I peeked at some of the code. I like the straight forwardness of the coding style. Hope you don't mind a few suggestions. I am not pointing out errors, all these examples work fine as is, which you obviously know already.
1) I noticed this in a few places:
double y = radius * sinf(angle_start);
Why use sinf() when y, radius and angle_start are all doubles?
2) What are you trying to do here, with the function style int cast?
double theta = 2.0 * M_PI * int(j) / int(segments);
j and segments are already int and will be promoted to doubles anyway.
3) I noticed in display.h that you change the loop variable every loop. No harm but it is not necessary.
4) Have you considered using an enum for OBJECT::type, instead of a string?
5) std::vector::reserve() is a good idea here:
Code:
std::vector<std::vector<double>> C; //2d array
C.reserve(object.control.size() + 2); // This is a good idea here.
C.push_back({object.start.x, object.start.y}); //spline startpoint
for(int i=0; i<object.control.size(); i++){
C.push_back({object.control.at(i).x, object.control.at(i).y}); //spline controlpoints
}
C.push_back({object.end.x, object.end.y}); //spline endpoint
draw_spline(C);
I saw the pocket milling pattern, that looks advanced. Nice work all around.
