Cannot compile with BUILD_GUI=OFF option

[Kiko-RWan]

Hello author!

According to the include in main.cc

SceneGraphFusion/app/GraphSLAM/main.cc

Line 19 in 5bf9017

#include "../libGUI3D/libGUI3D/GUI3D.h"

the program will eventually call imgui.h. However, imgui.h is only used when linking libGraphSLAMGUI according to makefile.txt, so BUILD_GUI=ON option must be enabled. Otherwise it leads to the related issue lossing imgui.h #29 #26 #12.

If I simply compile and link by adding BUILD_GUI=ON, even if I call ./exe_GraphSLAM, it will render in main.cc based on conditional compilation.

Since I don't have a graphical interface (unable to use X11 forwarding), I want to compile a version with BUILD_GUI=OFF. I am new to C++ programming and used a simple method that I could think of. I try modifying the main.cc code(delete parts involving conditional compilation related to GUI in main.cc to prevent GUI rendering), then camke -BUILD_GUI=ON .. . It runs but reports a core dump. Below are my modifications and results.

[Kiko-RWan]

Sorry, I didn't notice ifndef and ifdef, which means that even if BUILD_GUI=OFF is used, the renderer will still be called

SceneGraphFusion/app/GraphSLAM/main.cc

Lines 163 to 172 in 5bf9017

	#ifndef COMPILE_WITH_PSLAM_GUI
	std::unique_ptr<Renderer> renderer;
	if(params.use_render) {
	SCLOG(INFO) << "Building renderer...";
	renderer = std::make_unique<Renderer>(dataset_loader_->GetCamParamDepth().width,
	dataset_loader_->GetCamParamDepth().height,
	path, true
	);
	}
	#endif

and its base class GUI3D's base class GUI_base will still call GUI during initialization.

https://github.com/ShunChengWu/libGUI3D/blob/4529459b74f86c42992b731d28baf5d7fa7c4d7a/libGUI/GUI.cpp#L27-L30