How to load font file ? What is the proper path to a font file ? Because NOTHING is working !

[GeorgeFlorian]

Hello !

I am trying to make a simple code that can output a line of text on the display. But the font isn't loading.

This is what I've used to load the desired font:

const char *fontFile = "fonts/10x20.bdf";
//const char *fontFile = "10x20.bdf";

static void TextLine(Canvas *canvas, int x, int y, const char* line) {
    canvas->Fill(0,0,0);
    rgb_matrix::Color mRed(225, 20, 34);
    rgb_matrix::Color blackBg(0, 0, 0);
    rgb_matrix::Font font;
    if(!font.LoadFont(fontFile)) {
        std::cout<<"Couldn't load font file\n";
    }
    rgb_matrix::DrawText(canvas, font, x, y, mRed, &blackBg, line);

    int k = 10;
    while (k != 0) {
        TextLine(canvas,0,0,"Test 1");
        k--;
        usleep(1 * 1000);
    }

    canvas->Clear();
    delete canvas;
}

This is the full code:

#include "led-matrix.h"
#include "graphics.h"

#include <iostream>
#include <unistd.h>
#include <math.h>
#include <stdio.h>
#include <signal.h>

using rgb_matrix::GPIO;
using rgb_matrix::RGBMatrix;
using rgb_matrix::Canvas;

volatile bool interrupt_received = false;
static void InterruptHandler(int signo) {
  interrupt_received = true;
}

const char *fontFile = "fonts/10x20.bdf";

static void TextLine(Canvas *canvas, int x, int y, const char* line) {
    canvas->Fill(0,0,0);
    rgb_matrix::Color mRed(225, 20, 34);
    rgb_matrix::Color blackBg(0, 0, 0);
    rgb_matrix::Font font;
    if(!font.LoadFont(fontFile)) {
        std::cout<<"Couldn't load font file\n";
    }
    rgb_matrix::DrawText(canvas, font, x, y, mRed, &blackBg, line);

}

int main(int argc, char *argv[]) {

    RGBMatrix::Options defaults;
    defaults.hardware_mapping = "regular";  // or e.g. "adafruit-hat"
    defaults.rows = 32;
    defaults.chain_length = 1;
    defaults.parallel = 1;
    defaults.show_refresh_rate = true;
    Canvas *canvas = rgb_matrix::CreateMatrixFromFlags(&argc, &argv, &defaults);
    if (canvas == NULL)
        return 1;
    // It is always good to set up a signal handler to cleanly exit when we
    // receive a CTRL-C for instance. The DrawOnCanvas() routine is looking
    // for that.
    signal(SIGTERM, InterruptHandler);
    signal(SIGINT, InterruptHandler);

    int k = 10;
    while (k != 0) {
        TextLine(canvas,0,0,"Test 1");
        k--;
        usleep(1 * 1000);
    }

    canvas->Clear();
    delete canvas;

    return 0;
}

How do I properly load a font file ? Where did I go wrong ?

[GeorgeFlorian]

Guess what ? const char *fontFile = "rpi-rgb-led-matrix/fonts/10x20.bdf"; worked ! The font appears to be loading, but the code doesn't do anything. The display is black.