It's my first time using pangomm and I am trying to render some text to a Cairo::Context, but when i try to access anything from the Pango::Layout object the program throws the following error:
(process:7175): glibmm-CRITICAL **: 15:36:58.578: Glib::ObjectBase* Glib::wrap_create_new_wrapper(GObject*): assertion 'wrap_func_table != nullptr' failed
(process:7175): glibmm-WARNING **: 15:36:58.578: Failed to wrap object of type 'PangoLayout'. Hint: this error is commonlycaused by failing to call a library init() function.
[1] 7175 segmentation fault ./a.out
I could not backtrace the error using gdb.
Code
#include <cairomm/cairomm.h>
#include <pangomm.h>
int main() {
auto surf = Cairo::ImageSurface::create(Cairo::Format::FORMAT_ARGB32, 1920, 20);
auto cr = Cairo::Context::create(surf);
cr->set_source_rgb(0.0, 0.0, 0.0);
cr->paint();
cr->move_to(0.0, 0.0);
cr->set_source_rgb(1.0, 1.0, 1.0);
auto layout = Pango::Layout::create(cr);
auto font = Glib::ustring("Sans Bold 27");
Pango::FontDescription desc(font);
layout->set_font_description(desc);
auto text = Glib::ustring("Oi");
layout->set_text(text);
layout->show_in_cairo_context(cr);
surf->write_to_png("test.png");
return 0;
}
Compiling command
g++ -g -Wall `pkg-config --cflags cairomm-1.0 pangomm-1.4` main.cpp `pkg-config --libs cairomm-1.0 pangomm-1.4`
Since you use pangomm
without Gtk, you need to initialize pangomm
at the start of your program. This also initialized Glib. Call Pango::init();
and include <pangomm/init.h>
.
Thus your code becomes
...
#include <pangomm/init.h>
int main()
{
Pango::init();
...
}