include/harfbuzz/hb-draw.h

0001 /*
0002  * Copyright © 2019-2020  Ebrahim Byagowi
0003  *
0004  *  This is part of HarfBuzz, a text shaping library.
0005  *
0006  * Permission is hereby granted, without written agreement and without
0007  * license or royalty fees, to use, copy, modify, and distribute this
0008  * software and its documentation for any purpose, provided that the
0009  * above copyright notice and the following two paragraphs appear in
0010  * all copies of this software.
0011  *
0012  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
0013  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
0014  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
0015  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
0016  * DAMAGE.
0017  *
0018  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
0019  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
0020  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
0021  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
0022  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
0023  */
0024
0025 #if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
0026 #error "Include <hb.h> instead."
0027 #endif
0028
0029 #ifndef HB_DRAW_H
0030 #define HB_DRAW_H
0031
0032 #include "hb.h"
0033
0034 HB_BEGIN_DECLS
0035
0036
0037 /**
0038  * hb_draw_state_t
0039  * @path_open: Whether there is an open path
0040  * @path_start_x: X component of the start of current path
0041  * @path_start_y: Y component of the start of current path
0042  * @current_x: X component of current point
0043  * @current_y: Y component of current point
0044  *
0045  * Current drawing state.
0046  *
0047  * Since: 4.0.0
0048  **/
0049 typedef struct hb_draw_state_t {
0050   hb_bool_t path_open;
0051
0052   float path_start_x;
0053   float path_start_y;
0054
0055   float current_x;
0056   float current_y;
0057
0058   /*< private >*/
0059   hb_var_num_t   reserved1;
0060   hb_var_num_t   reserved2;
0061   hb_var_num_t   reserved3;
0062   hb_var_num_t   reserved4;
0063   hb_var_num_t   reserved5;
0064   hb_var_num_t   reserved6;
0065   hb_var_num_t   reserved7;
0066 } hb_draw_state_t;
0067
0068 /**
0069  * HB_DRAW_STATE_DEFAULT:
0070  *
0071  * The default #hb_draw_state_t at the start of glyph drawing.
0072  */
0073 #define HB_DRAW_STATE_DEFAULT {0, 0.f, 0.f, 0.f, 0.f, {0.}, {0.}, {0.}}
0074
0075
0076 /**
0077  * hb_draw_funcs_t:
0078  *
0079  * Glyph draw callbacks.
0080  *
0081  * #hb_draw_move_to_func_t, #hb_draw_line_to_func_t and
0082  * #hb_draw_cubic_to_func_t calls are necessary to be defined but we translate
0083  * #hb_draw_quadratic_to_func_t calls to #hb_draw_cubic_to_func_t if the
0084  * callback isn't defined.
0085  *
0086  * Since: 4.0.0
0087  **/
0088
0089 typedef struct hb_draw_funcs_t hb_draw_funcs_t;
0090
0091
0092 /**
0093  * hb_draw_move_to_func_t:
0094  * @dfuncs: draw functions object
0095  * @draw_data: The data accompanying the draw functions in hb_font_draw_glyph()
0096  * @st: current draw state
0097  * @to_x: X component of target point
0098  * @to_y: Y component of target point
0099  * @user_data: User data pointer passed to hb_draw_funcs_set_move_to_func()
0100  *
0101  * A virtual method for the #hb_draw_funcs_t to perform a "move-to" draw
0102  * operation.
0103  *
0104  * Since: 4.0.0
0105  *
0106  **/
0107 typedef void (*hb_draw_move_to_func_t) (hb_draw_funcs_t *dfuncs, void *draw_data,
0108                     hb_draw_state_t *st,
0109                     float to_x, float to_y,
0110                     void *user_data);
0111
0112 /**
0113  * hb_draw_line_to_func_t:
0114  * @dfuncs: draw functions object
0115  * @draw_data: The data accompanying the draw functions in hb_font_draw_glyph()
0116  * @st: current draw state
0117  * @to_x: X component of target point
0118  * @to_y: Y component of target point
0119  * @user_data: User data pointer passed to hb_draw_funcs_set_line_to_func()
0120  *
0121  * A virtual method for the #hb_draw_funcs_t to perform a "line-to" draw
0122  * operation.
0123  *
0124  * Since: 4.0.0
0125  *
0126  **/
0127 typedef void (*hb_draw_line_to_func_t) (hb_draw_funcs_t *dfuncs, void *draw_data,
0128                     hb_draw_state_t *st,
0129                     float to_x, float to_y,
0130                     void *user_data);
0131
0132 /**
0133  * hb_draw_quadratic_to_func_t:
0134  * @dfuncs: draw functions object
0135  * @draw_data: The data accompanying the draw functions in hb_font_draw_glyph()
0136  * @st: current draw state
0137  * @control_x: X component of control point
0138  * @control_y: Y component of control point
0139  * @to_x: X component of target point
0140  * @to_y: Y component of target point
0141  * @user_data: User data pointer passed to hb_draw_funcs_set_quadratic_to_func()
0142  *
0143  * A virtual method for the #hb_draw_funcs_t to perform a "quadratic-to" draw
0144  * operation.
0145  *
0146  * Since: 4.0.0
0147  *
0148  **/
0149 typedef void (*hb_draw_quadratic_to_func_t) (hb_draw_funcs_t *dfuncs, void *draw_data,
0150                          hb_draw_state_t *st,
0151                          float control_x, float control_y,
0152                          float to_x, float to_y,
0153                          void *user_data);
0154
0155 /**
0156  * hb_draw_cubic_to_func_t:
0157  * @dfuncs: draw functions object
0158  * @draw_data: The data accompanying the draw functions in hb_font_draw_glyph()
0159  * @st: current draw state
0160  * @control1_x: X component of first control point
0161  * @control1_y: Y component of first control point
0162  * @control2_x: X component of second control point
0163  * @control2_y: Y component of second control point
0164  * @to_x: X component of target point
0165  * @to_y: Y component of target point
0166  * @user_data: User data pointer passed to hb_draw_funcs_set_cubic_to_func()
0167  *
0168  * A virtual method for the #hb_draw_funcs_t to perform a "cubic-to" draw
0169  * operation.
0170  *
0171  * Since: 4.0.0
0172  *
0173  **/
0174 typedef void (*hb_draw_cubic_to_func_t) (hb_draw_funcs_t *dfuncs, void *draw_data,
0175                      hb_draw_state_t *st,
0176                      float control1_x, float control1_y,
0177                      float control2_x, float control2_y,
0178                      float to_x, float to_y,
0179                      void *user_data);
0180
0181 /**
0182  * hb_draw_close_path_func_t:
0183  * @dfuncs: draw functions object
0184  * @draw_data: The data accompanying the draw functions in hb_font_draw_glyph()
0185  * @st: current draw state
0186  * @user_data: User data pointer passed to hb_draw_funcs_set_close_path_func()
0187  *
0188  * A virtual method for the #hb_draw_funcs_t to perform a "close-path" draw
0189  * operation.
0190  *
0191  * Since: 4.0.0
0192  *
0193  **/
0194 typedef void (*hb_draw_close_path_func_t) (hb_draw_funcs_t *dfuncs, void *draw_data,
0195                        hb_draw_state_t *st,
0196                        void *user_data);
0197
0198 /**
0199  * hb_draw_funcs_set_move_to_func:
0200  * @dfuncs: draw functions object
0201  * @func: (closure user_data) (destroy destroy) (scope notified): move-to callback
0202  * @user_data: Data to pass to @func
0203  * @destroy: (nullable): The function to call when @user_data is not needed anymore
0204  *
0205  * Sets move-to callback to the draw functions object.
0206  *
0207  * Since: 4.0.0
0208  **/
0209 HB_EXTERN void
0210 hb_draw_funcs_set_move_to_func (hb_draw_funcs_t        *dfuncs,
0211                 hb_draw_move_to_func_t  func,
0212                 void *user_data, hb_destroy_func_t destroy);
0213
0214 /**
0215  * hb_draw_funcs_set_line_to_func:
0216  * @dfuncs: draw functions object
0217  * @func: (closure user_data) (destroy destroy) (scope notified): line-to callback
0218  * @user_data: Data to pass to @func
0219  * @destroy: (nullable): The function to call when @user_data is not needed anymore
0220  *
0221  * Sets line-to callback to the draw functions object.
0222  *
0223  * Since: 4.0.0
0224  **/
0225 HB_EXTERN void
0226 hb_draw_funcs_set_line_to_func (hb_draw_funcs_t        *dfuncs,
0227                 hb_draw_line_to_func_t  func,
0228                 void *user_data, hb_destroy_func_t destroy);
0229
0230 /**
0231  * hb_draw_funcs_set_quadratic_to_func:
0232  * @dfuncs: draw functions object
0233  * @func: (closure user_data) (destroy destroy) (scope notified): quadratic-to callback
0234  * @user_data: Data to pass to @func
0235  * @destroy: (nullable): The function to call when @user_data is not needed anymore
0236  *
0237  * Sets quadratic-to callback to the draw functions object.
0238  *
0239  * Since: 4.0.0
0240  **/
0241 HB_EXTERN void
0242 hb_draw_funcs_set_quadratic_to_func (hb_draw_funcs_t             *dfuncs,
0243                      hb_draw_quadratic_to_func_t  func,
0244                      void *user_data, hb_destroy_func_t destroy);
0245
0246 /**
0247  * hb_draw_funcs_set_cubic_to_func:
0248  * @dfuncs: draw functions
0249  * @func: (closure user_data) (destroy destroy) (scope notified): cubic-to callback
0250  * @user_data: Data to pass to @func
0251  * @destroy: (nullable): The function to call when @user_data is not needed anymore
0252  *
0253  * Sets cubic-to callback to the draw functions object.
0254  *
0255  * Since: 4.0.0
0256  **/
0257 HB_EXTERN void
0258 hb_draw_funcs_set_cubic_to_func (hb_draw_funcs_t         *dfuncs,
0259                  hb_draw_cubic_to_func_t  func,
0260                  void *user_data, hb_destroy_func_t destroy);
0261
0262 /**
0263  * hb_draw_funcs_set_close_path_func:
0264  * @dfuncs: draw functions object
0265  * @func: (closure user_data) (destroy destroy) (scope notified): close-path callback
0266  * @user_data: Data to pass to @func
0267  * @destroy: (nullable): The function to call when @user_data is not needed anymore
0268  *
0269  * Sets close-path callback to the draw functions object.
0270  *
0271  * Since: 4.0.0
0272  **/
0273 HB_EXTERN void
0274 hb_draw_funcs_set_close_path_func (hb_draw_funcs_t           *dfuncs,
0275                    hb_draw_close_path_func_t  func,
0276                    void *user_data, hb_destroy_func_t destroy);
0277
0278
0279 HB_EXTERN hb_draw_funcs_t *
0280 hb_draw_funcs_create (void);
0281
0282 HB_EXTERN hb_draw_funcs_t *
0283 hb_draw_funcs_get_empty (void);
0284
0285 HB_EXTERN hb_draw_funcs_t *
0286 hb_draw_funcs_reference (hb_draw_funcs_t *dfuncs);
0287
0288 HB_EXTERN void
0289 hb_draw_funcs_destroy (hb_draw_funcs_t *dfuncs);
0290
0291 HB_EXTERN hb_bool_t
0292 hb_draw_funcs_set_user_data (hb_draw_funcs_t *dfuncs,
0293                  hb_user_data_key_t *key,
0294                  void *              data,
0295                  hb_destroy_func_t   destroy,
0296                  hb_bool_t           replace);
0297
0298
0299 HB_EXTERN void *
0300 hb_draw_funcs_get_user_data (const hb_draw_funcs_t *dfuncs,
0301                  hb_user_data_key_t       *key);
0302
0303 HB_EXTERN void
0304 hb_draw_funcs_make_immutable (hb_draw_funcs_t *dfuncs);
0305
0306 HB_EXTERN hb_bool_t
0307 hb_draw_funcs_is_immutable (hb_draw_funcs_t *dfuncs);
0308
0309
0310 HB_EXTERN void
0311 hb_draw_move_to (hb_draw_funcs_t *dfuncs, void *draw_data,
0312          hb_draw_state_t *st,
0313          float to_x, float to_y);
0314
0315 HB_EXTERN void
0316 hb_draw_line_to (hb_draw_funcs_t *dfuncs, void *draw_data,
0317          hb_draw_state_t *st,
0318          float to_x, float to_y);
0319
0320 HB_EXTERN void
0321 hb_draw_quadratic_to (hb_draw_funcs_t *dfuncs, void *draw_data,
0322               hb_draw_state_t *st,
0323               float control_x, float control_y,
0324               float to_x, float to_y);
0325
0326 HB_EXTERN void
0327 hb_draw_cubic_to (hb_draw_funcs_t *dfuncs, void *draw_data,
0328           hb_draw_state_t *st,
0329           float control1_x, float control1_y,
0330           float control2_x, float control2_y,
0331           float to_x, float to_y);
0332
0333 HB_EXTERN void
0334 hb_draw_close_path (hb_draw_funcs_t *dfuncs, void *draw_data,
0335             hb_draw_state_t *st);
0336
0337
0338 HB_END_DECLS
0339
0340 #endif /* HB_DRAW_H */