src/hb-font.h

/*
 * Copyright (C) 2009  Red Hat, Inc.
 *
 *  This is part of HarfBuzz, an OpenType Layout engine library.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 *
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * Red Hat Author(s): Behdad Esfahbod
 */

#ifndef HB_FONT_H
#define HB_FONT_H

#include "hb-common.h"
#include "hb-blob.h"
#include "hb-unicode.h"

HB_BEGIN_DECLS

typedef struct _hb_face_t hb_face_t;
typedef struct _hb_font_t hb_font_t;

/*
 * hb_face_t
 */

hb_face_t *
hb_face_create_for_data (hb_blob_t    *blob,
			 unsigned int  index);

typedef hb_blob_t * (*hb_get_table_func_t)  (hb_tag_t tag, void *user_data);

/* calls destroy() when not needing user_data anymore */
hb_face_t *
hb_face_create_for_tables (hb_get_table_func_t  get_table,
			   hb_destroy_func_t    destroy,
			   void                *user_data);

hb_face_t *
hb_face_reference (hb_face_t *face);

unsigned int
hb_face_get_reference_count (hb_face_t *face);

void
hb_face_destroy (hb_face_t *face);

void
hb_face_set_unicode_funcs (hb_face_t *face,
			   hb_unicode_funcs_t *unicode_funcs);

hb_blob_t *
hb_face_get_table (hb_face_t *face,
		   hb_tag_t   tag);


/*
 * hb_font_funcs_t
 */

typedef struct _hb_font_funcs_t hb_font_funcs_t;

hb_font_funcs_t *
hb_font_funcs_create (void);

hb_font_funcs_t *
hb_font_funcs_reference (hb_font_funcs_t *ffuncs);

unsigned int
hb_font_funcs_get_reference_count (hb_font_funcs_t *ffuncs);

void
hb_font_funcs_destroy (hb_font_funcs_t *ffuncs);

hb_font_funcs_t *
hb_font_funcs_copy (hb_font_funcs_t *ffuncs);

void
hb_font_funcs_make_immutable (hb_font_funcs_t *ffuncs);


/* funcs */

typedef struct _hb_glyph_metrics_t hb_glyph_metrics_t;
struct _hb_glyph_metrics_t
{
    hb_position_t x_advance;
    hb_position_t y_advance;
    hb_position_t x_offset;
    hb_position_t y_offset;
    hb_position_t width;
    hb_position_t height;
};

typedef hb_codepoint_t (*hb_font_get_glyph_func_t) (hb_font_t *font, hb_face_t *face, const void *user_data,
						    hb_codepoint_t unicode, hb_codepoint_t variant_selector);
typedef hb_bool_t (*hb_font_get_contour_point_func_t) (hb_font_t *font, hb_face_t *face, const void *user_data,
						       unsigned int point_index,
						       hb_codepoint_t glyph, hb_position_t *x, hb_position_t *y);
typedef void (*hb_font_get_glyph_metrics_func_t) (hb_font_t *font, hb_face_t *face, const void *user_data,
						  hb_codepoint_t glyph, hb_glyph_metrics_t *metrics);
typedef hb_position_t (*hb_font_get_kerning_func_t) (hb_font_t *font, hb_face_t *face, const void *user_data,
						     hb_codepoint_t first_glyph, hb_codepoint_t second_glyph);


void
hb_font_funcs_set_glyph_func (hb_font_funcs_t *ffuncs,
			      hb_font_get_glyph_func_t glyph_func);

void
hb_font_funcs_set_contour_point_func (hb_font_funcs_t *ffuncs,
				      hb_font_get_contour_point_func_t contour_point_func);

void
hb_font_funcs_set_glyph_metrics_func (hb_font_funcs_t *ffuncs,
				      hb_font_get_glyph_metrics_func_t glyph_metrics_func);

void
hb_font_funcs_set_kerning_func (hb_font_funcs_t *ffuncs,
				hb_font_get_kerning_func_t kerning_func);


/*
 * hb_font_t
 */

/* Fonts are very light-weight objects */

hb_font_t *
hb_font_create (void);

hb_font_t *
hb_font_reference (hb_font_t *font);

unsigned int
hb_font_get_reference_count (hb_font_t *font);

void
hb_font_destroy (hb_font_t *font);

void
hb_font_set_funcs (hb_font_t       *font,
		   hb_font_funcs_t *klass);

/*
 * XXX
 * should we decompose this to units_per_EM and font-size?
 * units_per_EM setting then can go into the face, or better,
 * read from the 'head' table.
 *
 * Then we either need size+shape like freetype does, or a full
 * matrix.
 */
void
hb_font_set_scale (hb_font_t *font,
		   hb_16dot16_t x_scale,
		   hb_16dot16_t y_scale);

/*
 * A zero value means "no hinting in that direction"
 */
void
hb_font_set_ppem (hb_font_t *font,
		  unsigned int x_ppem,
		  unsigned int y_ppem);


HB_END_DECLS

#endif /* HB_FONT_H */