1 /* 2 * Copyright © 2011 Google, Inc. 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 * 24 * Google Author(s): Behdad Esfahbod 25 */ 26 27 #define HB_SHAPER fallback 28 #include "hb-shaper-impl-private.hh" 29 30 31 /* 32 * shaper face data 33 */ 34 35 struct hb_fallback_shaper_face_data_t {}; 36 37 hb_fallback_shaper_face_data_t * 38 _hb_fallback_shaper_face_data_create (hb_face_t *face HB_UNUSED) 39 { 40 return (hb_fallback_shaper_face_data_t *) HB_SHAPER_DATA_SUCCEEDED; 41 } 42 43 void 44 _hb_fallback_shaper_face_data_destroy (hb_fallback_shaper_face_data_t *data HB_UNUSED) 45 { 46 } 47 48 49 /* 50 * shaper font data 51 */ 52 53 struct hb_fallback_shaper_font_data_t {}; 54 55 hb_fallback_shaper_font_data_t * 56 _hb_fallback_shaper_font_data_create (hb_font_t *font HB_UNUSED) 57 { 58 return (hb_fallback_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED; 59 } 60 61 void 62 _hb_fallback_shaper_font_data_destroy (hb_fallback_shaper_font_data_t *data HB_UNUSED) 63 { 64 } 65 66 67 /* 68 * shaper shape_plan data 69 */ 70 71 struct hb_fallback_shaper_shape_plan_data_t {}; 72 73 hb_fallback_shaper_shape_plan_data_t * 74 _hb_fallback_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan HB_UNUSED, 75 const hb_feature_t *user_features HB_UNUSED, 76 unsigned int num_user_features HB_UNUSED, 77 const int *coords HB_UNUSED, 78 unsigned int num_coords HB_UNUSED) 79 { 80 return (hb_fallback_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED; 81 } 82 83 void 84 _hb_fallback_shaper_shape_plan_data_destroy (hb_fallback_shaper_shape_plan_data_t *data HB_UNUSED) 85 { 86 } 87 88 89 /* 90 * shaper 91 */ 92 93 hb_bool_t 94 _hb_fallback_shape (hb_shape_plan_t *shape_plan HB_UNUSED, 95 hb_font_t *font, 96 hb_buffer_t *buffer, 97 const hb_feature_t *features HB_UNUSED, 98 unsigned int num_features HB_UNUSED) 99 { 100 /* TODO 101 * 102 * - Apply fallback kern. 103 * - Handle Variation Selectors? 104 * - Apply normalization? 105 * 106 * This will make the fallback shaper into a dumb "TrueType" 107 * shaper which many people unfortunately still request. 108 */ 109 110 hb_codepoint_t space; 111 bool has_space = (bool) font->get_nominal_glyph (' ', &space); 112 113 buffer->clear_positions (); 114 115 hb_direction_t direction = buffer->props.direction; 116 hb_unicode_funcs_t *unicode = buffer->unicode; 117 unsigned int count = buffer->len; 118 hb_glyph_info_t *info = buffer->info; 119 hb_glyph_position_t *pos = buffer->pos; 120 for (unsigned int i = 0; i < count; i++) 121 { 122 if (has_space && unicode->is_default_ignorable (info[i].codepoint)) { 123 info[i].codepoint = space; 124 pos[i].x_advance = 0; 125 pos[i].y_advance = 0; 126 continue; 127 } 128 font->get_nominal_glyph (info[i].codepoint, &info[i].codepoint); 129 font->get_glyph_advance_for_direction (info[i].codepoint, 130 direction, 131 &pos[i].x_advance, 132 &pos[i].y_advance); 133 font->subtract_glyph_origin_for_direction (info[i].codepoint, 134 direction, 135 &pos[i].x_offset, 136 &pos[i].y_offset); 137 } 138 139 if (HB_DIRECTION_IS_BACKWARD (direction)) 140 hb_buffer_reverse (buffer); 141 142 return true; 143 }