diff options
Diffstat (limited to 'pango/itemize.c')
| -rw-r--r-- | pango/itemize.c | 182 |
1 files changed, 181 insertions, 1 deletions
diff --git a/pango/itemize.c b/pango/itemize.c index 059f24e9..6f99e2bd 100644 --- a/pango/itemize.c +++ b/pango/itemize.c @@ -1193,9 +1193,187 @@ apply_font_scale (PangoContext *context, } /* }}} */ +/* {{{ Handling Small Caps */ + +static gboolean +feature_is_requested (hb_feature_t *features, + guint num_features, + hb_tag_t tag) +{ + for (guint i = 0; i < num_features; i++) + { + if (features[i].tag == tag) + return features[i].value != 0; + } + + return FALSE; +} + + +static gboolean +feature_is_supported (hb_font_t *font, + const PangoAnalysis *analysis, + hb_tag_t table, + hb_tag_t feature) +{ + hb_face_t *face = hb_font_get_face (font); + hb_script_t script; + hb_language_t language; + guint script_count = HB_OT_MAX_TAGS_PER_SCRIPT; + hb_tag_t script_tags[HB_OT_MAX_TAGS_PER_SCRIPT]; + hb_tag_t chosen_script; + guint language_count = HB_OT_MAX_TAGS_PER_LANGUAGE; + hb_tag_t language_tags[HB_OT_MAX_TAGS_PER_LANGUAGE]; + guint script_index, language_index; + guint feature_index; + + script = g_unicode_script_to_iso15924 (analysis->script); + language = hb_language_from_string (pango_language_to_string (analysis->language), -1); + + hb_ot_tags_from_script_and_language (script, language, + &script_count, script_tags, + &language_count, language_tags); + hb_ot_layout_table_select_script (face, table, + script_count, script_tags, + &script_index, + &chosen_script); + hb_ot_layout_script_select_language (face, table, + script_index, + language_count, language_tags, + &language_index); + + return hb_ot_layout_language_find_feature (face, table, + script_index, language_index, + feature, + &feature_index); +} + +static gboolean +small_caps_is_requested (PangoItem *item) +{ + hb_feature_t features[32]; + unsigned int num_features = 0; + + pango_analysis_collect_features (&item->analysis, + features, G_N_ELEMENTS (features), + &num_features); + + return feature_is_requested (features, num_features, HB_TAG ('s', 'm', 'c', 'p')); +} + +static gboolean +small_caps_is_supported (PangoItem *item) +{ + hb_font_t *font = pango_font_get_hb_font (item->analysis.font); + + return feature_is_supported (font, &item->analysis, HB_OT_TAG_GSUB, HB_TAG ('s', 'm', 'c', 'p')); +} + +static void +split_item_for_small_caps (const char *text, + GList *list_item) +{ + PangoItem *item = list_item->data; + const char *start, *end; + const char *p, *p0; + gunichar wc; + + start = text + item->offset; + end = start + item->length; + + char *s = g_strndup (start, end - start); + g_free (s); + + p = start; + while (p < end) + { + p0 = p; + wc = g_utf8_get_char (p); + while (p < end && (g_unichar_islower (wc) || consider_as_space (wc))) + { + p = g_utf8_next_char (p); + wc = g_utf8_get_char (p); + } + + if (p0 < p) + { + PangoItem *new_item; + PangoAttribute *attr; + + /* p0 .. p is a lowercase segment */ + if (p < end) + { + new_item = pango_item_split (item, p - p0, g_utf8_strlen (p, p - p0)); + list_item->data = new_item; + list_item = g_list_insert_before (list_item, list_item->next, item); + list_item = list_item->next; + } + else + { + new_item = item; + } + + attr = pango_attr_text_transform_new (PANGO_TEXT_TRANSFORM_UPPERCASE); + attr->start_index = new_item->offset; + attr->end_index = new_item->offset + new_item->length; + new_item->analysis.extra_attrs = g_slist_prepend (new_item->analysis.extra_attrs, attr); + + attr = pango_attr_font_scale_new (PANGO_FONT_SCALE_SMALL_CAPS); + attr->start_index = new_item->offset; + attr->end_index = new_item->offset + new_item->length; + new_item->analysis.extra_attrs = g_slist_prepend (new_item->analysis.extra_attrs, attr); + } + + p0 = p; + wc = g_utf8_get_char (p); + while (p < end && (!g_unichar_islower (wc) || consider_as_space (wc))) + { + p = g_utf8_next_char (p); + wc = g_utf8_get_char (p); + } + + if (p0 < p && p < end) + { + PangoItem *new_item; + + /* p0 .. p is a uppercase segment */ + new_item = pango_item_split (item, p - p0, g_utf8_strlen (p, p - p0)); + list_item->data = new_item; + list_item = g_list_insert_before (list_item, list_item->next, item); + list_item = list_item->next; + } + } +} + +static void +handle_small_caps_for_item (const char *text, + GList *l) +{ + PangoItem *item = l->data; + + if (small_caps_is_requested (item) && + !small_caps_is_supported (item)) + split_item_for_small_caps (text, l); +} + +static void +handle_small_caps (const char *text, + GList *items) +{ + GList *next; + + for (GList *l = items; l; l = next) + { + next = l->next; + handle_small_caps_for_item (text, l); + } +} + +/* }}} */ static GList * post_process_items (PangoContext *context, + const char *text, GList *items) { items = g_list_reverse (items); @@ -1211,6 +1389,8 @@ post_process_items (PangoContext *context, } } + handle_small_caps (text, items); + /* apply font-scale */ apply_font_scale (context, items); @@ -1245,7 +1425,7 @@ pango_itemize_with_font (PangoContext *context, itemize_state_finish (&state); - return post_process_items (context, state.result); + return post_process_items (context, text, state.result); } /** |