| public GetVertexXY ( int index, double &x, double &y ) : void | ||
| index | int | |
| x | double | |
| y | double | |
| return | void | |
static bool IsCW(VertexStore myvxs, int start, int end)
{
// Calculate signed area (double area to be exact)
//---------------------
int np = end - start;
double area = 0.0;
int i;
for (i = 0; i < np; i++)
{
double x1, y1, x2, y2;
myvxs.GetVertexXY(start + i, out x1, out y1);
myvxs.GetVertexXY(start + (i + 1) % np, out x2, out y2);
area += x1 * y2 - y1 * x2;
}
return(area < 0.0);
//return (area < 0.0) ? ShapePath.FlagsAndCommand.FlagCW : ShapePath.FlagsAndCommand.FlagCCW;
}