Lines, circles and arcs

Create gives a drawing AutoCAD opens without a finding: the tables, the two space blocks, the layouts and the objects a release needs. Edit::Add puts an entity in model space unless told otherwise.

C++Copy
DxfIO::Document drawing = DxfIO::Create(DxfIO::Version::R2018);

Coordinates are in drawing units, in the world coordinate system for these two.

C++Copy
DxfIO::Entities::Point point{};
point.Position = {.X = 0, .Y = 0, .Z = 0};
DxfIO::Edit::Add(drawing, point);

DxfIO::Entities::Line line{};
line.Start = {.X = 0, .Y = 0, .Z = 0};
line.End = {.X = 100, .Y = 50, .Z = 0};
DxfIO::Edit::Add(drawing, line);

An arc runs counterclockwise from Start to End, both in degrees.

C++Copy
DxfIO::Entities::Circle circle{};
circle.Center = {.X = 150, .Y = 25, .Z = 0};
circle.Radius = 25;
DxfIO::Edit::Add(drawing, circle);

DxfIO::Entities::Arc arc{};
arc.Center = {.X = 220, .Y = 25, .Z = 0};
arc.Radius = 25;
arc.Start = 0;
arc.End = 180;
DxfIO::Edit::Add(drawing, arc);

Axis is the end of the major axis relative to the center, Ratio the minor axis over the major. Start and End are parameters in radians; the default 0 to a full turn closes it.

C++Copy
DxfIO::Entities::Ellipse ellipse{};
ellipse.Center = {.X = 300, .Y = 25, .Z = 0};
ellipse.Axis = {.X = 40, .Y = 0, .Z = 0};
ellipse.Ratio = 0.5;
DxfIO::Edit::Add(drawing, ellipse);

A SOLID fills three or four corners. AutoCAD fills them in Z order, so a square lists its last two corners swapped.

C++Copy
DxfIO::Entities::Solid square{};
square.Corners = {{
    {.X = 360, .Y = 0, .Z = 0},
    {.X = 410, .Y = 0, .Z = 0},
    {.X = 360, .Y = 50, .Z = 0},
    {.X = 410, .Y = 50, .Z = 0},
}};
DxfIO::Edit::Add(drawing, square);

C++Copy
const auto saved = DxfIO::SaveFile(drawing, "lines.dxf");
if (!saved)
{
  std::println("{}", saved.error().What);
  return 1;
}