summaryrefslogtreecommitdiff
path: root/modules/arabic/arabic-xft.c
diff options
context:
space:
mode:
Diffstat (limited to 'modules/arabic/arabic-xft.c')
-rw-r--r--modules/arabic/arabic-xft.c358
1 files changed, 358 insertions, 0 deletions
diff --git a/modules/arabic/arabic-xft.c b/modules/arabic/arabic-xft.c
new file mode 100644
index 00000000..b8f7b5ad
--- /dev/null
+++ b/modules/arabic/arabic-xft.c
@@ -0,0 +1,358 @@
+/* Pango
+ * arabic-xft.h:
+ *
+ * Copyright (C) 2000 Red Hat Software
+ * Author: Owen Taylor <otaylor@redhat.com>
+ *
+ * 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.
+ */
+
+#include <string.h>
+
+#include "arabic-ot.h"
+
+#include "pangoxft.h"
+#include "pango-utils.h"
+
+static PangoEngineRange arabic_ranges[] = {
+ /* Language characters */
+ { 0x060c, 0x06f9, "*" }, /* Arabic */
+};
+
+static PangoEngineInfo script_engines[] = {
+ {
+ "ArabicScriptEngineXft",
+ PANGO_ENGINE_TYPE_SHAPE,
+ PANGO_RENDER_TYPE_XFT,
+ arabic_ranges, G_N_ELEMENTS(arabic_ranges)
+ }
+};
+
+void
+maybe_add_feature (PangoOTRuleset *ruleset,
+ PangoOTInfo *info,
+ guint script_index,
+ PangoOTTag tag,
+ gulong property_bit)
+{
+ guint feature_index;
+
+ /* 0xffff == default language system */
+ if (pango_ot_info_find_feature (info, PANGO_OT_TABLE_GSUB,
+ tag, script_index, 0xffff, &feature_index))
+ pango_ot_ruleset_add_feature (ruleset, PANGO_OT_TABLE_GSUB, feature_index,
+ property_bit);
+}
+
+static PangoOTRuleset *
+get_ruleset (PangoFont *font)
+{
+ PangoOTRuleset *ruleset;
+ static GQuark ruleset_quark = 0;
+
+ PangoOTInfo *info = pango_xft_font_get_ot_info (font);
+
+ if (!ruleset_quark)
+ ruleset_quark = g_quark_from_string ("pango-arabic-ruleset");
+
+ if (!info)
+ return NULL;
+
+ ruleset = g_object_get_qdata (G_OBJECT (font), ruleset_quark);
+
+ if (!ruleset)
+ {
+ PangoOTTag arab_tag = FT_MAKE_TAG ('a', 'r', 'a', 'b');
+ guint script_index;
+
+ ruleset = pango_ot_ruleset_new (info);
+
+ if (pango_ot_info_find_script (info, PANGO_OT_TABLE_GSUB,
+ arab_tag, &script_index))
+ {
+ maybe_add_feature (ruleset, info, script_index, FT_MAKE_TAG ('i','s','o','l'), isolated);
+ maybe_add_feature (ruleset, info, script_index, FT_MAKE_TAG ('i','n','i','t'), initial);
+ maybe_add_feature (ruleset, info, script_index, FT_MAKE_TAG ('m','e','d','i'), medial);
+ maybe_add_feature (ruleset, info, script_index, FT_MAKE_TAG ('f','i','n','a'), final);
+ maybe_add_feature (ruleset, info, script_index, FT_MAKE_TAG ('l','i','g','a'), 0xFFFF);
+ }
+
+ g_object_set_qdata_full (G_OBJECT (font), ruleset_quark, ruleset,
+ (GDestroyNotify)g_object_unref);
+ }
+
+ return ruleset;
+}
+
+static void
+swap_range (PangoGlyphString *glyphs, int start, int end)
+{
+ int i, j;
+
+ for (i = start, j = end - 1; i < j; i++, j--)
+ {
+ PangoGlyphInfo glyph_info;
+ gint log_cluster;
+
+ glyph_info = glyphs->glyphs[i];
+ glyphs->glyphs[i] = glyphs->glyphs[j];
+ glyphs->glyphs[j] = glyph_info;
+
+ log_cluster = glyphs->log_clusters[i];
+ glyphs->log_clusters[i] = glyphs->log_clusters[j];
+ glyphs->log_clusters[j] = log_cluster;
+ }
+}
+
+static void
+set_glyph (PangoFont *font, PangoGlyphString *glyphs, int i, int offset, PangoGlyph glyph)
+{
+ glyphs->glyphs[i].glyph = glyph;
+ glyphs->log_clusters[i] = offset;
+}
+
+static guint
+find_char (FT_Face face, PangoFont *font, gunichar wc)
+{
+ int index = FT_Get_Char_Index (face, wc);
+
+ if (index && index <= face->num_glyphs)
+ return index;
+ else
+ return 0;
+}
+
+static void
+arabic_engine_shape (PangoFont *font,
+ const char *text,
+ gint length,
+ PangoAnalysis *analysis,
+ PangoGlyphString *glyphs)
+{
+ int n_chars;
+ int i;
+ const char *p;
+ gulong *properties = NULL;
+ gunichar *wcs = NULL;
+ FT_Face face;
+ PangoOTRuleset *ruleset;
+
+ g_return_if_fail (font != NULL);
+ g_return_if_fail (text != NULL);
+ g_return_if_fail (length >= 0);
+ g_return_if_fail (analysis != NULL);
+
+ face = pango_xft_font_get_face (font);
+ g_assert (face);
+
+ n_chars = g_utf8_strlen (text, length);
+ pango_glyph_string_set_size (glyphs, n_chars);
+
+ ruleset = get_ruleset (font);
+ if (ruleset)
+ {
+ wcs = g_utf8_to_ucs4 (text, length);
+ properties = g_new0 (gulong, n_chars);
+
+ Assign_Arabic_Properties (wcs, properties, n_chars);
+ }
+
+ p = text;
+ for (i=0; i < n_chars; i++)
+ {
+ gunichar wc;
+ gunichar mirrored_ch;
+ PangoGlyph index;
+ char buf[6];
+ const char *input;
+
+ wc = g_utf8_get_char (p);
+
+ input = p;
+ if (analysis->level % 2)
+ if (pango_get_mirror_char (wc, &mirrored_ch))
+ {
+ wc = mirrored_ch;
+
+ g_unichar_to_utf8 (wc, buf);
+ input = buf;
+ }
+
+ if (wc >= 0x200B && wc <= 0x200F) /* Zero-width characters */
+ {
+ set_glyph (font, glyphs, i, p - text, 0);
+ }
+ else
+ {
+ /* Hack - Microsoft fonts are strange and don't contain the
+ * correct rules to shape ARABIC LETTER FARSI YEH in
+ * medial/initial position. It looks identical to ARABIC LETTER
+ * YEH in these positions, so we substitute
+ */
+ if (wc == 0x6cc && ruleset &&
+ ((properties[i] & (initial | medial)) != (initial | medial)))
+ wc = 0x64a;
+
+ index = find_char (face, font, wc);
+
+ if (!index)
+ {
+ set_glyph (font, glyphs, i, p - text,
+ pango_xft_font_get_unknown_glyph (font, wc));
+ }
+ else
+ {
+ set_glyph (font, glyphs, i, p - text, index);
+
+ if (g_unichar_type (wc) == G_UNICODE_NON_SPACING_MARK)
+ {
+ if (i > 0)
+ {
+ glyphs->log_clusters[i] = glyphs->log_clusters[i-1];
+#if 0
+ PangoRectangle logical_rect, ink_rect;
+
+ glyphs->glyphs[i].geometry.width = MAX (glyphs->glyphs[i-1].geometry.width,
+ glyphs->glyphs[i].geometry.width);
+ glyphs->glyphs[i-1].geometry.width = 0;
+
+ /* Some heuristics to try to guess how overstrike glyphs are
+ * done and compensate
+ */
+ pango_font_get_glyph_extents (font, glyphs->glyphs[i].glyph, &ink_rect, &logical_rect);
+ if (logical_rect.width == 0 && ink_rect.x == 0)
+ glyphs->glyphs[i].geometry.x_offset = (glyphs->glyphs[i].geometry.width - ink_rect.width) / 2;
+#endif
+ }
+ }
+ }
+ }
+
+ p = g_utf8_next_char (p);
+ }
+
+ ruleset = get_ruleset (font);
+
+ if (ruleset)
+ {
+ pango_ot_ruleset_shape (ruleset, glyphs, properties);
+
+ g_free (wcs);
+ g_free (properties);
+
+ }
+
+ for (i = 0; i < glyphs->num_glyphs; i++)
+ {
+
+ if (glyphs->glyphs[i].glyph)
+ {
+ PangoRectangle logical_rect;
+
+ pango_font_get_glyph_extents (font, glyphs->glyphs[i].glyph, NULL, &logical_rect);
+ glyphs->glyphs[i].geometry.width = logical_rect.width;
+ }
+ else
+ glyphs->glyphs[i].geometry.width = 0;
+
+ glyphs->glyphs[i].geometry.x_offset = 0;
+ glyphs->glyphs[i].geometry.y_offset = 0;
+ }
+
+ /* Simple bidi support */
+
+ if (analysis->level % 2)
+ {
+ int start, end;
+
+ /* Swap all glyphs */
+ swap_range (glyphs, 0, glyphs->num_glyphs);
+
+ /* Now reorder glyphs within each cluster back to LTR */
+ for (start=0; start<glyphs->num_glyphs;)
+ {
+ end = start;
+ while (end < glyphs->num_glyphs &&
+ glyphs->log_clusters[end] == glyphs->log_clusters[start])
+ end++;
+
+ if (end > start + 1)
+ swap_range (glyphs, start, end);
+ start = end;
+ }
+ }
+}
+
+static PangoCoverage *
+arabic_engine_get_coverage (PangoFont *font,
+ const char *lang)
+{
+ return pango_font_get_coverage (font, lang);
+}
+
+static PangoEngine *
+arabic_engine_xft_new ()
+{
+ PangoEngineShape *result;
+
+ result = g_new (PangoEngineShape, 1);
+
+ result->engine.id = PANGO_RENDER_TYPE_XFT;
+ result->engine.type = PANGO_ENGINE_TYPE_SHAPE;
+ result->engine.length = sizeof (result);
+ result->script_shape = arabic_engine_shape;
+ result->get_coverage = arabic_engine_get_coverage;
+
+ return (PangoEngine *)result;
+}
+
+/* The following three functions provide the public module API for
+ * Pango. If we are compiling it is a module, then we name the
+ * entry points script_engine_list, etc. But if we are compiling
+ * it for inclusion directly in Pango, then we need them to
+ * to have distinct names for this module, so we prepend
+ * _pango_arabic_
+ */
+#ifdef MODULE_PREFIX
+#define MODULE_ENTRY(func) _pango_arabic_##func
+#else
+#define MODULE_ENTRY(func) func
+#endif
+
+/* List the engines contained within this module
+ */
+void
+MODULE_ENTRY(script_engine_list) (PangoEngineInfo **engines, gint *n_engines)
+{
+ *engines = script_engines;
+ *n_engines = G_N_ELEMENTS (script_engines);
+}
+
+/* Load a particular engine given the ID for the engine
+ */
+PangoEngine *
+MODULE_ENTRY(script_engine_load) (const char *id)
+{
+ if (!strcmp (id, "ArabicScriptEngineXft"))
+ return arabic_engine_xft_new ();
+ else
+ return NULL;
+}
+
+void
+MODULE_ENTRY(script_engine_unload) (PangoEngine *engine)
+{
+}
View Lorry Controller Status