Particle system

Editor

The editor is made using Dear ImGui.
The editor is being worked on pretty much all the time, as I am working to add new functions to the system in collaboration with our procedural artists.

Some features from the editor are:

• Change color of the particles
• Change spawnrate
• Make the particles spawn within a circle or square
• Add force/wind to particles
• Multiple bools for different interactions such as allowing movement, rotation, shrinking, growing, fading and more. 
• Loading particle systems with all parameters
• Loading sprites
• Saving all parameters into a .json file

The particle system can spawn particles on a trigger as shown below. 

Particle manager

The particle manager exists for the duration of the application runtime.

class ParticleManager
{
public:
	ParticleManager();
	~ParticleManager();
	void Add2D(ParticleSystem* aParicleSystem);
	void AddDebug2D(ParticleSystem aParicleSystem);
	void Add3D(ParticleSystem3D* aParicleSystem);
	void AddDebug3D(ParticleSystem3D aParicleSystem);
	void Clear();
	void Render(DreamEngine::SpriteDrawer& aSpriteDrawer);
	void RenderToGBuffer(DreamEngine::SpriteDrawer& aSpriteDrawer);
	void Update(float aDeltaTime);
	void SetCameraTransform(DreamEngine::Transform* aCameraTransform);
	void SetActionCamera(bool aActionCamera);
	void SetWorldScale(float aScale);
	void SetPlayerPosition(DE::Vector3f aPlayerPos);

#ifndef _RETAIL
	void ImGui2DDebugMenu();
	void ImGui3DDebugMenu();
#endif // !_RETAIL
private:
	std::vector<ParticleSystem*> my2DParticleSystems;
	std::vector<ParticleSystem> my2DDebugParticleSystems;
	std::vector<ParticleSystem3D*> my3DParticleSystems;
	std::vector<ParticleSystem3D> my3DDebugParticleSystems;
	std::array<char[50], 10> myParticleSystemNames;
	float myWorldScale;
	int myCurrentParticleSystem;
	int mySizeOf2DParticleSystems;
	int mySizeOf3DParticleSystems;
	bool myPaticle2DDebugMode;
	bool myPaticle3DDebugMode;
	bool myActionCamera;
	bool myShouldResetParticleSystem;
	DreamEngine::Transform* myCameraTransform;
	DE::Vector3f myPlayerPosition;
};

Particle system

The particle system holds all the particles and all of the debug data connected to the editor.

void ParticleSystem3D::Init(int aSize)
{
	myParticleAmount = aSize;
	myTotalTime = 0;
	for (size_t i = 0; i < myParticleAmount; i++)
	{
		Particle3D particle;
		if (myPosPtr != 0)
		{
			particle.Init(*myPosPtr, myParticleStartInstance.myColor, myParticleScale, myParticleStartDecayTime, { (float)myParticlesShouldMove,(float)myParticlesShouldRotate,(float)myParticlesShouldShrink,(float)myParticlesShouldFade }, myParticleDirMin, myParticleDirMax, myCameraTransform, myActionCamera);
			//particle.SetOrigin(*myPosPtr);
		}
		else
		{
			particle.Init(myPos, myParticleStartInstance.myColor, myParticleScale, myParticleStartDecayTime, { (float)myParticlesShouldMove,(float)myParticlesShouldRotate,(float)myParticlesShouldShrink,(float)myParticlesShouldFade }, myParticleDirMin, myParticleDirMax, myCameraTransform, myActionCamera);
			//particle.SetOrigin(myPos);
		}
		particle.SetParticleSize(ourParticleData.myTexture->CalculateTextureSize());
		particle.SetAlpha(0);
		particle.SetForce(myForce);
		myParticles.push_back(particle);
		myParticleInstances.push_back(particle.GetSpriteInstance());
	}
}

To load a particle system a saved .json file is loaded and puts all the corresponding data into the system and then initializes the particle system.

void ParticleSystem3D::LoadParticleSystem(std::string aParticleSystemPath)
{
	myLoadedData = true;
	std::ifstream file(aParticleSystemPath);
	if (std::filesystem::exists(aParticleSystemPath))
	{
		nlohmann::json jsonData = nlohmann::json::parse(file);
		file.close();

		if (!jsonData["ParticleAmount"].is_null())
		{
			myParticleAmount = jsonData["ParticleAmount"];
		}
		if (!jsonData["DecayTime"].is_null())
		{
			myParticleStartDecayTime = jsonData["DecayTime"];
		}
		if (!jsonData["LifeTime"].is_null())
		{
			myLifeTime = jsonData["LifeTime"];
		}

                ... ("more similar data input")

		for (int i = 0; i < myParticles.size(); i++)
		{
			myParticles[i].SetAlpha(0);
			myParticles[i].SetForce(myForce);
			myParticleInstances[i] = myParticles[i].GetSpriteInstance();
		}

		myUvs.clear();

		Init(myParticleAmount);
	}
}