initial commit, 4.5 stable

thirdparty/harfbuzz/src/hb-outline.cc

@@ -0,0 +1,327 @@
+/*
+ * 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;
+  }
+}
+
+void hb_outline_t::slant (float slant_xy)
+{
+  for (auto &p : points)
+    p.x += slant_xy * p.y;
+}
+
+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