Posted by fernandohildebrand on Feb 17, 2012; 7:08pm
URL: https://forum.librecad.org/Help-with-perpendicular-snap-tp5493585.html

Hi al...

Need some help with the code here. heres what i got so far:

rs_entitycontainer.cpp ->

RS_Vector RS_EntityContainer::getNearestPerpendicular(const RS_Vector& coord
                                                      ){

    RS_Vector closestPoint(false); // closest found endpoint
    RS_VectorSolutions sol;
    RS_Entity* closestEntity;

    closestEntity = getNearestEntity(coord, NULL, RS2::ResolveAll);

    if (closestEntity!=NULL) {
        for (RS_Entity* en = firstEntity(RS2::ResolveAll);
             en != NULL;
             en = nextEntity(RS2::ResolveAll)) {
            if (
                    !en->isVisible()
                    || en == closestEntity
                    || en->rtti() == RS2::EntityPoint         /**Point*/
                    || en->getParent()->rtti() == RS2::EntityInsert         /**Insert*/
                    || en->getParent()->rtti() == RS2::EntityText         /**< Text 15*/
                    || en->getParent()->rtti() == RS2::EntityDimAligned   /**< Aligned Dimension */
                    || en->getParent()->rtti() == RS2::EntityDimLinear    /**< Linear Dimension */
                    || en->getParent()->rtti() == RS2::EntityDimRadial    /**< Radial Dimension */
                    || en->getParent()->rtti() == RS2::EntityDimDiametric /**< Diametric Dimension */
                    || en->getParent()->rtti() == RS2::EntityDimAngular   /**< Angular Dimension */
                    || en->getParent()->rtti() == RS2::EntityDimLeader    /**< Leader Dimension */
                    ){//do not do intersection for point for Spline, Insert, text, Dim
                continue;
            }

            sol = RS_Information::getPerpendicular(closestEntity,
                                                  en);

            closestPoint = sol.getClosest(coord);
        }

    }

    return closestPoint;
}

rs_information.cpp->

RS_VectorSolutions RS_Information::getPerpendicular(RS_Entity* e1,RS_Entity* e2){

    RS_VectorSolutions ret;

    RS_VectorSolutions t1;
    RS_VectorSolutions t2;

    if (e1==NULL || e2==NULL ) {
        RS_DEBUG->print("RS_Information::getPerpendicular() for NULL entities");
        return ret;
    }
    if (e1->getId() == e2->getId()) {
        RS_DEBUG->print("RS_Information::getPerpendicular() of the same entity");
        return ret;
    }
    // unsupported entities / entity combinations:
    if (
        e1->rtti()==RS2::EntityText || e2->rtti()==RS2::EntityText ||
        isDimension(e1->rtti()) || isDimension(e2->rtti())) {
        return ret;
    }


    // arc,circle,elipse/arc,circle,elipse
    if(
        (e1->rtti()==RS2::EntityArc || e1->rtti()==RS2::EntityCircle
            || e1->rtti()==RS2::EntityEllipse) &&
        (e2->rtti()==RS2::EntityArc || e2->rtti()==RS2::EntityCircle
            || e2->rtti()==RS2::EntityEllipse)) {

        t1 = e1->getTangentPoint();
        t2 = e2->getTangentPoint();

        if(t1.dotP(t2)==0){
            ret = container->getNearestPointOnEntity(e1);
            return ret;
        }
    }
    // line/arc,circle,elipse , arc,circle,elipse/line
    if(e1->rtti()==RS2::EntityArc || e1->rtti()==RS2::EntityCircle
            || e1->rtti()==RS2::EntityEllipse){

         t1 = e1->getTangentPoint(e1->getNearestPointOnEntity(e2));

         if(t2.dotP(t1)==0){
             ret = container->getNearestPointOnEntity(e1);
             return ret;
         }
     }
     else if(e2->rtti()==RS2::EntityArc || e2->rtti()==RS2::EntityCircle
            || e2->rtti()==RS2::EntityEllipse){

         t2 = e2->getTangentPoint(e2->getNearestPointOnEntity(e1));

         if(t1.dotP(t2)==0){
             ret = container->getNearestPointOnEntity(e1);
             return ret;
         }
    }
    //line/line
    t1 = e1;
    t2 = e2;
    if(t1.dotP(t2)==0){
        ret = container->getNearestPointOnEntity(e1);
        return ret;
    }

    return ret;
}

See, my main problem is getting the tangent lines/vector/points from the entities on information so I can do a DotProduct, I still dont get vetor_solutions...
Help please?

--
Fernando da Motta Hildebrand