private static void BuildGeometryFromClipPaths(ShapeUtils.Geometry geom, List <List <IntPoint> > paths, List <Vector2> outVerts, List <UInt16> outInds, ref UInt16 maxIndex)
{
var vertices = new List <Vector2>(100);
var indices = new List <UInt16>(vertices.Capacity * 3);
var vertexIndex = new Dictionary <IntPoint, UInt16>();
foreach (var path in paths)
{
if (path.Count == 3)
{
// Triangle case, no need to tessellate
foreach (var pt in path)
{
StoreClipVertex(vertexIndex, vertices, indices, pt, ref maxIndex);
}
}
else if (path.Count > 3)
{
// Generic polygon case, we need to tessellate first
var tess = new Tess();
var contour = new ContourVertex[path.Count];
for (int i = 0; i < path.Count; ++i)
{
contour[i] = new ContourVertex()
{
Position = new Vec3()
{
X = path[i].X, Y = path[i].Y, Z = 0.0f
}
}
}
;
tess.AddContour(contour, ContourOrientation.Original);
var windingRule = WindingRule.NonZero;
tess.Tessellate(windingRule, ElementType.Polygons, 3);
foreach (var e in tess.Elements)
{
var v = tess.Vertices[e];
var pt = new IntPoint(v.Position.X, v.Position.Y);
StoreClipVertex(vertexIndex, vertices, indices, pt, ref maxIndex);
}
}
}
var invMatrix = geom.WorldTransform.Inverse();
outVerts.AddRange(vertices.Select(v => invMatrix * v));
outInds.AddRange(indices);
}
private static List <List <IntPoint> > BuildTriangleClipPaths(ShapeUtils.Geometry geom)
{
var paths = new List <List <IntPoint> >(geom.Indices.Length / 3);
var verts = geom.Vertices;
var inds = geom.Indices;
var indexCount = geom.Indices.Length;
var matrix = geom.WorldTransform;
for (int i = 0; i < indexCount; i += 3)
{
var v0 = matrix * verts[inds[i]];
var v1 = matrix * verts[inds[i + 1]];
var v2 = matrix * verts[inds[i + 2]];
var tri = new List <IntPoint>(3);
tri.Add(new IntPoint(v0.x * k_ClipperScale, v0.y * k_ClipperScale));
tri.Add(new IntPoint(v1.x * k_ClipperScale, v1.y * k_ClipperScale));
tri.Add(new IntPoint(v2.x * k_ClipperScale, v2.y * k_ClipperScale));
paths.Add(tri);
}
return(paths);
}
internal static void ClipGeometry(ShapeUtils.Geometry geom)
{
UnityEngine.Profiling.Profiler.BeginSample("ClipGeometry");
var clipper = new Clipper();
foreach (var clipperPaths in m_ClipStack)
{
var vertices = new List <Vector2>(geom.Vertices.Length);
var indices = new List <UInt16>(geom.Indices.Length);
var paths = BuildTriangleClipPaths(geom);
var result = new List <List <IntPoint> >();
UInt16 maxIndex = 0;
foreach (var path in paths)
{
clipper.AddPaths(clipperPaths, PolyType.ptClip, true);
clipper.AddPath(path, PolyType.ptSubject, true);
clipper.Execute(ClipType.ctIntersection, result, PolyFillType.pftNonZero, PolyFillType.pftNonZero);
if (result.Count > 0)
{
BuildGeometryFromClipPaths(geom, result, vertices, indices, ref maxIndex);
}
clipper.Clear();
result.Clear();
}
geom.Vertices = vertices.ToArray();
geom.Indices = indices.ToArray();
}
UnityEngine.Profiling.Profiler.EndSample();
}