//#endfor instanced to 'Vector2d'
//#foreach instanced to 'Vector2f'
/// <summary>
/// Tesselates an outline using options to array of triangles.
/// </summary>
/// <param name="data">The input data. If options has OutlineEnd.NoEnd options, last and first element
/// will be linked automatically (as with polygons). Otherwise, all points will be used.</param>
/// <param name="options">The options of tesselation.</param>
/// <param name="builder">The buolder that is used to build the mesh.</param>
public static void Tesselate([NotNull] Vector2f[] data, [NotNull] TesselationOptionsf options,
[NotNull] Storage.Builders.ITriangleBuilder2f builder)
{
if (data.Length < 2)
{
throw new ArgumentException("The data length must be at least 2, otherwise cannot tesselate.");
}
if (options.OutlineType == OutlineType.Line)
{
TesselateLine(data, options, builder);
}
else
{
throw new NotImplementedException("The feature not yet implemented.");
}
}
/// <summary>
/// Tesselates outline as line (most common).
/// </summary>
/// <param name="points"></param>
/// <param name="options"></param>
/// <param name="mesh"></param>
static void TesselateLine(Vector2f[] points, TesselationOptionsf options,
Storage.Builders.ITriangleBuilder2f mesh)
{
// This is actually half width, because we go both ways.
float width = options.LineThickness * (float)0.5;
// Previous lower and upper coordinates, usually pen dependant.
Vector2f grad = points[1] - points[0];
grad = new Vector2f(-grad.Y, grad.X).Normal;
Vector2f prevLower = points[0] - grad * width,
prevUpper = points[0] + grad * width;
// We check if it is closed.
bool isClosed = false;
if (Vector2f.NearEqual(points[0], points[points.Length - 1]))
{
isClosed = true;
// We correct prevLower and prevUpper.
Vector2f p0, p1, p2;
if (CalcPathIntersection(points[points.Length - 2], points[0], points[1],
width, out p0, out p1, out p2))
{
prevUpper = p0;
prevLower = p2;
}
else
{
prevUpper = p2;
prevLower = p0;
}
}
else
{
if (options.OutlineEnd == OutlineEnd.NoEnd)
{
throw new ArgumentException("The outline must be 'linked' in order to have no end.");
}
}
// We insert prevUpper and predLower.
uint prevUpperId = mesh.AddControlPoints(prevUpper, prevLower);
uint prevLowerId = prevUpperId + 1;
// We go through all points.
for (int i = 1; i < points.Length - 1; i++)
{
Vector2f p0, p1, p2;
if (CalcPathIntersection(points[i - 1], points[i], points[i + 1],
width, out p0, out p1, out p2))
{
// We now add new values.
uint p0Id = mesh.AddControlPoints(p0, p1, p2);
uint p1Id = p0Id + 1;
uint p2Id = p0Id + 2;
// We now add triangles.
mesh.AddIndexedTriangles(prevLowerId, p0Id, prevUpperId,
prevLowerId, p1Id, p0Id,
p0Id, p1Id, p2Id);
prevLowerId = p2Id;
prevUpperId = p0Id;
}
else
{
// We now add new values.
uint p0Id = mesh.AddControlPoints(p0, p1, p2);
uint p1Id = p0Id + 1;
uint p2Id = p0Id + 2;
mesh.AddIndexedTriangles(prevLowerId, p1Id, prevUpperId,
prevLowerId, p0Id, p1Id,
p0Id, p1Id, p2Id);
prevLowerId = p0Id;
prevUpperId = p2Id;
}
}
if (isClosed)
{
// If it is closed, we must close it correctly.
Vector2f p0, p1, p2;
if (CalcPathIntersection(points[points.Length - 2], points[0], points[1],
width, out p0, out p1, out p2))
{
// We now add new values.
uint p0Id = mesh.AddControlPoints(p0, p1, p2);
uint p1Id = p0Id + 1;
uint p2Id = p0Id + 2;
// We now add triangles.
mesh.AddIndexedTriangles(prevLowerId, p0Id, prevUpperId,
prevLowerId, p1Id, p0Id,
p0Id, p1Id, p2Id);
}
else
{
// We now add new values.
uint p0Id = mesh.AddControlPoints(p0, p1, p2);
uint p1Id = p0Id + 1;
uint p2Id = p0Id + 2;
mesh.AddIndexedTriangles(prevLowerId, p1Id, prevUpperId,
prevLowerId, p0Id, p1Id,
p0Id, p1Id, p2Id);
}
}
else
{
// TODO: may need to implement other endings.
if (options.OutlineEnd != OutlineEnd.Square)
{
throw new NotImplementedException("No other endings but 'Square' implemented.");
}
// Last point special again.
Vector2f last = points[points.Length - 1];
grad = last - points[points.Length - 2];
grad = new Vector2f(-grad.Y, grad.X).Normal;
Vector2f lower = last - grad * width;
Vector2f upper = last + grad * width;
// The lower id.
uint lowerId = mesh.AddControlPoints(lower, upper);
uint upperId = lowerId + 1;
mesh.AddIndexedTriangles(prevLowerId, lowerId, upperId,
prevLowerId, upperId, prevUpperId);
}
}
