How to fix the undefined reference error?

Question

When I compile https://code.sololearn.com/cvyy5StIOJ0n/#cpp, it complains:

..\Playground\~1\AppData\Local\Temp\ccMc1WGk.o:source.cpp:(.text+0x76): undefined reference to `GetStockObject@4'
..\Playground\~1\AppData\Local\Temp\ccMc1WGk.o:source.cpp:(.text+0x1b3): undefined reference to `glClearColor@16'

Answer 1

Your code probably doesn't work on Code Playground. There are some OS dependant stuff which isn't supported by the online compiler.