Add Harfbuzz dependency

modules/juce_graphics/fonts/harfbuzz/hb-shape.cc

@@ -0,0 +1,445 @@
+/*
+ * Copyright © 2009  Red Hat, Inc.
+ * Copyright © 2012  Google, Inc.
+ *
+ *  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.
+ *
+ * Red Hat Author(s): Behdad Esfahbod
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#include "hb.hh"
+
+#include "hb-shaper.hh"
+#include "hb-shape-plan.hh"
+#include "hb-buffer.hh"
+#include "hb-font.hh"
+#include "hb-machinery.hh"
+
+
+#ifndef HB_NO_SHAPER
+
+/**
+ * SECTION:hb-shape
+ * @title: hb-shape
+ * @short_description: Conversion of text strings into positioned glyphs
+ * @include: hb.h
+ *
+ * Shaping is the central operation of HarfBuzz. Shaping operates on buffers,
+ * which are sequences of Unicode characters that use the same font and have
+ * the same text direction, script, and language. After shaping the buffer
+ * contains the output glyphs and their positions.
+ **/
+
+
+static inline void free_static_shaper_list ();
+
+static const char * const nil_shaper_list[] = {nullptr};
+
+static struct hb_shaper_list_lazy_loader_t : hb_lazy_loader_t<const char *,
+							      hb_shaper_list_lazy_loader_t>
+{
+  static const char ** create ()
+  {
+    const char **shaper_list = (const char **) hb_calloc (1 + HB_SHAPERS_COUNT, sizeof (const char *));
+    if (unlikely (!shaper_list))
+      return nullptr;
+
+    const hb_shaper_entry_t *shapers = _hb_shapers_get ();
+    unsigned int i;
+    for (i = 0; i < HB_SHAPERS_COUNT; i++)
+      shaper_list[i] = shapers[i].name;
+    shaper_list[i] = nullptr;
+
+    hb_atexit (free_static_shaper_list);
+
+    return shaper_list;
+  }
+  static void destroy (const char **l)
+  { hb_free (l); }
+  static const char * const * get_null ()
+  { return nil_shaper_list; }
+} static_shaper_list;
+
+static inline
+void free_static_shaper_list ()
+{
+  static_shaper_list.free_instance ();
+}
+
+
+/**
+ * hb_shape_list_shapers:
+ *
+ * Retrieves the list of shapers supported by HarfBuzz.
+ *
+ * Return value: (transfer none) (array zero-terminated=1): an array of
+ *    constant strings
+ *
+ * Since: 0.9.2
+ **/
+const char **
+hb_shape_list_shapers ()
+{
+  return static_shaper_list.get_unconst ();
+}
+
+
+/**
+ * hb_shape_full:
+ * @font: an #hb_font_t to use for shaping
+ * @buffer: an #hb_buffer_t to shape
+ * @features: (array length=num_features) (nullable): an array of user
+ *    specified #hb_feature_t or `NULL`
+ * @num_features: the length of @features array
+ * @shaper_list: (array zero-terminated=1) (nullable): a `NULL`-terminated
+ *    array of shapers to use or `NULL`
+ *
+ * See hb_shape() for details. If @shaper_list is not `NULL`, the specified
+ * shapers will be used in the given order, otherwise the default shapers list
+ * will be used.
+ *
+ * Return value: false if all shapers failed, true otherwise
+ *
+ * Since: 0.9.2
+ **/
+hb_bool_t
+hb_shape_full (hb_font_t          *font,
+	       hb_buffer_t        *buffer,
+	       const hb_feature_t *features,
+	       unsigned int        num_features,
+	       const char * const *shaper_list)
+{
+  if (unlikely (!buffer->len))
+    return true;
+
+  buffer->enter ();
+
+  hb_buffer_t *text_buffer = nullptr;
+  if (buffer->flags & HB_BUFFER_FLAG_VERIFY)
+  {
+    text_buffer = hb_buffer_create ();
+    hb_buffer_append (text_buffer, buffer, 0, -1);
+  }
+
+  hb_shape_plan_t *shape_plan = hb_shape_plan_create_cached2 (font->face, &buffer->props,
+							      features, num_features,
+							      font->coords, font->num_coords,
+							      shaper_list);
+
+  hb_bool_t res = hb_shape_plan_execute (shape_plan, font, buffer, features, num_features);
+
+  if (buffer->max_ops <= 0)
+    buffer->shaping_failed = true;
+
+  hb_shape_plan_destroy (shape_plan);
+
+  if (text_buffer)
+  {
+    if (res && buffer->successful && !buffer->shaping_failed
+	    && text_buffer->successful
+	    && !buffer->verify (text_buffer,
+				font,
+				features,
+				num_features,
+				shaper_list))
+      res = false;
+    hb_buffer_destroy (text_buffer);
+  }
+
+  buffer->leave ();
+
+  return res;
+}
+
+/**
+ * hb_shape:
+ * @font: an #hb_font_t to use for shaping
+ * @buffer: an #hb_buffer_t to shape
+ * @features: (array length=num_features) (nullable): an array of user
+ *    specified #hb_feature_t or `NULL`
+ * @num_features: the length of @features array
+ *
+ * Shapes @buffer using @font turning its Unicode characters content to
+ * positioned glyphs. If @features is not `NULL`, it will be used to control the
+ * features applied during shaping. If two @features have the same tag but
+ * overlapping ranges the value of the feature with the higher index takes
+ * precedence.
+ *
+ * Since: 0.9.2
+ **/
+void
+hb_shape (hb_font_t           *font,
+	  hb_buffer_t         *buffer,
+	  const hb_feature_t  *features,
+	  unsigned int         num_features)
+{
+  hb_shape_full (font, buffer, features, num_features, nullptr);
+}
+
+
+#ifdef HB_EXPERIMENTAL_API
+
+static float
+buffer_advance (hb_buffer_t *buffer)
+{
+  float a = 0;
+  auto *pos = buffer->pos;
+  unsigned count = buffer->len;
+  if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction))
+    for (unsigned i = 0; i < count; i++)
+      a += pos[i].x_advance;
+  else
+    for (unsigned i = 0; i < count; i++)
+      a += pos[i].y_advance;
+  return a;
+}
+
+static void
+reset_buffer (hb_buffer_t *buffer,
+	      hb_array_t<const hb_glyph_info_t> text)
+{
+  assert (buffer->ensure (text.length));
+  buffer->have_positions = false;
+  buffer->len = text.length;
+  hb_memcpy (buffer->info, text.arrayZ, text.length * sizeof (buffer->info[0]));
+  hb_buffer_set_content_type (buffer, HB_BUFFER_CONTENT_TYPE_UNICODE);
+}
+
+/**
+ * hb_shape_justify:
+ * @font: a mutable #hb_font_t to use for shaping
+ * @buffer: an #hb_buffer_t to shape
+ * @features: (array length=num_features) (nullable): an array of user
+ *    specified #hb_feature_t or `NULL`
+ * @num_features: the length of @features array
+ * @shaper_list: (array zero-terminated=1) (nullable): a `NULL`-terminated
+ *    array of shapers to use or `NULL`
+ * @min_target_advance: Minimum advance width/height to aim for.
+ * @max_target_advance: Maximum advance width/height to aim for.
+ * @advance: (inout): Input/output advance width/height of the buffer.
+ * @var_tag: (out): Variation-axis tag used for justification.
+ * @var_value: (out): Variation-axis value used to reach target justification.
+ *
+ * See hb_shape_full() for basic details. If @shaper_list is not `NULL`, the specified
+ * shapers will be used in the given order, otherwise the default shapers list
+ * will be used.
+ *
+ * In addition, justify the shaping results such that the shaping results reach
+ * the target advance width/height, depending on the buffer direction.
+ *
+ * If the advance of the buffer shaped with hb_shape_full() is already known,
+ * put that in *advance. Otherwise set *advance to zero.
+ *
+ * This API is currently experimental and will probably change in the future.
+ *
+ * Return value: false if all shapers failed, true otherwise
+ *
+ * XSince: EXPERIMENTAL
+ **/
+hb_bool_t
+hb_shape_justify (hb_font_t          *font,
+		  hb_buffer_t        *buffer,
+		  const hb_feature_t *features,
+		  unsigned int        num_features,
+		  const char * const *shaper_list,
+		  float               min_target_advance,
+		  float               max_target_advance,
+		  float              *advance, /* IN/OUT */
+		  hb_tag_t           *var_tag, /* OUT */
+		  float              *var_value /* OUT */)
+{
+  // TODO Negative font scales?
+
+  /* If default advance already matches target, nothing to do. Shape and return. */
+  if (min_target_advance <= *advance && *advance <= max_target_advance)
+  {
+    *var_tag = HB_TAG_NONE;
+    *var_value = 0.0f;
+    return hb_shape_full (font, buffer,
+			  features, num_features,
+			  shaper_list);
+  }
+
+  hb_face_t *face = font->face;
+
+  /* Choose variation tag to use for justification. */
+
+  hb_tag_t tag = HB_TAG_NONE;
+  hb_ot_var_axis_info_t axis_info;
+
+  hb_tag_t tags[] =
+  {
+    HB_TAG ('j','s','t','f'),
+    HB_TAG ('w','d','t','h'),
+  };
+  for (unsigned i = 0; i < ARRAY_LENGTH (tags); i++)
+    if (hb_ot_var_find_axis_info (face, tags[i], &axis_info))
+    {
+      tag = *var_tag = tags[i];
+      break;
+    }
+
+  /* If no suitable variation axis found, can't justify.  Just shape and return. */
+  if (!tag)
+  {
+    *var_tag = HB_TAG_NONE;
+    *var_value = 0.0f;
+    if (hb_shape_full (font, buffer,
+		       features, num_features,
+		       shaper_list))
+    {
+      *advance = buffer_advance (buffer);
+      return true;
+    }
+    else
+      return false;
+  }
+
+  /* Copy buffer text as we need it so we can shape multiple times. */
+  unsigned text_len = buffer->len;
+  auto *text_info = (hb_glyph_info_t *) hb_malloc (text_len * sizeof (buffer->info[0]));
+  if (unlikely (text_len && !text_info))
+    return false;
+  hb_memcpy (text_info, buffer->info, text_len * sizeof (buffer->info[0]));
+  auto text = hb_array<const hb_glyph_info_t> (text_info, text_len);
+
+  /* If default advance was not provided to us, calculate it. */
+  if (!*advance)
+  {
+    hb_font_set_variation (font, tag, axis_info.default_value);
+    if (!hb_shape_full (font, buffer,
+			features, num_features,
+			shaper_list))
+      return false;
+    *advance = buffer_advance (buffer);
+  }
+
+  /* If default advance already matches target, nothing to do. Shape and return.
+   * Do this again, in case advance was just calculated.
+   */
+  if (min_target_advance <= *advance && *advance <= max_target_advance)
+  {
+    *var_tag = HB_TAG_NONE;
+    *var_value = 0.0f;
+    return true;
+  }
+
+  /* Prepare for running the solver. */
+  double a, b, ya, yb;
+  if (*advance < min_target_advance)
+  {
+    /* Need to expand. */
+    ya = (double) *advance;
+    a = (double) axis_info.default_value;
+    b = (double) axis_info.max_value;
+
+    /* Shape buffer for maximum expansion to use as other
+     * starting point for the solver. */
+    hb_font_set_variation (font, tag, (float) b);
+    reset_buffer (buffer, text);
+    if (!hb_shape_full (font, buffer,
+			features, num_features,
+			shaper_list))
+      return false;
+    yb = (double) buffer_advance (buffer);
+    /* If the maximum expansion is less than max target,
+     * there's nothing to solve for. Just return it. */
+    if (yb <= (double) max_target_advance)
+    {
+      *var_value = (float) b;
+      *advance = (float) yb;
+      return true;
+    }
+  }
+  else
+  {
+    /* Need to shrink. */
+    yb = (double) *advance;
+    a = (double) axis_info.min_value;
+    b = (double) axis_info.default_value;
+
+    /* Shape buffer for maximum shrinkate to use as other
+     * starting point for the solver. */
+    hb_font_set_variation (font, tag, (float) a);
+    reset_buffer (buffer, text);
+    if (!hb_shape_full (font, buffer,
+			features, num_features,
+			shaper_list))
+      return false;
+    ya = (double) buffer_advance (buffer);
+    /* If the maximum shrinkate is more than min target,
+     * there's nothing to solve for. Just return it. */
+    if (ya >= (double) min_target_advance)
+    {
+      *var_value = (float) a;
+      *advance = (float) ya;
+      return true;
+    }
+  }
+
+  /* Run the solver to find a var axis value that hits
+   * the desired width. */
+
+  double epsilon = (b - a) / (1<<14);
+  bool failed = false;
+
+  auto f = [&] (double x)
+  {
+    hb_font_set_variation (font, tag, (float) x);
+    reset_buffer (buffer, text);
+    if (unlikely (!hb_shape_full (font, buffer,
+				  features, num_features,
+				  shaper_list)))
+    {
+      failed = true;
+      return (double) min_target_advance;
+    }
+
+    double w = (double) buffer_advance (buffer);
+    DEBUG_MSG (JUSTIFY, nullptr, "Trying '%c%c%c%c' axis parameter %f. Advance %g. Target: min %g max %g",
+	       HB_UNTAG (tag), x, w,
+	       (double) min_target_advance, (double) max_target_advance);
+    return w;
+  };
+
+  double y = 0;
+  double itp = solve_itp (f,
+			  a, b,
+			  epsilon,
+			  (double) min_target_advance, (double) max_target_advance,
+			  ya, yb, y);
+
+  hb_free (text_info);
+
+  if (failed)
+    return false;
+
+  *var_value = (float) itp;
+  *advance = (float) y;
+
+  return true;
+}
+
+#endif
+
+
+#endif