public ShaderResourceView CreateTexArray(string arrayName, params string[] filenames)
{
if (_textures.ContainsKey(arrayName))
{
return(_textures[arrayName]);
}
//
// Load the texture elements individually from file. These textures
// won't be used by the GPU (0 bind flags), they are just used to
// load the image data from file. We use the STAGING usage so the
// CPU can read the resource.
//
int arraySize = filenames.Length;
var srcTex = new Texture2D[arraySize];
for (int i = 0; i < arraySize; ++i)
{
var loadInfo = new ImageLoadInformation
{
Usage = ResourceUsage.Staging,
BindFlags = BindFlags.None,
CpuAccessFlags = CpuAccessFlags.Read | CpuAccessFlags.Write,
OptionFlags = ResourceOptionFlags.None,
Format = Format.R8G8B8A8_UNorm,
FilterFlags = FilterFlags.None,
MipFilterFlags = FilterFlags.None
};
srcTex[i] = Texture2D.FromFile(_dxDevice, filenames[i], loadInfo);
}
//
// Create the texture array. Each element in the texture
// array has the same format/dimensions.
//
var texElementDesc = srcTex[0].Description;
var texArrayDesc = new Texture2DDescription
{
Width = texElementDesc.Width,
Height = texElementDesc.Height,
MipLevels = texElementDesc.MipLevels,
ArraySize = arraySize,
Format = Format.R8G8B8A8_UNorm,
SampleDescription = new SampleDescription(1, 0),
Usage = ResourceUsage.Default,
BindFlags = BindFlags.ShaderResource,
CpuAccessFlags = CpuAccessFlags.None,
OptionFlags = ResourceOptionFlags.None
};
var texArray = new Texture2D(_dxDevice, texArrayDesc);
//
// Copy individual texture elements into texture array.
//
// for each texture element...
for (int i = 0; i < arraySize; ++i)
{
// for each mipmap level...
for (int j = 0; j < texElementDesc.MipLevels; ++j)
{
var mappedTex2D = srcTex[i].Map(j, MapMode.Read, MapFlags.None);
_dxDevice.UpdateSubresource(
new DataBox(mappedTex2D.Pitch, 0, mappedTex2D.Data), texArray,
Resource.CalculateSubresourceIndex(j, i, texElementDesc.MipLevels));
srcTex[i].Unmap(j);
}
}
//
// Create a resource view to the texture array.
//
var viewDesc = new ShaderResourceViewDescription();
viewDesc.Format = texArrayDesc.Format;
viewDesc.Dimension = ShaderResourceViewDimension.Texture2DArray;
viewDesc.MostDetailedMip = 0;
viewDesc.MipLevels = texArrayDesc.MipLevels;
viewDesc.FirstArraySlice = 0;
viewDesc.ArraySize = arraySize;
var texArrayRV = new ShaderResourceView(_dxDevice, texArray, viewDesc);
//
// Cleanup--we only need the resource view.
//
texArray.Dispose();
for (int i = 0; i < arraySize; ++i)
{
srcTex[i].Dispose();
}
_textures.Add(arrayName, texArrayRV);
return(texArrayRV);
}