[SOLVED]no known conversion from derived class to base class

Projects Programming
1

I am currently programming my RGB LEDCube and therefor I want to create color gradients in seperate classes. Those classes are derived from colorgnt.h. I want wo pass colorgnts by a function argument but it only accepts the base class. I know why but I saw other people do it like that. How can I fix this issue?

/*
LEDCube.h
*/
#ifndef LEDCube_H
#define LEDCube_H
#include "Arduino.h"
#include <FastLED.h>
#include <Adafruit_NeoPixel.h>
#include "colorgnt.h"
#include "rainbowgnt.h"
#define NUMLEDS 343

class LEDCube
{
  public:
  LEDCube();
  //OTHER STUFF
  void rendergradient(colorgnt gradient);
};
#endif

/*
LEDCube.cpp
*/
#include "Arduino.h"
#include "LEDCube.h"

LEDCube::LEDCube() {
  FastLED.addLeds<WS2811, 7>(leds, 343);
  FastLED.setBrightness(255);
  FastLED.clear();
}

  //OTHER STUFF

void LEDCube::rendergradient(colorgnt *gradient) {
  rgb8bit whatever;
}


void LEDCube::test() {
	rainbowgnt *gnt;
	rendergradient(gnt);  //error note:   no known conversion for argument 1 from 'rainbowgnt*' to 'colorgnt'
}

/*
rainbowgnt.h
*/
#ifndef rainbowgnt_H
#define rainbowgnt_H
#include "colorgnt.h"
#include "LEDCube.h"
class colorgnt;  //is this neccessary? 
class rainbowgnt: public colorgnt {
  public:
  rainbowgnt() {}
  
  virtual  rgb8bit rgb(uint8_t position) {
	rgb8bit rgb;
	rgb.r = 255;
	rgb.g = 255;
	rgb.b = 255;
	return rgb;
  }
};
#endif

/*
colorgnt.h
*/
#ifndef colorgnt_H
#define colorgnt_H
#include "LEDCube.h"

typedef struct rgb8bit {
	uint8_t r;
	uint8_t g;
	uint8_t b;
};

class colorgnt {
  public:
  colorgnt() {}
  virtual rgb8bit rgb(uint8_t position) {}
};
#endif

I saw bitnluni's lab doing it like that: GitHub - bitluni/bitluniHomeAutomation
He did this:

#ifndef LED_FUNCTION_H
#define LED_FUNCTION_H

const char *rgbNames[] = {"r", "g", "b"};

class LedStates;
class LedFunction
{
  public:
  LedStates *state;
  LedFunction()
  {
  }
  //OTHER STUFF

#endif

class RainbowFunction: public LedFunction
{
  public:
  RainbowFunction()
  {    
  }
  //OTHER STUFF

and then he passed a dervied function to a function as an argument but the argument is defined as the base class:

bool checkFadeAndSetLedFunction(LedFunction *f)  //HERE he defined the argument as the base class
{
  int fade = getArgValue("fade");
  if(fade > -1)
  {
    targetLedStates.setFunction(f);
    ledFader.start(fade);
  }
  else
    currentLedStates.setFunction(f);  
}

server.on("/rainbow", [](){
    server.send(200, "text/plain", "rainbow");
    checkFadeAndSetLedFunction(new RainbowFunction());
  });

  server.on("/wave", [](){
    server.send(200, "text/plain", "wave");
    WaveFunction *f = new WaveFunction();
    f->init(server);
    checkFadeAndSetLedFunction(f); //HERE he passed it
  });

Thank you if you read until here

2 
/*
LEDCube.h
*/
void rendergradient(colorgnt gradient);

/*
LEDCube.cpp
*/
void LEDCube::rendergradient(colorgnt *gradient) {

Spot the difference...

3

Embarrassing... Thank you