1 #include <stdint.h>
2
3 #include <ft2build.h>
4 #include FT_FREETYPE_H
5 #include FT_TRUETYPE_TABLES_H
6
7 #if 0
8 #include <freetype/freetype.h>
9 #include <freetype/tttables.h>
10 #endif
11
12 #include <harfbuzz-shaper.h>
13 #include "harfbuzz-unicode.h"
14
15 static HB_Bool
hb_freetype_string_to_glyphs(HB_Font font,const HB_UChar16 * chars,hb_uint32 len,HB_Glyph * glyphs,hb_uint32 * numGlyphs,HB_Bool is_rtl)16 hb_freetype_string_to_glyphs(HB_Font font,
17 const HB_UChar16 *chars, hb_uint32 len,
18 HB_Glyph *glyphs, hb_uint32 *numGlyphs,
19 HB_Bool is_rtl) {
20 FT_Face face = (FT_Face) font->userData;
21 if (len > *numGlyphs)
22 return 0;
23
24 size_t i = 0, j = 0;
25 while (i < len) {
26 const uint32_t cp = utf16_to_code_point(chars, len, &i);
27 glyphs[j++] = FT_Get_Char_Index(face, cp);
28 }
29
30 *numGlyphs = j;
31
32 return 1;
33 }
34
35 static void
hb_freetype_advances_get(HB_Font font,const HB_Glyph * glyphs,hb_uint32 len,HB_Fixed * advances,int flags)36 hb_freetype_advances_get(HB_Font font, const HB_Glyph *glyphs, hb_uint32 len,
37 HB_Fixed *advances, int flags) {
38 FT_Face face = (FT_Face) font->userData;
39
40 hb_uint32 i;
41 for (i = 0; i < len; ++i) {
42 const FT_Error error = FT_Load_Glyph(face, glyphs[i], FT_LOAD_DEFAULT);
43 if (error) {
44 advances[i] = 0;
45 continue;
46 }
47
48 advances[i] = face->glyph->advance.x;
49 }
50 }
51
52 static HB_Bool
hb_freetype_can_render(HB_Font font,const HB_UChar16 * chars,hb_uint32 len)53 hb_freetype_can_render(HB_Font font, const HB_UChar16 *chars, hb_uint32 len) {
54 FT_Face face = (FT_Face)font->userData;
55
56 size_t i = 0;
57 while (i < len) {
58 const uint32_t cp = utf16_to_code_point(chars, len, &i);
59 if (FT_Get_Char_Index(face, cp) == 0)
60 return 0;
61 }
62
63 return 1;
64 }
65
66 static HB_Error
hb_freetype_outline_point_get(HB_Font font,HB_Glyph glyph,int flags,hb_uint32 point,HB_Fixed * xpos,HB_Fixed * ypos,hb_uint32 * n_points)67 hb_freetype_outline_point_get(HB_Font font, HB_Glyph glyph, int flags,
68 hb_uint32 point, HB_Fixed *xpos, HB_Fixed *ypos,
69 hb_uint32 *n_points) {
70 HB_Error error = HB_Err_Ok;
71 FT_Face face = (FT_Face) font->userData;
72
73 int load_flags = (flags & HB_ShaperFlag_UseDesignMetrics) ? FT_LOAD_NO_HINTING : FT_LOAD_DEFAULT;
74
75 if ((error = (HB_Error) FT_Load_Glyph(face, glyph, load_flags)))
76 return error;
77
78 if (face->glyph->format != ft_glyph_format_outline)
79 return (HB_Error)HB_Err_Invalid_SubTable;
80
81 *n_points = face->glyph->outline.n_points;
82 if (!(*n_points))
83 return HB_Err_Ok;
84
85 if (point > *n_points)
86 return (HB_Error)HB_Err_Invalid_SubTable;
87
88 *xpos = face->glyph->outline.points[point].x;
89 *ypos = face->glyph->outline.points[point].y;
90
91 return HB_Err_Ok;
92 }
93
94 static void
hb_freetype_glyph_metrics_get(HB_Font font,HB_Glyph glyph,HB_GlyphMetrics * metrics)95 hb_freetype_glyph_metrics_get(HB_Font font, HB_Glyph glyph,
96 HB_GlyphMetrics *metrics) {
97 FT_Face face = (FT_Face) font->userData;
98
99 const FT_Error error = FT_Load_Glyph(face, glyph, FT_LOAD_DEFAULT);
100 if (error) {
101 metrics->x = metrics->y = metrics->width = metrics->height = 0;
102 metrics->xOffset = metrics->yOffset = 0;
103 return;
104 }
105
106 const FT_Glyph_Metrics *ftmetrics = &face->glyph->metrics;
107 metrics->width = ftmetrics->width;
108 metrics->height = ftmetrics->height;
109 metrics->x = ftmetrics->horiAdvance;
110 metrics->y = 0; // unclear what this is
111 metrics->xOffset = ftmetrics->horiBearingX;
112 metrics->yOffset = ftmetrics->horiBearingY;
113 }
114
115 static HB_Fixed
hb_freetype_font_metric_get(HB_Font font,HB_FontMetric metric)116 hb_freetype_font_metric_get(HB_Font font, HB_FontMetric metric) {
117 FT_Face face = (FT_Face) font->userData;
118
119 switch (metric) {
120 case HB_FontAscent:
121 // Note that we aren't scanning the VDMX table which we probably would in
122 // an ideal world.
123 return face->ascender;
124 default:
125 return 0;
126 }
127 }
128
129 const HB_FontClass hb_freetype_class = {
130 hb_freetype_string_to_glyphs,
131 hb_freetype_advances_get,
132 hb_freetype_can_render,
133 hb_freetype_outline_point_get,
134 hb_freetype_glyph_metrics_get,
135 hb_freetype_font_metric_get,
136 };
137
138 HB_Error
hb_freetype_table_sfnt_get(void * voidface,const HB_Tag tag,HB_Byte * buffer,HB_UInt * len)139 hb_freetype_table_sfnt_get(void *voidface, const HB_Tag tag, HB_Byte *buffer, HB_UInt *len) {
140 FT_Face face = (FT_Face) voidface;
141 FT_ULong ftlen = *len;
142
143 if (!FT_IS_SFNT(face))
144 return HB_Err_Invalid_Argument;
145
146 const FT_Error error = FT_Load_Sfnt_Table(face, tag, 0, buffer, &ftlen);
147 *len = ftlen;
148 return (HB_Error) error;
149 }
150