/// <summary>
/// Function to convert the image to B4G4R4A4.
/// </summary>
/// <param name="baseImage">The base image to convert.</param>
/// <param name="dithering">Dithering to apply to the converstion to B8G8R8A8.</param>
/// <returns>The updated image.</returns>
private static IGorgonImage ConvertToB4G4R4A4(IGorgonImage baseImage, ImageDithering dithering)
{
// This temporary image will be used to convert to B8G8R8A8.
IGorgonImage newImage = baseImage;
IGorgonImageInfo destInfo = new GorgonImageInfo(baseImage.ImageType, BufferFormat.B4G4R4A4_UNorm)
{
Depth = baseImage.Depth,
Height = baseImage.Height,
Width = baseImage.Width,
ArrayCount = baseImage.ArrayCount,
MipCount = baseImage.MipCount
};
// This is our working buffer for B4G4R4A4.
IGorgonImage destImage = new GorgonImage(destInfo);
try
{
// If necessary, convert to B8G8R8A8. Otherwise, we'll just downsample directly.
if ((newImage.Format != BufferFormat.B8G8R8A8_UNorm) &&
(newImage.Format != BufferFormat.R8G8B8A8_UNorm))
{
newImage = baseImage.Clone();
ConvertToFormat(newImage, BufferFormat.B8G8R8A8_UNorm, dithering);
}
// The next step is to manually downsample to R4G4B4A4.
// Because we're doing this manually, dithering won't be an option unless unless we've downsampled from a much higher bit format when converting to B8G8R8A8.
for (int array = 0; array < newImage.ArrayCount; ++array)
{
for (int mip = 0; mip < newImage.MipCount; ++mip)
{
int depthCount = newImage.GetDepthCount(mip);
for (int depth = 0; depth < depthCount; depth++)
{
IGorgonImageBuffer destBuffer = destImage.Buffers[mip, destInfo.ImageType == ImageType.Image3D ? depth : array];
IGorgonImageBuffer srcBuffer = newImage.Buffers[mip, newImage.ImageType == ImageType.Image3D ? depth : array];
ConvertPixelsToB4G4R4A4(destBuffer, srcBuffer);
}
}
}
destImage.CopyTo(baseImage);
return(baseImage);
}
finally
{
destImage.Dispose();
if (newImage != baseImage)
{
newImage.Dispose();
}
}
}
/// <summary>
/// Function to convert the image data into a premultiplied format.
/// </summary>
/// <param name="baseImage">The image to convert.</param>
/// <returns>A <see cref="IGorgonImage"/> containing the image data with the premultiplied alpha pixel data.</returns>
/// <exception cref="ArgumentNullException">Thrown when the <paramref name="baseImage"/> is <b>null</b>.</exception>
/// <exception cref="ArgumentException">Thrown when the original format could not be converted to <see cref="BufferFormat.R8G8B8A8_UNorm"/>.</exception>
/// <remarks>
/// <para>
/// Use this to convert an image to a premultiplied format. This takes each Red, Green and Blue element and multiplies them by the Alpha element.
/// </para>
/// <para>
/// Because this method will only operate on <see cref="BufferFormat.R8G8B8A8_UNorm"/> formattted image data, the image will be converted to that format and converted back to its original format
/// after the alpha is premultiplied. This may cause color fidelity issues. If the image cannot be converted, then an exception will be thrown.
/// </para>
/// </remarks>
public static IGorgonImage ConvertToPremultipliedAlpha(this IGorgonImage baseImage)
{
IGorgonImage newImage = null;
if (baseImage == null)
{
throw new ArgumentNullException(nameof(baseImage));
}
try
{
// Worker image.
var cloneImageInfo = new GorgonImageInfo(baseImage)
{
HasPreMultipliedAlpha = true
};
newImage = new GorgonImage(cloneImageInfo);
baseImage.CopyTo(newImage);
if (newImage.Format != BufferFormat.R8G8B8A8_UNorm)
{
if (!newImage.CanConvertToFormat(BufferFormat.R8G8B8A8_UNorm))
{
throw new ArgumentException(string.Format(Resources.GORIMG_ERR_FORMAT_NOT_SUPPORTED, BufferFormat.R8G8B8A8_UNorm), nameof(baseImage));
}
// Clone the image so we can convert it to the correct format.
newImage.ConvertToFormat(BufferFormat.R8G8B8A8_UNorm);
}
unsafe
{
int *imagePtr = (int *)(newImage.ImageData);
for (int i = 0; i < newImage.SizeInBytes; i += newImage.FormatInfo.SizeInBytes)
{
var color = GorgonColor.FromABGR(*imagePtr);
color = new GorgonColor(color.Red * color.Alpha, color.Green * color.Alpha, color.Blue * color.Alpha, color.Alpha);
*(imagePtr++) = color.ToABGR();
}
}
if (newImage.Format != baseImage.Format)
{
newImage.ConvertToFormat(baseImage.Format);
}
newImage.CopyTo(baseImage);
return(baseImage);
}
finally
{
newImage?.Dispose();
}
}
/// <summary>
/// Function to convert the image from B4G4R4A4.
/// </summary>
/// <param name="baseImage">The base image to convert.</param>
/// <param name="destFormat">The destination format.</param>
/// <returns>The updated image.</returns>
private static IGorgonImage ConvertFromB4G4R4A4(IGorgonImage baseImage, BufferFormat destFormat)
{
// If we're converting to R8G8B8A8 or B8G8R8A8, then use those formats, otherwise, default to B8G8R8A8 as an intermediate buffer.
BufferFormat tempFormat = ((destFormat != BufferFormat.B8G8R8A8_UNorm) && (destFormat != BufferFormat.R8G8B8A8_UNorm)) ? BufferFormat.B8G8R8A8_UNorm : destFormat;
// Create an worker image in B8G8R8A8 format.
IGorgonImageInfo destInfo = new GorgonImageInfo(baseImage.ImageType, tempFormat)
{
Depth = baseImage.Depth,
Height = baseImage.Height,
Width = baseImage.Width,
ArrayCount = baseImage.ArrayCount,
MipCount = baseImage.MipCount
};
// Our destination image for B8G8R8A8 or R8G8B8A8.
var destImage = new GorgonImage(destInfo);
try
{
// We have to manually upsample from R4G4B4A4 to B8R8G8A8.
// Because we're doing this manually, dithering won't be an option unless
for (int array = 0; array < baseImage.ArrayCount; ++array)
{
for (int mip = 0; mip < baseImage.MipCount; ++mip)
{
int depthCount = baseImage.GetDepthCount(mip);
for (int depth = 0; depth < depthCount; depth++)
{
IGorgonImageBuffer destBuffer = destImage.Buffers[mip, baseImage.ImageType == ImageType.Image3D ? depth : array];
IGorgonImageBuffer srcBuffer = baseImage.Buffers[mip, baseImage.ImageType == ImageType.Image3D ? depth : array];
ConvertPixelsFromB4G4R4A4(destBuffer, srcBuffer);
}
}
}
// If the destination format is not R8G8B8A8 or B8G8R8A8, then we need to do more conversion.
if (destFormat != destImage.Format)
{
ConvertToFormat(destImage, destFormat);
}
// Update the base image with our worker image.
destImage.CopyTo(baseImage);
return(baseImage);
}
finally
{
destImage.Dispose();
}
}
/// <summary>
/// Function to convert the image data into a premultiplied format.
/// </summary>
/// <param name="baseImage">The image to convert.</param>
/// <returns>A <see cref="IGorgonImage"/> containing the image data with the premultiplied alpha pixel data.</returns>
/// <exception cref="ArgumentNullException">Thrown when the <paramref name="baseImage"/> is <b>null</b>.</exception>
/// <exception cref="ArgumentException">Thrown when image format is compressed.</exception>
/// <remarks>
/// <para>
/// Use this to convert an image to a premultiplied format. This takes each Red, Green and Blue element and multiplies them by the Alpha element.
/// </para>
/// <para>
/// If the image does not contain alpha then the method will return right away and no alterations to the image will be performed.
/// </para>
/// </remarks>
public static IGorgonImage ConvertToPremultipliedAlpha(this IGorgonImage baseImage)
{
IGorgonImage newImage = null;
GorgonNativeBuffer <byte> imageData = null;
if (baseImage == null)
{
throw new ArgumentNullException(nameof(baseImage));
}
if (!baseImage.FormatInfo.HasAlpha)
{
return(baseImage);
}
if (baseImage.FormatInfo.IsCompressed)
{
throw new ArgumentException(string.Format(Resources.GORIMG_ERR_FORMAT_NOT_SUPPORTED, baseImage.Format), nameof(baseImage));
}
try
{
var cloneImageInfo = new GorgonImageInfo(baseImage)
{
HasPreMultipliedAlpha = true
};
imageData = new GorgonNativeBuffer <byte>(baseImage.ImageData.Length);
baseImage.ImageData.CopyTo(imageData);
unsafe
{
newImage = new GorgonImage(cloneImageInfo, new GorgonReadOnlyPointer((void *)imageData, imageData.SizeInBytes));
int arrayOrDepth = newImage.ImageType == ImageType.Image3D ? newImage.Depth : newImage.ArrayCount;
for (int mip = 0; mip < newImage.MipCount; ++mip)
{
for (int i = 0; i < arrayOrDepth; ++i)
{
IGorgonImageBuffer buffer = newImage.Buffers[mip, i];
byte *ptr = (byte *)buffer.Data;
int rowPitch = buffer.PitchInformation.RowPitch;
for (int y = 0; y < buffer.Height; ++y)
{
ImageUtilities.SetPremultipliedScanline(ptr, rowPitch, ptr, rowPitch, buffer.Format);
ptr += rowPitch;
}
}
}
}
newImage.CopyTo(baseImage);
return(baseImage);
}
finally
{
imageData?.Dispose();
newImage?.Dispose();
}
}
/// <summary>
/// Function to generate a new mip map chain.
/// </summary>
/// <param name="baseImage">The image which will have its mip map chain updated.</param>
/// <param name="mipCount">The number of mip map levels.</param>
/// <param name="filter">[Optional] The filter to apply when copying the data from one mip level to another.</param>
/// <returns>A <see cref="IGorgonImage"/> containing the updated mip map data.</returns>
/// <exception cref="ArgumentNullException">Thrown when the <paramref name="baseImage"/> parameter is <b>null</b>.</exception>
/// <remarks>
/// <para>
/// This method will generate a new mip map chain for the <paramref name="mipCount"/>. If the current number of mip maps is not the same as the requested number, then the image buffer will be
/// adjusted to use the requested number of mip maps. If 0 is passed to <paramref name="mipCount"/>, then a full mip map chain is generated.
/// </para>
/// <para>
/// Note that the <paramref name="mipCount"/> may not be honored depending on the current width, height, and depth of the image. Check the width, height and/or depth property on the returned
/// <see cref="IGorgonImage"/> to determine how many mip levels were actually generated.
/// </para>
/// </remarks>
public static IGorgonImage GenerateMipMaps(this IGorgonImage baseImage, int mipCount, ImageFilter filter = ImageFilter.Point)
{
if (baseImage == null)
{
throw new ArgumentNullException(nameof(baseImage));
}
int maxMips = GorgonImage.CalculateMaxMipCount(baseImage);
// If we specify 0, then generate a full chain.
if ((mipCount <= 0) || (mipCount > maxMips))
{
mipCount = maxMips;
}
// If we don't have any mip levels, then return the image as-is.
if (mipCount < 2)
{
return(baseImage);
}
var destSettings = new GorgonImageInfo(baseImage)
{
MipCount = mipCount
};
var newImage = new GorgonImage(destSettings);
var wic = new WicUtilities();
try
{
// Copy the top mip level from the source image to the dest image.
for (int array = 0; array < baseImage.ArrayCount; ++array)
{
GorgonNativeBuffer <byte> buffer = newImage.Buffers[0, array].Data;
int size = buffer.SizeInBytes;
baseImage.Buffers[0, array].Data.CopyTo(buffer, count: size);
}
// If we have 4 bits per channel, then we need to convert to 8 bit per channel to make WIC happy.
if (baseImage.Format == BufferFormat.B4G4R4A4_UNorm)
{
newImage.ConvertToFormat(BufferFormat.R8G8B8A8_UNorm);
}
wic.GenerateMipImages(newImage, filter);
// Convert back if we asked for 4 bit per channel.
if (baseImage.Format == BufferFormat.B4G4R4A4_UNorm)
{
newImage.ConvertToFormat(BufferFormat.B4G4R4A4_UNorm);
}
newImage.CopyTo(baseImage);
return(baseImage);
}
finally
{
newImage.Dispose();
wic.Dispose();
}
}
