private static IEnumerable <uint> Encode(IPuntal puntal, TileGeometryTransform tgt)
{
const int CoordinateIndex = 0;
var geometry = (Geometry)puntal;
int currentX = 0, currentY = 0;
var parameters = new List <uint>();
for (int i = 0; i < geometry.NumGeometries; i++)
{
var point = (Point)geometry.GetGeometryN(i);
(int x, int y) = tgt.Transform(point.CoordinateSequence, CoordinateIndex, ref currentX, ref currentY);
if (i == 0 || x > 0 || y > 0)
{
parameters.Add(GenerateParameterInteger(x));
parameters.Add(GenerateParameterInteger(y));
}
}
// Return result
yield return(GenerateCommandInteger(MapboxCommandType.MoveTo, parameters.Count / 2));
foreach (uint parameter in parameters)
{
yield return(parameter);
}
}
private static IEnumerable <uint> Encode(CoordinateSequence sequence, TileGeometryTransform tgt,
ref int currentX, ref int currentY,
bool ring = false, bool ccw = false)
{
// how many parameters for LineTo command
int count = sequence.Count;
// if we have a ring we need to check orientation
if (ring)
{
if (ccw != Algorithm.Orientation.IsCCW(sequence))
{
sequence = sequence.Copy();
CoordinateSequences.Reverse(sequence);
}
}
var encoded = new List <uint>();
// Start point
encoded.Add(GenerateCommandInteger(MapboxCommandType.MoveTo, 1));
var position = tgt.Transform(sequence, 0, ref currentX, ref currentY);
encoded.Add(GenerateParameterInteger(position.x));
encoded.Add(GenerateParameterInteger(position.y));
// Add LineTo command (stub)
int lineToCount = 0;
encoded.Add(GenerateCommandInteger(MapboxCommandType.LineTo, lineToCount));
for (int i = 1; i < count; i++)
{
position = tgt.Transform(sequence, i, ref currentX, ref currentY);
if (position.x != 0 || position.y != 0)
{
encoded.Add(GenerateParameterInteger(position.x));
encoded.Add(GenerateParameterInteger(position.y));
lineToCount++;
}
}
if (lineToCount > 0)
{
encoded[3] = GenerateCommandInteger(MapboxCommandType.LineTo, lineToCount);
}
// Validate encoded data
if (ring)
{
// A ring has 1 MoveTo and 1 LineTo command.
// A ring is only valid if we have at least 3 points, otherwise collapse
if (encoded.Count - 2 >= 6)
{
encoded.Add(GenerateCommandInteger(MapboxCommandType.ClosePath, 1));
}
else
{
encoded.Clear();
}
}
else
{
// A line has 1 MoveTo and 1 LineTo command.
// A line is valid if it has at least 2 points
if (encoded.Count - 2 < 4)
{
encoded.Clear();
}
}
return(encoded);
}
