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Loading font from file in pango?

I have Cairo and Pango code to create an image:

#include<stdio.h>
#include<cairo.h>
#include<pango/pangocairo.h>

#define IMAGE_WIDTH  650
#define IMAGE_HEIGHT 150

#define TEXT "HELLO WORLD"
#define FONT "MizuFontAlphabet Normal 40"

/*
 * $ gcc $(pkg-config pangocairo cairo --cflags --libs) file.c
 */


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

    cairo_surface_t *surface;
    cairo_t *cr;

    PangoLayout *layout;
    PangoFontDescription *desc;
    PangoRectangle extents;

    surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, IMAGE_WIDTH, IMAGE_HEIGHT);
    cr      = cairo_create(surface);

    cairo_rectangle(cr, 0, 0, IMAGE_WIDTH, IMAGE_HEIGHT);
    cairo_set_source_rgb(cr, 0, 0, 0);
    cairo_fill(cr);
    cairo_stroke(cr);

    /* the font is needed to be installed in fonts directory */
    layout  = pango_cairo_create_layout(cr);
    pango_layout_set_text(layout, TEXT, -1);
    desc    = pango_font_description_from_string(FONT);
    pango_layout_set_font_description(layout, desc);
    pango_font_description_free (desc);

    pango_layout_get_pixel_extents(layout, NULL, &extents);
    int x   = (int) (IMAGE_WIDTH - extents.width) / 2;
    int y   = (int) (IMAGE_HEIGHT - extents.height) / 2;

    cairo_set_source_rgb(cr, 0.33, 0.55, 0.88);
    cairo_move_to(cr, x, y);
    pango_cairo_show_layout(cr, layout);

    g_object_unref(layout);

    cairo_surface_write_to_png(surface, "image.png");

    cairo_destroy(cr);
    cairo_surface_destroy(surface);

    return(0);
}

The font I'm using MizuFontAlphabetis a non-standard font, so it needs to be installed in the font directory so that I can use it with Pango:

    desc    = pango_font_description_from_string(FONT);

How can I download a font from a file if this font has not been installed?

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1 answer

This problem can be solved quite easily by adding a custom font to the local state of fontconfig:

#include <fontconfig/fontconfig.h>


std::string yourFontFilePath = "/home/testUser/bla.ttf";
const FcChar8 * file = (const FcChar8 *)yourFontFilePath.c_str();
FcBool fontAddStatus = FcConfigAppFontAddFile(FcConfigGetCurrent(), file);

The pango rendering engine will now use your custom font, simply using PangoFontDescription.

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