[dwrite] hb_directwrite_face_create, a new API

It makes a hb_face_t from IDWriteFontFace, useful when using
DirectWrite facilities for font selection, loading and rendering
but using harfbuzz for shaping.
This commit is contained in:
Ebrahim Byagowi 2019-02-22 13:13:42 +03:30 committed by Behdad Esfahbod
parent 45adc18526
commit 45149eb34f
2 changed files with 69 additions and 6 deletions

View File

@ -1,5 +1,5 @@
/*
* Copyright © 2015-2018 Ebrahim Byagowi
* Copyright © 2015-2019 Ebrahim Byagowi
*
* This is part of HarfBuzz, a text shaping library.
*
@ -658,10 +658,10 @@ retry_getglyphs:
* alignment needed after the WORD array. sizeof (WORD) == 2. */
unsigned int glyphs_size = (scratch_size * sizeof (int) - 2)
/ (sizeof (WORD) +
sizeof (DWRITE_SHAPING_GLYPH_PROPERTIES) +
sizeof (int) +
sizeof (DWRITE_GLYPH_OFFSET) +
sizeof (uint32_t));
sizeof (DWRITE_SHAPING_GLYPH_PROPERTIES) +
sizeof (int) +
sizeof (DWRITE_GLYPH_OFFSET) +
sizeof (uint32_t));
ALLOCATE_ARRAY (uint32_t, vis_clusters, glyphs_size);
#undef ALLOCATE_ARRAY
@ -868,3 +868,63 @@ hb_directwrite_shape_experimental_width (hb_font_t *font,
return res;
}
struct _hb_directwrite_font_table_context {
IDWriteFontFace *face;
void *table_context;
};
static void
_hb_directwrite_table_data_release (void *data)
{
_hb_directwrite_font_table_context *context = (_hb_directwrite_font_table_context *) data;
context->face->ReleaseFontTable (context->table_context);
delete context;
}
static hb_blob_t *
reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
{
IDWriteFontFace *dw_face = ((IDWriteFontFace *) user_data);
const void *data;
uint32_t length;
void *table_context;
BOOL exists;
if (!dw_face || FAILED (dw_face->TryGetFontTable (hb_uint32_swap (tag), &data,
&length, &table_context, &exists)))
return nullptr;
if (!data || !exists || !length)
{
dw_face->ReleaseFontTable (table_context);
return nullptr;
}
_hb_directwrite_font_table_context *context = new _hb_directwrite_font_table_context;
context->face = dw_face;
context->table_context = table_context;
return hb_blob_create ((const char *) data, length, HB_MEMORY_MODE_READONLY,
context, _hb_directwrite_table_data_release);
}
static void
_hb_directwrite_font_release (void *data)
{
if (data)
((IDWriteFontFace *) data)->Release ();
}
/**
* hb_directwrite_face_create:
* @font_face:
* Since: REPLACEME
**/
hb_face_t *
hb_directwrite_face_create (IDWriteFontFace *font_face)
{
if (font_face)
font_face->AddRef ();
return hb_face_create_for_tables (reference_table, font_face,
_hb_directwrite_font_release);
}

View File

@ -1,5 +1,5 @@
/*
* Copyright © 2015 Ebrahim Byagowi
* Copyright © 2015-2019 Ebrahim Byagowi
*
* This is part of HarfBuzz, a text shaping library.
*
@ -34,6 +34,9 @@ hb_directwrite_shape_experimental_width (hb_font_t *font, hb_buffer_t *buffer,
const hb_feature_t *features,
unsigned int num_features, float width);
HB_EXTERN hb_face_t *
hb_directwrite_face_create (IDWriteFontFace *font_face);
HB_END_DECLS
#endif /* HB_DIRECTWRITE_H */