grotius-cnc
commented
4 years ago Hi, I got a solution to increase the input values for a bulge higher then 1 and lower then -1. If the arc value passed bulge value 1 or lower then -1, then we split up the arc's in two arcs. 2 arc's. The output is perfect !
For your code, you could integrate a preprocess function like this:
std::vector
//https://github.com/jbuckmccready/CavalierContours/issues/17
//bulge neg=g2
//bulge pos=g3
double pi_angle_arc=0;
double pi_angle_start=0;
double pi_angle_end=0;
std::vector<double> bulge; //bulge[0]=bulge value, bulge[1]=0 (one arc), bulge[1]=1 (two arcs)
double r=it->radius;
POINT a=it->start;
POINT b=it->end;
POINT c=it->center;
if(it->d>0){ //g2, d=determinant
pi_angle_start = atan2(b.y-c.y, b.x-c.x);
pi_angle_end = atan2(a.y-c.y, a.x-c.x);
}
if(it->d<0){ //g3
pi_angle_start = atan2(a.y-c.y, a.x-c.x);
pi_angle_end = atan2(b.y-c.y, b.x-c.x);
}
if(it->d==0){
bulge.push_back(0); //draw straight line
bulge.push_back(0);
}
if(pi_angle_end<pi_angle_start){pi_angle_end+=2*M_PI;}
pi_angle_arc=pi_angle_end-pi_angle_start;
if(pi_angle_arc>M_PI){ //split up in 2 arcs
double half_pi_angle_arc=pi_angle_arc/2;
double bulges=tan(half_pi_angle_arc/4);
if(it->d<0){
bulge.push_back(abs(bulges));
bulge.push_back(1);
}
if(it->d>0){
bulge.push_back(-abs(bulges));
bulge.push_back(1);
}
} else {
if(it->d<0){
bulge.push_back(abs(tan(pi_angle_arc/4))); //keep it as 1 arc
bulge.push_back(0);
}
if(it->d>0){
bulge.push_back(-abs(tan(pi_angle_arc/4))); //keep it as 1 arc
bulge.push_back(0);
}
}
return bulge;}
Thank you !
The preview output : https://pasteboard.co/JgHxPRB.png
jbuckmccready
Thank you for your excellent work !
I have a little issue going on.
Why must the bulge factor between -1 and 1? I have arc's with higher bulge value's. This higher or lower value occur's when the arc center goes inside the arc segment.
This is the terminal output of your script : bulge should always be between -1 and 1"' failed.
In some cases an arc has a bulge factor of 7 or -7. See this example : http://people.fsv.cvut.cz/www/chourpav/Lisp/Chapter%2011.htm , and then figure 11.5
So far, i think i am correct. please correct me if this is not the case.
Can you provide a example how to calculate the bulge factor for an arc of 270 degrees with a output between -1 and 1? Thank you !
Another tiny thing to consider : island.addVertex(it3->x, it3->y, 0); Can you provide a : islands.clear(); to empty the vector?
This is my output so far. https://forum.linuxcnc.org/media/kunena/attachments/23278/cadcam_pocket_with_islands1.png