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Ellipse implementation: Several bug fixes

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I. Fix minor bug where wrong b was used to create ellipse internal geometry.

Tweak the internal geometry code a bit and reformat it so it isn't so wide.
Also begin debugging constraint conflicts on small circular ellipses.

There seem to be two issues currently in major/minor internal geometry lines:
  1) Sometimes minorLength > majorLength due to round-tripping doubles, and
  2) Constraint conflicts when majorLength > minorLength by an epsilon on the order of 1e-6

(cherry picked from commit 5c3e20af1a95c860112289dcdda54ea99778bc3a)

II. When testing for a valid ellipse, also ensure that the mangled major axis length > the mangled axis length.

This additional condition ensures that major and minor axis constraints don't conflict in the case of small
(nearly) circular ellipses.

The is still a potential bug in the solver when the major length is just slightly larger than the minor, but this fix
makes it nigh impossible to reproduce.
(cherry picked from commit 7e274bc32d9aa1a12ab52bfa33ed80353540b062)

III. Code clean up

Remove redundant 3d vectors.

(cherry picked from commit c656d5165c8bae8f101a2b46af6b12348d06cefe)
This commit is contained in:
Mark A. Taff 2014-10-27 20:25:14 -07:00 committed by wmayer
parent c8d7f70dba
commit 80120a6bac
1 changed files with 100 additions and 50 deletions
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150
src/Mod/Sketcher/Gui/CommandCreateGeo.cpp
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@ -2061,6 +2061,8 @@ private:
* +Z coming out of the sketch, this b position is in the +Y direction from the centroid.
*/
Base::Vector2D positiveB;
/// the other b position
Base::Vector2D negativeB;
/// cart. position vector for primary focus
Base::Vector2D f;
/// cart. position vector for other focus
@ -2396,19 +2398,27 @@ private:
* limit of 25 attempts, I have been unable to make it fail.
*/
// simulate loss of precision in centroid and periapsis
// simulate loss of precision in centroid, periapsis, and apoapsis
char cx[64];
char cy[64];
char px[64];
char py[64];
char ax[64];
char ay[64];
sprintf(cx, "%.6lf\n", centroid.fX);
sprintf(cy, "%.6lf\n", centroid.fY);
sprintf(px, "%.6lf\n", periapsis.fX);
sprintf(py, "%.6lf\n", periapsis.fY);
sprintf(ax, "%.6lf\n", apoapsis.fX);
sprintf(ay, "%.6lf\n", apoapsis.fY);
centroid.fX = atof(cx);
centroid.fY = atof(cy);
periapsis.fX = atof(px);
periapsis.fY = atof(py);
apoapsis.fX = atof(ax);
apoapsis.fY = atof(ay);
double majorLength = (periapsis - apoapsis).Length();
double minorLength = 0;
/* GC_MakeEllipse requires a right-handed coordinate system, with +X
* from centroid to periapsis, +Z out of the page.
@ -2420,87 +2430,127 @@ private:
int count = 0;
int limit = 25; // no infinite loops!
bool success = false;
double tempB = b;
// adjust b until our mangled vectors produce a good ellispe
// adjust b until our mangled vectors produce a good ellipse in GC_MakeEllipse
// and the mangled major and minor lines in LinePy::PyInit(...) are such that
// major is at least slightly larger than minor
do {
j = j.Normalize() * (b - double(count * beta));
tempB = b - double(count * beta);
j = j.Normalize() * tempB;
positiveB.fX = centroid.fX + j.x;
positiveB.fY = centroid.fY + j.y;
char bx[64];
char by[64];
sprintf(bx, "%.6lf\n", positiveB.fX);
sprintf(by, "%.6lf\n", positiveB.fY);
positiveB.fX = atof(bx);
positiveB.fY = atof(by);
negativeB.fX = centroid.fX + (j.x * -1);
negativeB.fY = centroid.fY + (j.y * -1);
char bpx[64];
char bpy[64];
char bnx[64];
char bny[64];
sprintf(bpx, "%.6lf\n", positiveB.fX);
sprintf(bpy, "%.6lf\n", positiveB.fY);
sprintf(bnx, "%.6lf\n", negativeB.fX);
sprintf(bny, "%.6lf\n", negativeB.fY);
positiveB.fX = atof(bpx);
positiveB.fY = atof(bpy);
negativeB.fX = atof(bnx);
negativeB.fY = atof(bny);
GC_MakeEllipse me(gp_Pnt(periapsis.fX,periapsis.fY,0),
gp_Pnt(positiveB.fX,positiveB.fY,0),
gp_Pnt(centroid.fX,centroid.fY,0));
minorLength = (negativeB - positiveB).Length();
count++;
success = me.IsDone();
success = me.IsDone() && (minorLength + beta < majorLength);
} while (!success && (count <= limit));
if (!success) {
qDebug() << "Failed to create a valid mangled ellipse after" << count << "attempts";
}
Base::Vector3d center = Base::Vector3d(centroid.fX,centroid.fY,0);
Base::Vector3d majorpositiveend = center + a * Base::Vector3d(cos(phi),sin(phi),0);
Base::Vector3d majornegativeend = center - a * Base::Vector3d(cos(phi),sin(phi),0);
Base::Vector3d minorpositiveend = center + b * Base::Vector3d(-sin(phi),cos(phi),0);
Base::Vector3d minornegativeend = center - b * Base::Vector3d(-sin(phi),cos(phi),0);
// save any changes to b, then recalculate ellipse as required due to change in b
b = tempB;
e = sqrt(1 - ((b * b) / (a * a)));
ae = a * e;
f = apseHat;
f.Scale(ae);
f = centroid + f;
fPrime = apseHat;
fPrime.Scale(-1 * ae);
fPrime = centroid + fPrime;
double cf = sqrt( abs(a*a - b*b) );//using abs, avoided using different formula for a>b/a<b cases
Base::Vector3d focus1P = center + cf * Base::Vector3d(cos(phi),sin(phi),0);
Base::Vector3d focus2P = center - cf * Base::Vector3d(cos(phi),sin(phi),0);
int currentgeoid = getHighestCurveIndex();//index of the arc of ellipse we just created
int currentgeoid = getHighestCurveIndex(); // index of the ellipse we just created
Gui::Command::openCommand("Add sketch ellipse");
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addGeometry(Part.Ellipse"
"(App.Vector(%f,%f,0),App.Vector(%f,%f,0),App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
periapsis.fX, periapsis.fY,
positiveB.fX, positiveB.fY,
centroid.fX, centroid.fY);
"App.ActiveDocument.%s.addGeometry(Part.Ellipse"
"(App.Vector(%f,%f,0),App.Vector(%f,%f,0),App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
periapsis.fX, periapsis.fY,
positiveB.fX, positiveB.fY,
centroid.fX, centroid.fY);
currentgeoid++;
try {
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.addGeometry(Part.Line(App.Vector(%f,%f,0),App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
majorpositiveend.x,majorpositiveend.y,majornegativeend.x,majornegativeend.y); // create line for major axis
// create line for major axis
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addGeometry(Part.Line"
"(App.Vector(%f,%f,0),App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
periapsis.fX,periapsis.fY,
apoapsis.fX,apoapsis.fY);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.toggleConstruction(%d) ",
sketchgui->getObject()->getNameInDocument(),currentgeoid+1);
sketchgui->getObject()->getNameInDocument(),currentgeoid+1);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.addConstraint(Sketcher.Constraint('InternalAlignment:EllipseMajorDiameter',%d,%d)) ",
sketchgui->getObject()->getNameInDocument(),currentgeoid+1,currentgeoid); // constrain major axis
// constrain major axis
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addConstraint(Sketcher.Constraint"
"('InternalAlignment:EllipseMajorDiameter',%d,%d)) ",
sketchgui->getObject()->getNameInDocument(),
currentgeoid+1,currentgeoid);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.addGeometry(Part.Line(App.Vector(%f,%f,0),App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
minorpositiveend.x,minorpositiveend.y,minornegativeend.x,minornegativeend.y); // create line for minor axis
// create line for minor axis
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addGeometry(Part.Line"
"(App.Vector(%f,%f,0),App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
positiveB.fX,positiveB.fY,
negativeB.fX,negativeB.fY);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.toggleConstruction(%d) ",
sketchgui->getObject()->getNameInDocument(),currentgeoid+2);
sketchgui->getObject()->getNameInDocument(),currentgeoid+2);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.addConstraint(Sketcher.Constraint('InternalAlignment:EllipseMinorDiameter',%d,%d)) ",
sketchgui->getObject()->getNameInDocument(),currentgeoid+2,currentgeoid); // constrain minor axis
// constrain minor axis
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addConstraint(Sketcher.Constraint"
"('InternalAlignment:EllipseMinorDiameter',%d,%d)) ",
sketchgui->getObject()->getNameInDocument(),
currentgeoid+2,currentgeoid);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.addGeometry(Part.Point(App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
focus1P.x,focus1P.y);
// create point for focus
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addGeometry(Part.Point(App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
f.fX,f.fY);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.addConstraint(Sketcher.Constraint('InternalAlignment:EllipseFocus1',%d,%d,%d)) ",
sketchgui->getObject()->getNameInDocument(),currentgeoid+3,Sketcher::start,currentgeoid);
// constrain focus
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addConstraint(Sketcher.Constraint"
"('InternalAlignment:EllipseFocus1',%d,%d,%d)) ",
sketchgui->getObject()->getNameInDocument(),
currentgeoid+3,Sketcher::start,currentgeoid);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.addGeometry(Part.Point(App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
focus2P.x,focus2P.y);
// create point for second focus
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addGeometry(Part.Point(App.Vector(%f,%f,0)))",
sketchgui->getObject()->getNameInDocument(),
fPrime.fX,fPrime.fY);
Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.addConstraint(Sketcher.Constraint('InternalAlignment:EllipseFocus2',%d,%d,%d)) ",
sketchgui->getObject()->getNameInDocument(),currentgeoid+4,Sketcher::start,currentgeoid);
// constrain second focus
Gui::Command::doCommand(Gui::Command::Doc,
"App.ActiveDocument.%s.addConstraint(Sketcher.Constraint"
"('InternalAlignment:EllipseFocus2',%d,%d,%d)) ",
sketchgui->getObject()->getNameInDocument(),
currentgeoid+4,Sketcher::start,currentgeoid);
}
catch (const Base::Exception& e) {
Base::Console().Error("%s\n", e.what());