Bsf Dear-Imgui Plugin

A submodule plugin of the bsf library. It's meant to be built as a cmake dependency of bsf. It is meant for fast prototyping of editor features and gamedev tools. It is not meant to be used as an in-game UI or as a replacement for the bsf gui library. While imgui has low overhead and a simple api, it's not meant for more complex guis. Need to have a custom scene editor? Yes use imgui. Need to render out a 3d interface for your spaceship cockpit? Don't use imgui. More thoughts can be found on this gist.

Features

• Implements dear-imgui library for fast dev prototyping
• Integrates with ImGuizmo library for 3d gizmo editing of bsf scene objects.
• Renders on core thread while the imgui interface can be built on the simulation thread

Usage

Usage is simple, just select the plugin as part of the bsf cmake options. The plugin can be manually loaded as a dynamic plugin.

DynLib* imguiPlugin = nullptr;
Application::instance().loadPlugin("bsfImgui", &imguiPlugin);
Application::instance().runMainLoop();
Application::instance().unloadPlugin(imguiPlugin);

See BsImgui_test.cpp file for example of how imgui can be drawn as part of the main thread components.

#include "imgui.h"
#include "BsImgui.h"
#include "BsImGuizmo.h"
class DemoUI : public Component {
public:
	DemoUI(const HSceneObject& parent)
		: Component(parent)
	{
		setFlag(ComponentFlag::AlwaysRun, true);
		setName("DemoUI");
	}

	void update() override {
		Component::update();
		demoImguiUI();
	}
};

class DemoEditTransform : public Component {
	// keep a modifiable reference to the scene object.
	HSceneObject mParent;
public:
	DemoEditTransform(HSceneObject parent)
		: Component(parent), mParent(parent)
	{
		setFlag(ComponentFlag::AlwaysRun, true);
		setName("DemoEditTransform");
	}

	void update() override {
		Component::update();
		Transform transform = mParent->getLocalTransform();

    ImGui::Begin("Transform example");    
			EditTransform(transform, gSceneManager().getMainCamera());
		ImGui::End();
		ManipulateTransform(transform, gSceneManager().getMainCamera());
		auto& so = SO();
		so->setLocalTransform(transform);
	}	
};

TODO

• try out imgui docking branch demo
• add useful widgets and bsf utilities to the repository as the plugin is adopted and used.