kindred/create
1
1
Fork 0
Code Issues 37 Pull Requests Actions Packages Projects 9 Releases 2 Wiki Activity

Fix CCW ellipse arcs

Browse Source
This commit is contained in:
wandererfan
2018-05-14 09:17:00 -04:00
committed by wmayer
parent 8c4a838740
commit f41598ee33
3 changed files with 50 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
src/Mod/Import/App/ImpExpDxf.cpp
View File

@@ -472,13 +472,21 @@ void ImpExpDxfWrite::exportEllipseArc(BRepAdaptor_Curve c)
gp_Vec v1(m,s);
gp_Vec v2(m,e);
gp_Vec v3(0,0,1);
double a = v3.DotCross(v1,v2);
double a = v3.DotCross(v1,v2); // a = v3 dot (v1 cross v2)
// relates to "handedness" of 3 vectors
// a > 0 ==> v2 is CCW from v1 (righthanded)?
// a < 0 ==> v2 is CW from v1 (lefthanded)?
double startAngle = fmod(f,2.0*M_PI);
double startAngle = fmod(f,2.0*M_PI); //revolutions
double endAngle = fmod(l,2.0*M_PI);
bool dir = (a < 0) ? true: false;
bool endIsCW = (a < 0) ? true: false; //if !endIsCW swap(start,end)
//not sure if this is a hack or not. seems to make valid arcs.
if (!endIsCW) {
startAngle = -startAngle;
endAngle = -endAngle;
}
WriteEllipse(center, major, minor, rotation, startAngle, endAngle, dir, getLayerName().c_str() );
WriteEllipse(center, major, minor, rotation, startAngle, endAngle, endIsCW, getLayerName().c_str());
}
void ImpExpDxfWrite::exportBSpline(BRepAdaptor_Curve c)