1al_get_glyph_advance(3) al_get_glyph_advance(3)
2
6 al_get_glyph_advance - Allegro 5 API
7
9 #include <allegro5/allegro_font.h>
10 int al_get_glyph_advance(const ALLEGRO_FONT *f, int codepoint1, int codepoint2)
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14 This function returns by how much the x position should be advanced for
15 left to right text drawing when the glyph that corresponds to code‐
16 point1 has been drawn, and the glyph that corresponds to codepoint2
17 will be the next to be drawn. This takes into consideration the hori‐
18 zontal advance width of the glyph that corresponds with codepoint1 as
19 well as the kerning between the glyphs of codepoint1 and codepoint2.
20 Kerning is the process of adjusting the spacing between glyphs in a
22 font, to obtain a more visually pleasing result. Kerning adjusts the
23 space between two individual glyphs with an offset determined by the
24 author of the font.
25 If you pass ALLEGRO_NO_KERNING as codepoint1 then al_get_glyph_advance
27 will return 0. this can be useful when drawing the first character of
28 a string in a loop.
29 Pass ALLEGRO_NO_KERNING as codepoint2 to get the horizontal advance
31 width of the glyph that corresponds to codepoint1 without taking any
32 kerning into consideration. This can be used, for example, when draw‐
33 ing the last character of a string in a loop.
34 This function will return zero if the glyph of codepoint1 is not
36 present in the font. If the glyph of codepoint2 is not present in the
37 font, the horizontal advance width of the glyph that corresponds to
38 codepoint1 without taking any kerning into consideration is returned.
39 When drawing a string one glyph at the time from the left to the right
41 with kerning, the x position of the glyph should be incremented by the
42 result of al_get_glyph_advance(3) applied to the previous glyph drawn
43 and the next glyph to draw.
44 Note that the return value of this function is a recommended advance
46 for optimal readability for left to right text determined by the author
47 of the font. However, if you like, you may want to draw the glyphs of
48 the font narrower or wider to each other than what al_get_glyph_ad‐
49 vance(3) returns for style or effect.
50 In the figure below is an example of what the result of
52 al_get_glyph_advance may be like for two glypphs A and l of the same
53 font that has kerning for the “Al” pair, without and with the ALLE‐
54 GRO_NO_KERNING flag.
55 al_get_glyph_advance(font, 'A', 'l')
57 ___|___
58 / \
59 -------------
60 /\ -|
61 / \ |
62 /____\ |
63 / \ |
64 / \ \_
65 -------------
66 al_get_glyph_advance(font, 'A', ALLEGRO_NO_KERNING)
69 ____|____
70 / \
71 ---------------
72 /\ -|
73 / \ |
74 /____\ |
75 / \ |
76 / \ \_
77 ---------------
78
80 5.1.12
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83 al_draw_glyph(3), al_get_glyph_width(3), al_get_glyph_dimensions(3).
84Allegro reference manual al_get_glyph_advance(3)