Fltk
https://www.fltk.org/
https://www.youtube.com/watch?v=6W3o8UGW2aM
Initialization

- Running without Installation
  https://www.youtube.com/watch?v=6W3o8UGW2aM
  first download source tar.gz from their official website download section https://www.fltk.org/software.php
  https://www.mediafire.com/file/pyfosfvge4did2p/fltk-1.3.9-source.tar.gz/file
  fltk-1.3.9-source.tar.gz	https://files.catbox.moe/grylch.gz
 
  Create a project folder and extract	
  Then extract that zip file in `project_folder/fltp-xxx/`
  go to that directory and compile using make. `make`. Now go back to project root
  Linking header path and lib path:
  Libraries of x11 are found in `/usr/lib/x86_64-linux-gnu` or `/usr/lib`
	`g++ main.cpp -Ifltk-1.3.9 -Lfltk-1.3.9/lib -lfltk -lX11 -lXfixes -lXext -lXft -lXrender -lfontconfig -lXcursor -lXinerama -ldl -o main`
Here `-I` represents header file path
`-L` represents library path
`-l` represents library files `-lfltk` means file named `libfltk.a`
  
- Running with installation
  https://www.youtube.com/watch?v=yHx1h25cyvc
  After using `make` and before going back to project root. use `sudo make install` to install the compiled fltk binary.
  In project root
  `fltk-config --use-images --compile main.cpp`
  For debugging information like `--debug` in gcc and g++ do this(adding `-g`)
  `fltk-config --use-images --compile main.cpp -g`