Edit
kc3-lang/harfbuzz/src/hb-outline.cc
Jason Simmons
- src/hb-outline.cc
-
/* * 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