harfbuzz/src/hb-ft.cc

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/*
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* Copyright © 2009 Red Hat, Inc.
* Copyright © 2009 Keith Stribley
* Copyright © 2015 Google, Inc.
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*
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* This is part of HarfBuzz, a text shaping library.
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*
* 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
* Google Author(s): Behdad Esfahbod
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*/
#include "hb-private.hh"
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#include "hb-ft.h"
#include "hb-font-private.hh"
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#include FT_ADVANCES_H
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#include FT_TRUETYPE_TABLES_H
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#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:
*
* - I remember seeing FT_Get_Advance() without the NO_HINTING flag to be buggy.
* Have not investigated.
*
* - FreeType works in 26.6 mode. Clients can decide to use that mode, and everything
* would work fine. However, we also abuse this API for performing in font-space,
* but don't pass the correct flags to FreeType. We just abuse the no-hinting mode
* for that, such that no rounding etc happens. As such, we don't set ppem, and
* pass NO_HINTING as load_flags. Would be much better to use NO_SCALE, and scale
* ourselves, like we do in uniscribe, etc.
*
* - We don't handle / allow for emboldening / obliqueing.
*
* - In the future, we should add constructors to create fonts in font space?
*
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* - FT_Load_Glyph() is exteremely costly. Do something about it?
*/
struct hb_ft_font_t
{
FT_Face ft_face;
int load_flags;
bool unref; /* Whether to destroy ft_face when done. */
};
static hb_ft_font_t *
_hb_ft_font_create (FT_Face ft_face, bool unref)
{
hb_ft_font_t *ft_font = (hb_ft_font_t *) calloc (1, sizeof (hb_ft_font_t));
if (unlikely (!ft_font))
return NULL;
ft_font->ft_face = ft_face;
ft_font->unref = unref;
ft_font->load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
return ft_font;
}
static void
_hb_ft_font_destroy (hb_ft_font_t *ft_font)
{
if (ft_font->unref)
FT_Done_Face (ft_font->ft_face);
free (ft_font);
}
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/**
* hb_ft_font_set_load_flags:
* @font:
* @load_flags:
*
*
*
* Since: 1.0.5
**/
void
hb_ft_font_set_load_flags (hb_font_t *font, int load_flags)
{
if (font->immutable)
return;
if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)
return;
hb_ft_font_t *ft_font = (hb_ft_font_t *) font->user_data;
ft_font->load_flags = load_flags;
}
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/**
* hb_ft_font_get_load_flags:
* @font:
*
*
*
* Return value:
* Since: 1.0.5
**/
int
hb_ft_font_get_load_flags (hb_font_t *font)
{
if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)
return 0;
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font->user_data;
return ft_font->load_flags;
}
FT_Face
hb_ft_font_get_face (hb_font_t *font)
{
if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)
return NULL;
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font->user_data;
return ft_font->ft_face;
}
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)
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{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
unsigned int g;
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if (likely (!variation_selector))
g = FT_Get_Char_Index (ft_font->ft_face, unicode);
else
g = FT_Face_GetCharVariantIndex (ft_font->ft_face, unicode, variation_selector);
if (unlikely (!g))
return false;
*glyph = g;
return true;
}
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)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Fixed v;
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if (unlikely (FT_Get_Advance (ft_font->ft_face, glyph, ft_font->load_flags, &v)))
return 0;
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if (font->x_scale < 0)
v = -v;
return (v + (1<<9)) >> 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)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Fixed v;
if (unlikely (FT_Get_Advance (ft_font->ft_face, glyph, ft_font->load_flags | FT_LOAD_VERTICAL_LAYOUT, &v)))
return 0;
if (font->y_scale < 0)
v = -v;
/* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
* have a Y growing upward. Hence the extra negation. */
return (-v + (1<<9)) >> 10;
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}
static hb_bool_t
hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
void *font_data,
hb_codepoint_t glyph,
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hb_position_t *x,
hb_position_t *y,
void *user_data HB_UNUSED)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Face ft_face = ft_font->ft_face;
if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
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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);
if (font->x_scale < 0)
*x = -*x;
if (font->y_scale < 0)
*y = -*y;
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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)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Vector kerningv;
FT_Kerning_Mode mode = font->x_ppem ? FT_KERNING_DEFAULT : FT_KERNING_UNFITTED;
if (FT_Get_Kerning (ft_font->ft_face, left_glyph, right_glyph, mode, &kerningv))
return 0;
return kerningv.x;
}
static hb_bool_t
hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,
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void *font_data,
hb_codepoint_t glyph,
hb_glyph_extents_t *extents,
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void *user_data HB_UNUSED)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Face ft_face = ft_font->ft_face;
if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
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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;
if (font->x_scale < 0)
{
extents->x_bearing = -extents->x_bearing;
extents->width = -extents->width;
}
if (font->y_scale < 0)
{
extents->y_bearing = -extents->y_bearing;
extents->height = -extents->height;
}
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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)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Face ft_face = ft_font->ft_face;
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if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
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return false;
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if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
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return false;
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if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points))
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return false;
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*x = ft_face->glyph->outline.points[point_index].x;
*y = ft_face->glyph->outline.points[point_index].y;
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return true;
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}
static hb_bool_t
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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)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
hb_bool_t ret = !FT_Get_Glyph_Name (ft_font->ft_face, glyph, name, size);
if (ret && (size && !*name))
ret = false;
return ret;
}
static hb_bool_t
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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)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Face ft_face = ft_font->ft_face;
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);
}
if (*glyph == 0)
{
/* Check whether the given name was actually the name of glyph 0. */
char buf[128];
if (!FT_Get_Glyph_Name(ft_face, 0, buf, sizeof (buf)) &&
len < 0 ? !strcmp (buf, name) : !strncmp (buf, name, len))
return true;
}
return *glyph != 0;
}
static hb_bool_t
hb_ft_get_font_h_extents (hb_font_t *font HB_UNUSED,
void *font_data,
hb_font_extents_t *metrics,
void *user_data HB_UNUSED)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Face ft_face = ft_font->ft_face;
metrics->ascender = ft_face->ascender;
metrics->descender = ft_face->descender;
metrics->line_gap = ft_face->height - (ft_face->ascender - ft_face->descender);
if (font->y_scale < 0)
{
metrics->ascender = -metrics->ascender;
metrics->descender = -metrics->descender;
metrics->line_gap = -metrics->line_gap;
}
return true;
}
static hb_font_funcs_t *static_ft_funcs = NULL;
#ifdef HB_USE_ATEXIT
static
void free_static_ft_funcs (void)
{
hb_font_funcs_destroy (static_ft_funcs);
}
#endif
static void
_hb_ft_font_set_funcs (hb_font_t *font, FT_Face ft_face, bool unref)
{
retry:
hb_font_funcs_t *funcs = (hb_font_funcs_t *) hb_atomic_ptr_get (&static_ft_funcs);
if (unlikely (!funcs))
{
funcs = hb_font_funcs_create ();
hb_font_funcs_set_font_h_extents_func (funcs, hb_ft_get_font_h_extents, NULL, NULL);
//hb_font_funcs_set_font_v_extents_func (funcs, hb_ft_get_font_v_extents, NULL, NULL);
hb_font_funcs_set_glyph_func (funcs, hb_ft_get_glyph, NULL, NULL);
hb_font_funcs_set_glyph_h_advance_func (funcs, hb_ft_get_glyph_h_advance, NULL, NULL);
hb_font_funcs_set_glyph_v_advance_func (funcs, hb_ft_get_glyph_v_advance, NULL, NULL);
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//hb_font_funcs_set_glyph_h_origin_func (funcs, hb_ft_get_glyph_h_origin, NULL, NULL);
hb_font_funcs_set_glyph_v_origin_func (funcs, hb_ft_get_glyph_v_origin, NULL, NULL);
hb_font_funcs_set_glyph_h_kerning_func (funcs, hb_ft_get_glyph_h_kerning, NULL, NULL);
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//hb_font_funcs_set_glyph_v_kerning_func (funcs, hb_ft_get_glyph_v_kerning, NULL, NULL);
hb_font_funcs_set_glyph_extents_func (funcs, hb_ft_get_glyph_extents, NULL, NULL);
hb_font_funcs_set_glyph_contour_point_func (funcs, hb_ft_get_glyph_contour_point, NULL, NULL);
hb_font_funcs_set_glyph_name_func (funcs, hb_ft_get_glyph_name, NULL, NULL);
hb_font_funcs_set_glyph_from_name_func (funcs, hb_ft_get_glyph_from_name, NULL, NULL);
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hb_font_funcs_make_immutable (funcs);
if (!hb_atomic_ptr_cmpexch (&static_ft_funcs, NULL, funcs)) {
hb_font_funcs_destroy (funcs);
goto retry;
}
#ifdef HB_USE_ATEXIT
atexit (free_static_ft_funcs); /* First person registers atexit() callback. */
#endif
};
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hb_font_set_funcs (font,
funcs,
_hb_ft_font_create (ft_face, unref),
(hb_destroy_func_t) _hb_ft_font_destroy);
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}
static hb_blob_t *
reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
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{
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 */
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error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length);
if (error)
return NULL;
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buffer = (FT_Byte *) malloc (length);
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if (buffer == NULL)
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return NULL;
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error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length);
if (error)
return NULL;
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return hb_blob_create ((const char *) buffer, length,
HB_MEMORY_MODE_WRITABLE,
buffer, free);
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}
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/**
* hb_ft_face_create:
* @ft_face: (destroy destroy) (scope notified):
* @destroy:
*
*
*
* Return value: (transfer full):
* Since: 0.9.2
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**/
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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) {
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hb_blob_t *blob;
blob = hb_blob_create ((const char *) ft_face->stream->base,
(unsigned int) ft_face->stream->size,
HB_MEMORY_MODE_READONLY,
ft_face, destroy);
face = hb_face_create (blob, ft_face->face_index);
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hb_blob_destroy (blob);
} else {
face = hb_face_create_for_tables (reference_table, ft_face, destroy);
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}
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hb_face_set_index (face, ft_face->face_index);
hb_face_set_upem (face, ft_face->units_per_EM);
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return face;
}
[ft] Add hb_ft_face_create_referenced() and hb_ft_font_create_referenced() When I originally wrote hb-ft, FreeType objects did not support reference counting. As such, hb_ft_face_create() and hb_ft_font_create() had a "destroy" callback and client was responsible for making sure FT_Face is kept around as long as the hb-font/face are alive. However, since this was not clearly documented, some clienets didn't correctly did that. In particular, some clients assumed that it's safe to destroy FT_Face and then hb_face_t. This, indeed, used to work, until 45fd9424c723f115ca98995b8f8a25185a6fc71d, which make face destroy access font tables. Now, I fixed that issue in 395b35903e052aecc97d0807e4f813c64c0d2b0b since the access was not needed, but the problem remains that not all clients handle this correctly. See: https://bugs.freedesktop.org/show_bug.cgi?id=86300 Fortunately, FT_Reference_Face() was added to FreeType in 2010, and so we can use it now. Originally I wanted to change hb_ft_face_create() and hb_ft_font_create() to reference the face if destroy==NULL was passed in. That would improve pretty much all clients, with little undesired effects. Except that FreeType itself, when compiled with HarfBuzz support, calls hb_ft_font_create() with destroy==NULL and saves the resulting hb-font on the ft-face (why does it not free it immediately?). Making hb-face reference ft-face causes a cycling reference there. At least, that's my current understanding. At any rate, a cleaner approach, even if it means all clients will need a change, is to introduce brand new API. Which this commit does. Some comments added to hb-ft.h, hoping to make future clients make better choices. Fixes https://bugs.freedesktop.org/show_bug.cgi?id=75299
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/**
* hb_ft_face_create_referenced:
* @ft_face:
*
*
*
* Return value: (transfer full):
* Since: 0.9.38
[ft] Add hb_ft_face_create_referenced() and hb_ft_font_create_referenced() When I originally wrote hb-ft, FreeType objects did not support reference counting. As such, hb_ft_face_create() and hb_ft_font_create() had a "destroy" callback and client was responsible for making sure FT_Face is kept around as long as the hb-font/face are alive. However, since this was not clearly documented, some clienets didn't correctly did that. In particular, some clients assumed that it's safe to destroy FT_Face and then hb_face_t. This, indeed, used to work, until 45fd9424c723f115ca98995b8f8a25185a6fc71d, which make face destroy access font tables. Now, I fixed that issue in 395b35903e052aecc97d0807e4f813c64c0d2b0b since the access was not needed, but the problem remains that not all clients handle this correctly. See: https://bugs.freedesktop.org/show_bug.cgi?id=86300 Fortunately, FT_Reference_Face() was added to FreeType in 2010, and so we can use it now. Originally I wanted to change hb_ft_face_create() and hb_ft_font_create() to reference the face if destroy==NULL was passed in. That would improve pretty much all clients, with little undesired effects. Except that FreeType itself, when compiled with HarfBuzz support, calls hb_ft_font_create() with destroy==NULL and saves the resulting hb-font on the ft-face (why does it not free it immediately?). Making hb-face reference ft-face causes a cycling reference there. At least, that's my current understanding. At any rate, a cleaner approach, even if it means all clients will need a change, is to introduce brand new API. Which this commit does. Some comments added to hb-ft.h, hoping to make future clients make better choices. Fixes https://bugs.freedesktop.org/show_bug.cgi?id=75299
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**/
hb_face_t *
hb_ft_face_create_referenced (FT_Face ft_face)
{
FT_Reference_Face (ft_face);
return hb_ft_face_create (ft_face, (hb_destroy_func_t) FT_Done_Face);
}
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static void
hb_ft_face_finalize (FT_Face ft_face)
{
hb_face_destroy ((hb_face_t *) ft_face->generic.data);
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}
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/**
* hb_ft_face_create_cached:
* @ft_face:
*
*
*
* Return value: (transfer full):
* Since: 0.9.2
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**/
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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))
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{
if (ft_face->generic.finalizer)
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ft_face->generic.finalizer (ft_face);
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ft_face->generic.data = hb_ft_face_create (ft_face, NULL);
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ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize;
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}
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return hb_face_reference ((hb_face_t *) ft_face->generic.data);
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}
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/**
* hb_ft_font_create:
* @ft_face: (destroy destroy) (scope notified):
* @destroy:
*
*
*
* Return value: (transfer full):
* Since: 0.9.2
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**/
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hb_font_t *
hb_ft_font_create (FT_Face ft_face,
hb_destroy_func_t destroy)
{
hb_font_t *font;
hb_face_t *face;
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face = hb_ft_face_create (ft_face, destroy);
font = hb_font_create (face);
hb_face_destroy (face);
_hb_ft_font_set_funcs (font, ft_face, false);
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hb_font_set_scale (font,
(int) (((uint64_t) ft_face->size->metrics.x_scale * (uint64_t) ft_face->units_per_EM + (1<<15)) >> 16),
(int) (((uint64_t) ft_face->size->metrics.y_scale * (uint64_t) ft_face->units_per_EM + (1<<15)) >> 16));
#if 0 /* hb-ft works in no-hinting model */
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hb_font_set_ppem (font,
ft_face->size->metrics.x_ppem,
ft_face->size->metrics.y_ppem);
#endif
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return font;
}
2010-07-23 21:11:18 +02:00
[ft] Add hb_ft_face_create_referenced() and hb_ft_font_create_referenced() When I originally wrote hb-ft, FreeType objects did not support reference counting. As such, hb_ft_face_create() and hb_ft_font_create() had a "destroy" callback and client was responsible for making sure FT_Face is kept around as long as the hb-font/face are alive. However, since this was not clearly documented, some clienets didn't correctly did that. In particular, some clients assumed that it's safe to destroy FT_Face and then hb_face_t. This, indeed, used to work, until 45fd9424c723f115ca98995b8f8a25185a6fc71d, which make face destroy access font tables. Now, I fixed that issue in 395b35903e052aecc97d0807e4f813c64c0d2b0b since the access was not needed, but the problem remains that not all clients handle this correctly. See: https://bugs.freedesktop.org/show_bug.cgi?id=86300 Fortunately, FT_Reference_Face() was added to FreeType in 2010, and so we can use it now. Originally I wanted to change hb_ft_face_create() and hb_ft_font_create() to reference the face if destroy==NULL was passed in. That would improve pretty much all clients, with little undesired effects. Except that FreeType itself, when compiled with HarfBuzz support, calls hb_ft_font_create() with destroy==NULL and saves the resulting hb-font on the ft-face (why does it not free it immediately?). Making hb-face reference ft-face causes a cycling reference there. At least, that's my current understanding. At any rate, a cleaner approach, even if it means all clients will need a change, is to introduce brand new API. Which this commit does. Some comments added to hb-ft.h, hoping to make future clients make better choices. Fixes https://bugs.freedesktop.org/show_bug.cgi?id=75299
2014-12-29 02:44:26 +01:00
/**
* hb_ft_font_create_referenced:
* @ft_face:
*
*
*
* Return value: (transfer full):
* Since: 0.9.38
[ft] Add hb_ft_face_create_referenced() and hb_ft_font_create_referenced() When I originally wrote hb-ft, FreeType objects did not support reference counting. As such, hb_ft_face_create() and hb_ft_font_create() had a "destroy" callback and client was responsible for making sure FT_Face is kept around as long as the hb-font/face are alive. However, since this was not clearly documented, some clienets didn't correctly did that. In particular, some clients assumed that it's safe to destroy FT_Face and then hb_face_t. This, indeed, used to work, until 45fd9424c723f115ca98995b8f8a25185a6fc71d, which make face destroy access font tables. Now, I fixed that issue in 395b35903e052aecc97d0807e4f813c64c0d2b0b since the access was not needed, but the problem remains that not all clients handle this correctly. See: https://bugs.freedesktop.org/show_bug.cgi?id=86300 Fortunately, FT_Reference_Face() was added to FreeType in 2010, and so we can use it now. Originally I wanted to change hb_ft_face_create() and hb_ft_font_create() to reference the face if destroy==NULL was passed in. That would improve pretty much all clients, with little undesired effects. Except that FreeType itself, when compiled with HarfBuzz support, calls hb_ft_font_create() with destroy==NULL and saves the resulting hb-font on the ft-face (why does it not free it immediately?). Making hb-face reference ft-face causes a cycling reference there. At least, that's my current understanding. At any rate, a cleaner approach, even if it means all clients will need a change, is to introduce brand new API. Which this commit does. Some comments added to hb-ft.h, hoping to make future clients make better choices. Fixes https://bugs.freedesktop.org/show_bug.cgi?id=75299
2014-12-29 02:44:26 +01:00
**/
hb_font_t *
hb_ft_font_create_referenced (FT_Face ft_face)
{
FT_Reference_Face (ft_face);
return hb_ft_font_create (ft_face, (hb_destroy_func_t) FT_Done_Face);
}
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/* Thread-safe, lock-free, FT_Library */
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static FT_Library ft_library;
#ifdef HB_USE_ATEXIT
static
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void free_ft_library (void)
{
FT_Done_FreeType (ft_library);
}
#endif
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static FT_Library
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get_ft_library (void)
{
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retry:
FT_Library library = (FT_Library) hb_atomic_ptr_get (&ft_library);
if (unlikely (!library))
{
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/* 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 HB_USE_ATEXIT
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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;
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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);
FT_Set_Char_Size (ft_face,
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abs (font->x_scale), abs (font->y_scale),
0, 0);
#if 0
font->x_ppem * 72 * 64 / font->x_scale,
font->y_ppem * 72 * 64 / font->y_scale);
#endif
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if (font->x_scale < 0 || font->y_scale < 0)
{
FT_Matrix matrix = { font->x_scale < 0 ? -1 : +1, 0,
0, font->y_scale < 0 ? -1 : +1};
FT_Set_Transform (ft_face, &matrix, NULL);
}
ft_face->generic.data = blob;
ft_face->generic.finalizer = (FT_Generic_Finalizer) _release_blob;
_hb_ft_font_set_funcs (font, ft_face, true);
hb_ft_font_set_load_flags (font, FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING);
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}