tor-browser

hb-draw.cc (14346B)

---

/*
* Copyright © 2019-2020  Ebrahim Byagowi
*
*  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.
*/

#include "hb.hh"

#ifndef HB_NO_DRAW

#include "hb-draw.hh"

#include "hb-geometry.hh"

#include "hb-machinery.hh"


/**
* SECTION:hb-draw
* @title: hb-draw
* @short_description: Glyph drawing
* @include: hb.h
*
* Functions for drawing (extracting) glyph shapes.
*
* The #hb_draw_funcs_t struct can be used with hb_font_draw_glyph().
**/

static void
hb_draw_move_to_nil (hb_draw_funcs_t *dfuncs HB_UNUSED, void *draw_data HB_UNUSED,
	     hb_draw_state_t *st HB_UNUSED,
	     float to_x HB_UNUSED, float to_y HB_UNUSED,
	     void *user_data HB_UNUSED) {}

static void
hb_draw_line_to_nil (hb_draw_funcs_t *dfuncs HB_UNUSED, void *draw_data HB_UNUSED,
	     hb_draw_state_t *st HB_UNUSED,
	     float to_x HB_UNUSED, float to_y HB_UNUSED,
	     void *user_data HB_UNUSED) {}

static void
hb_draw_quadratic_to_nil (hb_draw_funcs_t *dfuncs, void *draw_data,
		  hb_draw_state_t *st,
		  float control_x, float control_y,
		  float to_x, float to_y,
		  void *user_data HB_UNUSED)
{
#define HB_TWO_THIRD 0.66666666666666666666666667f
 dfuncs->emit_cubic_to (draw_data, *st,
		 st->current_x + (control_x - st->current_x) * HB_TWO_THIRD,
		 st->current_y + (control_y - st->current_y) * HB_TWO_THIRD,
		 to_x + (control_x - to_x) * HB_TWO_THIRD,
		 to_y + (control_y - to_y) * HB_TWO_THIRD,
		 to_x, to_y);
#undef HB_TWO_THIRD
}

static void
hb_draw_cubic_to_nil (hb_draw_funcs_t *dfuncs HB_UNUSED, void *draw_data HB_UNUSED,
	      hb_draw_state_t *st HB_UNUSED,
	      float control1_x HB_UNUSED, float control1_y HB_UNUSED,
	      float control2_x HB_UNUSED, float control2_y HB_UNUSED,
	      float to_x HB_UNUSED, float to_y HB_UNUSED,
	      void *user_data HB_UNUSED) {}

static void
hb_draw_close_path_nil (hb_draw_funcs_t *dfuncs HB_UNUSED, void *draw_data HB_UNUSED,
		hb_draw_state_t *st HB_UNUSED,
		void *user_data HB_UNUSED) {}


static bool
_hb_draw_funcs_set_preamble (hb_draw_funcs_t    *dfuncs,
		     bool                func_is_null,
		     void              **user_data,
		     hb_destroy_func_t  *destroy)
{
 if (hb_object_is_immutable (dfuncs))
 {
   if (*destroy)
     (*destroy) (*user_data);
   return false;
 }

 if (func_is_null)
 {
   if (*destroy)
     (*destroy) (*user_data);
   *destroy = nullptr;
   *user_data = nullptr;
 }

 return true;
}

static bool
_hb_draw_funcs_set_middle (hb_draw_funcs_t   *dfuncs,
		   void              *user_data,
		   hb_destroy_func_t  destroy)
{
 if (user_data && !dfuncs->user_data)
 {
   dfuncs->user_data = (decltype (dfuncs->user_data)) hb_calloc (1, sizeof (*dfuncs->user_data));
   if (unlikely (!dfuncs->user_data))
     goto fail;
 }
 if (destroy && !dfuncs->destroy)
 {
   dfuncs->destroy = (decltype (dfuncs->destroy)) hb_calloc (1, sizeof (*dfuncs->destroy));
   if (unlikely (!dfuncs->destroy))
     goto fail;
 }

 return true;

fail:
 if (destroy)
   (destroy) (user_data);
 return false;
}

#define HB_DRAW_FUNC_IMPLEMENT(name)						\
									\
void										\
hb_draw_funcs_set_##name##_func (hb_draw_funcs_t	 *dfuncs,		\
			 hb_draw_##name##_func_t  func,			\
			 void			 *user_data,		\
			 hb_destroy_func_t	  destroy)		\
{										\
 if (!_hb_draw_funcs_set_preamble (dfuncs, !func, &user_data, &destroy))\
     return;                                                            \
									\
 if (dfuncs->destroy && dfuncs->destroy->name)					\
   dfuncs->destroy->name (!dfuncs->user_data ? nullptr : dfuncs->user_data->name); \
								 \
 if (!_hb_draw_funcs_set_middle (dfuncs, user_data, destroy))           \
     return;                                                            \
								\
 if (func)								\
   dfuncs->func.name = func;						\
 else									\
   dfuncs->func.name = hb_draw_##name##_nil;				\
								\
 if (dfuncs->user_data)						\
   dfuncs->user_data->name = user_data;				\
 if (dfuncs->destroy)							\
   dfuncs->destroy->name = destroy;					\
}

HB_DRAW_FUNCS_IMPLEMENT_CALLBACKS
#undef HB_DRAW_FUNC_IMPLEMENT

/**
* hb_draw_funcs_create:
*
* Creates a new draw callbacks object.
*
* Return value: (transfer full):
* A newly allocated #hb_draw_funcs_t with a reference count of 1. The initial
* reference count should be released with hb_draw_funcs_destroy when you are
* done using the #hb_draw_funcs_t. This function never returns `NULL`. If
* memory cannot be allocated, a special singleton #hb_draw_funcs_t object will
* be returned.
*
* Since: 4.0.0
**/
hb_draw_funcs_t *
hb_draw_funcs_create ()
{
 hb_draw_funcs_t *dfuncs;
 if (unlikely (!(dfuncs = hb_object_create<hb_draw_funcs_t> ())))
   return const_cast<hb_draw_funcs_t *> (&Null (hb_draw_funcs_t));

 dfuncs->func =  Null (hb_draw_funcs_t).func;

 return dfuncs;
}

DEFINE_NULL_INSTANCE (hb_draw_funcs_t) =
{
 HB_OBJECT_HEADER_STATIC,

 {
#define HB_DRAW_FUNC_IMPLEMENT(name) hb_draw_##name##_nil,
   HB_DRAW_FUNCS_IMPLEMENT_CALLBACKS
#undef HB_DRAW_FUNC_IMPLEMENT
 }
};

/**
* hb_draw_funcs_get_empty:
*
* Fetches the singleton empty draw-functions structure.
*
* Return value: (transfer full): The empty draw-functions structure
*
* Since: 7.0.0
**/
hb_draw_funcs_t *
hb_draw_funcs_get_empty ()
{
 return const_cast<hb_draw_funcs_t *> (&Null (hb_draw_funcs_t));
}

/**
* hb_draw_funcs_reference: (skip)
* @dfuncs: draw functions
*
* Increases the reference count on @dfuncs by one.
*
* This prevents @dfuncs from being destroyed until a matching
* call to hb_draw_funcs_destroy() is made.
*
* Return value: (transfer full):
* The referenced #hb_draw_funcs_t.
*
* Since: 4.0.0
**/
hb_draw_funcs_t *
hb_draw_funcs_reference (hb_draw_funcs_t *dfuncs)
{
 return hb_object_reference (dfuncs);
}

/**
* hb_draw_funcs_destroy: (skip)
* @dfuncs: draw functions
*
* Deallocate the @dfuncs.
* Decreases the reference count on @dfuncs by one. If the result is zero, then
* @dfuncs and all associated resources are freed. See hb_draw_funcs_reference().
*
* Since: 4.0.0
**/
void
hb_draw_funcs_destroy (hb_draw_funcs_t *dfuncs)
{
 if (!hb_object_destroy (dfuncs)) return;

 if (dfuncs->destroy)
 {
#define HB_DRAW_FUNC_IMPLEMENT(name) \
   if (dfuncs->destroy->name) dfuncs->destroy->name (!dfuncs->user_data ? nullptr : dfuncs->user_data->name);
     HB_DRAW_FUNCS_IMPLEMENT_CALLBACKS
#undef HB_DRAW_FUNC_IMPLEMENT
 }

 hb_free (dfuncs->destroy);
 hb_free (dfuncs->user_data);

 hb_free (dfuncs);
}

/**
* hb_draw_funcs_set_user_data: (skip)
* @dfuncs: The draw-functions structure
* @key: The user-data key
* @data: A pointer to the user data
* @destroy: (nullable): A callback to call when @data is not needed anymore
* @replace: Whether to replace an existing data with the same key
*
* Attaches a user-data key/data pair to the specified draw-functions structure.
*
* Return value: `true` if success, `false` otherwise
*
* Since: 7.0.0
**/
hb_bool_t
hb_draw_funcs_set_user_data (hb_draw_funcs_t *dfuncs,
		     hb_user_data_key_t *key,
		     void *              data,
		     hb_destroy_func_t   destroy,
		     hb_bool_t           replace)
{
 return hb_object_set_user_data (dfuncs, key, data, destroy, replace);
}

/**
* hb_draw_funcs_get_user_data: (skip)
* @dfuncs: The draw-functions structure
* @key: The user-data key to query
*
* Fetches the user-data associated with the specified key,
* attached to the specified draw-functions structure.
*
* Return value: (transfer none): A pointer to the user data
*
* Since: 7.0.0
**/
void *
hb_draw_funcs_get_user_data (const hb_draw_funcs_t *dfuncs,
		     hb_user_data_key_t       *key)
{
 return hb_object_get_user_data (dfuncs, key);
}

/**
* hb_draw_funcs_make_immutable:
* @dfuncs: draw functions
*
* Makes @dfuncs object immutable.
*
* Since: 4.0.0
**/
void
hb_draw_funcs_make_immutable (hb_draw_funcs_t *dfuncs)
{
 if (hb_object_is_immutable (dfuncs))
   return;

 hb_object_make_immutable (dfuncs);
}

/**
* hb_draw_funcs_is_immutable:
* @dfuncs: draw functions
*
* Checks whether @dfuncs is immutable.
*
* Return value: `true` if @dfuncs is immutable, `false` otherwise
*
* Since: 4.0.0
**/
hb_bool_t
hb_draw_funcs_is_immutable (hb_draw_funcs_t *dfuncs)
{
 return hb_object_is_immutable (dfuncs);
}


/**
* hb_draw_move_to:
* @dfuncs: draw functions
* @draw_data: associated draw data passed by the caller
* @st: current draw state
* @to_x: X component of target point
* @to_y: Y component of target point
*
* Perform a "move-to" draw operation.
*
* Since: 4.0.0
**/
void
hb_draw_move_to (hb_draw_funcs_t *dfuncs, void *draw_data,
	 hb_draw_state_t *st,
	 float to_x, float to_y)
{
 dfuncs->move_to (draw_data, *st,
	   to_x, to_y);
}

/**
* hb_draw_line_to:
* @dfuncs: draw functions
* @draw_data: associated draw data passed by the caller
* @st: current draw state
* @to_x: X component of target point
* @to_y: Y component of target point
*
* Perform a "line-to" draw operation.
*
* Since: 4.0.0
**/
void
hb_draw_line_to (hb_draw_funcs_t *dfuncs, void *draw_data,
	 hb_draw_state_t *st,
	 float to_x, float to_y)
{
 dfuncs->line_to (draw_data, *st,
	   to_x, to_y);
}

/**
* hb_draw_quadratic_to:
* @dfuncs: draw functions
* @draw_data: associated draw data passed by the caller
* @st: current draw state
* @control_x: X component of control point
* @control_y: Y component of control point
* @to_x: X component of target point
* @to_y: Y component of target point
*
* Perform a "quadratic-to" draw operation.
*
* Since: 4.0.0
**/
void
hb_draw_quadratic_to (hb_draw_funcs_t *dfuncs, void *draw_data,
	      hb_draw_state_t *st,
	      float control_x, float control_y,
	      float to_x, float to_y)
{
 dfuncs->quadratic_to (draw_data, *st,
		control_x, control_y,
		to_x, to_y);
}

/**
* hb_draw_cubic_to:
* @dfuncs: draw functions
* @draw_data: associated draw data passed by the caller
* @st: current draw state
* @control1_x: X component of first control point
* @control1_y: Y component of first control point
* @control2_x: X component of second control point
* @control2_y: Y component of second control point
* @to_x: X component of target point
* @to_y: Y component of target point
*
* Perform a "cubic-to" draw operation.
*
* Since: 4.0.0
**/
void
hb_draw_cubic_to (hb_draw_funcs_t *dfuncs, void *draw_data,
	  hb_draw_state_t *st,
	  float control1_x, float control1_y,
	  float control2_x, float control2_y,
	  float to_x, float to_y)
{
 dfuncs->cubic_to (draw_data, *st,
	    control1_x, control1_y,
	    control2_x, control2_y,
	    to_x, to_y);
}

/**
* hb_draw_close_path:
* @dfuncs: draw functions
* @draw_data: associated draw data passed by the caller
* @st: current draw state
*
* Perform a "close-path" draw operation.
*
* Since: 4.0.0
**/
void
hb_draw_close_path (hb_draw_funcs_t *dfuncs, void *draw_data,
	    hb_draw_state_t *st)
{
 dfuncs->close_path (draw_data, *st);
}


static void
hb_draw_extents_move_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
		 void *data,
		 hb_draw_state_t *st,
		 float to_x, float to_y,
		 void *user_data HB_UNUSED)
{
 hb_extents_t<> *extents = (hb_extents_t<> *) data;

 extents->add_point (to_x, to_y);
}

static void
hb_draw_extents_line_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
		 void *data,
		 hb_draw_state_t *st,
		 float to_x, float to_y,
		 void *user_data HB_UNUSED)
{
 hb_extents_t<> *extents = (hb_extents_t<> *) data;

 extents->add_point (to_x, to_y);
}

static void
hb_draw_extents_quadratic_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
		      void *data,
		      hb_draw_state_t *st,
		      float control_x, float control_y,
		      float to_x, float to_y,
		      void *user_data HB_UNUSED)
{
 hb_extents_t<> *extents = (hb_extents_t<> *) data;

 extents->add_point (control_x, control_y);
 extents->add_point (to_x, to_y);
}

static void
hb_draw_extents_cubic_to (hb_draw_funcs_t *dfuncs HB_UNUSED,
		  void *data,
		  hb_draw_state_t *st,
		  float control1_x, float control1_y,
		  float control2_x, float control2_y,
		  float to_x, float to_y,
		  void *user_data HB_UNUSED)
{
 hb_extents_t<> *extents = (hb_extents_t<> *) data;

 extents->add_point (control1_x, control1_y);
 extents->add_point (control2_x, control2_y);
 extents->add_point (to_x, to_y);
}

static inline void free_static_draw_extents_funcs ();

static struct hb_draw_extents_funcs_lazy_loader_t : hb_draw_funcs_lazy_loader_t<hb_draw_extents_funcs_lazy_loader_t>
{
 static hb_draw_funcs_t *create ()
 {
   hb_draw_funcs_t *funcs = hb_draw_funcs_create ();

   hb_draw_funcs_set_move_to_func (funcs, hb_draw_extents_move_to, nullptr, nullptr);
   hb_draw_funcs_set_line_to_func (funcs, hb_draw_extents_line_to, nullptr, nullptr);
   hb_draw_funcs_set_quadratic_to_func (funcs, hb_draw_extents_quadratic_to, nullptr, nullptr);
   hb_draw_funcs_set_cubic_to_func (funcs, hb_draw_extents_cubic_to, nullptr, nullptr);

   hb_draw_funcs_make_immutable (funcs);

   hb_atexit (free_static_draw_extents_funcs);

   return funcs;
 }
} static_draw_extents_funcs;

static inline
void free_static_draw_extents_funcs ()
{
 static_draw_extents_funcs.free_instance ();
}

hb_draw_funcs_t *
hb_draw_extents_get_funcs ()
{
 return static_draw_extents_funcs.get_unconst ();
}


#endif