Подскажите простой способ создать GUI в Си

#include <gtk/gtk.h>
#include <math.h>
 
#define STEP_FREQ (10.0)
#define STEP_FUNC (0.1)
 
gboolean draw_callback(GtkWidget * widget, cairo_t * cr, gpointer data) {
    gdouble width = gtk_widget_get_allocated_width(widget);
    gdouble height = gtk_widget_get_allocated_height(widget);
    gdouble step = height / ( 2.0 * STEP_FREQ );
    
    cairo_set_source_rgb(cr, 1., 1., 1.);
    cairo_rectangle(cr, 0, 0, width, height);
    cairo_fill(cr);
    
    cairo_set_source_rgba(cr, 0.3, 0.3, 0.3, 0.6);
    cairo_set_line_width(cr, 0.2);
    
    for ( gdouble xpos = 0.; xpos < width; xpos += step ) {
        cairo_move_to(cr, xpos, 0.);
        cairo_rel_line_to(cr, 0., height);
        cairo_stroke(cr);
    }
    
    for ( gdouble ypos = 0.; ypos < height; ypos += step ) {
        cairo_move_to(cr, 0., ypos);
        cairo_rel_line_to(cr, width, 0.);
        cairo_stroke(cr);
    }
    
    cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.);
    cairo_set_line_width(cr, 0.6);
    cairo_move_to(cr, 0, height / 2.);
    cairo_rel_line_to(cr, width, 0);
    cairo_stroke(cr);
    cairo_move_to(cr, width / 2., 0);
    cairo_rel_line_to(cr, 0, height);
    cairo_stroke(cr);
    
    cairo_set_source_rgb(cr, 1.0, 0.0, 0.0);
    cairo_set_line_width(cr, 1.0);
    
    cairo_move_to(cr, 0.0, height / 2.0);
    for ( gdouble x = STEP_FUNC; x < width; x += STEP_FUNC ) {
        gdouble y = (sin(x / width * STEP_FREQ) * height / 2.0) + height / 2.0;
        cairo_line_to(cr, x, y);
    }
    cairo_stroke(cr);
    
    return FALSE;
}
 
int main(int argc, char ** argv) {
    gtk_init(&argc, &argv);
    
    GtkWidget * win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(win), "y = a * sin(x) + b");
    g_signal_connect(win, "destroy", G_CALLBACK(gtk_main_quit), NULL);
    
    GtkWidget * da = gtk_drawing_area_new();
    gtk_container_add(GTK_CONTAINER(win), da);
    gtk_widget_set_size_request(da, 800, 400);
    g_signal_connect(G_OBJECT(da), "draw", G_CALLBACK(draw_callback), NULL);
    
    gtk_widget_show_all(win);
    gtk_main();
    
    return 0;
}