XNA texture GetData exception

Question

When using this code:

public static Texture2D MakeTexRed(Texture2D tex)
    {
        Texture2D drawTex = new Texture2D(Game1.graphics.GraphicsDevice, tex.Width, tex.Height);
        Color[] data = new Color[tex.Width * tex.Height];
        tex.GetData<Color>(data);
        for (int i = 0; i < data.Length; i++)
        {
            data[i].R = (byte)((data[i].R + 255) / 2);
            data[i].G /= 2;
            data[i].B /= 2;
        }
        drawTex.SetData(data);

        return drawTex;
    }

I'm getting this exception:

The type you are using for T in this method is an invalid size for this resource.

The size of the texture I'm using is 64x64 pixel.

When using this line:

Texture2D drawTex = new Texture2D(Game1.graphics.GraphicsDevice, tex.Width, tex.Height, false, SurfaceFormat.Color);

it still doesn't work.

Answer 1

So here are the possible format types.

you are going to have to check tex.Format and use the correct datastructure for tex's SurfaceFormat.

For example.

var b = new Bgr565[result.Width * result.Height];
tex.SetData(b);

The below SurfaceFormat have a corresponding value types that can be used.

Color
Bgr565
Bgra5551
Bgra4444
NormalizedByte2
NormalizedByte4
Rgba1010102
Rg32
Rgba64
Alpha8
Single
Vector2
Vector4
HalfSingle
HalfVector2
HalfVector4

For the Dxt formats means that the texture is compressed you are going to need to know the size after the texture is compressed get the data and then decompress it.

After some searching I found a DXT1 and DXT5 decompression library. Unfortunately I can't find anything managed so unsafe C# code is probably the best bet for converting it over. According to Wikipedia 16 pixels are stored in 8 bytes which makes have a byte per pixel so theoretically byte[] data = new byte[(Width * Height) / 2] should work for extracting the data.

Dxt1
Dxt3
Dxt5

This one is a special case just use HalfVector4 for the type and you are fine.

HdrBlendable

Answer 2

Have your tried not specifying the T when calling GetData() ?

tex.GetData<Color>(data);

To :

tex.GetData(data);

The error you posted refers to the Color you pass as T.