private List <ShxGlyphCommand> ParseCommands(byte[] data, ShxFontEncoding encoding = ShxFontEncoding.Unicode)
{
var reader = new ByteReader(data);
var commands = ShxGlyph.ParseCommands(reader, encoding, isBigFont: false);
return(commands);
}
private ShxGlyphCommand ParseCommand(byte[] data, ShxFontEncoding encoding = ShxFontEncoding.Unicode)
{
var commands = ParseCommands(data, encoding);
return(commands.Single());
}
internal static List <ShxGlyphCommand> ParseCommands(ByteReader reader, ShxFontEncoding fontEncoding, bool isBigFont)
{
var commands = new List <ShxGlyphCommand>();
while (reader.TryReadByte(out var command) && command != 0)
{
var distance = (command & 0xF0) >> 4;
var direction = command & 0x0F;
var isBareCommand = distance == 0;
if (isBareCommand)
{
// special command handling for no movement
switch (command)
{
case 1:
// pen down
commands.Add(new ShxGlyphCommandPenDown());
break;
case 2:
// pen up
commands.Add(new ShxGlyphCommandPenUp());
break;
case 3:
// divide scaling vector by specified value
if (reader.TryReadByte(out var divr))
{
commands.Add(new ShxGlyphCommandUpdateScaleVector(1.0 / divr));
}
break;
case 4:
// multiply scaling vector by specified value
if (reader.TryReadByte(out var mulr))
{
commands.Add(new ShxGlyphCommandUpdateScaleVector(mulr));;
}
break;
case 5:
// push location
commands.Add(new ShxGlyphCommandPushPoint());
break;
case 6:
// pop location
commands.Add(new ShxGlyphCommandPopPoint());
break;
case 7:
{
if (isBigFont)
{
// https://help.autodesk.com/view/ACD/2020/ENU/?guid=GUID-00ED0CC6-A4BE-4591-93FA-598CC40AA43D
if (reader.TryReadByte(out var replayCode))
{
if (replayCode == 0 &&
reader.TryReadSByte(out var xoffset) &&
reader.TryReadSByte(out var yoffset) &&
reader.TryReadByte(out var width) &&
reader.TryReadByte(out var height))
{
commands.Add(new ShxGlyphCommandReplayCharacter(replayCode, xoffset, yoffset, width, height));
}
}
else
{
// sometimes it's not zero?
reader.TryReadByte(out var lowerByte);
var fullCode = (ushort)((replayCode << 8) | lowerByte);
commands.Add(new ShxGlyphCommandReplayCharacter(fullCode));
}
}
else
{
// replay the given character code
if (fontEncoding == ShxFontEncoding.Unicode)
{
if (reader.TryReadUInt16BigEndian(out var replayCode))
{
commands.Add(new ShxGlyphCommandReplayCharacter(replayCode));
}
}
else
{
if (reader.TryReadByte(out var replayCode))
{
commands.Add(new ShxGlyphCommandReplayCharacter(replayCode));
}
}
}
}
break;
case 8:
{
// move x, y
if (reader.TryReadSByte(out var xOffset) &&
reader.TryReadSByte(out var yOffset))
{
commands.Add(new ShxGlyphCommandMoveCursor(xOffset, yOffset));
}
}
break;
case 9:
{
// move x, y until 0, 0
while (reader.TryReadSByte(out var xOffset) &&
reader.TryReadSByte(out var yOffset))
{
if (xOffset == 0.0 && yOffset == 0.0)
{
// done
break;
}
commands.Add(new ShxGlyphCommandMoveCursor(xOffset, yOffset));
}
}
break;
case 0xA:
{
// octant arc
if (reader.TryReadByte(out var radius) &&
reader.TryReadByte(out var sc))
{
var isCounterClockwise = (sc & 0b10000000) == 0;
var startingOctant = (sc & 0b01110000) >> 4;
var octantCount = sc & 0b00000111;
commands.Add(new ShxGlyphCommandOctantArc(radius, startingOctant, octantCount, isCounterClockwise));
}
}
break;
case 0xB:
{
// fractional arc
if (reader.TryReadByte(out var startOffset) &&
reader.TryReadByte(out var endOffset) &&
reader.TryReadByte(out var highRadius) &&
reader.TryReadByte(out var radius) &&
reader.TryReadByte(out var sc))
{
var isCounterClockwise = (sc & 0b10000000) == 0;
var startingOctant = (sc & 0b01110000) >> 4;
var octantCount = sc & 0b00000111;
commands.Add(new ShxGlyphCommandFractionalArc(startOffset, endOffset, highRadius, radius, startingOctant, octantCount, isCounterClockwise));
}
}
break;
case 0xC:
{
// arc
if (reader.TryReadSByte(out var xDisplacement) &&
reader.TryReadSByte(out var yDisplacement) &&
reader.TryReadSByte(out var bulge))
{
commands.Add(new ShxGlyphCommandArc(xDisplacement, yDisplacement, bulge));
}
}
break;
case 0xD:
{
// continuous arcs
while (reader.TryReadSByte(out var xDisplacement) &&
reader.TryReadSByte(out var yDisplacement))
{
if (xDisplacement == 0 && yDisplacement == 0)
{
break;
}
if (reader.TryReadSByte(out var bulge))
{
commands.Add(new ShxGlyphCommandArc(xDisplacement, yDisplacement, bulge));
}
}
}
break;
case 0xE:
// skip next command if in horizontal mode
commands.Add(new ShxGlyphCommandSkipNextIfHorizontal());
break;
case 0xF:
// TODO: unknown/unsupported
break;
case 0:
// shouldn't happen
break;
default:
break;
}
}
else
{
var vector = DirectionVectors[direction];
var delta = vector * distance;
commands.Add(new ShxGlyphCommandMoveCursor(delta.X, delta.Y));
}
}
return(commands);
}