[ft] API: Add hb_font_[sg]et_load_flags() API

This changes the default load_flags of fonts created using
hb_ft_font_create() from NO_HINTING to DEFAULT.  Hope that doesn't
break too much client code.

Code calling hb_ft_font_set_funcs() is unaffected.
This commit is contained in:
Behdad Esfahbod 2015-10-07 17:33:20 -04:00
parent 3224a594dc
commit 2a9627c564
2 changed files with 118 additions and 58 deletions

View File

@ -1,6 +1,7 @@
/*
* Copyright © 2009 Red Hat, Inc.
* Copyright © 2009 Keith Stribley
* Copyright © 2015 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
@ -23,6 +24,7 @@
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#include "hb-private.hh"
@ -46,17 +48,15 @@
* 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.
* - 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
* - 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 around. This seems to work best, until we go ahead and add a full
* load_flags API.
* 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.
*
@ -66,6 +66,76 @@
*/
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;
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);
}
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;
}
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,
@ -75,13 +145,13 @@ hb_ft_get_glyph (hb_font_t *font HB_UNUSED,
void *user_data HB_UNUSED)
{
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
unsigned int g;
FT_Face ft_face = (FT_Face) font_data;
if (likely (!variation_selector))
g = FT_Get_Char_Index (ft_face, unicode);
g = FT_Get_Char_Index (ft_font->ft_face, unicode);
else
g = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector);
g = FT_Face_GetCharVariantIndex (ft_font->ft_face, unicode, variation_selector);
if (unlikely (!g))
return false;
@ -96,11 +166,10 @@ hb_ft_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
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;
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Fixed v;
if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &v)))
if (unlikely (FT_Get_Advance (ft_font->ft_face, glyph, ft_font->load_flags, &v)))
return 0;
if (font->x_scale < 0)
@ -115,11 +184,10 @@ hb_ft_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
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;
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
FT_Fixed v;
if (unlikely (FT_Get_Advance (ft_face, glyph, load_flags, &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)
@ -150,10 +218,10 @@ hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
hb_position_t *y,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
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, load_flags)))
if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
return false;
/* Note: FreeType's vertical metrics grows downward while other FreeType coordinates
@ -176,11 +244,11 @@ hb_ft_get_glyph_h_kerning (hb_font_t *font,
hb_codepoint_t right_glyph,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
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_face, left_glyph, right_glyph, mode, &kerningv))
if (FT_Get_Kerning (ft_font->ft_face, left_glyph, right_glyph, mode, &kerningv))
return 0;
return kerningv.x;
@ -204,10 +272,10 @@ hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,
hb_glyph_extents_t *extents,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
int load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
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, load_flags)))
if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
return false;
extents->x_bearing = ft_face->glyph->metrics.horiBearingX;
@ -226,10 +294,10 @@ hb_ft_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
hb_position_t *y,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
int load_flags = FT_LOAD_DEFAULT;
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, load_flags)))
if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))
return false;
if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
@ -251,9 +319,9 @@ hb_ft_get_glyph_name (hb_font_t *font HB_UNUSED,
char *name, unsigned int size,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;
hb_bool_t ret = !FT_Get_Glyph_Name (ft_face, glyph, name, size);
hb_bool_t ret = !FT_Get_Glyph_Name (ft_font->ft_face, glyph, name, size);
if (ret && (size && !*name))
ret = false;
@ -267,7 +335,8 @@ hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED,
hb_codepoint_t *glyph,
void *user_data HB_UNUSED)
{
FT_Face ft_face = (FT_Face) font_data;
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);
@ -293,8 +362,8 @@ hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED,
}
static hb_font_funcs_t *
_hb_ft_get_font_funcs (void)
static void
_hb_ft_font_set_funcs (hb_font_t *font, FT_Face ft_face, bool unref)
{
static const hb_font_funcs_t ft_ffuncs = {
HB_OBJECT_HEADER_STATIC,
@ -308,7 +377,10 @@ _hb_ft_get_font_funcs (void)
}
};
return const_cast<hb_font_funcs_t *> (&ft_ffuncs);
hb_font_set_funcs (font,
const_cast<hb_font_funcs_t *> (&ft_ffuncs),
_hb_ft_font_create (ft_face, unref),
(hb_destroy_func_t) _hb_ft_font_destroy);
}
@ -420,11 +492,6 @@ hb_ft_face_create_cached (FT_Face ft_face)
return hb_face_reference ((hb_face_t *) ft_face->generic.data);
}
static void
_do_nothing (void)
{
}
/**
* hb_ft_font_create:
@ -446,9 +513,7 @@ hb_ft_font_create (FT_Face ft_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_ft_font_set_funcs (font, ft_face, false);
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));
@ -562,18 +627,6 @@ hb_ft_font_set_funcs (hb_font_t *font)
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;
_hb_ft_font_set_funcs (font, ft_face, true);
hb_ft_font_set_load_flags (font, FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING);
}

View File

@ -1,5 +1,6 @@
/*
* Copyright © 2009 Red Hat, Inc.
* Copyright © 2015 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
@ -22,6 +23,7 @@
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_FT_H
@ -105,14 +107,19 @@ hb_ft_font_create (FT_Face ft_face,
hb_font_t *
hb_ft_font_create_referenced (FT_Face ft_face);
FT_Face
hb_ft_font_get_face (hb_font_t *font);
void
hb_ft_font_set_load_flags (hb_font_t *font, int load_flags);
int
hb_ft_font_get_load_flags (hb_font_t *font);
/* Makes an hb_font_t use FreeType internally to implement font functions. */
void
hb_ft_font_set_funcs (hb_font_t *font);
FT_Face
hb_ft_font_get_face (hb_font_t *font);
HB_END_DECLS