Getting rpi_ws281x library up and running in c++

I am trying to get this library jgarff/rpi_ws281x up and running and installed it as described in the readme.md

When running the python examples the stripe works as expected but I don't get the C++ code up and running.

Here is what I am trying:

    #include <boost/filesystem.hpp>
#include <boost/range/iterator_range.hpp>
#include <boost/thread.hpp>
#include <boost/chrono.hpp>
#include <iostream>
#include <stdio.h>
#include <wiringPiI2C.h>
#include <rpi_ws281x/ws2811.h>
#include <cstdint>

/*
    Defines für ws2811 LED Stripes
*/

#define TARGET_FREQ                             WS2811_TARGET_FREQ
#define GPIO_PIN                                18
#define DMA                                     5
#define STRIP_TYPE                              WS2811_STRIP_RGB        // WS2812/SK6812RGB integrated chip+leds
//#define STRIP_TYPE                            WS2811_STRIP_GBR        // WS2812/SK6812RGB integrated chip+leds
//#define STRIP_TYPE                            SK6812_STRIP_RGBW       // SK6812RGBW (NOT SK6812RGB)
#define LED_COUNT                               10

ws2811_led_t dotcolors[] =
{
    0x00200000,  // red
    0x00201000,  // orange
    0x00202000,  // yellow
    0x00002000,  // green
    0x00002020,  // lightblue
    0x00000020,  // blue
    0x00100010,  // purple
    0x00200010,  // pink
};

ws2811_led_t dotcolors_rgbw[] =
{
    0x00200000,  // red
    0x10200000,  // red + W
    0x00002000,  // green
    0x10002000,  // green + W
    0x00000020,  // blue
    0x10000020,  // blue + W
    0x00101010,  // white
    0x10101010,  // white + W

};

ws2811_t ledstring =
{
    nullptr,
    TARGET_FREQ,
    DMA,

    0, GPIO_PIN, 0, LED_COUNT, 255, STRIP_TYPE,
    0

};

using namespace std;
using namespace boost;
using namespace boost::filesystem;

int main()
{
    ws2811_init(&ledstring);

    int c = 0;

    for (int i = 0; i < LED_COUNT; i++)
    {
        if (ledstring.channel[0].strip_type == SK6812_STRIP_RGBW) {
            ledstring.channel[0].leds[i] = dotcolors_rgbw[c];
        }
        else {
            ledstring.channel[0].leds[i] = dotcolors[c];
        }
        
        c++;
        
        ws2811_render(&ledstring);

        if (c == sizeof(dotcolors))
        {
            c = 0;
        }

        usleep(1000000);
    }
    return 0;
}

This code compiles fine (using -fpermissive) and runs without errors - but all LEDs stay dark :(

I don't see any issues and wonder what I am doing wrong??

Any help is really appreciated. Thanks!

Just found the issue myself and discovered that the initialization of the ledstrig struct was wrong.

The correct one needs to look like this:

ws2811_t ledstring =
{
    0,
    0,
    TARGET_FREQ,
    DMA,

    GPIO_PIN, 0, LED_COUNT, 125, STRIP_TYPE,
    0

};

I still don't understand how this initialization works - but at least this one gives the right values in the reqired fields.