Cairo Paint Glyphs

main.c

#include <cairo/cairo.h>
#include <stddef.h>
#include <stdio.h>

#define FONT_FACE "Liberation Serif"
#define FONT_SIZE 16.0

void paint(cairo_t *cr) {
    cairo_select_font_face(cr, FONT_FACE, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
    cairo_set_font_size(cr, FONT_SIZE);

    cairo_font_options_t *options = cairo_font_options_create();
    cairo_font_options_set_hint_metrics(options, CAIRO_HINT_METRICS_OFF);
    cairo_font_options_set_hint_style(options, CAIRO_HINT_STYLE_NONE);
    cairo_set_font_options(cr, options);

    const char *text = "Hello World";
    cairo_glyph_t *glyphs = NULL;
    int num_glyphs;
    cairo_scaled_font_t *font = cairo_get_scaled_font(cr);
    cairo_scaled_font_text_to_glyphs(font, 0.0, FONT_SIZE, text, -1, &glyphs, &num_glyphs, NULL, NULL, NULL);

    for (int i = 0; i < num_glyphs; i++) {
        fprintf(stderr, "%lu:\t%f\t%f\n", glyphs[i].index, glyphs[i].x, glyphs[i].y);
    }

    cairo_set_source_rgb(cr, 0.0, 0.0, 0.0);
    cairo_show_glyphs(cr, glyphs, num_glyphs);
}

int main() {
    cairo_surface_t *surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 100, 100);
    cairo_t *cr = cairo_create(surface);

    cairo_set_source_rgb(cr, 1.0, 1.0, 1.0);
    cairo_paint(cr);

    paint(cr);

    cairo_surface_write_to_png(surface, "result.png");
}

Makefile

main: main.c
	gcc -g -O0 -o $@ $^ `pkg-config --cflags --libs cairo`