func newTexture(file string) uint32 {
imgFile, err := os.Open(file)
if err != nil {
panic(err)
}
img, _, err := image.Decode(imgFile)
if err != nil {
panic(err)
}
rgba := image.NewRGBA(img.Bounds())
if rgba.Stride != rgba.Rect.Size().X*4 {
panic("unsupported stride")
}
draw.Draw(rgba, rgba.Bounds(), img, image.Point{0, 0}, draw.Src)
var texture uint32
gl.Enable(gl.TEXTURE_2D)
gl.GenTextures(1, &texture)
gl.BindTexture(gl.TEXTURE_2D, texture)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
gl.TexImage2D(
gl.TEXTURE_2D,
0,
gl.RGBA,
int32(rgba.Rect.Size().X),
int32(rgba.Rect.Size().Y),
0,
gl.RGBA,
gl.UNSIGNED_BYTE,
gl.Ptr(rgba.Pix))
return texture
}
func drawScene() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.MatrixMode(gl.MODELVIEW)
gl.LoadIdentity()
gl.Translatef(0, 0, -3.0)
gl.Rotatef(rotationX, 1, 0, 0)
gl.Rotatef(rotationY, 0, 1, 0)
rotationX += 0.5
rotationY += 0.5
gl.BindTexture(gl.TEXTURE_2D, texture)
gl.Color4f(1, 1, 1, 1)
gl.Begin(gl.QUADS)
gl.Normal3f(0, 0, 1)
gl.TexCoord2f(0, 0)
gl.Vertex3f(-1, -1, 1)
gl.TexCoord2f(1, 0)
gl.Vertex3f(1, -1, 1)
gl.TexCoord2f(1, 1)
gl.Vertex3f(1, 1, 1)
gl.TexCoord2f(0, 1)
gl.Vertex3f(-1, 1, 1)
gl.Normal3f(0, 0, -1)
gl.TexCoord2f(1, 0)
gl.Vertex3f(-1, -1, -1)
gl.TexCoord2f(1, 1)
gl.Vertex3f(-1, 1, -1)
gl.TexCoord2f(0, 1)
gl.Vertex3f(1, 1, -1)
gl.TexCoord2f(0, 0)
gl.Vertex3f(1, -1, -1)
gl.Normal3f(0, 1, 0)
gl.TexCoord2f(0, 1)
gl.Vertex3f(-1, 1, -1)
gl.TexCoord2f(0, 0)
gl.Vertex3f(-1, 1, 1)
gl.TexCoord2f(1, 0)
gl.Vertex3f(1, 1, 1)
gl.TexCoord2f(1, 1)
gl.Vertex3f(1, 1, -1)
gl.Normal3f(0, -1, 0)
gl.TexCoord2f(1, 1)
gl.Vertex3f(-1, -1, -1)
gl.TexCoord2f(0, 1)
gl.Vertex3f(1, -1, -1)
gl.TexCoord2f(0, 0)
gl.Vertex3f(1, -1, 1)
gl.TexCoord2f(1, 0)
gl.Vertex3f(-1, -1, 1)
gl.Normal3f(1, 0, 0)
gl.TexCoord2f(1, 0)
gl.Vertex3f(1, -1, -1)
gl.TexCoord2f(1, 1)
gl.Vertex3f(1, 1, -1)
gl.TexCoord2f(0, 1)
gl.Vertex3f(1, 1, 1)
gl.TexCoord2f(0, 0)
gl.Vertex3f(1, -1, 1)
gl.Normal3f(-1, 0, 0)
gl.TexCoord2f(0, 0)
gl.Vertex3f(-1, -1, -1)
gl.TexCoord2f(1, 0)
gl.Vertex3f(-1, -1, 1)
gl.TexCoord2f(1, 1)
gl.Vertex3f(-1, 1, 1)
gl.TexCoord2f(0, 1)
gl.Vertex3f(-1, 1, -1)
gl.End()
}
