{

/// <summary>

/// Encapsulates a Targa image data. Exposes the raw pixel data, for better or worse.

/// Supports only a small subset of actual Targa formats: 32bpp with alpha, uncompressed.

/// </summary>

static class Targa

{

/// <summary>Loads a .tga image directly into a <see cref="BitmapRam"/> instance.</summary>

public static BitmapRam Load(Stream file)

{

var header = file.Read(18);

if (header[0] != 0) throw new NotSupportedException("Only images with no offset are supported");

if (header[1] != 0) throw new NotSupportedException("Only RGB images are supported");

if (header[2] != 2) throw new NotSupportedException("Only RGB images are supported");

if (header[8] != 0 || header[9] != 0 || header[10] != 0 || header[11] != 0)

throw new NotSupportedException("Only images with origin at 0,0 are supported");

var width = (header[13] << 8) + header[12];

var height = (header[15] << 8) + header[14];

if (width > 2048 || height > 2048) // an arbitrary limit; more for sanity check than anything else

throw new NotSupportedException("Only images up to 2048x2048 are supported");

if (width == 0 || height == 0)

throw new NotSupportedException("Images with a zero width or height are not supported");

if (header[16] != 32) throw new NotSupportedException("Only 32 bits per pixel images are supported");

bool rightWayUp = (header[17] & 32) != 0;

var raw = file.Read(width * height * 4);

var result = new BitmapRam(width, height);

result.CopyPixelsFrom(raw, width, height, width * 4, !rightWayUp);

return result;

}

/// <summary>A convenience method to save a GDI image directly to a .tga file.</summary>

public static unsafe void Save(BitmapBase image, string filename)

{

using (image.UseRead())

using (var file = File.Open(filename, FileMode.Create, FileAccess.Write, FileShare.Read))

{

var header = new byte[18];

header[2] = 2;

header[12] = (byte) (image.Width);

header[13] = (byte) (image.Width >> 8);

header[14] = (byte) (image.Height);

header[15] = (byte) (image.Height >> 8);

header[16] = 32;

header[17] = 32;

file.Write(header);

byte[] dummy = new byte[image.Width * 4];

for (int y = 0; y < image.Height; y++)

{

Ut.MemCpy(dummy, image.Data + y * image.Stride, image.Width * 4);

file.Write(dummy);

}

}

}

}