1 #include <cairo.h>
2 #include <gtk/gtk.h>
3 #include <math.h>
4 
draw_aligned_text(cairo_t * cr,const char * font,double x,double y,double fontsize,const char * text,int alignment)5 static void draw_aligned_text(cairo_t *cr, const char *font, double x, double y,
6 			       double fontsize, const char *text, int alignment)
7 {
8 #define CENTERED 0
9 #define LEFT_JUSTIFIED 1
10 #define RIGHT_JUSTIFIED 2
11 
12 	double factor, direction;
13 	cairo_text_extents_t extents;
14 
15 	switch (alignment) {
16 		case CENTERED:
17 			direction = -1.0;
18 			factor = 0.5;
19 			break;
20 		case RIGHT_JUSTIFIED:
21 			direction = -1.0;
22 			factor = 1.0;
23 			break;
24 		case LEFT_JUSTIFIED:
25 		default:
26 			direction = 1.0;
27 			factor = 0.0;
28 			break;
29 	}
30 	cairo_select_font_face(cr, font, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
31 
32 	cairo_set_font_size(cr, fontsize);
33 	cairo_text_extents(cr, text, &extents);
34 	x = x + direction * (factor * extents.width  + extents.x_bearing);
35 	y = y - (extents.height / 2 + extents.y_bearing);
36 
37 	cairo_move_to(cr, x, y);
38 	cairo_show_text(cr, text);
39 }
40 
draw_centered_text(cairo_t * cr,const char * font,double x,double y,double fontsize,const char * text)41 void draw_centered_text(cairo_t *cr, const char *font, double x, double y,
42 			       double fontsize, const char *text)
43 {
44 	draw_aligned_text(cr, font, x, y, fontsize, text, CENTERED);
45 }
46 
draw_right_justified_text(cairo_t * cr,const char * font,double x,double y,double fontsize,const char * text)47 void draw_right_justified_text(cairo_t *cr, const char *font,
48 				double x, double y,
49 				double fontsize, const char *text)
50 {
51 	draw_aligned_text(cr, font, x, y, fontsize, text, RIGHT_JUSTIFIED);
52 }
53 
draw_left_justified_text(cairo_t * cr,const char * font,double x,double y,double fontsize,const char * text)54 void draw_left_justified_text(cairo_t *cr, const char *font,
55 				double x, double y,
56 				double fontsize, const char *text)
57 {
58 	draw_aligned_text(cr, font, x, y, fontsize, text, LEFT_JUSTIFIED);
59 }
60 
draw_vertical_centered_text(cairo_t * cr,const char * font,double x,double y,double fontsize,const char * text)61 void draw_vertical_centered_text(cairo_t *cr, const char *font, double x,
62 					double y, double fontsize,
63 					const char *text)
64 {
65 	double sx, sy;
66 	cairo_text_extents_t extents;
67 
68 	cairo_select_font_face(cr, font, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
69 
70 	cairo_set_font_size(cr, fontsize);
71 	cairo_text_extents(cr, text, &extents);
72 	sx = x;
73 	sy = y;
74 	y = y + (extents.width / 2.0 + extents.x_bearing);
75 	x = x - (extents.height / 2.0 + extents.y_bearing);
76 
77 	cairo_move_to(cr, x, y);
78 	cairo_save(cr);
79 	cairo_translate(cr, -sx, -sy);
80 	cairo_rotate(cr, -90.0 * M_PI / 180.0);
81 	cairo_translate(cr, sx, sy);
82 	cairo_show_text(cr, text);
83 	cairo_restore(cr);
84 }
85 
86