[TD]implement BrokenView

src/Mod/TechDraw/App/DrawUtil.cpp

@@ -642,6 +642,7 @@ gp_Vec DrawUtil::closestBasis(gp_Vec inVec)
     return gp_Vec(togp_Dir(closestBasis(toVector3d(inVec))));
 }
 
+//! returns stdX, stdY or stdZ.
 Base::Vector3d DrawUtil::closestBasis(Base::Vector3d v)
 {
     Base::Vector3d result(0.0, -1, 0);
@@ -698,6 +699,63 @@ Base::Vector3d DrawUtil::closestBasis(Base::Vector3d v)
     return Base::Vector3d(1.0, 0.0, 0.0);
 }
 
+//! returns +/- stdX, stdY or stdZ.
+Base::Vector3d DrawUtil::closestBasisOriented(Base::Vector3d v)
+{
+    Base::Vector3d result(0.0, -1, 0);
+    Base::Vector3d stdX(1.0, 0.0, 0.0);
+    Base::Vector3d stdY(0.0, 1.0, 0.0);
+    Base::Vector3d stdZ(0.0, 0.0, 1.0);
+    Base::Vector3d stdXr(-1.0, 0.0, 0.0);
+    Base::Vector3d stdYr(0.0, -1.0, 0.0);
+    Base::Vector3d stdZr(0.0, 0.0, -1.0);
+
+    //first check if already a basis
+    if (v.Dot(stdX) == 1.0 || v.Dot(stdY) == 1.0 || v.Dot(stdZ) == 1.0) {
+        return v;
+    }
+    if (v.Dot(stdX) == -1.0 || v.Dot(stdY) == -1.0 || v.Dot(stdZ) == -1.0) {
+        return v;
+    }
+
+    //not a basis. find smallest angle with a basis.
+    double angleX, angleY, angleZ, angleXr, angleYr, angleZr, angleMin;
+    angleX = stdX.GetAngle(v);
+    angleY = stdY.GetAngle(v);
+    angleZ = stdZ.GetAngle(v);
+    angleXr = stdXr.GetAngle(v);
+    angleYr = stdYr.GetAngle(v);
+    angleZr = stdZr.GetAngle(v);
+
+    angleMin = std::min({angleX, angleY, angleZ, angleXr, angleYr, angleZr});
+    if (angleX == angleMin) {
+        return Base::Vector3d(1.0, 0.0, 0.0);
+    }
+
+    if (angleY == angleMin) {
+        return Base::Vector3d(0.0, 1.0, 0.0);
+    }
+
+    if (angleZ == angleMin) {
+        return Base::Vector3d(0.0, 0.0, 1.0);
+    }
+
+    if (angleXr == angleMin) {
+        return Base::Vector3d(-1.0, 0.0, 0.0);
+    }
+
+    if (angleYr == angleMin) {
+        return Base::Vector3d(0.0, -1.0, 0.0);
+    }
+
+    if (angleZr == angleMin) {
+        return Base::Vector3d(0.0, 0.0, -1.0);
+    }
+
+    //should not get to here
+    return Base::Vector3d(1.0, 0.0, 0.0);
+}
+
 Base::Vector3d DrawUtil::closestBasis(Base::Vector3d vDir, gp_Ax2 coordSys)
 {
     gp_Dir gDir(vDir.x, vDir.y, vDir.z);