public override Codec.DecodeResult Decode(Stream input)
{
var imgData = new ImageData();
var output = new MemoryStream();
int imageID;
int imageFormat, bytesPerPixel;
// create and bind a new image
Il.ilGenImages(1, out imageID);
Il.ilBindImage(imageID);
// create a temp buffer and write the stream into it
var buffer = new byte[input.Length];
input.Read(buffer, 0, buffer.Length);
// Put it right side up
Il.ilEnable(Il.IL_ORIGIN_SET);
Il.ilSetInteger(Il.IL_ORIGIN_MODE, Il.IL_ORIGIN_UPPER_LEFT);
// Keep DXTC(compressed) data if present
Il.ilSetInteger(Il.IL_KEEP_DXTC_DATA, Il.IL_TRUE);
// load the data into DevIL
Il.ilLoadL(this._ilType, buffer, buffer.Length);
// check for an error
var ilError = Il.ilGetError();
if (ilError != Il.IL_NO_ERROR)
{
throw new AxiomException("Error while decoding image data: '{0}'", Ilu.iluErrorString(ilError));
}
imageFormat = Il.ilGetInteger(Il.IL_IMAGE_FORMAT);
var imageType = Il.ilGetInteger(Il.IL_IMAGE_TYPE);
// Convert image if imageType is incompatible with us (double or long)
if (imageType != Il.IL_BYTE && imageType != Il.IL_UNSIGNED_BYTE && imageType != Il.IL_FLOAT &&
imageType != Il.IL_UNSIGNED_SHORT && imageType != Il.IL_SHORT)
{
Il.ilConvertImage(imageFormat, Il.IL_FLOAT);
imageType = Il.IL_FLOAT;
}
// Converted paletted images
if (imageFormat == Il.IL_COLOR_INDEX)
{
Il.ilConvertImage(Il.IL_BGRA, Il.IL_UNSIGNED_BYTE);
imageFormat = Il.IL_BGRA;
imageType = Il.IL_UNSIGNED_BYTE;
}
// populate the image data
bytesPerPixel = Il.ilGetInteger(Il.IL_IMAGE_BYTES_PER_PIXEL);
imgData.format = ILUtil.Convert(imageFormat, imageType);
imgData.width = Il.ilGetInteger(Il.IL_IMAGE_WIDTH);
imgData.height = Il.ilGetInteger(Il.IL_IMAGE_HEIGHT);
imgData.depth = Il.ilGetInteger(Il.IL_IMAGE_DEPTH);
imgData.numMipMaps = Il.ilGetInteger(Il.IL_NUM_MIPMAPS);
if (imgData.format == PixelFormat.Unknown)
{
throw new AxiomException("Unsupported devil format ImageFormat={0} ImageType={1}", imageFormat, imageType);
}
// Check for cubemap
var numFaces = Il.ilGetInteger(Il.IL_NUM_IMAGES) + 1;
if (numFaces == 6)
{
imgData.flags |= ImageFlags.CubeMap;
}
else
{
numFaces = 1; // Support only 1 or 6 face images for now
}
// Keep DXT data (if present at all and the GPU supports it)
var dxtFormat = Il.ilGetInteger(Il.IL_DXTC_DATA_FORMAT);
if (dxtFormat != Il.IL_DXT_NO_COMP &&
Root.Instance.RenderSystem.Capabilities.HasCapability(Axiom.Graphics.Capabilities.TextureCompressionDXT))
{
imgData.format = ILUtil.Convert(dxtFormat, imageType);
imgData.flags |= ImageFlags.Compressed;
// Validate that this devil version loads DXT mipmaps
if (imgData.numMipMaps > 0)
{
Il.ilBindImage(imageID);
Il.ilActiveMipmap(1);
if ((uint)Il.ilGetInteger(Il.IL_DXTC_DATA_FORMAT) != dxtFormat)
{
imgData.numMipMaps = 0;
LogManager.Instance.Write(
"Warning: Custom mipmaps for compressed image were ignored because they are not loaded by this DevIL version.");
}
}
}
// Calculate total size from number of mipmaps, faces and size
imgData.size = Image.CalculateSize(imgData.numMipMaps, numFaces, imgData.width, imgData.height, imgData.depth,
imgData.format);
// get the decoded data
BufferBase BufferHandle;
// Dimensions of current mipmap
var width = imgData.width;
var height = imgData.height;
var depth = imgData.depth;
// Transfer data
for (var mip = 0; mip <= imgData.numMipMaps; ++mip)
{
for (var i = 0; i < numFaces; ++i)
{
Il.ilBindImage(imageID);
if (numFaces > 1)
{
Il.ilActiveImage(i);
}
if (imgData.numMipMaps > 0)
{
Il.ilActiveMipmap(mip);
}
// Size of this face
var imageSize = PixelUtil.GetMemorySize(width, height, depth, imgData.format);
buffer = new byte[imageSize];
if ((imgData.flags & ImageFlags.Compressed) != 0)
{
// Compare DXT size returned by DevIL with our idea of the compressed size
if (imageSize == Il.ilGetDXTCData(IntPtr.Zero, 0, dxtFormat))
{
// Retrieve data from DevIL
using (BufferHandle = BufferBase.Wrap(buffer))
{
Il.ilGetDXTCData(BufferHandle.Pin(), imageSize, dxtFormat);
BufferHandle.UnPin();
}
}
else
{
LogManager.Instance.Write("Warning: compressed image size mismatch, devilsize={0} oursize={1}",
Il.ilGetDXTCData(IntPtr.Zero, 0, dxtFormat), imageSize);
}
}
else
{
// Retrieve data from DevIL
using (BufferHandle = BufferBase.Wrap(buffer))
{
var dst = new PixelBox(width, height, depth, imgData.format, BufferHandle);
ILUtil.ConvertFromIL(dst);
}
}
// write the decoded data to the output stream
output.Write(buffer, 0, buffer.Length);
}
// Next mip
if (width != 1)
{
width /= 2;
}
if (height != 1)
{
height /= 2;
}
if (depth != 1)
{
depth /= 2;
}
}
// Restore IL state
Il.ilDisable(Il.IL_ORIGIN_SET);
Il.ilDisable(Il.IL_FORMAT_SET);
Il.ilDeleteImages(1, ref imageID);
return(new DecodeResult(output, imgData));
}
