src/hb-wasm-api.h

   1 /*
   2  * Copyright © 2023  Behdad Esfahbod
   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
  25 #ifndef HB_WASM_API_H
  26 #define HB_WASM_API_H
  27
  28 /*
  29 #include "hb.h"
  30 */
  31
  32 #include <stdint.h>
  33
  34
  35 #ifndef HB_WASM_BEGIN_DECLS
  36 # ifdef __cplusplus
  37 #  define HB_WASM_BEGIN_DECLS   extern "C" {
  38 #  define HB_WASM_END_DECLS     }
  39 # else /* !__cplusplus */
  40 #  define HB_WASM_BEGIN_DECLS
  41 #  define HB_WASM_END_DECLS
  42 # endif /* !__cplusplus */
  43 #endif
  44
  45
  46 HB_WASM_BEGIN_DECLS
  47
  48 #ifndef HB_WASM_API
  49 #define HB_WASM_API(ret_t, name) ret_t name
  50 #endif
  51 #ifndef HB_WASM_API_COMPOUND /* compound return type */
  52 #define HB_WASM_API_COMPOUND(ret_t, name) HB_WASM_API(ret_t, name)
  53 #endif
  54 #ifndef HB_WASM_INTERFACE
  55 #define HB_WASM_INTERFACE(ret_t, name) ret_t name
  56 #endif
  57 #ifndef HB_WASM_EXEC_ENV
  58 #define HB_WASM_EXEC_ENV
  59 #endif
  60 #ifndef HB_WASM_EXEC_ENV_COMPOUND
  61 #define HB_WASM_EXEC_ENV_COMPOUND HB_WASM_EXEC_ENV
  62 #endif
  63
  64
  65 #ifndef bool_t
  66 #define bool_t uint32_t
  67 #endif
  68 #ifndef ptr_t
  69 #define ptr_t(type_t) type_t *
  70 #endif
  71 #ifndef ptr_d
  72 #define ptr_d(type_t, name) type_t *name
  73 #endif
  74
  75 typedef uint32_t codepoint_t;
  76 typedef int32_t position_t;
  77 typedef uint32_t mask_t;
  78 typedef uint32_t tag_t;
  79 #define TAG(c1,c2,c3,c4) ((tag_t)((((uint32_t)(c1)&0xFF)<<24)|(((uint32_t)(c2)&0xFF)<<16)|(((uint32_t)(c3)&0xFF)<<8)|((uint32_t)(c4)&0xFF)))
  80
  81 typedef enum {
  82   DIRECTION_INVALID = 0,
  83   DIRECTION_LTR = 4,
  84   DIRECTION_RTL,
  85   DIRECTION_TTB,
  86   DIRECTION_BTT
  87 } direction_t;
  88 #define DIRECTION_IS_VALID(dir)         ((((unsigned int) (dir)) & ~3U) == 4)
  89 #define DIRECTION_IS_HORIZONTAL(dir)    ((((unsigned int) (dir)) & ~1U) == 4)
  90 #define DIRECTION_IS_VERTICAL(dir)      ((((unsigned int) (dir)) & ~1U) == 6)
  91 #define DIRECTION_IS_FORWARD(dir)       ((((unsigned int) (dir)) & ~2U) == 4)
  92 #define DIRECTION_IS_BACKWARD(dir)      ((((unsigned int) (dir)) & ~2U) == 5)
  93 #define DIRECTION_REVERSE(dir)          ((direction_t) (((unsigned int) (dir)) ^ 1))
  94
  95 typedef tag_t script_t; /* ISO 15924 representation of Unicode scripts. */
  96
  97
  98 /* common */
  99
 100 HB_WASM_API (direction_t, script_get_horizontal_direction) (HB_WASM_EXEC_ENV
 101                                                             script_t script);
 102
 103
 104 /* blob */
 105
 106 typedef struct
 107 {
 108   uint32_t length;
 109   ptr_t(char) data;
 110 } blob_t;
 111 #define BLOB_INIT {0, 0}
 112
 113 HB_WASM_API (void, blob_free) (HB_WASM_EXEC_ENV
 114                                ptr_d(blob_t, blob));
 115
 116 /* buffer */
 117
 118 typedef struct
 119 {
 120   uint32_t codepoint;
 121   uint32_t mask;
 122   uint32_t cluster;
 123   uint32_t var1;
 124   uint32_t var2;
 125 } glyph_info_t;
 126
 127 typedef struct
 128 {
 129   position_t x_advance;
 130   position_t y_advance;
 131   position_t x_offset;
 132   position_t y_offset;
 133   uint32_t var;
 134 } glyph_position_t;
 135
 136 typedef struct
 137 {
 138   uint32_t length;
 139   ptr_t(glyph_info_t) info;
 140   ptr_t(glyph_position_t) pos;
 141 } buffer_contents_t;
 142 #define BUFFER_CONTENTS_INIT {0, 0, 0}
 143
 144 HB_WASM_API (bool_t, buffer_contents_realloc) (HB_WASM_EXEC_ENV
 145                                                ptr_d(buffer_contents_t, contents),
 146                                                uint32_t size);
 147
 148 HB_WASM_API (void, buffer_contents_free) (HB_WASM_EXEC_ENV
 149                                           ptr_d(buffer_contents_t, contents));
 150
 151 typedef struct buffer_t buffer_t;
 152
 153 HB_WASM_API (bool_t, buffer_copy_contents) (HB_WASM_EXEC_ENV
 154                                             ptr_d(buffer_t, buffer),
 155                                             ptr_d(buffer_contents_t, contents));
 156
 157 HB_WASM_API (bool_t, buffer_set_contents) (HB_WASM_EXEC_ENV
 158                                            ptr_d(buffer_t, buffer),
 159                                            ptr_d(const buffer_contents_t, contents));
 160
 161 HB_WASM_API (direction_t, buffer_get_direction) (HB_WASM_EXEC_ENV
 162                                                  ptr_d(buffer_t, buffer));
 163
 164 HB_WASM_API (script_t, buffer_get_script) (HB_WASM_EXEC_ENV
 165                                            ptr_d(buffer_t, buffer));
 166
 167 HB_WASM_API (void, buffer_reverse) (HB_WASM_EXEC_ENV
 168                                     ptr_d(buffer_t, buffer));
 169
 170 HB_WASM_API (void, buffer_reverse_clusters) (HB_WASM_EXEC_ENV
 171                                              ptr_d(buffer_t, buffer));
 172
 173 /* face */
 174
 175 typedef struct face_t face_t;
 176
 177 HB_WASM_API (ptr_t(face_t), face_create) (HB_WASM_EXEC_ENV
 178                                           ptr_d(blob_t, blob),
 179                                           unsigned int);
 180
 181 HB_WASM_API (bool_t, face_copy_table) (HB_WASM_EXEC_ENV
 182                                        ptr_d(face_t, face),
 183                                        tag_t table_tag,
 184                                        ptr_d(blob_t, blob));
 185
 186 HB_WASM_API (unsigned, face_get_upem) (HB_WASM_EXEC_ENV
 187                                        ptr_d(face_t, face));
 188
 189 /* font */
 190
 191 typedef struct font_t font_t;
 192
 193 HB_WASM_API (ptr_t(font_t), font_create) (HB_WASM_EXEC_ENV
 194                                           ptr_d(face_t, face));
 195
 196 HB_WASM_API (ptr_t(face_t), font_get_face) (HB_WASM_EXEC_ENV
 197                                             ptr_d(font_t, font));
 198
 199 HB_WASM_API (void, font_get_scale) (HB_WASM_EXEC_ENV
 200                                     ptr_d(font_t, font),
 201                                     ptr_d(int32_t, x_scale),
 202                                     ptr_d(int32_t, y_scale));
 203
 204 HB_WASM_API (codepoint_t, font_get_glyph) (HB_WASM_EXEC_ENV
 205                                               ptr_d(font_t, font),
 206                                               codepoint_t unicode,
 207                                               codepoint_t variation_selector);
 208
 209 HB_WASM_API (position_t, font_get_glyph_h_advance) (HB_WASM_EXEC_ENV
 210                                                     ptr_d(font_t, font),
 211                                                     codepoint_t glyph);
 212
 213 HB_WASM_API (position_t, font_get_glyph_v_advance) (HB_WASM_EXEC_ENV
 214                                                     ptr_d(font_t, font),
 215                                                     codepoint_t glyph);
 216
 217 typedef struct
 218 {
 219   position_t x_bearing;
 220   position_t y_bearing;
 221   position_t width;
 222   position_t height;
 223 } glyph_extents_t;
 224
 225 HB_WASM_API (bool_t, font_get_glyph_extents) (HB_WASM_EXEC_ENV
 226                                               ptr_d(font_t, font),
 227                                               codepoint_t glyph,
 228                                               ptr_d(glyph_extents_t, extents));
 229
 230 HB_WASM_API (void, font_glyph_to_string) (HB_WASM_EXEC_ENV
 231                                           ptr_d(font_t, font),
 232                                           codepoint_t glyph,
 233                                           char *s, uint32_t size);
 234
 235
 236 typedef struct
 237 {
 238   unsigned int length;
 239   ptr_t(int) coords;
 240 } coords_t;
 241
 242 HB_WASM_API (bool_t, font_copy_coords) (HB_WASM_EXEC_ENV
 243                                           ptr_d(font_t, font),
 244                                           ptr_d(coords_t, coords));
 245
 246 HB_WASM_API (bool_t, font_set_coords) (HB_WASM_EXEC_ENV
 247                                           ptr_d(font_t, font),
 248                                           ptr_d(coords_t, coords));
 249
 250 /* outline */
 251
 252 enum glyph_outline_point_type_t
 253 {
 254   MOVE_TO,
 255   LINE_TO,
 256   QUADRATIC_TO,
 257   CUBIC_TO,
 258 };
 259
 260 typedef struct
 261 {
 262   float x;
 263   float y;
 264   uint32_t type;
 265 } glyph_outline_point_t;
 266
 267 typedef struct
 268 {
 269   uint32_t n_points;
 270   ptr_t(glyph_outline_point_t) points;
 271   uint32_t n_contours;
 272   ptr_t(uint32_t) contours;
 273 } glyph_outline_t;
 274 #define GLYPH_OUTLINE_INIT {0, 0, 0, 0}
 275
 276 HB_WASM_API (void, glyph_outline_free) (HB_WASM_EXEC_ENV
 277                                         ptr_d(glyph_outline_t, outline));
 278
 279 HB_WASM_API (bool_t, font_copy_glyph_outline) (HB_WASM_EXEC_ENV
 280                                                ptr_d(font_t, font),
 281                                                codepoint_t glyph,
 282                                                ptr_d(glyph_outline_t, outline));
 283
 284
 285 /* shape */
 286
 287 typedef struct
 288 {
 289   tag_t    tag;
 290   uint32_t value;
 291   uint32_t start;
 292   uint32_t end;
 293 } feature_t;
 294 #define FEATURE_GLOBAL_START    0
 295 #define FEATURE_GLOBAL_END      ((uint32_t) -1)
 296
 297 HB_WASM_API (bool_t, shape_with) (HB_WASM_EXEC_ENV
 298                                   ptr_d(font_t, font),
 299                                   ptr_d(buffer_t, buffer),
 300                                   ptr_d(const feature_t, features),
 301                                   uint32_t num_features,
 302                                   const char *shaper);
 303
 304 /* Implement these in your shaper. */
 305
 306 HB_WASM_INTERFACE (ptr_t(void), shape_plan_create) (ptr_d(face_t, face));
 307
 308 HB_WASM_INTERFACE (bool_t, shape) (ptr_d(void, shape_plan),
 309                                    ptr_d(font_t, font),
 310                                    ptr_d(buffer_t, buffer),
 311                                    ptr_d(const feature_t, features),
 312                                    uint32_t num_features);
 313
 314 HB_WASM_INTERFACE (void, shape_plan_destroy) (ptr_d(void, shape_plan));
 315
 316
 317 HB_WASM_END_DECLS
 318
 319 #endif /* HB_WASM_API_H */