Writing AutoCad DXF files

This article demonstrate how to write an ASCII DXF files. A DXF file is a file composed of sections and associated values. They are read by AutoCad and then converted to a drawing.

I have developped a class CDxf to write a DXF file from an application. Then the user must use AutoCad to interpret the DXF file.

I have included only a small portion of what can be do with DXF files. All the details are contained in the following document from the AutoDesk web site : http://www.autodesk.com/techpubs/autocad/dxf/.

// Here is the code to write a DXF file that will draw a circle in AutoCad.

// 

void CDxf::Circle ()
{
	// 1000 diameter circle

	// Creation of an output stream objet in text mode.

	// ios::app : append

	ofstream FichierDxf ("TestDxf.dxf", ios::app);

	// Draw the circle

	FichierDxf << 0          << endl;
	FichierDxf << "CIRCLE"   << endl;
	FichierDxf << 8          << endl;       // Group code for layer name

	FichierDxf << 0          << endl;       // Layer number

	FichierDxf << 10         << endl;       // Center point of circle

	FichierDxf << 0.0        << endl;       // X in OCS coordinates

	FichierDxf << 20         << endl;
	FichierDxf << 0.0        << endl;       // Y in OCS coordinates

	FichierDxf << 30         << endl;
	FichierDxf << 0.0        << endl;       // Z in OCS coordinates

	FichierDxf << 40         << endl;       // radius of circle

	FichierDxf << 500.0      << endl;       

	FichierDxf.close();
}

By being able to write a DXF file, I can integrate into my applications a way to share information with AutoCad. Obviously there is a lot more that can be added to this class.