internal static bool Make(VGPath path, out StencilVertex[] vertices, out int tris)
{
vertices = null;
// Count triangles
tris =
path.GetCount(VGPath.SegmentType.CurveTo) * 2 +
path.GetCount(VGPath.SegmentType.LineTo) +
path.GetCount(VGPath.SegmentType._Tesselated);
if (tris == 0)
return false;
// Tesselate
vertices = new StencilVertex[tris * 3];
StencilVertex start = new StencilVertex();
Vector2 last = new Vector2();
int index = 0;
start.Set(0, 0, Constants.Coef_Solid);
for (var s = path.FirstSegment; s != null; s = s.Next)
{
switch (s.Value.Type)
{
case VGPath.SegmentType.CurveTo:
{
vertices[index++].Set(last.X, last.Y, Constants.Coef_Solid);
vertices[index++].Set(s.Value.Target.X, s.Value.Target.Y, Constants.Coef_Solid);
vertices[index++] = start;
vertices[index++].Set(last.X, last.Y, Constants.Coef_BezierStart);
vertices[index++].Set(s.Value.Controls[0].X, s.Value.Controls[0].Y, Constants.Coef_BezierControl);
vertices[index++].Set(s.Value.Target.X, s.Value.Target.Y, Constants.Coef_BezierEnd);
}
break;
case VGPath.SegmentType.LineTo:
case VGPath.SegmentType._Tesselated:
{
vertices[index++].Set(last.X, last.Y, Constants.Coef_Solid);
vertices[index++].Set(s.Value.Target.X, s.Value.Target.Y, Constants.Coef_Solid);
vertices[index++] = start;
}
break;
case VGPath.SegmentType.MoveTo:
{
start.Set(s.Value.Target.X, s.Value.Target.Y, Constants.Coef_Solid);
}
break;
default:
continue;
}
last = s.Value.Target;
}
return true;
}
internal StrokeMesh(GraphicsDevice device, VGPath path, VGLineCap startCap, VGLineCap endCap, VGLineJoin join, float miterLimit)
{
int solidCount, radialCount, i, j, moves;
// No triangles at all, don't bother...
if (path.IsEmpty)
return;
// Approximate triangle counts
moves = path.GetCount(VGPath.SegmentType.MoveTo);
GetCapTris(startCap, out i, out j);
solidCount = moves * i;
radialCount = moves * j;
GetCapTris(endCap, out i, out j);
solidCount += moves * i;
radialCount += moves * j;
GetJoinTris(join, out i, out j);
solidCount += path.Count * i;
radialCount += path.Count * j;
solidCount += (path.GetCount(VGPath.SegmentType.LineTo) + path.GetCount(VGPath.SegmentType._Tesselated)) * 2;
// Initialize
_solid = new SolidStrokeBuilder(solidCount, miterLimit);
_radial = new RadialStrokeBuilder(radialCount);
var startCapFunc = GetCapFunction(startCap);
var endCapFunc = GetCapFunction(endCap);
var joinFunc = GetJoinFunction(join);
// Tesselate
VGPath.Segment last = null;
Vector2 lastNormal = Vector2.Zero;
var lastStart = path.FirstSegment;
for (var s = lastStart; s != null; s = s.Next)
{
switch (s.Value.Type)
{
case VGPath.SegmentType.LineTo:
{
Vector2 n, mn;
VectorMath.GetLeftNormal(last.Target, s.Value.Target, out n);
mn = -n;
_solid.AddVertex(last.Target, mn);
_solid.AddVertex(last.Target, n);
_solid.AddVertex(s.Value.Target, n);
_solid.AddVertex(last.Target, mn);
_solid.AddVertex(s.Value.Target, n);
_solid.AddVertex(s.Value.Target, mn);
}
break;
case VGPath.SegmentType._Tesselated:
{
if (last.Type != VGPath.SegmentType._Tesselated)
VectorMath.GetLeftNormal(last.Target, s.Value.Target, out lastNormal);
Vector2 lastRtNormal = -lastNormal;
_solid.AddVertex(last.Target, lastRtNormal);
_solid.AddVertex(last.Target, lastNormal);
_solid.AddVertex(s.Value.Target, s.Value.Controls[0]);
_solid.AddVertex(last.Target, lastRtNormal);
_solid.AddVertex(s.Value.Target, s.Value.Controls[0]);
_solid.AddVertex(s.Value.Target, -s.Value.Controls[0]);
lastNormal = s.Value.Controls[0];
}
break;
case VGPath.SegmentType.MoveTo:
{
if (s.Previous != null && s.Previous.Value.Type != VGPath.SegmentType.Close && s.Previous.Value.Type != VGPath.SegmentType.MoveTo)
{
startCapFunc(lastStart, true);
endCapFunc(s.Previous, false);
}
lastStart = s;
}
break;
case VGPath.SegmentType.Close:
break;
default:
throw new InvalidOperationException("Trying to stroke non-flattened path!");
}
if (s.Value.MakeJoin && s.Next != null)
joinFunc(s);
last = s.Value;
}
// Do the caps
if (path.LastSegment.Value.Type != VGPath.SegmentType.Close && path.LastSegment.Value.Type != VGPath.SegmentType.MoveTo)
{
startCapFunc(lastStart, true);
endCapFunc(path.LastSegment, false);
}
// Create buffer
_vertices[0] = _solid.Build(device, out _tris[0]);
_vertices[1] = _radial.Build(device, out _tris[1]);
// Free builders
_radial = null;
_solid = null;
}
