Simple rainbow generator for ddnet-based servers

rainbow_generator.cpp

#include "rainbow_generator.h"

#include <base/color.h>
#include <base/system.h>

CRainbowGenerator *CRainbowGenerator::ms_SInstance = nullptr;

CRainbowGenerator *CRainbowGenerator::GetInstance()
{
	if(ms_SInstance == nullptr)
	{
		ms_SInstance = new CRainbowGenerator();
	}
	return ms_SInstance;
}

CRainbowGenerator::CRainbowGenerator()
{
	for(int &Seed : m_Seed)
		Seed = secure_rand() % 256 + 1;

	m_Hue = secure_rand() % 256 + 1;
}

void CRainbowGenerator::Tick()
{
	m_Hue = Clamp(++m_Hue);
}

int CRainbowGenerator::Clamp(const int Color)
{
	if(Color > 256)
		return Color % 255;
	return Color;
}

unsigned CRainbowGenerator::Rainbow(const int ClientId, const unsigned OffsetMultiplier) const
{
	return ColorHSLA(Clamp(m_Hue + (m_Seed[ClientId] * OffsetMultiplier)), 1, 0.3f).Pack();
}

rainbow_generator.h

#ifndef BASE_UTILS_RAINBOW_GENERATOR_H
#define BASE_UTILS_RAINBOW_GENERATOR_H

#include <engine/shared/protocol.h> // MAX_CLIENTS

class CRainbowGenerator
{
public:
	CRainbowGenerator(CRainbowGenerator &Other) = delete;
	void operator=(const CRainbowGenerator &) = delete;
	static CRainbowGenerator *GetInstance();

	void Tick();

	unsigned Rainbow(int ClientId, unsigned OffsetMultiplier = 1) const;

private:
	CRainbowGenerator();
	static CRainbowGenerator *ms_SInstance;

	int m_Seed[MAX_CLIENTS];
	int m_Hue;

	static int Clamp(int Color);
};

#endif // BASE_UTILS_RAINBOW_GENERATOR_H

rainbow_generator.md

Singleton class for generating and smoothly changing rainbow.

Offered API:

	static CRainbowGenerator *GetInstance(); // Returns instance of generator
	void Tick(); // Ticks Hue 
	unsigned Rainbow(int ClientId, unsigned OffsetMultiplier = 1) const; // Returns color in TW-code

Each ClientId holds individual offset to make different colors for every player.
If you want to make 2 different colors for single ClientId, use OffsetMultiplier, default is 1, increment it.

Usage

Smoothly 'ticking' hue:

void CGameContext::OnTick()
{
  // some code
  CRainbowGenerator::GetInstance()->Tick();
  // some code
}

Apply rainbow to player skin and feet:

void CPlayer::Snap(int SnappingClient)
{
  // some code
  pClientInfo->m_UseCustomColor = m_Rainbow ? true : m_TeeInfos.m_UseCustomColor;
  pClientInfo->m_ColorBody = m_Rainbow ? CRainbowGenerator::GetInstance()->Rainbow(m_ClientId) : m_TeeInfos.m_ColorBody;
  pClientInfo->m_ColorFeet = m_Rainbow ? CRainbowGenerator::GetInstance()->Rainbow(m_ClientId) : m_TeeInfos.m_ColorFeet;
  // some code 
}

Apply rainbow to player skin and feet, make offset for feet:

void CPlayer::Snap(int SnappingClient)
{
  // some code
  pClientInfo->m_UseCustomColor = m_Rainbow ? true : m_TeeInfos.m_UseCustomColor;
  pClientInfo->m_ColorBody = m_Rainbow ? CRainbowGenerator::GetInstance()->Rainbow(m_ClientId) : m_TeeInfos.m_ColorBody;
  pClientInfo->m_ColorFeet = m_Rainbow ? CRainbowGenerator::GetInstance()->Rainbow(m_ClientId, 2) : m_TeeInfos.m_ColorFeet;
  // some code 
}