OpenGL Link Error for GLFW DDS Load function - c++

Question

I have been working my way through the OpenGL-tutorial.org tutorial series. All has been working fine, however I have not been able to get Tutorial 5 to work in my playground executable, though it does work when run from the example tutorial 5 executable. This is true even when I copy and paste the example code over.
I receive the following errors:
Undefined symbols for architecture x86_64:
"loadDDS(char const*)", referenced from:
_main in playground.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Below is the link log:
Ld playground/playground normal x86_64
cd /Users/RufusVijayaratnam/rufus/Coding/ogl-master
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -target x86_64-apple-macos10.15 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -L/Users/RufusVijayaratnam/rufus/Coding/ogl-master/playground -F/Users/RufusVijayaratnam/rufus/Coding/ogl-master/playground -filelist /Users/RufusVijayaratnam/rufus/Coding/OpenGL/Tutorials.build/Debug/playground.build/Objects-normal/x86_64/playground.LinkFileList -Xlinker -object_path_lto -Xlinker /Users/RufusVijayaratnam/rufus/Coding/OpenGL/Tutorials.build/Debug/playground.build/Objects-normal/x86_64/playground_lto.o -Xlinker -no_deduplicate -Wl,-search_paths_first -Wl,-headerpad_max_install_names -framework OpenGL -framework OpenGL /Users/RufusVijayaratnam/rufus/Coding/OpenGL/external/glfw-3.1.2/src/Debug/libglfw3.a /Users/RufusVijayaratnam/rufus/Coding/OpenGL/external/Debug/libGLEW_1130.a -framework Cocoa -framework OpenGL -framework IOKit -framework CoreFoundation -framework CoreVideo -Xlinker -dependency_info -Xlinker /Users/RufusVijayaratnam/rufus/Coding/OpenGL/Tutorials.build/Debug/playground.build/Objects-normal/x86_64/playground_dependency_info.dat -o /Users/RufusVijayaratnam/rufus/Coding/ogl-master/playground/playground
So the error appears to be that when the function loadDDS() is called that it is not found. I am unsure as to why this is. The function is declared in texture.ccp which is in a folder (called 'common'), along with texture.hpp. texture.hpp has the code below:
#ifndef TEXTURE_HPP
#define TEXTURE_HPP
// Load a .DDS file using GLFW's own loader
GLuint loadDDS(const char * imagepath);
#endif
In playground.cpp there is:
include<texture.hpp>
Why can't loadDDS() be found, even though I have set the working directory of the playground function to the same as that for Tutorial 5, and the code in playground.ccp and 'tutorial05.ccp' is exactly the same?

Answer 1

for the playground executable (doesn't work)
# User playground add_executable(playground
playground/playground.cpp
common/shader.cpp
common/shader.hpp )
and finally for tutorial 5 (does work)
# Tutorial 5
add_executable(tutorial05_textured_cube
tutorial05_textured_cube/tutorial05.cpp
common/shader.cpp
common/shader.hpp
common/texture.cpp
common/texture.hpp
So I'm making the educated guess that loadDDS() is implemented in texture.cpp, and since you did not add this file, it won't be compiled, and the resulting object file won't be linked, and the symbol will just not be found.