private void LoadTGAHeaderInfo(BinaryReader binReader)
{
if (binReader != null && binReader.BaseStream != null && binReader.BaseStream.Length > 0 && binReader.BaseStream.CanSeek == true) {
try {
// set the cursor at the beginning of the file.
binReader.BaseStream.Seek(0, SeekOrigin.Begin);
// read the header properties from the file
this.objTargaHeader.SetImageIDLength(binReader.ReadByte());
this.objTargaHeader.SetColorMapType((ColorMapType)binReader.ReadByte());
this.objTargaHeader.SetImageType((ImageType)binReader.ReadByte());
this.objTargaHeader.SetColorMapFirstEntryIndex(binReader.ReadInt16());
this.objTargaHeader.SetColorMapLength(binReader.ReadInt16());
this.objTargaHeader.SetColorMapEntrySize(binReader.ReadByte());
this.objTargaHeader.SetXOrigin(binReader.ReadInt16());
this.objTargaHeader.SetYOrigin(binReader.ReadInt16());
this.objTargaHeader.SetWidth(binReader.ReadInt16());
this.objTargaHeader.SetHeight(binReader.ReadInt16());
byte pixeldepth = binReader.ReadByte();
switch (pixeldepth) {
case 8:
case 16:
case 24:
case 32:
this.objTargaHeader.SetPixelDepth(pixeldepth);
break;
default:
this.ClearAll();
throw new Exception("Targa Image only supports 8, 16, 24, or 32 bit pixel depths.");
}
byte ImageDescriptor = binReader.ReadByte();
this.objTargaHeader.SetAttributeBits((byte)Utilities.GetBits(ImageDescriptor, 0, 4));
this.objTargaHeader.SetVerticalTransferOrder((VerticalTransferOrder)Utilities.GetBits(ImageDescriptor, 5, 1));
this.objTargaHeader.SetHorizontalTransferOrder((HorizontalTransferOrder)Utilities.GetBits(ImageDescriptor, 4, 1));
// load ImageID value if any
if (this.objTargaHeader.ImageIDLength > 0) {
byte[] ImageIDValueBytes = binReader.ReadBytes(this.objTargaHeader.ImageIDLength);
this.objTargaHeader.SetImageIDValue(System.Text.Encoding.ASCII.GetString(ImageIDValueBytes).TrimEnd('\0'));
}
} catch {
this.ClearAll();
throw;
}
// load color map if it's included and/or needed
// Only needed for UNCOMPRESSED_COLOR_MAPPED and RUN_LENGTH_ENCODED_COLOR_MAPPED
// image types. If color map is included for other file types we can ignore it.
if (this.objTargaHeader.ColorMapType == ColorMapType.COLOR_MAP_INCLUDED) {
if (this.objTargaHeader.ImageType == ImageType.UNCOMPRESSED_COLOR_MAPPED ||
this.objTargaHeader.ImageType == ImageType.RUN_LENGTH_ENCODED_COLOR_MAPPED) {
if (this.objTargaHeader.ColorMapLength > 0) {
try {
for (int i = 0; i < this.objTargaHeader.ColorMapLength; i++) {
int a = 0;
int r = 0;
int g = 0;
int b = 0;
// load each color map entry based on the ColorMapEntrySize value
switch (this.objTargaHeader.ColorMapEntrySize) {
case 15:
byte[] color15 = binReader.ReadBytes(2);
// remember that the bytes are stored in reverse oreder
this.objTargaHeader.ColorMap.Add(Utilities.GetColorFrom2Bytes(color15[1], color15[0]));
break;
case 16:
byte[] color16 = binReader.ReadBytes(2);
// remember that the bytes are stored in reverse oreder
this.objTargaHeader.ColorMap.Add(Utilities.GetColorFrom2Bytes(color16[1], color16[0]));
break;
case 24:
b = Convert.ToInt32(binReader.ReadByte());
g = Convert.ToInt32(binReader.ReadByte());
r = Convert.ToInt32(binReader.ReadByte());
this.objTargaHeader.ColorMap.Add(System.Drawing.Color.FromArgb(r, g, b));
break;
case 32:
a = Convert.ToInt32(binReader.ReadByte());
b = Convert.ToInt32(binReader.ReadByte());
g = Convert.ToInt32(binReader.ReadByte());
r = Convert.ToInt32(binReader.ReadByte());
this.objTargaHeader.ColorMap.Add(System.Drawing.Color.FromArgb(a, r, g, b));
break;
default:
this.ClearAll();
throw new Exception("TargaImage only supports ColorMap Entry Sizes of 15, 16, 24 or 32 bits.");
}
}
} catch {
this.ClearAll();
throw;
}
} else {
this.ClearAll();
throw new Exception("Image Type requires a Color Map and Color Map Length is zero.");
}
}
} else {
if (this.objTargaHeader.ImageType == ImageType.UNCOMPRESSED_COLOR_MAPPED ||
this.objTargaHeader.ImageType == ImageType.RUN_LENGTH_ENCODED_COLOR_MAPPED) {
this.ClearAll();
throw new Exception("Image Type requires a Color Map and there was not a Color Map included in the file.");
}
}
} else {
this.ClearAll();
throw new Exception(@"Error loading file, could not read file from disk.");
}
}
