public static void WritePAA(BinaryWriterEx writer, ColorRgba32[,] image, PAAType type = PAAType.UNDEFINED, PAAFlags flags = PAAFlags.InterpolatedAlpha)
{
var max = new ColorRgba32(0, 0, 0, 0);
ulong sumR = 0;
ulong sumG = 0;
ulong sumB = 0;
ulong sumA = 0;
byte minA = 255;
ulong totalPixels = 0;
for (int y = 0; y < image.GetLength(0); ++y)
{
for (int x = 0; x < image.GetLength(1); ++x)
{
var color = image[y, x];
max.r = Math.Max(color.r, max.r);
max.g = Math.Max(color.g, max.g);
max.b = Math.Max(color.b, max.b);
max.a = Math.Max(color.a, max.a);
minA = Math.Min(color.a, minA);
if (color.a > 128)
{
sumR += color.r;
sumG += color.g;
sumB += color.b;
sumA += color.a;
totalPixels++;
}
}
}
var avg = new ColorRgba32((byte)(sumR / totalPixels), (byte)(sumG / totalPixels), (byte)(sumB / totalPixels), (byte)(sumA / totalPixels));
if (type == PAAType.UNDEFINED)
{
if (minA == 255)
{
type = PAAType.DXT1;
}
else
{
type = PAAType.DXT5;
}
}
WritePAA(writer, new ReadOnlyMemory2D <ColorRgba32>(image), max, avg, type, flags);
}
public static void WritePAA(BinaryWriterEx writer, ReadOnlyMemory2D <ColorRgba32> image, ColorRgba32 max, ColorRgba32 avg, PAAType type = PAAType.DXT5, PAAFlags flags = PAAFlags.InterpolatedAlpha)
{
if (type != PAAType.DXT5 && type != PAAType.DXT1)
{
throw new NotSupportedException();
}
var enc = new BCnEncoder.Encoder.BcEncoder(type == PAAType.DXT5 ? CompressionFormat.Bc3 : CompressionFormat.Bc1);
var mipmaps = new List <MipmapEncoder>();
var width = image.Width;
var height = image.Width;
var offset = type == PAAType.DXT5 ? 128 : 112;
foreach (var mipmap in enc.EncodeToRawBytes(image))
{
if (width > 2 || height > 2)
{
var menc = new MipmapEncoder(mipmap, width, height, offset);
offset += menc.MipmapEntrySize;
mipmaps.Add(menc);
width = width / 2;
height = height / 2;
}
}
writer.Write(type == PAAType.DXT5 ? (ushort)0xff05 : (ushort)0xff01);
writer.WriteAscii("GGATCGVA", 8);
writer.Write((uint)4);
writer.Write(avg.r);
writer.Write(avg.g);
writer.Write(avg.b);
writer.Write(avg.a);
writer.WriteAscii("GGATCXAM", 8);
writer.Write((uint)4);
writer.Write(max.r);
writer.Write(max.g);
writer.Write(max.b);
writer.Write(max.a);
if (type == PAAType.DXT5)
{
writer.WriteAscii("GGATGALF", 8);
writer.Write((uint)4);
writer.Write((uint)flags);
}
writer.WriteAscii("GGATSFFO", 8);
writer.Write(16 * 4);
for (int i = 0; i < 16; ++i)
{
if (i < mipmaps.Count)
{
writer.Write((uint)mipmaps[i].Offset);
}
else
{
writer.Write((uint)0);
}
}
writer.Write((ushort)0x0000);
int index = 0;
foreach (var mipmap in mipmaps)
{
if (writer.Position != mipmap.Offset)
{
throw new Exception($"Wrong offset @{mipmap.Width} : {writer.Position} != { mipmap.Offset}");
}
writer.Write(mipmap.WidthEncoded);
writer.Write(mipmap.Height);
writer.WriteUInt24((uint)mipmap.PaaData.Length);
writer.Write(mipmap.PaaData);
index++;
width = width / 2;
height = height / 2;
}
writer.Write((uint)0x0000);
writer.Write((ushort)0x0000);
}
public static void WritePAA(string file, ColorRgba32[,] image, PAAType type = PAAType.UNDEFINED, PAAFlags flags = PAAFlags.InterpolatedAlpha)
{
using (var writer = new BinaryWriterEx(File.Create(file)))
{
WritePAA(writer, image, type, flags);
}
}
