Filling a Dwg_Data structure with points' coordinates and exporting it in a .dwg file format

[danikolovv]

Hello,

I have a question in regard to filling an empty Dwg_Data object with point coordinates. I iterate through a file with coordinates and the extracted x, y, z have to be written in the Dwg_Data object. Then this Dwg_Data object has to be exported.

1. What is needed for LibreDWG to export this object's points in a .dwg file.
2. Which functions you use for making a correct header (header have to be R2000 or lower, which points to AutoCAD version 2000 or older). This is important for LibreDWG to export Dwg_Data structure in a .dwg file format (according to LibreDWG documentation). Also creating a point object with the coordinates, adding coordinates to a Dwg_Data structure and extracting the structure in a .dwg file.

I need to understand the functions I have to use for making this happen. Also please add if something is needed for points' coordinates to be saved correctly in a .dwg file format.

Finally I want to know if this (fill Dwg_Data structure with points' coordinates and extract it in .dwg file format) is possible to be extracted in .dll to be used later additionally in a bigger project (creating more abstraction).

I have used Dwg_Object_BLOCK_HEADER structure for allocating header. Also I have used:

Dwg_Data* dwg;
dwg->header.version = R_2000;
// for version assignment

I created a layer with

dwg_add_LAYER(dwg, "0"); // Only 0 for a name

I have used:

dwg_point_3d point_3d;
point_3d.x = /*... X coordinate ... */;
point_3d.y = /*... Y coordinate ... */;
point_3d.z = /*... Z coordinate ... */;

// Finally I used dwg_add_POINT as so
dwg_add_POINT(&hdr, &point_3d); // hdr is a structure of Dwg_Object_BLOCK_HEADER hdr;

If everything is right we come to the moment of exporting dwg structure into a .dwg file format. This is where I need an explanation for the exporting into .dwg file format and later into a .dll file format.

Great thanks for reading and helping in advance!

Regards,
Daniel Nikolov

[rurban]

See the dwgadd examples. This already does all of the boilerplate for you. You just need to add the coords to the file to dwgadd.

[danikolovv]

Hello,

The project I develop is for windows os. Does a function which receives a point coordinates, fills them in Dwg_Data structure and extracts them in a .dwg file exists in LibreDWG? Is there a function with this description already in a pre-compiled .dll file from which I can extract it? The program in the dwgadd.c file is extracting points into a Dwg_Data structure and then into a .dwg file, but how exactly is it used? The documentation says that it accepts a very simple file with commands to create entities or objects and set its properties, but is there a function in a .dll file that I can extract and use with point coordinates as input?

Please guide me through dwgadd, so I can use it as described.

Thank you! Help is much appreciated!

Regards,
Daniel Nikolov

[rurban]

There are tests which are doing exactly this, in dwgadd_test.sh.
See the code in examples/dwgadd.c

[danikolovv]

Hello,

I found a .dll file named "dwgadd" into the examples folder.
Function for adding Dwg_Data structure into a .dwg file receives this.

static int dwg_add_dat (Dwg_Data **dwgp, Bit_Chain *dat);

My question is: What exactly is the "Bit_Chain" here? What does it expect to be forwarded to?

For what is pointer to Bit_Chain used?

Thank you!

Regards,
Daniel Nikolov

[danikolovv]

Hello,

Can you explain why the data type Bit_Chain is expected by "dwg_add_dat" ?
When I make a dwg_point_3d save data for x, y and z coordinates, then how can I make a structure (what structure is it used) for saving those dwg_point_3d data types in it?
I extract the dwg_add_dat function from the "dwg_add" .dll file.

Help is much appreciated!

Regards,
Daniel Nikolov