/*
* Copyright © 2023 Behdad Esfahbod
* Copyright © 1999 David Turner
* Copyright © 2005 Werner Lemberg
* Copyright © 2013-2015 Alexei Podtelezhnikov
*
* 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_OUTLINE
#include "hb-outline.hh"
#include "hb-machinery.hh"
void hb_outline_t::replay (hb_draw_funcs_t *pen, void *pen_data) const
{
hb_draw_state_t st = HB_DRAW_STATE_DEFAULT;
unsigned first = 0;
for (unsigned contour : contours)
{
auto it = points.as_array ().sub_array (first, contour - first);
while (it)
{
hb_outline_point_t p1 = *it++;
switch (p1.type)
{
case hb_outline_point_t::type_t::MOVE_TO:
{
pen->move_to (pen_data, st,
p1.x, p1.y);
}
break;
case hb_outline_point_t::type_t::LINE_TO:
{
pen->line_to (pen_data, st,
p1.x, p1.y);
}
break;
case hb_outline_point_t::type_t::QUADRATIC_TO:
{
hb_outline_point_t p2 = *it++;
pen->quadratic_to (pen_data, st,
p1.x, p1.y,
p2.x, p2.y);
}
break;
case hb_outline_point_t::type_t::CUBIC_TO:
{
hb_outline_point_t p2 = *it++;
hb_outline_point_t p3 = *it++;
pen->cubic_to (pen_data, st,
p1.x, p1.y,
p2.x, p2.y,
p3.x, p3.y);
}
break;
}
}
pen->close_path (pen_data, st);
first = contour;
}
}
float hb_outline_t::control_area () const
{
float a = 0;
unsigned first = 0;
for (unsigned contour : contours)
{
for (unsigned i = first; i < contour; i++)
{
unsigned j = i + 1 < contour ? i + 1 : first;
auto &pi = points[i];
auto &pj = points[j];
a += pi.x * pj.y - pi.y * pj.x;
}
first = contour;
}
return a * .5f;
}
void hb_outline_t::embolden (float x_strength, float y_strength,
float x_shift, float y_shift)
{
/* This function is a straight port of FreeType's FT_Outline_EmboldenXY.
* Permission has been obtained from the FreeType authors of the code
* to relicense it under the HarfBuzz license. */
if (!x_strength && !y_strength) return;
if (!points) return;
x_strength /= 2.f;
y_strength /= 2.f;
bool orientation_negative = control_area () < 0;
signed first = 0;
for (unsigned c = 0; c < contours.length; c++)
{
hb_outline_vector_t in, out, anchor, shift;
float l_in, l_out, l_anchor = 0, l, q, d;
l_in = 0;
signed last = (int) contours[c] - 1;
/* pacify compiler */
in.x = in.y = anchor.x = anchor.y = 0;
/* Counter j cycles though the points; counter i advances only */
/* when points are moved; anchor k marks the first moved point. */
for ( signed i = last, j = first, k = -1;
j != i && i != k;
j = j < last ? j + 1 : first )
{
if ( j != k )
{
out.x = points[j].x - points[i].x;
out.y = points[j].y - points[i].y;
l_out = out.normalize_len ();
if ( l_out == 0 )
continue;
}
else
{
out = anchor;
l_out = l_anchor;
}
if ( l_in != 0 )
{
if ( k < 0 )
{
k = i;
anchor = in;
l_anchor = l_in;
}
d = in.x * out.x + in.y * out.y;
/* shift only if turn is less than ~160 degrees */
if ( d > -15.f/16.f )
{
d = d + 1.f;
/* shift components along lateral bisector in proper orientation */
shift.x = in.y + out.y;
shift.y = in.x + out.x;
if ( orientation_negative )
shift.x = -shift.x;
else
shift.y = -shift.y;
/* restrict shift magnitude to better handle collapsing segments */
q = out.x * in.y - out.y * in.x;
if ( orientation_negative )
q = -q;
l = hb_min (l_in, l_out);
/* non-strict inequalities avoid divide-by-zero when q == l == 0 */
if (x_strength * q <= l * d)
shift.x = shift.x * x_strength / d;
else
shift.x = shift.x * l / q;
if (y_strength * q <= l * d)
shift.y = shift.y * y_strength / d;
else
shift.y = shift.y * l / q;
}
else
shift.x = shift.y = 0;
for ( ;
i != j;
i = i < last ? i + 1 : first )
{
points[i].x += x_shift + shift.x;
points[i].y += y_shift + shift.y;
}
}
else
i = j;
in = out;
l_in = l_out;
}
first = last + 1;
}
}
static void
hb_outline_recording_pen_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_outline_t *c = (hb_outline_t *) data;
c->points.push (hb_outline_point_t {to_x, to_y, hb_outline_point_t::type_t::MOVE_TO});
}
static void
hb_outline_recording_pen_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_outline_t *c = (hb_outline_t *) data;
c->points.push (hb_outline_point_t {to_x, to_y, hb_outline_point_t::type_t::LINE_TO});
}
static void
hb_outline_recording_pen_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_outline_t *c = (hb_outline_t *) data;
c->points.push (hb_outline_point_t {control_x, control_y, hb_outline_point_t::type_t::QUADRATIC_TO});
c->points.push (hb_outline_point_t {to_x, to_y, hb_outline_point_t::type_t::QUADRATIC_TO});
}
static void
hb_outline_recording_pen_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_outline_t *c = (hb_outline_t *) data;
c->points.push (hb_outline_point_t {control1_x, control1_y, hb_outline_point_t::type_t::CUBIC_TO});
c->points.push (hb_outline_point_t {control2_x, control2_y, hb_outline_point_t::type_t::CUBIC_TO});
c->points.push (hb_outline_point_t {to_x, to_y, hb_outline_point_t::type_t::CUBIC_TO});
}
static void
hb_outline_recording_pen_close_path (hb_draw_funcs_t *dfuncs HB_UNUSED,
void *data,
hb_draw_state_t *st,
void *user_data HB_UNUSED)
{
hb_outline_t *c = (hb_outline_t *) data;
c->contours.push (c->points.length);
}
static inline void free_static_outline_recording_pen_funcs ();
static struct hb_outline_recording_pen_funcs_lazy_loader_t : hb_draw_funcs_lazy_loader_t<hb_outline_recording_pen_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_outline_recording_pen_move_to, nullptr, nullptr);
hb_draw_funcs_set_line_to_func (funcs, hb_outline_recording_pen_line_to, nullptr, nullptr);
hb_draw_funcs_set_quadratic_to_func (funcs, hb_outline_recording_pen_quadratic_to, nullptr, nullptr);
hb_draw_funcs_set_cubic_to_func (funcs, hb_outline_recording_pen_cubic_to, nullptr, nullptr);
hb_draw_funcs_set_close_path_func (funcs, hb_outline_recording_pen_close_path, nullptr, nullptr);
hb_draw_funcs_make_immutable (funcs);
hb_atexit (free_static_outline_recording_pen_funcs);
return funcs;
}
} static_outline_recording_pen_funcs;
static inline
void free_static_outline_recording_pen_funcs ()
{
static_outline_recording_pen_funcs.free_instance ();
}
hb_draw_funcs_t *
hb_outline_recording_pen_get_funcs ()
{
return static_outline_recording_pen_funcs.get_unconst ();
}
#endif