Start fleshing out builtin font functions
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc new file mode 100644 index 0000000..1a35057 --- /dev/null +++ b/src/hb-ot-font.cc
@@ -0,0 +1,260 @@ +/* + * Copyright © 2011,2014 Google, Inc. + * + * 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. + * + * Google Author(s): Behdad Esfahbod, Roozbeh Pournader + */ + +#include "hb-private.hh" + +#include "hb-ot.h" + +#include "hb-font-private.hh" + +#include "hb-ot-hhea-table.hh" +#include "hb-ot-hmtx-table.hh" + + + +struct hb_ot_font_t +{ + unsigned int num_glyphs; + unsigned int num_hmetrics; + const OT::hmtx *hmtx; + hb_blob_t *hmtx_blob; +}; + + +static hb_ot_font_t * +_hb_ot_font_create (hb_font_t *font) +{ + hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t)); + + if (unlikely (!ot_font)) + return NULL; + + ot_font->num_glyphs = font->face->get_num_glyphs (); + + { + hb_blob_t *hhea_blob = OT::Sanitizer<OT::hhea>::sanitize (font->face->reference_table (HB_OT_TAG_hhea)); + const OT::hhea *hhea = OT::Sanitizer<OT::hhea>::lock_instance (hhea_blob); + ot_font->num_hmetrics = hhea->numberOfHMetrics; + hb_blob_destroy (hhea_blob); + } + ot_font->hmtx_blob = OT::Sanitizer<OT::hmtx>::sanitize (font->face->reference_table (HB_OT_TAG_hmtx)); + if (unlikely (!ot_font->num_hmetrics || + 2 * (ot_font->num_hmetrics + ot_font->num_glyphs) < hb_blob_get_length (ot_font->hmtx_blob))) + { + hb_blob_destroy (ot_font->hmtx_blob); + free (ot_font); + return NULL; + } + + ot_font->hmtx = OT::Sanitizer<OT::hmtx>::lock_instance (ot_font->hmtx_blob); + + return ot_font; +} + +static void +_hb_ot_font_destroy (hb_ot_font_t *ot_font) +{ + hb_blob_destroy (ot_font->hmtx_blob); + + free (ot_font); +} + + +static hb_bool_t +hb_ot_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) + +{ +#if 0 + 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); + return *glyph != 0; + } +#endif + + *glyph = FT_Get_Char_Index (ft_face, unicode); + return *glyph != 0; +#endif + return true; +} + +static hb_position_t +hb_ot_get_glyph_h_advance (hb_font_t *font, + void *font_data, + hb_codepoint_t glyph, + void *user_data HB_UNUSED) +{ + const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data; + + if (unlikely (glyph >= ot_font->num_glyphs)) + return 0; /* Maybe better to return notdef's advance instead? */ + + if (glyph >= ot_font->num_hmetrics) + glyph = ot_font->num_hmetrics - 1; + + return font->em_scale_x (ot_font->hmtx->longHorMetric[glyph].advanceWidth); +} + +static hb_position_t +hb_ot_get_glyph_v_advance (hb_font_t *font HB_UNUSED, + void *font_data, + hb_codepoint_t glyph, + void *user_data HB_UNUSED) +{ + /* TODO */ + return 0; +} + +static hb_bool_t +hb_ot_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_ot_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) +{ + /* TODO */ + return false; +} + +static hb_position_t +hb_ot_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) +{ + /* TODO */ + return 0; +} + +static hb_position_t +hb_ot_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) +{ + return 0; +} + +static hb_bool_t +hb_ot_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) +{ + /* TODO */ + return false; +} + +static hb_bool_t +hb_ot_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) +{ + /* TODO */ + return false; +} + +static hb_bool_t +hb_ot_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) +{ + /* TODO */ + return false; +} + +static hb_bool_t +hb_ot_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) +{ + /* TODO */ + return false; +} + + +static hb_font_funcs_t * +_hb_ot_get_font_funcs (void) +{ + static const hb_font_funcs_t ot_ffuncs = { + HB_OBJECT_HEADER_STATIC, + + true, /* immutable */ + + { +#define HB_FONT_FUNC_IMPLEMENT(name) hb_ot_get_##name, + HB_FONT_FUNCS_IMPLEMENT_CALLBACKS +#undef HB_FONT_FUNC_IMPLEMENT + } + }; + + return const_cast<hb_font_funcs_t *> (&ot_ffuncs); +} + + +void +hb_ot_font_set_funcs (hb_font_t *font) +{ + hb_ot_font_t *ot_font = _hb_ot_font_create (font); + if (unlikely (!ot_font)) + return; + + hb_font_set_funcs (font, + _hb_ot_get_font_funcs (), + ot_font, + (hb_destroy_func_t) _hb_ot_font_destroy); +}