Undefined reference to `stbi_load` error in C++ project: LearnOpenGL example

This error indicates that the linker (ld.exe) is unable to locate the definitions for functions like stbi_load during the linking process. This usually happens when the necessary library files are not provided during linking or the paths to these libraries are incorrectly specified.

To resolve this issue, carefully review the linker settings within your Makefile. Ensure the following:

1. Library Inclusion: Double-check if the stbi_load function is part of an external library (like stb_image.h). If so, make sure that the library file (e.g., libstb_image.a) is explicitly included in the linker command.
2. Library Path: Confirm that the correct path to the library file is specified in the linker settings. This path is often referred to as the LIBRARY_PATH or -L flag within the Makefile.

For example, if the libstb_image.a library is located in the /usr/local/lib directory, you might add the following line to your Makefile:

LDFLAGS += -L/usr/local/lib 

3. Library Name: In addition to the path, ensure that the library name itself is correctly specified in the linker command. This is usually done with the -l flag. For libstb_image.a, you would use -lstb_image in your linker flags.

Specific Example (LearnOpenGL):

In the LearnOpenGL examples, the stbi_load function is likely provided by the stb_image.h header file and the corresponding library file (e.g., libstb_image.a). Verify that:

• The stb_image.h header file is correctly included in your project.
• The libstb_image.a library is present and accessible by the linker.
• The linker settings in the Makefile correctly specify the path to libstb_image.a and include -lstb_image.

By carefully checking these points and making necessary adjustments, you should be able to resolve the undefined reference to stbi_load error and successfully link your project.