スマホでVR写真表示アプリを作る(Xamarin) - OpenGLView LoadTexture

OGLView.cs

private void LoadTexture(int tex_id, byte[] texture)
{
  GL.BindTexture(TextureTarget.Texture2D, tex_id);

  GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)All.NearestMipmapLinear);
  GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Nearest);
  GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.Repeat);
  GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)TextureWrapMode.Repeat);

  //
  // 画像のロード＆RGBA色空間への変換＆OpenGLへの適用は、デバイス依存の処理になる
#if __ANDROID__
  using (var ms = new MemoryStream(texture))
  {
    var b = BitmapFactory.DecodeStream(ms);
    //
    // GLUTの関数を使って、良しなに設定する
    Android.Opengl.GLUtils.TexImage2D((int)All.Texture2D, 0, b, 0);

    b.Recycle();
  }
#endif

#if __IOS__
  var b = UIImage.LoadFromData(NSData.FromArray(texture));
  CGImage cgimage = b.CGImage;

  using (var dataProvider = cgimage.DataProvider)
  using (var data = dataProvider.CopyData())
  {
    GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba,
            (int)cgimage.Width, (int)cgimage.Height, 0,
            PixelFormat.Rgba, PixelType.UnsignedByte,
            data.Bytes);
  }
#endif
  GL.GenerateMipmap(TextureTarget.Texture2D);
}