How to create a PNG image with custom fonts from text

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I am making a program in C which will take a text as a user input and produce a png image as an output with the same text rendered in custom fonts.

I know that C doesn't have standard libraries for graphics, so I am trying to identify what is the most efficient library to use for beginner developers.

My Operating system is Ubuntu and I want to make CLI tool

For example https://github.com/matsuyoshi30/germanium

1 Answers

For such a simple requirement you can use cairo, just adjust the png sizes and font:

#include <cairo.h>

int main(void)
{
    cairo_surface_t *surface;
    cairo_t *cr;

    surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 250, 50);
    cr = cairo_create(surface);

    cairo_set_source_rgb(cr, 0, 0, 0);
    cairo_select_font_face(cr, "Sans", CAIRO_FONT_SLANT_NORMAL,
      CAIRO_FONT_WEIGHT_NORMAL);
    cairo_set_font_size(cr, 40.0);

    cairo_move_to(cr, 10.0, 35.0);
    cairo_show_text(cr, "Hello world!");

    cairo_surface_write_to_png(surface, "image.png");

    cairo_destroy(cr);
    cairo_surface_destroy(surface);

    return 0;
}

Since you are on ubuntu:

sudo apt-get install -y libcairo2-dev

And compile with:

gcc demo.c -o demo `pkg-config --cflags --libs cairo`

For more complex uses, you should combine cairo with pango:

https://fossies.org/linux/pango/examples/cairosimple.c

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