/* Pango * pango-context.c: Contexts for itemization and shaping * * Copyright (C) 2000, 2006 Red Hat Software * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /** * SECTION:main * @title:Rendering * @short_description:Functions to run the rendering pipeline * * The Pango rendering pipeline takes a string of * Unicode characters and converts it into glyphs. * The functions described in this section accomplish * various steps of this process. */ #include "config.h" #include #include #include "pango-context.h" #include "pango-impl-utils.h" #include "pango-engine-private.h" #include "pango-script-private.h" /** * PangoContext: * * The #PangoContext structure stores global information * used to control the itemization process. */ struct _PangoContext { GObject parent_instance; guint serial; guint fontmap_serial; PangoLanguage *set_language; PangoLanguage *language; PangoDirection base_dir; PangoGravity base_gravity; PangoGravity resolved_gravity; PangoGravityHint gravity_hint; PangoFontDescription *font_desc; PangoMatrix *matrix; PangoFontMap *font_map; }; struct _PangoContextClass { GObjectClass parent_class; }; static void pango_context_finalize (GObject *object); static void context_changed (PangoContext *context); G_DEFINE_TYPE (PangoContext, pango_context, G_TYPE_OBJECT) static void pango_context_init (PangoContext *context) { context->base_dir = PANGO_DIRECTION_WEAK_LTR; context->resolved_gravity = context->base_gravity = PANGO_GRAVITY_SOUTH; context->gravity_hint = PANGO_GRAVITY_HINT_NATURAL; context->serial = 1; context->set_language = NULL; context->language = pango_language_get_default (); context->font_map = NULL; context->font_desc = pango_font_description_new (); pango_font_description_set_family_static (context->font_desc, "serif"); pango_font_description_set_style (context->font_desc, PANGO_STYLE_NORMAL); pango_font_description_set_variant (context->font_desc, PANGO_VARIANT_NORMAL); pango_font_description_set_weight (context->font_desc, PANGO_WEIGHT_NORMAL); pango_font_description_set_stretch (context->font_desc, PANGO_STRETCH_NORMAL); pango_font_description_set_size (context->font_desc, 12 * PANGO_SCALE); } static void pango_context_class_init (PangoContextClass *klass) { GObjectClass *object_class = G_OBJECT_CLASS (klass); object_class->finalize = pango_context_finalize; } static void pango_context_finalize (GObject *object) { PangoContext *context; context = PANGO_CONTEXT (object); if (context->font_map) g_object_unref (context->font_map); pango_font_description_free (context->font_desc); if (context->matrix) pango_matrix_free (context->matrix); G_OBJECT_CLASS (pango_context_parent_class)->finalize (object); } /** * pango_context_new: * * Creates a new #PangoContext initialized to default values. * * This function is not particularly useful as it should always * be followed by a pango_context_set_font_map() call, and the * function pango_font_map_create_context() does these two steps * together and hence users are recommended to use that. * * If you are using Pango as part of a higher-level system, * that system may have it's own way of create a #PangoContext. * For instance, the GTK+ toolkit has, among others, * gdk_pango_context_get_for_screen(), and * gtk_widget_get_pango_context(). Use those instead. * * Return value: the newly allocated #PangoContext, which should * be freed with g_object_unref(). **/ PangoContext * pango_context_new (void) { PangoContext *context; context = g_object_new (PANGO_TYPE_CONTEXT, NULL); return context; } static void update_resolved_gravity (PangoContext *context) { if (context->base_gravity == PANGO_GRAVITY_AUTO) context->resolved_gravity = pango_gravity_get_for_matrix (context->matrix); else context->resolved_gravity = context->base_gravity; } /** * pango_context_set_matrix: * @context: a #PangoContext * @matrix: (allow-none): a #PangoMatrix, or %NULL to unset any existing * matrix. (No matrix set is the same as setting the identity matrix.) * * Sets the transformation matrix that will be applied when rendering * with this context. Note that reported metrics are in the user space * coordinates before the application of the matrix, not device-space * coordinates after the application of the matrix. So, they don't scale * with the matrix, though they may change slightly for different * matrices, depending on how the text is fit to the pixel grid. * * Since: 1.6 **/ void pango_context_set_matrix (PangoContext *context, const PangoMatrix *matrix) { g_return_if_fail (PANGO_IS_CONTEXT (context)); if (context->matrix || matrix) context_changed (context); if (context->matrix) pango_matrix_free (context->matrix); if (matrix) context->matrix = pango_matrix_copy (matrix); else context->matrix = NULL; update_resolved_gravity (context); } /** * pango_context_get_matrix: * @context: a #PangoContext * * Gets the transformation matrix that will be applied when * rendering with this context. See pango_context_set_matrix(). * * Return value: (nullable): the matrix, or %NULL if no matrix has * been set (which is the same as the identity matrix). The returned * matrix is owned by Pango and must not be modified or freed. * * Since: 1.6 **/ const PangoMatrix * pango_context_get_matrix (PangoContext *context) { g_return_val_if_fail (PANGO_IS_CONTEXT (context), NULL); return context->matrix; } /** * pango_context_set_font_map: * @context: a #PangoContext * @font_map: the #PangoFontMap to set. * * Sets the font map to be searched when fonts are looked-up in this context. * This is only for internal use by Pango backends, a #PangoContext obtained * via one of the recommended methods should already have a suitable font map. **/ void pango_context_set_font_map (PangoContext *context, PangoFontMap *font_map) { g_return_if_fail (PANGO_IS_CONTEXT (context)); g_return_if_fail (!font_map || PANGO_IS_FONT_MAP (font_map)); if (font_map == context->font_map) return; context_changed (context); if (font_map) g_object_ref (font_map); if (context->font_map) g_object_unref (context->font_map); context->font_map = font_map; context->fontmap_serial = pango_font_map_get_serial (font_map); } /** * pango_context_get_font_map: * @context: a #PangoContext * * Gets the #PangoFontMap used to look up fonts for this context. * * Return value: (transfer none): the font map for the #PangoContext. * This value is owned by Pango and should not be unreferenced. * * Since: 1.6 **/ PangoFontMap * pango_context_get_font_map (PangoContext *context) { g_return_val_if_fail (PANGO_IS_CONTEXT (context), NULL); return context->font_map; } /** * pango_context_list_families: * @context: a #PangoContext * @families: (out) (array length=n_families) (transfer container): location to store a pointer to * an array of #PangoFontFamily *. This array should be freed * with g_free(). * @n_families: (out): location to store the number of elements in @descs * * List all families for a context. **/ void pango_context_list_families (PangoContext *context, PangoFontFamily ***families, int *n_families) { g_return_if_fail (context != NULL); g_return_if_fail (families == NULL || n_families != NULL); if (n_families == NULL) return; if (context->font_map == NULL) { *n_families = 0; if (families) *families = NULL; return; } else pango_font_map_list_families (context->font_map, families, n_families); } /** * pango_context_load_font: * @context: a #PangoContext * @desc: a #PangoFontDescription describing the font to load * * Loads the font in one of the fontmaps in the context * that is the closest match for @desc. * * Returns: (transfer full) (nullable): the newly allocated #PangoFont * that was loaded, or %NULL if no font matched. **/ PangoFont * pango_context_load_font (PangoContext *context, const PangoFontDescription *desc) { g_return_val_if_fail (context != NULL, NULL); g_return_val_if_fail (context->font_map != NULL, NULL); return pango_font_map_load_font (context->font_map, context, desc); } /** * pango_context_load_fontset: * @context: a #PangoContext * @desc: a #PangoFontDescription describing the fonts to load * @language: a #PangoLanguage the fonts will be used for * * Load a set of fonts in the context that can be used to render * a font matching @desc. * * Returns: (transfer full) (nullable): the newly allocated * #PangoFontset loaded, or %NULL if no font matched. **/ PangoFontset * pango_context_load_fontset (PangoContext *context, const PangoFontDescription *desc, PangoLanguage *language) { g_return_val_if_fail (context != NULL, NULL); return pango_font_map_load_fontset (context->font_map, context, desc, language); } /** * pango_context_set_font_description: * @context: a #PangoContext * @desc: the new pango font description * * Set the default font description for the context **/ void pango_context_set_font_description (PangoContext *context, const PangoFontDescription *desc) { g_return_if_fail (context != NULL); g_return_if_fail (desc != NULL); if (desc != context->font_desc && (!desc || !context->font_desc || !pango_font_description_equal(desc, context->font_desc))) { context_changed (context); pango_font_description_free (context->font_desc); context->font_desc = pango_font_description_copy (desc); } } /** * pango_context_get_font_description: * @context: a #PangoContext * * Retrieve the default font description for the context. * * Return value: (transfer none): a pointer to the context's default font * description. This value must not be modified or freed. **/ PangoFontDescription * pango_context_get_font_description (PangoContext *context) { g_return_val_if_fail (context != NULL, NULL); return context->font_desc; } /** * pango_context_set_language: * @context: a #PangoContext * @language: the new language tag. * * Sets the global language tag for the context. The default language * for the locale of the running process can be found using * pango_language_get_default(). **/ void pango_context_set_language (PangoContext *context, PangoLanguage *language) { g_return_if_fail (context != NULL); if (language != context->language) context_changed (context); context->set_language = language; if (language) context->language = language; else context->language = pango_language_get_default (); } /** * pango_context_get_language: * @context: a #PangoContext * * Retrieves the global language tag for the context. * * Return value: the global language tag. **/ PangoLanguage * pango_context_get_language (PangoContext *context) { g_return_val_if_fail (context != NULL, NULL); return context->set_language; } /** * pango_context_set_base_dir: * @context: a #PangoContext * @direction: the new base direction * * Sets the base direction for the context. * * The base direction is used in applying the Unicode bidirectional * algorithm; if the @direction is %PANGO_DIRECTION_LTR or * %PANGO_DIRECTION_RTL, then the value will be used as the paragraph * direction in the Unicode bidirectional algorithm. A value of * %PANGO_DIRECTION_WEAK_LTR or %PANGO_DIRECTION_WEAK_RTL is used only * for paragraphs that do not contain any strong characters themselves. **/ void pango_context_set_base_dir (PangoContext *context, PangoDirection direction) { g_return_if_fail (context != NULL); if (direction != context->base_dir) context_changed (context); context->base_dir = direction; } /** * pango_context_get_base_dir: * @context: a #PangoContext * * Retrieves the base direction for the context. See * pango_context_set_base_dir(). * * Return value: the base direction for the context. **/ PangoDirection pango_context_get_base_dir (PangoContext *context) { g_return_val_if_fail (context != NULL, PANGO_DIRECTION_LTR); return context->base_dir; } /** * pango_context_set_base_gravity: * @context: a #PangoContext * @gravity: the new base gravity * * Sets the base gravity for the context. * * The base gravity is used in laying vertical text out. * * Since: 1.16 **/ void pango_context_set_base_gravity (PangoContext *context, PangoGravity gravity) { g_return_if_fail (context != NULL); if (gravity != context->base_gravity) context_changed (context); context->base_gravity = gravity; update_resolved_gravity (context); } /** * pango_context_get_base_gravity: * @context: a #PangoContext * * Retrieves the base gravity for the context. See * pango_context_set_base_gravity(). * * Return value: the base gravity for the context. * * Since: 1.16 **/ PangoGravity pango_context_get_base_gravity (PangoContext *context) { g_return_val_if_fail (context != NULL, PANGO_GRAVITY_SOUTH); return context->base_gravity; } /** * pango_context_get_gravity: * @context: a #PangoContext * * Retrieves the gravity for the context. This is similar to * pango_context_get_base_gravity(), except for when the base gravity * is %PANGO_GRAVITY_AUTO for which pango_gravity_get_for_matrix() is used * to return the gravity from the current context matrix. * * Return value: the resolved gravity for the context. * * Since: 1.16 **/ PangoGravity pango_context_get_gravity (PangoContext *context) { g_return_val_if_fail (context != NULL, PANGO_GRAVITY_SOUTH); return context->resolved_gravity; } /** * pango_context_set_gravity_hint: * @context: a #PangoContext * @hint: the new gravity hint * * Sets the gravity hint for the context. * * The gravity hint is used in laying vertical text out, and is only relevant * if gravity of the context as returned by pango_context_get_gravity() * is set %PANGO_GRAVITY_EAST or %PANGO_GRAVITY_WEST. * * Since: 1.16 **/ void pango_context_set_gravity_hint (PangoContext *context, PangoGravityHint hint) { g_return_if_fail (context != NULL); if (hint != context->gravity_hint) context_changed (context); context->gravity_hint = hint; } /** * pango_context_get_gravity_hint: * @context: a #PangoContext * * Retrieves the gravity hint for the context. See * pango_context_set_gravity_hint() for details. * * Return value: the gravity hint for the context. * * Since: 1.16 **/ PangoGravityHint pango_context_get_gravity_hint (PangoContext *context) { g_return_val_if_fail (context != NULL, PANGO_GRAVITY_HINT_NATURAL); return context->gravity_hint; } /**********************************************************************/ static gboolean advance_attr_iterator_to (PangoAttrIterator *iterator, int start_index) { int start_range, end_range; pango_attr_iterator_range (iterator, &start_range, &end_range); while (start_index >= end_range) { if (!pango_attr_iterator_next (iterator)) return FALSE; pango_attr_iterator_range (iterator, &start_range, &end_range); } if (start_range > start_index) g_warning ("In pango_itemize(), the cached iterator passed in " "had already moved beyond the start_index"); return TRUE; } /*************************************************************************** * We cache the results of character,fontset => font,shaper in a hash table ***************************************************************************/ typedef struct { GHashTable *hash; } FontCache; typedef struct { PangoFont *font; } FontElement; static void font_cache_destroy (FontCache *cache) { g_hash_table_destroy (cache->hash); g_slice_free (FontCache, cache); } static void font_element_destroy (FontElement *element) { if (element->font) g_object_unref (element->font); g_slice_free (FontElement, element); } static FontCache * get_font_cache (PangoFontset *fontset) { FontCache *cache; static GQuark cache_quark = 0; /* MT-safe */ if (G_UNLIKELY (!cache_quark)) cache_quark = g_quark_from_static_string ("pango-shaper-font-cache"); retry: cache = g_object_get_qdata (G_OBJECT (fontset), cache_quark); if (G_UNLIKELY (!cache)) { cache = g_slice_new (FontCache); cache->hash = g_hash_table_new_full (g_direct_hash, NULL, NULL, (GDestroyNotify)font_element_destroy); if (!g_object_replace_qdata (G_OBJECT (fontset), cache_quark, NULL, cache, (GDestroyNotify)font_cache_destroy, NULL)) { font_cache_destroy (cache); goto retry; } } return cache; } static gboolean font_cache_get (FontCache *cache, gunichar wc, PangoFont **font) { FontElement *element; element = g_hash_table_lookup (cache->hash, GUINT_TO_POINTER (wc)); if (element) { *font = element->font; return TRUE; } else return FALSE; } static void font_cache_insert (FontCache *cache, gunichar wc, PangoFont *font) { FontElement *element = g_slice_new (FontElement); element->font = font ? g_object_ref (font) : NULL; g_hash_table_insert (cache->hash, GUINT_TO_POINTER (wc), element); } /**********************************************************************/ typedef enum { EMBEDDING_CHANGED = 1 << 0, SCRIPT_CHANGED = 1 << 1, LANG_CHANGED = 1 << 2, FONT_CHANGED = 1 << 3, DERIVED_LANG_CHANGED = 1 << 4, WIDTH_CHANGED = 1 << 5 } ChangedFlags; typedef struct _PangoWidthIter PangoWidthIter; struct _PangoWidthIter { const gchar *text_start; const gchar *text_end; const gchar *start; const gchar *end; gboolean wide; }; typedef struct _ItemizeState ItemizeState; struct _ItemizeState { PangoContext *context; const char *text; const char *end; const char *run_start; const char *run_end; GList *result; PangoItem *item; guint8 *embedding_levels; int embedding_end_offset; const char *embedding_end; guint8 embedding; PangoGravity gravity; PangoGravityHint gravity_hint; PangoGravity resolved_gravity; PangoGravity font_desc_gravity; gboolean centered_baseline; PangoAttrIterator *attr_iter; gboolean free_attr_iter; const char *attr_end; PangoFontDescription *font_desc; PangoLanguage *lang; GSList *extra_attrs; gboolean copy_extra_attrs; ChangedFlags changed; PangoScriptIter script_iter; const char *script_end; PangoScript script; PangoWidthIter width_iter; PangoLanguage *derived_lang; PangoEngineLang *lang_engine; PangoFontset *current_fonts; FontCache *cache; PangoFont *base_font; gboolean enable_fallback; }; static void update_embedding_end (ItemizeState *state) { state->embedding = state->embedding_levels[state->embedding_end_offset]; while (state->embedding_end < state->end && state->embedding_levels[state->embedding_end_offset] == state->embedding) { state->embedding_end_offset++; state->embedding_end = g_utf8_next_char (state->embedding_end); } state->changed |= EMBEDDING_CHANGED; } static PangoAttribute * find_attribute (GSList *attr_list, PangoAttrType type) { GSList *node; for (node = attr_list; node; node = node->next) if (((PangoAttribute *) node->data)->klass->type == type) return (PangoAttribute *) node->data; return NULL; } static void update_attr_iterator (ItemizeState *state) { PangoLanguage *old_lang; PangoAttribute *attr; int end_index; pango_attr_iterator_range (state->attr_iter, NULL, &end_index); if (end_index < state->end - state->text) state->attr_end = state->text + end_index; else state->attr_end = state->end; old_lang = state->lang; if (state->font_desc) pango_font_description_free (state->font_desc); state->font_desc = pango_font_description_copy_static (state->context->font_desc); pango_attr_iterator_get_font (state->attr_iter, state->font_desc, &state->lang, &state->extra_attrs); if (pango_font_description_get_set_fields (state->font_desc) & PANGO_FONT_MASK_GRAVITY) state->font_desc_gravity = pango_font_description_get_gravity (state->font_desc); else state->font_desc_gravity = PANGO_GRAVITY_AUTO; state->copy_extra_attrs = FALSE; if (!state->lang) state->lang = state->context->language; attr = find_attribute (state->extra_attrs, PANGO_ATTR_FALLBACK); state->enable_fallback = (attr == NULL || ((PangoAttrInt *)attr)->value); attr = find_attribute (state->extra_attrs, PANGO_ATTR_GRAVITY); state->gravity = attr == NULL ? PANGO_GRAVITY_AUTO : ((PangoAttrInt *)attr)->value; attr = find_attribute (state->extra_attrs, PANGO_ATTR_GRAVITY_HINT); state->gravity_hint = attr == NULL ? state->context->gravity_hint : (PangoGravityHint)((PangoAttrInt *)attr)->value; state->changed |= FONT_CHANGED; if (state->lang != old_lang) state->changed |= LANG_CHANGED; } static void update_end (ItemizeState *state) { state->run_end = state->embedding_end; if (state->attr_end < state->run_end) state->run_end = state->attr_end; if (state->script_end < state->run_end) state->run_end = state->script_end; if (state->width_iter.end < state->run_end) state->run_end = state->width_iter.end; } /* g_unichar_iswide() uses EastAsianWidth, which is broken. * We should switch to using VerticalTextLayout: * http://www.unicode.org/reports/tr50/#Data50 * * In the mean time, fixup Hangul jamo to be all wide so we * don't break run in the middle. The EastAsianWidth has * 'W' for L-jamo, and 'N' for T and V jamo! * * https://bugzilla.gnome.org/show_bug.cgi?id=705727 */ static gboolean width_iter_iswide (gunichar ch) { if ((0x1100u <= ch && ch <= 0x11FFu) || (0xA960u <= ch && ch <= 0xA97Cu) || (0xD7B0u <= ch && ch <= 0xD7FBu)) return TRUE; return g_unichar_iswide (ch); } static void width_iter_next(PangoWidthIter* iter) { gboolean met_joiner = FALSE; iter->start = iter->end; if (iter->end < iter->text_end) { gunichar ch = g_utf8_get_char (iter->end); iter->wide = width_iter_iswide (ch); } while (iter->end < iter->text_end) { gunichar ch = g_utf8_get_char (iter->end); /* for zero width joiner */ if (ch == 0x200D) { iter->end = g_utf8_next_char (iter->end); met_joiner = TRUE; continue; } /* ignore the wide check if met joiner */ if (met_joiner) { iter->end = g_utf8_next_char (iter->end); met_joiner = FALSE; continue; } /* for variation selector, tag and emoji modifier. */ if (G_UNLIKELY(ch == 0xFE0EU || ch == 0xFE0FU || (ch >= 0xE0020 && ch <= 0xE007F) || (ch >= 0x1F3FB && ch <= 0x1F3FF))) { iter->end = g_utf8_next_char (iter->end); continue; } if (width_iter_iswide (ch) != iter->wide) break; iter->end = g_utf8_next_char (iter->end); } } static void width_iter_init (PangoWidthIter* iter, const char* text, int length) { iter->text_start = text; iter->text_end = text + length; iter->start = iter->end = text; width_iter_next (iter); } static void itemize_state_init (ItemizeState *state, PangoContext *context, const char *text, PangoDirection base_dir, int start_index, int length, PangoAttrList *attrs, PangoAttrIterator *cached_iter, const PangoFontDescription *desc) { state->context = context; state->text = text; state->end = text + start_index + length; state->result = NULL; state->item = NULL; state->run_start = text + start_index; /* First, apply the bidirectional algorithm to break * the text into directional runs. */ state->embedding_levels = pango_log2vis_get_embedding_levels (text + start_index, length, &base_dir); state->embedding_end_offset = 0; state->embedding_end = text + start_index; update_embedding_end (state); /* Initialize the attribute iterator */ if (cached_iter) { state->attr_iter = cached_iter; state->free_attr_iter = FALSE; } else if (attrs) { state->attr_iter = pango_attr_list_get_iterator (attrs); state->free_attr_iter = TRUE; } else { state->attr_iter = NULL; state->free_attr_iter = FALSE; } if (state->attr_iter) { state->font_desc = NULL; state->lang = NULL; advance_attr_iterator_to (state->attr_iter, start_index); update_attr_iterator (state); } else { state->font_desc = pango_font_description_copy_static (desc ? desc : state->context->font_desc); state->lang = state->context->language; state->extra_attrs = NULL; state->copy_extra_attrs = FALSE; state->attr_end = state->end; state->enable_fallback = TRUE; } /* Initialize the script iterator */ _pango_script_iter_init (&state->script_iter, text + start_index, length); pango_script_iter_get_range (&state->script_iter, NULL, &state->script_end, &state->script); /* Initialize the width iterator */ width_iter_init (&state->width_iter, text + start_index, length); update_end (state); if (pango_font_description_get_set_fields (state->font_desc) & PANGO_FONT_MASK_GRAVITY) state->font_desc_gravity = pango_font_description_get_gravity (state->font_desc); else state->font_desc_gravity = PANGO_GRAVITY_AUTO; state->gravity = PANGO_GRAVITY_AUTO; state->centered_baseline = PANGO_GRAVITY_IS_VERTICAL (state->context->resolved_gravity); state->gravity_hint = state->context->gravity_hint; state->resolved_gravity = PANGO_GRAVITY_AUTO; state->derived_lang = NULL; state->lang_engine = NULL; state->current_fonts = NULL; state->cache = NULL; state->base_font = NULL; state->changed = EMBEDDING_CHANGED | SCRIPT_CHANGED | LANG_CHANGED | FONT_CHANGED | WIDTH_CHANGED; } static gboolean itemize_state_next (ItemizeState *state) { if (state->run_end == state->end) return FALSE; state->changed = 0; state->run_start = state->run_end; if (state->run_end == state->embedding_end) { update_embedding_end (state); } if (state->run_end == state->attr_end) { pango_attr_iterator_next (state->attr_iter); update_attr_iterator (state); } if (state->run_end == state->script_end) { pango_script_iter_next (&state->script_iter); pango_script_iter_get_range (&state->script_iter, NULL, &state->script_end, &state->script); state->changed |= SCRIPT_CHANGED; } if (state->run_end == state->width_iter.end) { width_iter_next (&state->width_iter); state->changed |= WIDTH_CHANGED; } update_end (state); return TRUE; } static GSList * copy_attr_slist (GSList *attr_slist) { GSList *new_list = NULL; GSList *l; for (l = attr_slist; l; l = l->next) new_list = g_slist_prepend (new_list, pango_attribute_copy (l->data)); return g_slist_reverse (new_list); } static void itemize_state_fill_shaper (ItemizeState *state, PangoEngineShape *shape_engine, PangoFont *font) { GList *l; for (l = state->result; l; l = l->next) { PangoItem *item = l->data; if (item->analysis.shape_engine) break; if (font) item->analysis.font = g_object_ref (font); else item->analysis.font = NULL; item->analysis.shape_engine = shape_engine; } } static void itemize_state_add_character (ItemizeState *state, PangoEngineShape *shape_engine, PangoFont *font, gboolean force_break, const char *pos) { if (state->item) { if (!state->item->analysis.shape_engine && shape_engine) { itemize_state_fill_shaper (state, shape_engine, font); } else if (state->item->analysis.shape_engine && !shape_engine) { font = state->item->analysis.font; shape_engine = state->item->analysis.shape_engine; } if (!force_break && state->item->analysis.lang_engine == state->lang_engine && state->item->analysis.shape_engine == shape_engine && state->item->analysis.font == font) { state->item->num_chars++; return; } state->item->length = (pos - state->text) - state->item->offset; } state->item = pango_item_new (); state->item->offset = pos - state->text; state->item->length = 0; state->item->num_chars = 1; state->item->analysis.shape_engine = shape_engine; state->item->analysis.lang_engine = state->lang_engine; if (font) g_object_ref (font); state->item->analysis.font = font; state->item->analysis.level = state->embedding; state->item->analysis.gravity = state->resolved_gravity; /* The level vs. gravity dance: * - If gravity is SOUTH, leave level untouched. * - If gravity is NORTH, step level one up, to * not get mirrored upside-down text. * - If gravity is EAST, step up to an even level, as * it's a clockwise-rotated layout, so the rotated * top is unrotated left. * - If gravity is WEST, step up to an odd level, as * it's a counter-clockwise-rotated layout, so the rotated * top is unrotated right. * * A similar dance is performed in pango-layout.c: * line_set_resolved_dir(). Keep in synch. */ switch (state->item->analysis.gravity) { case PANGO_GRAVITY_SOUTH: default: break; case PANGO_GRAVITY_NORTH: state->item->analysis.level++; break; case PANGO_GRAVITY_EAST: state->item->analysis.level += 1; state->item->analysis.level &= ~1; break; case PANGO_GRAVITY_WEST: state->item->analysis.level |= 1; break; } state->item->analysis.flags = state->centered_baseline ? PANGO_ANALYSIS_FLAG_CENTERED_BASELINE : 0; state->item->analysis.script = state->script; state->item->analysis.language = state->derived_lang; if (state->copy_extra_attrs) { state->item->analysis.extra_attrs = copy_attr_slist (state->extra_attrs); } else { state->item->analysis.extra_attrs = state->extra_attrs; state->copy_extra_attrs = TRUE; } state->result = g_list_prepend (state->result, state->item); } typedef struct { PangoLanguage *lang; gunichar wc; PangoFont *font; } GetFontInfo; static gboolean get_font_foreach (PangoFontset *fontset, PangoFont *font, gpointer data) { GetFontInfo *info = data; PangoEngineShape *engine; PangoCoverageLevel level; if (G_UNLIKELY (!font)) return FALSE; engine = pango_font_find_shaper (font, info->lang, info->wc), level = _pango_engine_shape_covers (engine, font, info->lang, info->wc); if (level != PANGO_COVERAGE_NONE) { info->font = font; return TRUE; } if (!fontset) { info->font = font; return TRUE; } return FALSE; } static PangoFont * get_base_font (ItemizeState *state) { if (!state->base_font) state->base_font = pango_font_map_load_font (state->context->font_map, state->context, state->font_desc); return state->base_font; } static PangoScript get_script (ItemizeState *state) { /* Always use a basic shaper for vertical layout (ie, east/west gravity) * as none of our script shapers support vertical shaping right now. * * XXX Should move the knowledge into the shaper interface. */ if (PANGO_GRAVITY_IS_VERTICAL (state->resolved_gravity)) return PANGO_SCRIPT_COMMON; else return state->script; } static gboolean get_shaper_and_font (ItemizeState *state, gunichar wc, PangoEngineShape **shape_engine, PangoFont **font) { GetFontInfo info; /* We'd need a separate cache when fallback is disabled, but since lookup * with fallback disabled is faster anyways, we just skip caching */ if (state->enable_fallback && font_cache_get (state->cache, wc, font)) { *shape_engine = pango_font_find_shaper (*font, state->derived_lang, wc); return TRUE; } info.lang = state->derived_lang; info.wc = wc; info.font = NULL; if (state->enable_fallback) pango_fontset_foreach (state->current_fonts, get_font_foreach, &info); else get_font_foreach (NULL, get_base_font (state), &info); *font = info.font; *shape_engine = pango_font_find_shaper (*font, state->derived_lang, wc); /* skip caching if fallback disabled (see above) */ if (state->enable_fallback) font_cache_insert (state->cache, wc, *font); return TRUE; } static PangoLanguage * compute_derived_language (PangoLanguage *lang, PangoScript script) { PangoLanguage *derived_lang; /* Make sure the language tag is consistent with the derived * script. There is no point in marking up a section of * Arabic text with the "en" language tag. */ if (lang && pango_language_includes_script (lang, script)) derived_lang = lang; else { derived_lang = pango_script_get_sample_language (script); /* If we don't find a sample language for the script, we * use a language tag that shouldn't actually be used * anywhere. This keeps fontconfig (for the PangoFc* * backend) from using the language tag to affect the * sort order. I don't have a reference for 'xx' being * safe here, though Keith Packard claims it is. */ if (!derived_lang) derived_lang = pango_language_from_string ("xx"); } return derived_lang; } static void itemize_state_update_for_new_run (ItemizeState *state) { /* This block should be moved to update_attr_iterator, but I'm too lazy to * do it right now */ if (state->changed & (FONT_CHANGED | SCRIPT_CHANGED | WIDTH_CHANGED)) { PangoGravity old_gravity = state->resolved_gravity; /* Font-desc gravity overrides everything */ if (state->font_desc_gravity != PANGO_GRAVITY_AUTO) { state->resolved_gravity = state->font_desc_gravity; } else { PangoGravity gravity = state->gravity; PangoGravityHint gravity_hint = state->gravity_hint; if (G_LIKELY (gravity == PANGO_GRAVITY_AUTO)) gravity = state->context->resolved_gravity; state->resolved_gravity = pango_gravity_get_for_script_and_width (state->script, state->width_iter.wide, gravity, gravity_hint); } if (old_gravity != state->resolved_gravity) { pango_font_description_set_gravity (state->font_desc, state->resolved_gravity); state->changed |= FONT_CHANGED; } } if (state->changed & (SCRIPT_CHANGED | LANG_CHANGED)) { PangoLanguage *old_derived_lang = state->derived_lang; state->derived_lang = compute_derived_language (state->lang, state->script); if (old_derived_lang != state->derived_lang) state->changed |= DERIVED_LANG_CHANGED; } if ((state->changed & DERIVED_LANG_CHANGED) || !state->lang_engine) { state->lang_engine = _pango_get_language_engine (); } if (state->changed & (FONT_CHANGED | DERIVED_LANG_CHANGED) && state->current_fonts) { g_object_unref (state->current_fonts); state->current_fonts = NULL; state->cache = NULL; } if (!state->current_fonts) { state->current_fonts = pango_font_map_load_fontset (state->context->font_map, state->context, state->font_desc, state->derived_lang); state->cache = get_font_cache (state->current_fonts); } if ((state->changed & FONT_CHANGED) && state->base_font) { g_object_unref (state->base_font); state->base_font = NULL; } } static const char * string_from_script (PangoScript script) { static GEnumClass *class = NULL; /* MT-safe */ GEnumValue *value; if (g_once_init_enter (&class)) g_once_init_leave(&class, (gpointer)g_type_class_ref (PANGO_TYPE_SCRIPT)); value = g_enum_get_value (class, script); if (!value) return string_from_script (PANGO_SCRIPT_INVALID_CODE); return value->value_nick; } static void itemize_state_process_run (ItemizeState *state) { const char *p; gboolean last_was_forced_break = FALSE; /* Only one character has type G_UNICODE_LINE_SEPARATOR in Unicode 4.0; * update this if that changes. */ #define LINE_SEPARATOR 0x2028 itemize_state_update_for_new_run (state); /* We should never get an empty run */ g_assert (state->run_end != state->run_start); for (p = state->run_start; p < state->run_end; p = g_utf8_next_char (p)) { gunichar wc = g_utf8_get_char (p); gboolean is_forced_break = (wc == '\t' || wc == LINE_SEPARATOR); PangoEngineShape *shape_engine; PangoFont *font; GUnicodeType type; /* We don't want space characters to affect font selection; in general, * it's always wrong to select a font just to render a space. * We assume that all fonts have the ASCII space, and for other space * characters if they don't, HarfBuzz will compatibility-decompose them * to ASCII space... * See bugs #355987 and #701652. * * We don't want to change fonts just for variation selectors. * See bug #781123. */ type = g_unichar_type (wc); if (G_UNLIKELY (type == G_UNICODE_CONTROL || type == G_UNICODE_FORMAT || type == G_UNICODE_SURROGATE || (type == G_UNICODE_SPACE_SEPARATOR && wc != 0x1680u /* OGHAM SPACE MARK */) || (wc >= 0xfe00u && wc <= 0xfe0fu) || (wc >= 0xe0100u && wc <= 0xe01efu))) { shape_engine = NULL; font = NULL; } else { get_shaper_and_font (state, wc, &shape_engine, &font); } itemize_state_add_character (state, shape_engine, font, is_forced_break || last_was_forced_break, p); last_was_forced_break = is_forced_break; } /* Finish the final item from the current segment */ state->item->length = (p - state->text) - state->item->offset; if (!state->item->analysis.shape_engine) { PangoEngineShape *shape_engine; PangoFont *font; if (G_UNLIKELY (!get_shaper_and_font (state, ' ', &shape_engine, &font))) { /* If no shaper was found, warn only once per fontmap/script pair */ PangoFontMap *fontmap = state->context->font_map; const char *script_name = string_from_script (get_script (state)); if (!g_object_get_data (G_OBJECT (fontmap), script_name)) { G_GNUC_BEGIN_IGNORE_DEPRECATIONS g_warning ("failed to choose a font, expect ugly output. engine-type='%s', script='%s'", pango_font_map_get_shape_engine_type (fontmap), script_name); G_GNUC_END_IGNORE_DEPRECATIONS g_object_set_data_full (G_OBJECT (fontmap), script_name, GINT_TO_POINTER (1), NULL); } shape_engine = _pango_get_fallback_shaper (); font = NULL; } itemize_state_fill_shaper (state, shape_engine, font); } state->item = NULL; } static void itemize_state_finish (ItemizeState *state) { g_free (state->embedding_levels); if (state->free_attr_iter) pango_attr_iterator_destroy (state->attr_iter); _pango_script_iter_fini (&state->script_iter); pango_font_description_free (state->font_desc); if (state->current_fonts) g_object_unref (state->current_fonts); if (state->base_font) g_object_unref (state->base_font); } /** * pango_itemize_with_base_dir: * @context: a structure holding information that affects * the itemization process. * @base_dir: base direction to use for bidirectional processing * @text: the text to itemize. * @start_index: first byte in @text to process * @length: the number of bytes (not characters) to process * after @start_index. This must be >= 0. * @attrs: the set of attributes that apply to @text. * @cached_iter: (allow-none): Cached attribute iterator, or %NULL * * Like pango_itemize(), but the base direction to use when * computing bidirectional levels (see pango_context_set_base_dir ()), * is specified explicitly rather than gotten from the #PangoContext. * * Return value: (transfer full) (element-type Pango.Item): a #GList of * #PangoItem structures. The items should be freed using * pango_item_free() probably in combination with * g_list_foreach(), and the list itself using g_list_free(). * * Since: 1.4 */ GList * pango_itemize_with_base_dir (PangoContext *context, PangoDirection base_dir, const char *text, int start_index, int length, PangoAttrList *attrs, PangoAttrIterator *cached_iter) { ItemizeState state; g_return_val_if_fail (context != NULL, NULL); g_return_val_if_fail (start_index >= 0, NULL); g_return_val_if_fail (length >= 0, NULL); g_return_val_if_fail (length == 0 || text != NULL, NULL); if (length == 0) return NULL; itemize_state_init (&state, context, text, base_dir, start_index, length, attrs, cached_iter, NULL); do itemize_state_process_run (&state); while (itemize_state_next (&state)); itemize_state_finish (&state); return g_list_reverse (state.result); } static GList * itemize_with_font (PangoContext *context, const char *text, int start_index, int length, const PangoFontDescription *desc) { ItemizeState state; if (length == 0) return NULL; itemize_state_init (&state, context, text, context->base_dir, start_index, length, NULL, NULL, desc); do itemize_state_process_run (&state); while (itemize_state_next (&state)); itemize_state_finish (&state); return g_list_reverse (state.result); } /** * pango_itemize: * @context: a structure holding information that affects the itemization process. * @text: the text to itemize. * @start_index: first byte in @text to process * @length: the number of bytes (not characters) to process * after @start_index. * This must be >= 0. * @attrs: the set of attributes that apply to @text. * @cached_iter: (allow-none): Cached attribute iterator, or %NULL * * Breaks a piece of text into segments with consistent * directional level and shaping engine. Each byte of @text will * be contained in exactly one of the items in the returned list; * the generated list of items will be in logical order (the start * offsets of the items are ascending). * * @cached_iter should be an iterator over @attrs currently positioned at a * range before or containing @start_index; @cached_iter will be advanced to * the range covering the position just after @start_index + @length. * (i.e. if itemizing in a loop, just keep passing in the same @cached_iter). * * Return value: (transfer full) (element-type Pango.Item): a #GList of #PangoItem * structures. The items should be freed using pango_item_free() * probably in combination with g_list_foreach(), and the list itself * using g_list_free(). */ GList * pango_itemize (PangoContext *context, const char *text, int start_index, int length, PangoAttrList *attrs, PangoAttrIterator *cached_iter) { g_return_val_if_fail (context != NULL, NULL); g_return_val_if_fail (start_index >= 0, NULL); g_return_val_if_fail (length >= 0, NULL); g_return_val_if_fail (length == 0 || text != NULL, NULL); return pango_itemize_with_base_dir (context, context->base_dir, text, start_index, length, attrs, cached_iter); } static gboolean get_first_metrics_foreach (PangoFontset *fontset, PangoFont *font, gpointer data) { PangoFontMetrics *fontset_metrics = data; PangoLanguage *language = PANGO_FONTSET_GET_CLASS (fontset)->get_language (fontset); PangoFontMetrics *font_metrics = pango_font_get_metrics (font, language); guint save_ref_count; /* Initialize the fontset metrics to metrics of the first font in the * fontset; saving the refcount and restoring it is a bit of hack but avoids * having to update this code for each metrics addition. */ save_ref_count = fontset_metrics->ref_count; *fontset_metrics = *font_metrics; fontset_metrics->ref_count = save_ref_count; pango_font_metrics_unref (font_metrics); return TRUE; /* Stops iteration */ } static PangoFontMetrics * get_base_metrics (PangoFontset *fontset) { PangoFontMetrics *metrics = pango_font_metrics_new (); /* Initialize the metrics from the first font in the fontset */ pango_fontset_foreach (fontset, get_first_metrics_foreach, metrics); return metrics; } static void update_metrics_from_items (PangoFontMetrics *metrics, PangoLanguage *language, const char *text, unsigned int text_len, GList *items) { GHashTable *fonts_seen = g_hash_table_new (NULL, NULL); PangoGlyphString *glyphs = pango_glyph_string_new (); GList *l; glong text_width; /* This should typically be called with a sample text string. */ g_return_if_fail (text_len > 0); metrics->approximate_char_width = 0; for (l = items; l; l = l->next) { PangoItem *item = l->data; PangoFont *font = item->analysis.font; if (font != NULL && g_hash_table_lookup (fonts_seen, font) == NULL) { PangoFontMetrics *raw_metrics = pango_font_get_metrics (font, language); g_hash_table_insert (fonts_seen, font, font); /* metrics will already be initialized from the first font in the fontset */ metrics->ascent = MAX (metrics->ascent, raw_metrics->ascent); metrics->descent = MAX (metrics->descent, raw_metrics->descent); pango_font_metrics_unref (raw_metrics); } pango_shape_full (text + item->offset, item->length, text, text_len, &item->analysis, glyphs); metrics->approximate_char_width += pango_glyph_string_get_width (glyphs); } pango_glyph_string_free (glyphs); g_hash_table_destroy (fonts_seen); text_width = pango_utf8_strwidth (text); g_assert (text_width > 0); metrics->approximate_char_width /= text_width; } /** * pango_context_get_metrics: * @context: a #PangoContext * @desc: (allow-none): a #PangoFontDescription structure. %NULL means that the * font description from the context will be used. * @language: (allow-none): language tag used to determine which script to get * the metrics for. %NULL means that the language tag from the context * will be used. If no language tag is set on the context, metrics * for the default language (as determined by pango_language_get_default()) * will be returned. * * Get overall metric information for a particular font * description. Since the metrics may be substantially different for * different scripts, a language tag can be provided to indicate that * the metrics should be retrieved that correspond to the script(s) * used by that language. * * The #PangoFontDescription is interpreted in the same way as * by pango_itemize(), and the family name may be a comma separated * list of figures. If characters from multiple of these families * would be used to render the string, then the returned fonts would * be a composite of the metrics for the fonts loaded for the * individual families. * * Return value: a #PangoFontMetrics object. The caller must call pango_font_metrics_unref() * when finished using the object. **/ PangoFontMetrics * pango_context_get_metrics (PangoContext *context, const PangoFontDescription *desc, PangoLanguage *language) { PangoFontset *current_fonts = NULL; PangoFontMetrics *metrics; const char *sample_str; unsigned int text_len; GList *items; g_return_val_if_fail (PANGO_IS_CONTEXT (context), NULL); if (!desc) desc = context->font_desc; if (!language) language = context->language; current_fonts = pango_font_map_load_fontset (context->font_map, context, desc, language); metrics = get_base_metrics (current_fonts); sample_str = pango_language_get_sample_string (language); text_len = strlen (sample_str); items = itemize_with_font (context, sample_str, 0, text_len, desc); update_metrics_from_items (metrics, language, sample_str, text_len, items); g_list_foreach (items, (GFunc)pango_item_free, NULL); g_list_free (items); g_object_unref (current_fonts); return metrics; } static void context_changed (PangoContext *context) { context->serial++; if (context->serial == 0) context->serial++; } /** * pango_context_changed: * @context: a #PangoContext * * Forces a change in the context, which will cause any #PangoLayout * using this context to re-layout. * * This function is only useful when implementing a new backend * for Pango, something applications won't do. Backends should * call this function if they have attached extra data to the context * and such data is changed. * * Since: 1.32.4 **/ void pango_context_changed (PangoContext *context) { context_changed (context); } static void check_fontmap_changed (PangoContext *context) { guint old_serial = context->fontmap_serial; if (!context->font_map) return; context->fontmap_serial = pango_font_map_get_serial (context->font_map); if (old_serial != context->fontmap_serial) context_changed (context); } /** * pango_context_get_serial: * @context: a #PangoContext * * Returns the current serial number of @context. The serial number is * initialized to an small number larger than zero when a new context * is created and is increased whenever the context is changed using any * of the setter functions, or the #PangoFontMap it uses to find fonts has * changed. The serial may wrap, but will never have the value 0. Since it * can wrap, never compare it with "less than", always use "not equals". * * This can be used to automatically detect changes to a #PangoContext, and * is only useful when implementing objects that need update when their * #PangoContext changes, like #PangoLayout. * * Return value: The current serial number of @context. * * Since: 1.32.4 **/ guint pango_context_get_serial (PangoContext *context) { check_fontmap_changed (context); return context->serial; }