#include <math.h>
#include <stdio.h>
#include <cairo.h>

int
main (int argc, char *argv[])
{
	/* Variable declarations */
	cairo_surface_t *surface;
	cairo_t *cr;
	double x, y, px, ux=1, uy=1, dashlength;
	char text[]="joy";
	cairo_font_extents_t fe;
	cairo_text_extents_t te;

	/* Prepare drawing area */
	surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 240, 240);
	cr = cairo_create (surface);
	/* Example is in 26.0 x 1.0 coordinate space */
	cairo_scale (cr, 240, 240);
	cairo_set_font_size (cr, 0.5);

	/* Drawing code goes here */
	cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
	cairo_select_font_face (cr, "Georgia",
			CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
	cairo_font_extents (cr, &fe);

	cairo_device_to_user_distance (cr, &ux, &uy);
	if (ux > uy)
		px = ux;
	else
		px = uy;
	cairo_font_extents (cr, &fe);
	cairo_text_extents (cr, text, &te);
	x = 0.5 - te.x_bearing - te.width / 2;
	y = 0.5 - fe.descent + fe.height / 2;

	/* baseline, descent, ascent, height */
	cairo_set_line_width (cr, 4*px);
	dashlength = 9*px;
	cairo_set_dash (cr, &dashlength, 1, 0);
	cairo_set_source_rgba (cr, 0, 0.6, 0, 0.5);
	cairo_move_to (cr, x + te.x_bearing, y);
	cairo_rel_line_to (cr, te.width, 0);
	cairo_move_to (cr, x + te.x_bearing, y + fe.descent);
	cairo_rel_line_to (cr, te.width, 0);
	cairo_move_to (cr, x + te.x_bearing, y - fe.ascent);
	cairo_rel_line_to (cr, te.width, 0);
	cairo_move_to (cr, x + te.x_bearing, y - fe.height);
	cairo_rel_line_to (cr, te.width, 0);
	cairo_stroke (cr);

	/* extents: width & height */
	cairo_set_source_rgba (cr, 0, 0, 0.75, 0.5);
	cairo_set_line_width (cr, px);
	dashlength = 3*px;
	cairo_set_dash (cr, &dashlength, 1, 0);
	cairo_rectangle (cr, x + te.x_bearing, y + te.y_bearing, te.width, te.height);
	cairo_stroke (cr);

	/* text */
	cairo_move_to (cr, x, y);
	cairo_set_source_rgb (cr, 0, 0, 0);
	cairo_show_text (cr, text);

	/* bearing */
	cairo_set_dash (cr, NULL, 0, 0);
	cairo_set_line_width (cr, 2 * px);
	cairo_set_source_rgba (cr, 0, 0, 0.75, 0.5);
	cairo_move_to (cr, x, y);
	cairo_rel_line_to (cr, te.x_bearing, te.y_bearing);
	cairo_stroke (cr);

	/* text's advance */
	cairo_set_source_rgba (cr, 0, 0, 0.75, 0.5);
	cairo_arc (cr, x + te.x_advance, y + te.y_advance, 5 * px, 0, 2 * M_PI);
	cairo_fill (cr);

	/* reference point */
	cairo_arc (cr, x, y, 5 * px, 0, 2 * M_PI);
	cairo_set_source_rgba (cr, 0.75, 0, 0, 0.5);
	cairo_fill (cr);

	/* Write output and clean up */
	cairo_surface_write_to_png (surface, "textextents.png");
	cairo_destroy (cr);
	cairo_surface_destroy (surface);

	return 0;
}