1+ #include < cstdint>
2+ #include < math.h>
3+ #include < string.h>
4+ #include < algorithm>
5+ #include < vector>
6+ #include < optional>
7+ #include < map>
8+
9+ #include " alright_fonts.hpp"
10+
11+ using namespace pretty_poly ;
12+
13+ namespace alright_fonts {
14+ /*
15+ utility functions
16+ */
17+ pretty_poly::rect_t measure_character (text_metrics_t &tm, uint16_t codepoint) {
18+ if (tm.face .glyphs .count (codepoint) == 1 ) {
19+ glyph_t glyph = tm.face .glyphs [codepoint];
20+
21+ return {0 , 0 , ((glyph.advance * tm.size ) / 128 ), tm.size };
22+ }
23+
24+ return {0 , 0 , 0 , 0 };
25+ }
26+
27+ /*
28+ render functions
29+ */
30+
31+ void render_character (text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t <int > origin) {
32+ if (tm.face .glyphs .count (codepoint) == 1 ) {
33+ glyph_t glyph = tm.face .glyphs [codepoint];
34+
35+ // scale is a fixed point 16:16 value, our font data is already scaled to
36+ // -128..127 so to get the pixel size we want we can just shift the
37+ // users requested size up one bit
38+ unsigned scale = tm.size << 9 ;
39+
40+ pretty_poly::draw_polygon<int8_t >(glyph.contours , origin, scale);
41+ }
42+ }
43+
44+ void render_character (text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t <int > origin, pretty_poly::mat3_t transform) {
45+ if (tm.face .glyphs .count (codepoint) == 1 ) {
46+ glyph_t glyph = tm.face .glyphs [codepoint];
47+
48+ // scale is a fixed point 16:16 value, our font data is already scaled to
49+ // -128..127 so to get the pixel size we want we can just shift the
50+ // users requested size up one bit
51+ unsigned scale = tm.size << 9 ;
52+
53+ std::vector<pretty_poly::contour_t <int8_t >> contours;
54+
55+ for (auto i = 0u ; i < glyph.contours .size (); i++) {
56+ unsigned int count = glyph.contours [i].count ;
57+ point_t <int8_t > *points = (point_t <int8_t > *)malloc (sizeof (point_t <int8_t >) * count);
58+ for (auto j = 0u ; j < count; j++) {
59+ point_t <float > point (glyph.contours [i].points [j].x , glyph.contours [i].points [j].y );
60+ point *= transform;
61+ points[j] = point_t <int8_t >(point.x , point.y );
62+ }
63+ contours.emplace_back (points, count);
64+ }
65+
66+ pretty_poly::draw_polygon<int8_t >(contours, origin, scale);
67+
68+ for (auto contour : contours) {
69+ free (contour.points );
70+ }
71+ }
72+ }
73+
74+ /*
75+ load functions
76+ */
77+
78+ // big endian stream value helpers
79+ uint16_t ru16 (file_io &ifs) {uint8_t w[2 ]; ifs.read ((char *)w, 2 ); return w[0 ] << 8 | w[1 ];}
80+ int16_t rs16 (file_io &ifs) {uint8_t w[2 ]; ifs.read ((char *)w, 2 ); return w[0 ] << 8 | w[1 ];}
81+ uint32_t ru32 (file_io &ifs) {uint8_t dw[4 ]; ifs.read ((char *)dw, 4 ); return dw[0 ] << 24 | dw[1 ] << 16 | dw[2 ] << 8 | dw[3 ];}
82+ uint8_t ru8 (file_io &ifs) {uint8_t w; ifs.read (&w, 1 ); return w;}
83+ int8_t rs8 (file_io &ifs) {int8_t w; ifs.read (&w, 1 ); return w;}
84+
85+ bool face_t::load (file_io &ifs) {
86+ char marker[4 ];
87+ ifs.read (marker, sizeof (marker));
88+
89+ // check header magic bytes are present
90+ if (memcmp (marker, " af!?" 4 ) != 0 ) {
91+ // doesn't start with magic marker
92+ return false ;
93+ }
94+
95+ // number of glyphs embedded in font file
96+ this ->glyph_count = ru16 (ifs);
97+
98+ // extract flags and ensure none set
99+ this ->flags = ru16 (ifs);
100+ if (this ->flags != 0 ) {
101+ // unknown flags set
102+ return false ;
103+ }
104+
105+ // extract glyph dictionary
106+ uint16_t glyph_entry_size = 9 ;
107+ uint32_t contour_data_offset = 8 + this ->glyph_count * glyph_entry_size;
108+ for (auto i = 0 ; i < this ->glyph_count ; i++) {
109+ glyph_t g;
110+ g.codepoint = ru16 (ifs);
111+ g.bounds .x = rs8 (ifs);
112+ g.bounds .y = rs8 (ifs);
113+ g.bounds .w = ru8 (ifs);
114+ g.bounds .h = ru8 (ifs);
115+ g.advance = ru8 (ifs);
116+
117+ if (ifs.fail ()) {
118+ // could not read glyph dictionary entry
119+ return false ;
120+ }
121+
122+ // allocate space for the contour data and read it from the font file
123+ uint16_t contour_data_length = ru16 (ifs);
124+
125+ // remember where we are in the dictionary
126+ int pos = ifs.tell ();
127+
128+ // read contour data
129+ ifs.seek (contour_data_offset);
130+ while (true ) {
131+ // get number of points in contour
132+ uint16_t count = ru16 (ifs);
133+
134+ // if count is zero then this is the end of contour marker
135+ if (count == 0 ) {
136+ break ;
137+ }
138+
139+ // allocate space to store point data for contour and read
140+ // from file
141+ pretty_poly::point_t <int8_t > *points = new pretty_poly::point_t <int8_t >[count];
142+ ifs.read ((char *)points, count * 2 );
143+
144+ g.contours .push_back ({points, count});
145+ }
146+
147+ // return back to position in dictionary
148+ ifs.seek (pos);
149+ contour_data_offset += contour_data_length;
150+
151+ if (ifs.fail ()) {
152+ // could not read glyph contour data
153+ return false ;
154+ }
155+
156+ this ->glyphs [g.codepoint ] = g;
157+ }
158+
159+ return true ;
160+ }
161+
162+ bool face_t::load (std::string_view path) {
163+ file_io ifs (path);
164+ if (ifs.fail ()) {
165+ // could not open file
166+ return false ;
167+ }
168+ return load (ifs);
169+ }
170+
171+ }
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