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view libs/drawtext/drawtext.h @ 20:2b85d05df3f2
animation controls for easier screenshot grabbing
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Fri, 02 Oct 2015 04:54:55 +0300 |
| parents | |
| children |
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1 /*
2 libdrawtext - a simple library for fast text rendering in OpenGL
3 Copyright (C) 2011-2014 John Tsiombikas <nuclear@member.fsf.org>
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18 #ifndef LIBDRAWTEXT_H_
19 #define LIBDRAWTEXT_H_
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include "assman.h"
25 struct dtx_font;
26 struct dtx_glyphmap;
28 /* draw buffering modes */
29 enum {
30 DTX_NBF, /* unbuffered */
31 DTX_LBF, /* line buffered */
32 DTX_FBF /* fully buffered */
33 };
35 struct dtx_box {
36 float x, y;
37 float width, height;
38 };
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
44 /* Open a truetype/opentype/whatever font.
45 *
46 * If sz is non-zero, the default ASCII glyphmap at the requested point size is
47 * automatically created as well, and ready to use.
48 *
49 * To use other unicode ranges and different font sizes you must first call
50 * dtx_prepare or dtx_prepare_range before issuing any drawing calls, otherwise
51 * nothing will be rendered.
52 */
53 struct dtx_font *dtx_open_font(const char *fname, int sz);
54 /* open a font by loading a precompiled glyphmap (see: dtx_save_glyphmap)
55 * this works even when compiled without freetype support
56 */
57 struct dtx_font *dtx_open_font_glyphmap(const char *fname);
58 /* close a font opened by either of the above */
59 void dtx_close_font(struct dtx_font *fnt);
61 /* prepare an ASCII glyphmap for the specified font size */
62 void dtx_prepare(struct dtx_font *fnt, int sz);
63 /* prepare an arbitrary unicode range glyphmap for the specified font size */
64 void dtx_prepare_range(struct dtx_font *fnt, int sz, int cstart, int cend);
66 int dtx_get_font_glyphmap_count(struct dtx_font *fnt);
67 struct dtx_glyphmap *dtx_get_font_glyphmap_idx(struct dtx_font *fnt, int idx);
69 /* Finds the glyphmap that contains the specified character code and matches the requested size
70 * Returns null if it hasn't been created (you should call dtx_prepare/dtx_prepare_range).
71 */
72 struct dtx_glyphmap *dtx_get_font_glyphmap(struct dtx_font *fnt, int sz, int code);
74 /* Finds the glyphmap that contains the specified unicode range and matches the requested font size
75 * Will automatically generate one if it can't find it.
76 */
77 struct dtx_glyphmap *dtx_get_font_glyphmap_range(struct dtx_font *fnt, int sz, int cstart, int cend);
79 /* Creates and returns a glyphmap for a particular unicode range and font size.
80 * The generated glyphmap is added to the font's list of glyphmaps.
81 */
82 struct dtx_glyphmap *dtx_create_glyphmap_range(struct dtx_font *fnt, int sz, int cstart, int cend);
83 /* free a glyphmap */
84 void dtx_free_glyphmap(struct dtx_glyphmap *gmap);
86 /* returns a pointer to the raster image of a glyphmap (1 byte per pixel grayscale) */
87 unsigned char *dtx_get_glyphmap_image(struct dtx_glyphmap *gmap);
88 /* returns the point size of the glyphmap */
89 int dtx_get_glyphmap_ptsize(struct dtx_glyphmap *gmap);
90 /* returns the width of the glyphmap image in pixels */
91 int dtx_get_glyphmap_width(struct dtx_glyphmap *gmap);
92 /* returns the height of the glyphmap image in pixels */
93 int dtx_get_glyphmap_height(struct dtx_glyphmap *gmap);
95 /* The following functions can be used even when the library is compiled without
96 * freetype support.
97 */
98 struct dtx_glyphmap *dtx_load_glyphmap(const char *fname);
99 struct dtx_glyphmap *dtx_load_glyphmap_stream(FILE *fp);
100 struct dtx_glyphmap *dtx_load_glyphmap_asset(ass_file *fp);
101 int dtx_save_glyphmap(const char *fname, const struct dtx_glyphmap *gmap);
102 int dtx_save_glyphmap_stream(FILE *fp, const struct dtx_glyphmap *gmap);
104 /* adds a glyphmap to a font */
105 void dtx_add_glyphmap(struct dtx_font *fnt, struct dtx_glyphmap *gmap);
107 /* ---- rendering ---- */
109 /* before drawing anything this function must set the font to use */
110 void dtx_use_font(struct dtx_font *fnt, int sz);
112 /* sets the buffering mode
113 * - DTX_NBUF: every call to dtx_string gets rendered immediately.
114 * - DTX_LBUF: renders when the buffer is full or the string contains a newline.
115 * - DTX_FBUF: renders only when the buffer is full (you must call dtx_flush explicitly).
116 */
117 void dtx_draw_buffering(int mode);
119 /* Sets the vertex attribute indices to use for passing vertex and texture coordinate
120 * data. By default both are -1 which means you don't have to use a shader, and if you
121 * do they are accessible through gl_Vertex and gl_MultiTexCoord0, as usual.
122 *
123 * NOTE: If you are using OpenGL ES 2.x or OpenGL >= 3.1 pure (non-compatibility) context
124 * you must specify valid attribute indices.
125 */
126 void dtx_vertex_attribs(int vert_attr, int tex_attr);
128 /* draws a single glyph at the origin */
129 void dtx_glyph(int code);
130 /* draws a utf-8 string starting at the origin. \n \r and \t are handled appropriately. */
131 void dtx_string(const char *str);
133 void dtx_printf(const char *fmt, ...);
135 /* render any pending glyphs (see dtx_draw_buffering) */
136 void dtx_flush(void);
139 /* ---- encodings ---- */
141 /* returns a pointer to the next character in a utf-8 stream */
142 char *dtx_utf8_next_char(char *str);
144 /* returns the unicode character codepoint of the utf-8 character starting at str */
145 int dtx_utf8_char_code(const char *str);
147 /* returns the number of bytes of the utf-8 character starting at str */
148 int dtx_utf8_nbytes(const char *str);
150 /* returns the number of utf-8 character in a zero-terminated utf-8 string */
151 int dtx_utf8_char_count(const char *str);
153 /* Converts a unicode code-point to a utf-8 character by filling in the buffer
154 * passed at the second argument, and returns the number of bytes taken by that
155 * utf-8 character.
156 * It's valid to pass a null buffer pointer, in which case only the byte count is
157 * returned (useful to figure out how much memory to allocate for a buffer).
158 */
159 size_t dtx_utf8_from_char_code(int code, char *buf);
161 /* Converts a unicode utf-16 wchar_t string to utf-8, filling in the buffer passed
162 * at the second argument. Returns the size of the resulting string in bytes.
163 *
164 * It's valid to pass a null buffer pointer, in which case only the size gets
165 * calculated and returned, which is useful for figuring out how much memory to
166 * allocate for the utf-8 buffer.
167 */
168 size_t dtx_utf8_from_string(const wchar_t *str, char *buf);
171 /* ---- metrics ---- */
172 float dtx_line_height(void);
174 /* rendered dimensions of a single glyph */
175 void dtx_glyph_box(int code, struct dtx_box *box);
176 float dtx_glyph_width(int code);
177 float dtx_glyph_height(int code);
179 /* rendered dimensions of a string */
180 void dtx_string_box(const char *str, struct dtx_box *box);
181 float dtx_string_width(const char *str);
182 float dtx_string_height(const char *str);
184 /* returns the horizontal position of the n-th character of the rendered string
185 * (useful for placing cursors)
186 */
187 float dtx_char_pos(const char *str, int n);
189 int dtx_char_at_pt(const char *str, float pt);
191 #ifdef __cplusplus
192 }
193 #endif
195 #endif /* LIBDRAWTEXT_H_ */