private static void SaveLayer(BinaryReverseWriter writer, BitmapLayer layer, AbrFileVersion fileVersion, bool rle)
{
writer.Write((short)AbrBrushType.Sampled);
using (new LengthWriter(writer))
{
// Write the miscellaneous data, unused.
writer.Write(0);
// Write the spacing.
string spacingMetaData = layer.Metadata.GetUserValue(AbrMetadataNames.BrushSpacing);
if (spacingMetaData != null &&
int.TryParse(spacingMetaData, NumberStyles.Number, CultureInfo.InvariantCulture, out int spacing))
{
writer.Write((short)spacing);
}
else
{
writer.Write((short)DefaultSpacingPercent);
}
// Write the brush name, if applicable.
if (fileVersion == AbrFileVersion.Version2)
{
writer.WriteUnicodeString(layer.Name);
}
Rectangle imageBounds = GetImageRectangle(layer.Surface);
// Write the anti-aliasing.
if (imageBounds.Width < 32 && imageBounds.Height < 32)
{
// Only brushes less than 32x32 pixels are anti-aliased by Photoshop.
writer.Write((byte)1);
}
else
{
writer.Write((byte)0);
}
// Write the Int16 bounds.
writer.WriteInt16Rectangle(imageBounds);
// Write the Int32 bounds.
writer.WriteInt32Rectangle(imageBounds);
// Write the depth.
writer.Write((short)8);
byte[] alpha = GetBrushAlphaData(layer.Surface, imageBounds);
int rowsRemaining = imageBounds.Height;
int rowsRead = 0;
do
{
// Brushes taller than 16384 pixels are split into 16384 line chunks.
int chunkHeight = Math.Min(rowsRemaining, 16384);
if (rle)
{
// Write the RLE compressed header.
writer.Write((byte)AbrImageCompression.RLE);
long rowCountOffset = writer.BaseStream.Position;
for (int i = 0; i < chunkHeight; i++)
{
// Placeholder for the row byte count.
writer.Write(short.MaxValue);
}
short[] rowByteCount = new short[chunkHeight];
for (int y = 0; y < chunkHeight; y++)
{
int row = rowsRead + y;
rowByteCount[y] = (short)RLEHelper.EncodedRow(writer.BaseStream, alpha, row * imageBounds.Width, imageBounds.Width);
}
long current = writer.BaseStream.Position;
writer.BaseStream.Position = rowCountOffset;
for (int i = 0; i < chunkHeight; i++)
{
writer.Write(rowByteCount[i]);
}
writer.BaseStream.Position = current;
}
else
{
// Write the uncompressed header.
writer.Write((byte)AbrImageCompression.Raw);
for (int y = 0; y < chunkHeight; y++)
{
int row = rowsRead + y;
writer.Write(alpha, row * imageBounds.Width, imageBounds.Width);
}
}
rowsRemaining -= 16384;
rowsRead += 16384;
} while (rowsRemaining > 0);
}
}