nuclear@24: /*
nuclear@24: libdrawtext - a simple library for fast text rendering in OpenGL
nuclear@29: Copyright (C) 2011-2012  John Tsiombikas <nuclear@member.fsf.org>
nuclear@24: 
nuclear@24: This program is free software: you can redistribute it and/or modify
nuclear@24: it under the terms of the GNU Lesser General Public License as published by
nuclear@24: the Free Software Foundation, either version 3 of the License, or
nuclear@24: (at your option) any later version.
nuclear@24: 
nuclear@24: This program is distributed in the hope that it will be useful,
nuclear@24: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@24: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@24: GNU Lesser General Public License for more details.
nuclear@24: 
nuclear@24: You should have received a copy of the GNU Lesser General Public License
nuclear@24: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@24: */
nuclear@24: #ifndef TEXT_H_
nuclear@24: #define TEXT_H_
nuclear@24: 
nuclear@24: #include <stdio.h>
nuclear@24: #include <stdlib.h>
nuclear@24: 
nuclear@24: struct dtx_font;
nuclear@24: struct dtx_glyphmap;
nuclear@24: 
nuclear@24: /* draw buffering modes */
nuclear@24: enum {
nuclear@24: 	DTX_NBF,	/* unbuffered */
nuclear@24: 	DTX_LBF,	/* line buffered */
nuclear@24: 	DTX_FBF		/* fully buffered */
nuclear@24: };
nuclear@24: 
nuclear@24: struct dtx_box {
nuclear@24: 	float x, y;
nuclear@24: 	float width, height;
nuclear@24: };
nuclear@24: 
nuclear@24: #ifdef __cplusplus
nuclear@24: extern "C" {
nuclear@24: #endif
nuclear@24: 
nuclear@24: /* Open a truetype/opentype/whatever font.
nuclear@24:  *
nuclear@24:  * If sz is non-zero, the default ASCII glyphmap at the requested point size is
nuclear@24:  * automatically created as well, and ready to use.
nuclear@24:  *
nuclear@24:  * To use other unicode ranges and different font sizes you must first call
nuclear@24:  * dtx_prepare or dtx_prepare_range before issuing any drawing calls, otherwise
nuclear@24:  * nothing will be rendered.
nuclear@24:  */
nuclear@24: struct dtx_font *dtx_open_font(const char *fname, int sz);
nuclear@24: void dtx_close_font(struct dtx_font *fnt);
nuclear@24: 
nuclear@24: /* prepare an ASCII glyphmap for the specified font size */
nuclear@24: void dtx_prepare(struct dtx_font *fnt, int sz);
nuclear@24: /* prepare an arbitrary unicode range glyphmap for the specified font size */
nuclear@24: void dtx_prepare_range(struct dtx_font *fnt, int sz, int cstart, int cend);
nuclear@24: 
nuclear@24: /* Finds the glyphmap that contains the specified character code and matches the requested size
nuclear@24:  * Returns null if it hasn't been created (you should call dtx_prepare/dtx_prepare_range).
nuclear@24:  */
nuclear@24: struct dtx_glyphmap *dtx_get_font_glyphmap(struct dtx_font *fnt, int sz, int code);
nuclear@24: 
nuclear@24: /* Finds the glyphmap that contains the specified unicode range and matches the requested font size
nuclear@24:  * Will automatically generate one if it can't find it.
nuclear@24:  */
nuclear@24: struct dtx_glyphmap *dtx_get_font_glyphmap_range(struct dtx_font *fnt, int sz, int cstart, int cend);
nuclear@24: 
nuclear@24: /* Creates and returns a glyphmap for a particular unicode range and font size.
nuclear@24:  * The generated glyphmap is added to the font's list of glyphmaps.
nuclear@24:  */
nuclear@24: struct dtx_glyphmap *dtx_create_glyphmap_range(struct dtx_font *fnt, int sz, int cstart, int cend);
nuclear@24: /* free a glyphmap */
nuclear@24: void dtx_free_glyphmap(struct dtx_glyphmap *gmap);
nuclear@24: 
nuclear@24: /* returns a pointer to the raster image of a glyphmap (1 byte per pixel grayscale) */
nuclear@24: unsigned char *dtx_get_glyphmap_image(struct dtx_glyphmap *gmap);
nuclear@24: /* returns the width of the glyphmap image in pixels */
nuclear@24: int dtx_get_glyphmap_width(struct dtx_glyphmap *gmap);
nuclear@24: /* returns the height of the glyphmap image in pixels */
nuclear@24: int dtx_get_glyphmap_height(struct dtx_glyphmap *gmap);
nuclear@24: 
nuclear@24: /* The following functions can be used even when the library is compiled without
nuclear@24:  * freetype support. (TODO)
nuclear@24:  */
nuclear@24: struct dtx_glyphmap *dtx_load_glyphmap(const char *fname);
nuclear@24: struct dtx_glyphmap *dtx_load_glyphmap_stream(FILE *fp);
nuclear@24: int dtx_save_glyphmap(const char *fname, const struct dtx_glyphmap *gmap);
nuclear@24: int dtx_save_glyphmap_stream(FILE *fp, const struct dtx_glyphmap *gmap);
nuclear@24: 
nuclear@24: 
nuclear@24: /* ---- rendering ---- */
nuclear@24: 
nuclear@24: /* before drawing anything this function must set the font to use */
nuclear@24: void dtx_use_font(struct dtx_font *fnt, int sz);
nuclear@24: 
nuclear@24: /* sets the buffering mode
nuclear@24:  * - DTX_NBUF: every call to dtx_string gets rendered immediately.
nuclear@24:  * - DTX_LBUF: renders when the buffer is full or the string contains a newline.
nuclear@24:  * - DTX_FBUF: renders only when the buffer is full (you must call dtx_flush explicitly).
nuclear@24:  */
nuclear@24: void dtx_draw_buffering(int mode);
nuclear@24: 
nuclear@24: /* Sets the vertex attribute indices to use for passing vertex and texture coordinate
nuclear@24:  * data. By default both are -1 which means you don't have to use a shader, and if you
nuclear@24:  * do they are accessible through gl_Vertex and gl_MultiTexCoord0, as usual.
nuclear@24:  *
nuclear@24:  * NOTE: If you are using OpenGL ES 2.x or OpenGL >= 3.1 pure (non-compatibility) context
nuclear@24:  * you must specify valid attribute indices.
nuclear@24:  */
nuclear@24: void dtx_vertex_attribs(int vert_attr, int tex_attr);
nuclear@24: 
nuclear@24: /* draws a single glyph at the origin */
nuclear@24: void dtx_glyph(int code);
nuclear@24: /* draws a utf-8 string starting at the origin. \n \r and \t are handled appropriately. */
nuclear@24: void dtx_string(const char *str);
nuclear@24: 
nuclear@24: /* render any pending glyphs (see dtx_draw_buffering) */
nuclear@24: void dtx_flush(void);
nuclear@24: 
nuclear@24: 
nuclear@24: /* ---- encodings ---- */
nuclear@24: 
nuclear@24: /* returns a pointer to the next character in a utf-8 stream */
nuclear@24: char *dtx_utf8_next_char(char *str);
nuclear@24: 
nuclear@24: /* returns the unicode character codepoint of the utf-8 character starting at str */
nuclear@24: int dtx_utf8_char_code(const char *str);
nuclear@24: 
nuclear@24: /* returns the number of bytes of the utf-8 character starting at str */
nuclear@24: int dtx_utf8_nbytes(const char *str);
nuclear@24: 
nuclear@24: /* returns the number of utf-8 character in a zero-terminated utf-8 string */
nuclear@24: int dtx_utf8_char_count(const char *str);
nuclear@24: 
nuclear@24: /* Converts a unicode code-point to a utf-8 character by filling in the buffer
nuclear@24:  * passed at the second argument, and returns the number of bytes taken by that
nuclear@24:  * utf-8 character.
nuclear@24:  * It's valid to pass a null buffer pointer, in which case only the byte count is
nuclear@24:  * returned (useful to figure out how much memory to allocate for a buffer).
nuclear@24:  */
nuclear@24: size_t dtx_utf8_from_char_code(int code, char *buf);
nuclear@24: 
nuclear@24: /* Converts a unicode utf-16 wchar_t string to utf-8, filling in the buffer passed
nuclear@24:  * at the second argument. Returns the size of the resulting string in bytes.
nuclear@24:  *
nuclear@24:  * It's valid to pass a null buffer pointer, in which case only the size gets
nuclear@24:  * calculated and returned, which is useful for figuring out how much memory to
nuclear@24:  * allocate for the utf-8 buffer.
nuclear@24:  */
nuclear@24: size_t dtx_utf8_from_string(const wchar_t *str, char *buf);
nuclear@24: 
nuclear@24: 
nuclear@24: /* ---- metrics ---- */
nuclear@29: float dtx_line_height(void);
nuclear@24: 
nuclear@24: /* rendered dimensions of a single glyph */
nuclear@24: void dtx_glyph_box(int code, struct dtx_box *box);
nuclear@24: float dtx_glyph_width(int code);
nuclear@24: float dtx_glyph_height(int code);
nuclear@24: 
nuclear@24: /* rendered dimensions of a string */
nuclear@24: void dtx_string_box(const char *str, struct dtx_box *box);
nuclear@24: float dtx_string_width(const char *str);
nuclear@24: float dtx_string_height(const char *str);
nuclear@24: 
nuclear@24: /* returns the horizontal position of the n-th character of the rendered string
nuclear@24:  * (useful for placing cursors)
nuclear@24:  */
nuclear@24: float dtx_char_pos(const char *str, int n);
nuclear@24: 
nuclear@24: int dtx_char_at_pt(const char *str, float pt);
nuclear@24: 
nuclear@24: #ifdef __cplusplus
nuclear@24: }
nuclear@24: #endif
nuclear@24: 
nuclear@24: #endif	/* TEXT_H_ */