* Google Author(s): Behdad Esfahbod
*/
-#include "hb-ot-shape-complex-private.hh"
+#include "hb-ot-shape-complex-arabic-private.hh"
#include "hb-ot-shape-private.hh"
+#ifndef HB_DEBUG_ARABIC
+#define HB_DEBUG_ARABIC (HB_DEBUG+0)
+#endif
+
+
/* buffer var allocations */
#define arabic_shaping_action() complex_var_u8_0() /* arabic shaping action */
+#define HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH HB_BUFFER_SCRATCH_FLAG_COMPLEX0
+
+/* See:
+ * https://github.com/behdad/harfbuzz/commit/6e6f82b6f3dde0fc6c3c7d991d9ec6cfff57823d#commitcomment-14248516 */
+#define HB_ARABIC_GENERAL_CATEGORY_IS_WORD(gen_cat) \
+ (FLAG_SAFE (gen_cat) & \
+ (FLAG (HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_PRIVATE_USE) | \
+ /*FLAG (HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER) |*/ \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER) | \
+ /*FLAG (HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER) |*/ \
+ /*FLAG (HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER) |*/ \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_LETTER_NUMBER) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_NUMBER) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_CURRENCY_SYMBOL) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_MATH_SYMBOL) | \
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_OTHER_SYMBOL)))
+
+
+/*
+ * Joining types:
+ */
/*
* Bits used in the joining tables
*/
-enum {
+enum hb_arabic_joining_type_t {
JOINING_TYPE_U = 0,
JOINING_TYPE_L = 1,
JOINING_TYPE_R = 2,
JOINING_TYPE_X = 8 /* means: use general-category to choose between U or T. */
};
-/*
- * Joining types:
- */
-
#include "hb-ot-shape-complex-arabic-table.hh"
static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_category_t gen_cat)
if (likely (j_type != JOINING_TYPE_X))
return j_type;
- return (FLAG(gen_cat) &
+ return (FLAG_SAFE(gen_cat) &
(FLAG(HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) |
FLAG(HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) |
FLAG(HB_UNICODE_GENERAL_CATEGORY_FORMAT))
/* Same order as the feature array */
-enum {
+enum arabic_action_t {
ISOL,
FINA,
FIN2,
NONE,
- ARABIC_NUM_FEATURES = NONE
+ ARABIC_NUM_FEATURES = NONE,
+
+ /* We abuse the same byte for other things... */
+ STCH_FIXED,
+ STCH_REPEATING,
};
static const struct arabic_state_table_entry {
hb_buffer_t *buffer);
static void
+record_stch (const hb_ot_shape_plan_t *plan,
+ hb_font_t *font,
+ hb_buffer_t *buffer);
+
+static void
collect_features_arabic (hb_ot_shape_planner_t *plan)
{
hb_ot_map_builder_t *map = &plan->map;
map->add_gsub_pause (nuke_joiners);
+ map->add_global_bool_feature (HB_TAG('s','t','c','h'));
+ map->add_gsub_pause (record_stch);
+
map->add_global_bool_feature (HB_TAG('c','c','m','p'));
map->add_global_bool_feature (HB_TAG('l','o','c','l'));
map->add_gsub_pause (arabic_fallback_shape);
map->add_global_bool_feature (HB_TAG('c','a','l','t'));
- map->add_gsub_pause (NULL);
/* The spec includes 'cswh'. Earlier versions of Windows
* used to enable this by default, but testing suggests
* Note that IranNastaliq uses this feature extensively
* to fixup broken glyph sequences. Oh well...
* Test case: U+0643,U+0640,U+0631. */
+ //map->add_gsub_pause (NULL);
//map->add_global_bool_feature (HB_TAG('c','s','w','h'));
map->add_global_bool_feature (HB_TAG('m','s','e','t'));
}
* mask_array[NONE] == 0. */
hb_mask_t mask_array[ARABIC_NUM_FEATURES + 1];
- bool do_fallback;
arabic_fallback_plan_t *fallback_plan;
+
+ unsigned int do_fallback : 1;
+ unsigned int has_stch : 1;
};
-static void *
+void *
data_create_arabic (const hb_ot_shape_plan_t *plan)
{
arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) calloc (1, sizeof (arabic_shape_plan_t));
return NULL;
arabic_plan->do_fallback = plan->props.script == HB_SCRIPT_ARABIC;
+ arabic_plan->has_stch = !!plan->map.get_1_mask (HB_TAG ('s','t','c','h'));
for (unsigned int i = 0; i < ARABIC_NUM_FEATURES; i++) {
arabic_plan->mask_array[i] = plan->map.get_1_mask (arabic_features[i]);
arabic_plan->do_fallback = arabic_plan->do_fallback &&
return arabic_plan;
}
-static void
+void
data_destroy_arabic (void *data)
{
arabic_shape_plan_t *arabic_plan = (arabic_shape_plan_t *) data;
info[i].arabic_shaping_action() = info[i - 1].arabic_shaping_action();
}
-static void
-setup_masks_arabic (const hb_ot_shape_plan_t *plan,
- hb_buffer_t *buffer,
- hb_font_t *font HB_UNUSED)
+void
+setup_masks_arabic_plan (const arabic_shape_plan_t *arabic_plan,
+ hb_buffer_t *buffer,
+ hb_script_t script)
{
HB_BUFFER_ALLOCATE_VAR (buffer, arabic_shaping_action);
- const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
-
arabic_joining (buffer);
- if (plan->props.script == HB_SCRIPT_MONGOLIAN)
+ if (script == HB_SCRIPT_MONGOLIAN)
mongolian_variation_selectors (buffer);
unsigned int count = buffer->len;
hb_glyph_info_t *info = buffer->info;
for (unsigned int i = 0; i < count; i++)
info[i].mask |= arabic_plan->mask_array[info[i].arabic_shaping_action()];
+}
- HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
+static void
+setup_masks_arabic (const hb_ot_shape_plan_t *plan,
+ hb_buffer_t *buffer,
+ hb_font_t *font HB_UNUSED)
+{
+ const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
+ setup_masks_arabic_plan (arabic_plan, buffer, plan->props.script);
}
arabic_fallback_plan_shape (fallback_plan, font, buffer);
}
+/*
+ * Stretch feature: "stch".
+ * See example here:
+ * https://www.microsoft.com/typography/OpenTypeDev/syriac/intro.htm
+ * We implement this in a generic way, such that the Arabic subtending
+ * marks can use it as well.
+ */
+
+static void
+record_stch (const hb_ot_shape_plan_t *plan,
+ hb_font_t *font,
+ hb_buffer_t *buffer)
+{
+ const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
+ if (!arabic_plan->has_stch)
+ return;
+
+ /* 'stch' feature was just applied. Look for anything that multiplied,
+ * and record it for stch treatment later. Note that rtlm, frac, etc
+ * are applied before stch, but we assume that they didn't result in
+ * anything multiplying into 5 pieces, so it's safe-ish... */
+
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ for (unsigned int i = 0; i < count; i++)
+ if (unlikely (_hb_glyph_info_multiplied (&info[i])))
+ {
+ unsigned int comp = _hb_glyph_info_get_lig_comp (&info[i]);
+ info[i].arabic_shaping_action() = comp % 2 ? STCH_REPEATING : STCH_FIXED;
+ buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH;
+ }
+}
+
+static void
+apply_stch (const hb_ot_shape_plan_t *plan,
+ hb_buffer_t *buffer,
+ hb_font_t *font)
+{
+ if (likely (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH)))
+ return;
+
+ /* The Arabic shaper currently always processes in RTL mode, so we should
+ * stretch / position the stretched pieces to the left / preceding glyphs. */
+
+ /* We do a two pass implementation:
+ * First pass calculates the exact number of extra glyphs we need,
+ * We then enlarge buffer to have that much room,
+ * Second pass applies the stretch, copying things to the end of buffer.
+ */
+
+ int sign = font->x_scale < 0 ? -1 : +1;
+ unsigned int extra_glyphs_needed = 0; // Set during MEASURE, used during CUT
+ typedef enum { MEASURE, CUT } step_t;
+
+ for (step_t step = MEASURE; step <= CUT; step = (step_t) (step + 1))
+ {
+ unsigned int count = buffer->len;
+ hb_glyph_info_t *info = buffer->info;
+ hb_glyph_position_t *pos = buffer->pos;
+ unsigned int new_len = count + extra_glyphs_needed; // write head during CUT
+ unsigned int j = new_len;
+ for (unsigned int i = count; i; i--)
+ {
+ if (!hb_in_range<unsigned> (info[i - 1].arabic_shaping_action(), STCH_FIXED, STCH_REPEATING))
+ {
+ if (step == CUT)
+ {
+ --j;
+ info[j] = info[i - 1];
+ pos[j] = pos[i - 1];
+ }
+ continue;
+ }
+
+ /* Yay, justification! */
+
+ hb_position_t w_total = 0; // Total to be filled
+ hb_position_t w_fixed = 0; // Sum of fixed tiles
+ hb_position_t w_repeating = 0; // Sum of repeating tiles
+ int n_fixed = 0;
+ int n_repeating = 0;
+
+ unsigned int end = i;
+ while (i &&
+ hb_in_range<unsigned> (info[i - 1].arabic_shaping_action(), STCH_FIXED, STCH_REPEATING))
+ {
+ i--;
+ hb_position_t width = font->get_glyph_h_advance (info[i].codepoint);
+ if (info[i].arabic_shaping_action() == STCH_FIXED)
+ {
+ w_fixed += width;
+ n_fixed++;
+ }
+ else
+ {
+ w_repeating += width;
+ n_repeating++;
+ }
+ }
+ unsigned int start = i;
+ unsigned int context = i;
+ while (context &&
+ !hb_in_range<unsigned> (info[context - 1].arabic_shaping_action(), STCH_FIXED, STCH_REPEATING) &&
+ (_hb_glyph_info_is_default_ignorable (&info[context - 1]) ||
+ HB_ARABIC_GENERAL_CATEGORY_IS_WORD (_hb_glyph_info_get_general_category (&info[context - 1]))))
+ {
+ context--;
+ w_total += pos[context].x_advance;
+ }
+ i++; // Don't touch i again.
+
+ DEBUG_MSG (ARABIC, NULL, "%s stretch at (%d,%d,%d)",
+ step == MEASURE ? "measuring" : "cutting", context, start, end);
+ DEBUG_MSG (ARABIC, NULL, "rest of word: count=%d width %d", start - context, w_total);
+ DEBUG_MSG (ARABIC, NULL, "fixed tiles: count=%d width=%d", n_fixed, w_fixed);
+ DEBUG_MSG (ARABIC, NULL, "repeating tiles: count=%d width=%d", n_repeating, w_repeating);
+
+ /* Number of additional times to repeat each repeating tile. */
+ int n_copies = 0;
+
+ hb_position_t w_remaining = w_total - w_fixed;
+ if (sign * w_remaining > sign * w_repeating && sign * w_repeating > 0)
+ n_copies = (sign * w_remaining) / (sign * w_repeating) - 1;
+
+ /* See if we can improve the fit by adding an extra repeat and squeezing them together a bit. */
+ hb_position_t extra_repeat_overlap = 0;
+ hb_position_t shortfall = sign * w_remaining - sign * w_repeating * (n_copies + 1);
+ if (shortfall > 0)
+ {
+ ++n_copies;
+ hb_position_t excess = (n_copies + 1) * sign * w_repeating - sign * w_remaining;
+ if (excess > 0)
+ extra_repeat_overlap = excess / (n_copies * n_repeating);
+ }
+
+ if (step == MEASURE)
+ {
+ extra_glyphs_needed += n_copies * n_repeating;
+ DEBUG_MSG (ARABIC, NULL, "will add extra %d copies of repeating tiles", n_copies);
+ }
+ else
+ {
+ hb_position_t x_offset = 0;
+ for (unsigned int k = end; k > start; k--)
+ {
+ hb_position_t width = font->get_glyph_h_advance (info[k - 1].codepoint);
+
+ unsigned int repeat = 1;
+ if (info[k - 1].arabic_shaping_action() == STCH_REPEATING)
+ repeat += n_copies;
+
+ DEBUG_MSG (ARABIC, NULL, "appending %d copies of glyph %d; j=%d",
+ repeat, info[k - 1].codepoint, j);
+ for (unsigned int n = 0; n < repeat; n++)
+ {
+ x_offset -= width;
+ if (n > 0)
+ x_offset += extra_repeat_overlap;
+ pos[k - 1].x_offset = x_offset;
+ /* Append copy. */
+ --j;
+ info[j] = info[k - 1];
+ pos[j] = pos[k - 1];
+ }
+ }
+ }
+ }
+
+ if (step == MEASURE)
+ {
+ if (unlikely (!buffer->ensure (count + extra_glyphs_needed)))
+ break;
+ }
+ else
+ {
+ assert (j == 0);
+ buffer->len = new_len;
+ }
+ }
+}
+
+
+static void
+postprocess_glyphs_arabic (const hb_ot_shape_plan_t *plan,
+ hb_buffer_t *buffer,
+ hb_font_t *font)
+{
+ apply_stch (plan, buffer, font);
+
+ HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
+}
const hb_ot_complex_shaper_t _hb_ot_complex_shaper_arabic =
{
NULL, /* override_features */
data_create_arabic,
data_destroy_arabic,
- NULL, /* preprocess_text_arabic */
+ NULL, /* preprocess_text */
+ postprocess_glyphs_arabic,
HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT,
NULL, /* decompose */
NULL, /* compose */
projects / platform / upstream / harfbuzz.git / blobdiff