public static unsafe void InjectThumb(Bitmap preview, IniFile map) {
BitmapData bmd = preview.LockBits(new Rectangle(0, 0, preview.Width, preview.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
byte[] image = new byte[preview.Width * preview.Height * 3];
int idx = 0;
// invert rgb->bgr
for (int y = 0; y < bmd.Height; y++) {
byte* p = (byte*)bmd.Scan0 + bmd.Stride * y;
for (int x = 0; x < bmd.Width; x++) {
byte r = *p++;
byte g = *p++;
byte b = *p++;
image[idx++] = b;
image[idx++] = g;
image[idx++] = r;
}
}
// encode
byte[] image_compressed = Format5.Encode(image, 5);
// base64 encode
string image_base64 = Convert.ToBase64String(image_compressed, Base64FormattingOptions.None);
// now overwrite [Preview] and [PreviewPack], inserting them directly after [Basic] if not yet existing
map.GetOrCreateSection("Preview").SetValue("Size", string.Format("0,0,{0},{1}", preview.Width, preview.Height));
var section = map.GetOrCreateSection("PreviewPack", "Preview");
section.Clear();
section.Index = 0;
int rowNum = 1;
for (int i = 0; i < image_base64.Length; i += 70) {
section.SetValue(rowNum++.ToString(CultureInfo.InvariantCulture), image_base64.Substring(i, Math.Min(70, image_base64.Length - i)));
}
}