textureID))
+		if textureID == 0 {
+			panic("glGenTexture failed")
+		}
 		C.glPixelStorei(C.GL_UNPACK_ALIGNMENT, 4)
 		C.glBindTexture(C.GL_TEXTURE_2D, C.GLuint(textureID))
-		if textureID != 0 {
-			panic("glBindTexture failed")
-		}
 		
 		ptr := unsafe.Pointer(nil)
 		if pixels != nil {
@@ -71,10 +75,6 @@ func createTexture(width, height int, pixels []uint8) *Texture{
 		ch<- textureID
 		close(ch)
 	})
-	// TODO: should wait?
-	go func() {
-		texture.id = <-ch
-	}()
 
 	return texture
 }