shape.cc - mozsearch

Enable keyboard shortcuts

#define HB_WASM_INTERFACE(ret_t, name) __attribute__((export_name(#name))) ret_t name

#include <hb-wasm-api.h>

#include <graphite2/Segment.h>

#include <stdlib.h>

#include <string.h>

void debugprint1 (char *s, int32_t);

void debugprint2 (char *s, int32_t, int32_t);

static const void *copy_table (const void *data, unsigned int tag, size_t *len)

  face_t *face = (face_t *) data;

  blob_t blob = BLOB_INIT;

  if (!face_copy_table (face, tag, &blob))

    abort ();

  *len = blob.length;

  return blob.data;

static void free_table (const void *data, const void *table_data)

  blob_t blob;

  blob.length = 0; // Doesn't matter

  blob.data = (char *) table_data;

  blob_free (&blob);

void *

shape_plan_create (face_t *face)

  const gr_face_ops ops = {sizeof (gr_face_ops), &copy_table, &free_table};

  gr_face *grface = gr_make_face_with_ops (face, &ops, gr_face_preloadAll);

  return grface;

void

shape_plan_destroy (void *data)

  gr_face_destroy ((gr_face *) data);

bool_t

shape (void *shape_plan,

       font_t *font,

       buffer_t *buffer,

       const feature_t *features,

       uint32_t num_features)

  face_t *face = font_get_face (font);

  gr_face *grface = (gr_face *) shape_plan;

  direction_t direction = buffer_get_direction (buffer);

  direction_t horiz_dir = script_get_horizontal_direction (buffer_get_script (buffer));

  /* TODO vertical:

   * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType

   * Ogham fonts are supposed to be implemented BTT or not.  Need to research that

   * first. */

  if ((DIRECTION_IS_HORIZONTAL (direction) &&

       direction != horiz_dir && horiz_dir != DIRECTION_INVALID) ||

      (DIRECTION_IS_VERTICAL   (direction) &&

       direction != DIRECTION_TTB))

    buffer_reverse_clusters (buffer);

    direction = DIRECTION_REVERSE (direction);

  buffer_contents_t contents = BUFFER_CONTENTS_INIT;

  if (!buffer_copy_contents (buffer, &contents))

    return false;

  gr_segment *seg = nullptr;

  const gr_slot *is;

  unsigned int ci = 0, ic = 0;

  unsigned int curradvx = 0, curradvy = 0;

  unsigned length = contents.length;

  uint32_t *chars = (uint32_t *) malloc (length * sizeof (uint32_t));

  if (!chars)

    return false;

  for (unsigned int i = 0; i < contents.length; ++i)

    chars[i] = contents.info[i].codepoint;

  seg = gr_make_seg (nullptr, grface,

		     0, // https://github.com/harfbuzz/harfbuzz/issues/3439#issuecomment-1442650148

		     nullptr,

		     gr_utf32, chars, contents.length,

		     2 | (direction == DIRECTION_RTL ? 1 : 0));

  free (chars);

  if (!seg)

    return false;

  unsigned int glyph_count = gr_seg_n_slots (seg);

  struct cluster_t {

    unsigned int base_char;

    unsigned int num_chars;

    unsigned int base_glyph;

    unsigned int num_glyphs;

    unsigned int cluster;

    int advance;

};

  length = glyph_count;

  if (!buffer_contents_realloc (&contents, length))

    return false;

  cluster_t *clusters = (cluster_t *) malloc (length * sizeof (cluster_t));

  uint32_t *gids = (uint32_t *) malloc (length * sizeof (uint32_t));

  if (!clusters || !gids)

    free (clusters);

    free (gids);

    return false;

  memset (clusters, 0, sizeof (clusters[0]) * length);

  codepoint_t *pg = gids;

  clusters[0].cluster = contents.info[0].cluster;

  unsigned int upem = face_get_upem (face);

  int32_t font_x_scale, font_y_scale;

  font_get_scale (font, &font_x_scale, &font_y_scale);

  float xscale = (float) font_x_scale / upem;

  float yscale = (float) font_y_scale / upem;

  yscale *= yscale / xscale;

  unsigned int curradv = 0;

  if (DIRECTION_IS_BACKWARD (direction))

    curradv = gr_slot_origin_X(gr_seg_first_slot(seg)) * xscale;

    clusters[0].advance = gr_seg_advance_X(seg) * xscale - curradv;

  else

    clusters[0].advance = 0;

  for (is = gr_seg_first_slot (seg), ic = 0; is; is = gr_slot_next_in_segment (is), ic++)

    unsigned int before = gr_slot_before (is);

    unsigned int after = gr_slot_after (is);

    *pg = gr_slot_gid (is);

    pg++;

    while (clusters[ci].base_char > before && ci)

      clusters[ci-1].num_chars += clusters[ci].num_chars;

      clusters[ci-1].num_glyphs += clusters[ci].num_glyphs;

      clusters[ci-1].advance += clusters[ci].advance;

      ci--;

    if (gr_slot_can_insert_before (is) && clusters[ci].num_chars && before >= clusters[ci].base_char + clusters[ci].num_chars)

      cluster_t *c = clusters + ci + 1;

      c->base_char = clusters[ci].base_char + clusters[ci].num_chars;

      c->cluster = contents.info[c->base_char].cluster;

      c->num_chars = before - c->base_char;

      c->base_glyph = ic;

      c->num_glyphs = 0;

      if (DIRECTION_IS_BACKWARD (direction))

	c->advance = curradv - gr_slot_origin_X(is) * xscale;

	curradv -= c->advance;

      else

	auto origin_X = gr_slot_origin_X (is) * xscale;

	c->advance = 0;

	clusters[ci].advance += origin_X - curradv;

	curradv = origin_X;

      ci++;

    clusters[ci].num_glyphs++;

    if (clusters[ci].base_char + clusters[ci].num_chars < after + 1)

	clusters[ci].num_chars = after + 1 - clusters[ci].base_char;

  if (DIRECTION_IS_BACKWARD (direction))

    clusters[ci].advance += curradv;

  else

    clusters[ci].advance += gr_seg_advance_X(seg) * xscale - curradv;

  ci++;

  for (unsigned int i = 0; i < ci; ++i)

    for (unsigned int j = 0; j < clusters[i].num_glyphs; ++j)

      glyph_info_t *info = &contents.info[clusters[i].base_glyph + j];

      info->codepoint = gids[clusters[i].base_glyph + j];

      info->cluster = clusters[i].cluster;

      info->var1 = (unsigned) clusters[i].advance;     // all glyphs in the cluster get the same advance

  contents.length = glyph_count;

  /* Positioning. */

  unsigned int currclus = 0xFFFFFFFF;

  const glyph_info_t *info = contents.info;

  glyph_position_t *pPos = contents.pos;

  if (!DIRECTION_IS_BACKWARD (direction))

    curradvx = 0;

    for (is = gr_seg_first_slot (seg); is; pPos++, ++info, is = gr_slot_next_in_segment (is))

      pPos->x_offset = gr_slot_origin_X (is) * xscale - curradvx;

      pPos->y_offset = gr_slot_origin_Y (is) * yscale - curradvy;

      if (info->cluster != currclus) {

	pPos->x_advance = (int) info->var1;

	curradvx += pPos->x_advance;

	currclus = info->cluster;

      } else

	pPos->x_advance = 0.;

      pPos->y_advance = gr_slot_advance_Y (is, grface, nullptr) * yscale;

      curradvy += pPos->y_advance;

    buffer_set_contents (buffer, &contents);

  else

    curradvx = gr_seg_advance_X(seg) * xscale;

    for (is = gr_seg_first_slot (seg); is; pPos++, info++, is = gr_slot_next_in_segment (is))

      if (info->cluster != currclus)

	pPos->x_advance = (int) info->var1;

	curradvx -= pPos->x_advance;

	currclus = info->cluster;

      } else

	pPos->x_advance = 0.;

      pPos->y_advance = gr_slot_advance_Y (is, grface, nullptr) * yscale;

      curradvy -= pPos->y_advance;

      pPos->x_offset = gr_slot_origin_X (is) * xscale - (int) info->var1 - curradvx + pPos->x_advance;

      pPos->y_offset = gr_slot_origin_Y (is) * yscale - curradvy;

    buffer_set_contents (buffer, &contents);

    buffer_reverse_clusters (buffer);

  gr_seg_destroy (seg);

  free (clusters);

  free (gids);

  bool ret = glyph_count;

  return ret;