Use LibreDWG to parse information from DWG file

[danikolovv]

Hello,

Correct me if this is not exactly right:

DWG file structure into LibreDWG is as I understand it yet by reading documentation and testing.

DWG file

• Header
  Into Header there are Variables, among which exist paper_space, model_space and other blocks.

Paper_space, model_space and blocks each contain entities (which are the graphical elements).

So I relate to the 7.1 Decoding section from LibreDWG documentation.

I made this implementation:

Dwg_Object_BLOCK_CONTROL* block_control = dwg_block_control(&dwg);
Dwg_Object_Ref* ref = dwg.header_vars.BLOCK_RECORD_MSPACE;
Dwg_Object* objct = get_first_owned_entity(ref->obj);
while (objct)
    process_object(dwg, objct);

dwg_block_control() and get_first_owned_entity() are API functions

On row where get_first_owned_entity() is used, program breaks due to an exception - Access violation executing location 0x00000000.

Can you give me feedback on DWG file struct in LibreDWG and code implementation used later for iteration through layers, specific entities from paper_space or model_space?