private byte[] LoadImage(string fileName, out int width, out int height)
{
byte[] bitmap = null;
Stream imageStream = null;
#if !__MOBILE__
Bitmap image = null;
Assembly assembly = Assembly.GetEntryAssembly();
// if the file in included in the resources, load it as stream
if (assembly.GetManifestResourceNames().Contains<string>(fileName))
{
imageStream = assembly.GetManifestResourceStream(fileName);
}
if (imageStream != null)
{
image = new Bitmap(imageStream);
}
else {
image = new Bitmap(fileName);
}
using (image)
{
// to avoid losing a ref
Bitmap _image = image;
bitmap = new byte[image.Width * image.Height * 4];
width = image.Width;
height = image.Height;
// if the image is not rgba, let's fix it
if (image.PixelFormat != System.Drawing.Imaging.PixelFormat.Format32bppArgb)
{
Bitmap tmpBitmap = new Bitmap(image.Width, image.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
using (Graphics gfx = Graphics.FromImage(tmpBitmap))
{
gfx.DrawImageUnscaled(image, 0, 0);
}
_image = tmpBitmap;
}
System.Drawing.Imaging.BitmapData data = _image.LockBits(new Rectangle(0, 0, width, height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
Marshal.Copy(data.Scan0, bitmap, 0, bitmap.Length);
_image.UnlockBits(data);
for (int y = 0; y < _image.Height; y++)
{
for (int x = 0; x < _image.Width; x++)
{
int position = (y * _image.Width * 4) + (x * 4);
// bgra -> rgba
byte b = bitmap[position];
byte r = bitmap[position + 2];
bitmap[position] = r;
bitmap[position + 2] = b;
// premultiply
byte a = bitmap[position + 3];
bitmap[position] = (byte) (bitmap[position] * (a / 255f));
bitmap[position+1] = (byte)(bitmap[position+1] * (a / 255f));
bitmap[position+2] = (byte)(bitmap[position+2] * (a / 255f));
}
}
premultiplied = true;
}
#else
Bitmap image = null;
if (imageStream == null)
{
if (fileName.StartsWith("Assets/"))
{
string newFileName = fileName.Substring(7);
imageStream = Window.Assets.Open(newFileName);
}
}
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.InPreferredConfig = global::Android.Graphics.Bitmap.Config.Argb8888;
image = BitmapFactory.DecodeStream(imageStream, new global::Android.Graphics.Rect(0, 0, 0, 0), bitmapOptions);
width = image.Width;
height = image.Height;
bitmap = new byte[width * height * 4];
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
int pixel = image.GetPixel(x, y);
byte a = (byte)((pixel >> 24) & 0xff);
byte r = (byte)((pixel >> 16) & 0xff);
byte g = (byte)((pixel >> 8) & 0xff);
byte b = (byte)(pixel & 0xff);
// premultiply;
int position = (y * width * 4) + (x * 4);
bitmap[position] = (byte)(r * (a / 255f));
bitmap[position + 1] = (byte)(g * (a / 255f));
bitmap[position + 2] = (byte)(b * (a / 255f));
bitmap[position + 3] = a;
}
}
premultiplied = true;
#endif
return bitmap;
}
