/*
* Copyright © 2009 Red Hat, Inc.
* Copyright © 2009 Keith Stribley
*
* This is part of HarfBuzz, a text shaping 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
*/
#include "hb-private.hh"
#include "hb-ft.h"
#include "hb-font-private.hh"
#include FT_ADVANCES_H
#include FT_TRUETYPE_TABLES_H
#ifndef HB_DEBUG_FT
#define HB_DEBUG_FT (HB_DEBUG+0)
#endif
/* TODO:
*
* In general, this file does a fine job of what it's supposed to do.
* There are, however, things that need more work:
*
* - We don't handle any load_flags. That definitely has API implications. :(
* I believe hb_ft_font_create() should take load_flags input.
* In particular, FT_Get_Advance() without the NO_HINTING flag seems to be
* buggy.
*
* - We don't handle / allow for emboldening / obliqueing.
*
* - In the future, we should add constructors to create fonts in font space?
*
* - FT_Load_Glyph() is exteremely costly. Do something about it?
*/
static hb_bool_t
hb_ft_get_glyph (hb_font_t *font HB_UNUSED,
void *font_data,
hb_codepoint_t unicode,
hb_codepoint_t variation_selector,
hb_codepoint_t *glyph,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
#ifdef HAVE_FT_FACE_GETCHARVARIANTINDEX
if (unlikely (variation_selector)) {
*glyph = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector);
if (*glyph)
return true;
}
#endif
*glyph = FT_Get_Char_Index (ft_face, unicode);
return *glyph != 0;
}
static hb_position_t
hb_ft_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
void *font_data,
hb_codepoint_t glyph,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
FT_Fixed v;
if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
return 0;
return v >> 10;
}
static hb_position_t
hb_ft_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
void *font_data,
hb_codepoint_t glyph,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING | FT_LOAD_VERTICAL_LAYOUT;
FT_Fixed v;
if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
return 0;
/* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
* have a Y growing upward. Hence the extra negation. */
return -v >> 10;
}
static hb_bool_t
hb_ft_get_glyph_h_origin (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t glyph HB_UNUSED,
hb_position_t *x HB_UNUSED,
hb_position_t *y HB_UNUSED,
void *user_data HB_UNUSED)
{
/* We always work in the horizontal coordinates. */
return true;
}
static hb_bool_t
hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
void *font_data,
hb_codepoint_t glyph,
hb_position_t *x,
hb_position_t *y,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
int load_flags = FT_LOAD_DEFAULT;
if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
return false;
/* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
* have a Y growing upward. Hence the extra negation. */
*x = ft_face->glyph->metrics.horiBearingX - ft_face->glyph->metrics.vertBearingX;
*y = ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY);
return true;
}
static hb_position_t
hb_ft_get_glyph_h_kerning (hb_font_t *font,
void *font_data,
hb_codepoint_t left_glyph,
hb_codepoint_t right_glyph,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
FT_Vector kerningv;
FT_Kerning_Mode mode = font->x_ppem ? FT_KERNING_DEFAULT : FT_KERNING_UNFITTED;
if (FT_Get_Kerning (ft_face, left_glyph, right_glyph, mode, &kerningv))
return 0;
return kerningv.x;
}
static hb_position_t
hb_ft_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t top_glyph HB_UNUSED,
hb_codepoint_t bottom_glyph HB_UNUSED,
void *user_data HB_UNUSED)
{
/* FreeType API doesn't support vertical kerning */
return 0;
}
static hb_bool_t
hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,
void *font_data,
hb_codepoint_t glyph,
hb_glyph_extents_t *extents,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
int load_flags = FT_LOAD_DEFAULT;
if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
return false;
extents->x_bearing = ft_face->glyph->metrics.horiBearingX;
extents->y_bearing = ft_face->glyph->metrics.horiBearingY;
extents->width = ft_face->glyph->metrics.width;
extents->height = -ft_face->glyph->metrics.height;
return true;
}
static hb_bool_t
hb_ft_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
void *font_data,
hb_codepoint_t glyph,
unsigned int point_index,
hb_position_t *x,
hb_position_t *y,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
int load_flags = FT_LOAD_DEFAULT;
if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
return false;
if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
return false;
if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points))
return false;
*x = ft_face->glyph->outline.points[point_index].x;
*y = ft_face->glyph->outline.points[point_index].y;
return true;
}
static hb_bool_t
hb_ft_get_glyph_name (hb_font_t *font HB_UNUSED,
void *font_data,
hb_codepoint_t glyph,
char *name, unsigned int size,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
hb_bool_t ret = !FT_Get_Glyph_Name (ft_face, glyph, name, size);
if (ret && (size && !*name))
ret = false;
return ret;
}
static hb_bool_t
hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED,
void *font_data,
const char *name, int len, /* -1 means nul-terminated */
hb_codepoint_t *glyph,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
if (len < 0)
*glyph = FT_Get_Name_Index (ft_face, (FT_String *) name);
else {
/* Make a nul-terminated version. */
char buf[128];
len = MIN (len, (int) sizeof (buf) - 1);
strncpy (buf, name, len);
buf[len] = '\0';
*glyph = FT_Get_Name_Index (ft_face, buf);
}
return *glyph != 0;
}
static hb_font_funcs_t *
_hb_ft_get_font_funcs (void)
{
static const hb_font_funcs_t ft_ffuncs = {
HB_OBJECT_HEADER_STATIC,
true, /* immutable */
{
#define HB_FONT_FUNC_IMPLEMENT(name) hb_ft_get_##name,
HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
#undef HB_FONT_FUNC_IMPLEMENT
}
};
return const_cast<hb_font_funcs_t *> (&ft_ffuncs);
}
static hb_blob_t *
reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
{
FT_Face ft_face = (FT_Face) user_data;
FT_Byte *buffer;
FT_ULong length = 0;
FT_Error error;
/* Note: FreeType like HarfBuzz uses the NONE tag for fetching the entire blob */
error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length);
if (error)
return NULL;
buffer = (FT_Byte *) malloc (length);
if (buffer == NULL)
return NULL;
error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length);
if (error)
return NULL;
return hb_blob_create ((const char *) buffer, length,
HB_MEMORY_MODE_WRITABLE,
buffer, free);
}
hb_face_t *
hb_ft_face_create (FT_Face ft_face,
hb_destroy_func_t destroy)
{
hb_face_t *face;
if (ft_face->stream->read == NULL) {
hb_blob_t *blob;
blob = hb_blob_create ((const char *) ft_face->stream->base,
(unsigned int) ft_face->stream->size,
/* TODO: We assume that it's mmap()'ed, but FreeType code
* suggests that there are cases we reach here but font is
* not mmapped. For example, when mmap() fails. No idea
* how to deal with it better here. */
HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE,
ft_face, destroy);
face = hb_face_create (blob, ft_face->face_index);
hb_blob_destroy (blob);
} else {
face = hb_face_create_for_tables (reference_table, ft_face, destroy);
}
hb_face_set_index (face, ft_face->face_index);
hb_face_set_upem (face, ft_face->units_per_EM);
return face;
}
static void
hb_ft_face_finalize (FT_Face ft_face)
{
hb_face_destroy ((hb_face_t *) ft_face->generic.data);
}
hb_face_t *
hb_ft_face_create_cached (FT_Face ft_face)
{
if (unlikely (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer) hb_ft_face_finalize))
{
if (ft_face->generic.finalizer)
ft_face->generic.finalizer (ft_face);
ft_face->generic.data = hb_ft_face_create (ft_face, NULL);
ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize;
}
return hb_face_reference ((hb_face_t *) ft_face->generic.data);
}
static void
_do_nothing (void)
{
}
hb_font_t *
hb_ft_font_create (FT_Face ft_face,
hb_destroy_func_t destroy)
{
hb_font_t *font;
hb_face_t *face;
face = hb_ft_face_create (ft_face, destroy);
font = hb_font_create (face);
hb_face_destroy (face);
hb_font_set_funcs (font,
_hb_ft_get_font_funcs (),
ft_face, (hb_destroy_func_t) _do_nothing);
hb_font_set_scale (font,
((uint64_t) ft_face->size->metrics.x_scale * (uint64_t) ft_face->units_per_EM) >> 16,
((uint64_t) ft_face->size->metrics.y_scale * (uint64_t) ft_face->units_per_EM) >> 16);
hb_font_set_ppem (font,
ft_face->size->metrics.x_ppem,
ft_face->size->metrics.y_ppem);
return font;
}
/* Thread-safe, lock-free, FT_Library */
static FT_Library ft_library;
static inline
void free_ft_library (void)
{
FT_Done_FreeType (ft_library);
}
static FT_Library
get_ft_library (void)
{
retry:
FT_Library library = (FT_Library) hb_atomic_ptr_get (&ft_library);
if (unlikely (!library))
{
/* Not found; allocate one. */
if (FT_Init_FreeType (&library))
return NULL;
if (!hb_atomic_ptr_cmpexch (&ft_library, NULL, library)) {
FT_Done_FreeType (library);
goto retry;
}
#ifdef HAVE_ATEXIT
atexit (free_ft_library); /* First person registers atexit() callback. */
#endif
}
return library;
}
static void
_release_blob (FT_Face ft_face)
{
hb_blob_destroy ((hb_blob_t *) ft_face->generic.data);
}
void
hb_ft_font_set_funcs (hb_font_t *font)
{
hb_blob_t *blob = hb_face_reference_blob (font->face);
unsigned int blob_length;
const char *blob_data = hb_blob_get_data (blob, &blob_length);
if (unlikely (!blob_length))
DEBUG_MSG (FT, font, "Font face has empty blob");
FT_Face ft_face = NULL;
FT_Error err = FT_New_Memory_Face (get_ft_library (),
(const FT_Byte *) blob_data,
blob_length,
hb_face_get_index (font->face),
&ft_face);
if (unlikely (err)) {
hb_blob_destroy (blob);
DEBUG_MSG (FT, font, "Font face FT_New_Memory_Face() failed");
return;
}
FT_Select_Charmap (ft_face, FT_ENCODING_UNICODE);
assert (font->y_scale >= 0);
FT_Set_Char_Size (ft_face,
font->x_scale, font->y_scale,
0, 0);
#if 0
font->x_ppem * 72 * 64 / font->x_scale,
font->y_ppem * 72 * 64 / font->y_scale);
#endif
ft_face->generic.data = blob;
ft_face->generic.finalizer = (FT_Generic_Finalizer) _release_blob;
hb_font_set_funcs (font,
_hb_ft_get_font_funcs (),
ft_face,
(hb_destroy_func_t) FT_Done_Face);
}
FT_Face
hb_ft_font_get_face (hb_font_t *font)
{
if (font->destroy == (hb_destroy_func_t) FT_Done_Face ||
font->destroy == (hb_destroy_func_t) _do_nothing)
return (FT_Face) font->user_data;
return NULL;
}