Implement Unicode compatibility decompositions

Based on patch from Philip Withnall.
https://bugs.freedesktop.org/show_bug.cgi?id=41095
This commit is contained in:
Behdad Esfahbod 2012-07-31 21:36:16 -04:00
parent 321ec29cc2
commit 378d279bbf
8 changed files with 214 additions and 21 deletions

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@ -336,6 +336,36 @@ hb_glib_unicode_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
return ret; return ret;
} }
static unsigned int
hb_glib_unicode_decompose_compatibility (hb_unicode_funcs_t *ufuncs,
hb_codepoint_t u,
hb_codepoint_t *decomposed,
void *user_data HB_UNUSED)
{
#if GLIB_CHECK_VERSION(2,29,12)
return g_unichar_fully_decompose (u, TRUE, decomposed, HB_UNICODE_MAX_DECOMPOSITION_LEN);
#endif
/* If the user doesn't have GLib >= 2.29.12 we have to perform
* a round trip to UTF-8 and the associated memory management dance. */
gchar utf8[6];
gchar *utf8_decomposed, *c;
gsize utf8_len, utf8_decomposed_len, i;
/* Convert @u to UTF-8 and normalise it in NFKD mode. This performs the compatibility decomposition. */
utf8_len = g_unichar_to_utf8 (u, utf8);
utf8_decomposed = g_utf8_normalize (utf8, utf8_len, G_NORMALIZE_NFKD);
utf8_decomposed_len = g_utf8_strlen (utf8_decomposed, -1);
assert (utf8_decomposed_len <= HB_UNICODE_MAX_DECOMPOSITION_LEN);
for (i = 0, c = utf8_decomposed; i < utf8_decomposed_len; i++, c = g_utf8_next_char (c))
*decomposed++ = g_utf8_get_char (c);
g_free (utf8_decomposed);
return utf8_decomposed_len;
}
extern HB_INTERNAL const hb_unicode_funcs_t _hb_glib_unicode_funcs; extern HB_INTERNAL const hb_unicode_funcs_t _hb_glib_unicode_funcs;
const hb_unicode_funcs_t _hb_glib_unicode_funcs = { const hb_unicode_funcs_t _hb_glib_unicode_funcs = {

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@ -207,7 +207,7 @@ hb_icu_unicode_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t *b, hb_codepoint_t *b,
void *user_data HB_UNUSED) void *user_data HB_UNUSED)
{ {
UChar utf16[2], normalized[20]; UChar utf16[2], normalized[2 * HB_UNICODE_MAX_DECOMPOSITION_LEN + 1];
int len; int len;
hb_bool_t ret, err; hb_bool_t ret, err;
UErrorCode icu_err; UErrorCode icu_err;
@ -271,6 +271,40 @@ hb_icu_unicode_decompose (hb_unicode_funcs_t *ufuncs HB_UNUSED,
return ret; return ret;
} }
static unsigned int
hb_icu_unicode_decompose_compatibility (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t u,
hb_codepoint_t *decomposed,
void *user_data HB_UNUSED)
{
UChar utf16[2], normalized[2 * HB_UNICODE_MAX_DECOMPOSITION_LEN + 1];
gint len;
int32_t utf32_len;
hb_bool_t err;
UErrorCode icu_err;
/* Copy @u into a UTF-16 array to be passed to ICU. */
len = 0;
err = FALSE;
U16_APPEND (utf16, len, ARRAY_LENGTH (utf16), u, err);
if (err)
return 0;
/* Normalise the codepoint using NFKD mode. */
icu_err = U_ZERO_ERROR;
len = unorm_normalize (utf16, len, UNORM_NFKD, 0, normalized, ARRAY_LENGTH (normalized), &icu_err);
if (icu_err)
return 0;
/* Convert the decomposed form from UTF-16 to UTF-32. */
icu_err = U_ZERO_ERROR;
u_strToUTF32 ((UChar32*) decomposed, HB_UNICODE_MAX_DECOMPOSITION_LEN, &utf32_len, normalized, len, &icu_err);
if (icu_err)
return 0;
return utf32_len;
}
extern HB_INTERNAL const hb_unicode_funcs_t _hb_icu_unicode_funcs; extern HB_INTERNAL const hb_unicode_funcs_t _hb_icu_unicode_funcs;
const hb_unicode_funcs_t _hb_icu_unicode_funcs = { const hb_unicode_funcs_t _hb_icu_unicode_funcs = {

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@ -62,7 +62,8 @@
* knowledge too. We need to provide assistance to the itemizer. * knowledge too. We need to provide assistance to the itemizer.
* *
* - When a font does not support a character but supports its decomposition, * - When a font does not support a character but supports its decomposition,
* well, use the decomposition. * well, use the decomposition (preferring the canonical decomposition, but
* falling back to the compatibility decomposition if necessary).
* *
* - The Indic shaper requests decomposed output. This will handle splitting * - The Indic shaper requests decomposed output. This will handle splitting
* matra for the Indic shaper. * matra for the Indic shaper.
@ -111,29 +112,45 @@ decompose (hb_font_t *font, hb_buffer_t *buffer,
return false; return false;
} }
static void static bool
decompose_current_glyph (hb_font_t *font, hb_buffer_t *buffer, decompose_compatibility (hb_font_t *font, hb_buffer_t *buffer,
bool shortest) hb_codepoint_t u)
{ {
if (decompose (font, buffer, shortest, buffer->cur().codepoint)) unsigned int len, i;
buffer->skip_glyph (); hb_codepoint_t decomposed[HB_UNICODE_MAX_DECOMPOSITION_LEN];
else
buffer->next_glyph (); len = hb_unicode_decompose_compatibility (buffer->unicode, u, decomposed);
if (!len)
return false;
hb_codepoint_t glyph;
for (i = 0; i < len; i++)
if (!hb_font_get_glyph (font, decomposed[i], 0, &glyph))
return false;
for (i = 0; i < len; i++)
output_glyph (buffer, decomposed[i]);
return true;
} }
static void static void
decompose_single_char_cluster (hb_font_t *font, hb_buffer_t *buffer, decompose_current_character (hb_font_t *font, hb_buffer_t *buffer,
bool will_recompose) bool shortest)
{ {
hb_codepoint_t glyph; hb_codepoint_t glyph;
/* If recomposing and font supports this, we're good to go */ /* Kind of a cute waterfall here... */
if (will_recompose && hb_font_get_glyph (font, buffer->cur().codepoint, 0, &glyph)) { if (shortest && hb_font_get_glyph (font, buffer->cur().codepoint, 0, &glyph))
buffer->next_glyph ();
else if (decompose (font, buffer, shortest, buffer->cur().codepoint))
buffer->skip_glyph ();
else if (!shortest && hb_font_get_glyph (font, buffer->cur().codepoint, 0, &glyph))
buffer->next_glyph ();
else if (decompose_compatibility (font, buffer, buffer->cur().codepoint))
buffer->skip_glyph ();
else
buffer->next_glyph (); buffer->next_glyph ();
return;
}
decompose_current_glyph (font, buffer, will_recompose);
} }
static void static void
@ -149,7 +166,7 @@ decompose_multi_char_cluster (hb_font_t *font, hb_buffer_t *buffer,
} }
while (buffer->idx < end) while (buffer->idx < end)
decompose_current_glyph (font, buffer, false); decompose_current_character (font, buffer, false);
} }
static int static int
@ -188,7 +205,7 @@ _hb_ot_shape_normalize (hb_font_t *font, hb_buffer_t *buffer,
break; break;
if (buffer->idx + 1 == end) if (buffer->idx + 1 == end)
decompose_single_char_cluster (font, buffer, recompose); decompose_current_character (font, buffer, recompose);
else { else {
decompose_multi_char_cluster (font, buffer, end); decompose_multi_char_cluster (font, buffer, end);
has_multichar_clusters = true; has_multichar_clusters = true;

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@ -50,6 +50,7 @@
HB_UNICODE_FUNC_IMPLEMENT (script) \ HB_UNICODE_FUNC_IMPLEMENT (script) \
HB_UNICODE_FUNC_IMPLEMENT (compose) \ HB_UNICODE_FUNC_IMPLEMENT (compose) \
HB_UNICODE_FUNC_IMPLEMENT (decompose) \ HB_UNICODE_FUNC_IMPLEMENT (decompose) \
HB_UNICODE_FUNC_IMPLEMENT (decompose_compatibility) \
/* ^--- Add new callbacks here */ /* ^--- Add new callbacks here */
/* Simple callbacks are those taking a hb_codepoint_t and returning a hb_codepoint_t */ /* Simple callbacks are those taking a hb_codepoint_t and returning a hb_codepoint_t */

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@ -99,6 +99,15 @@ hb_unicode_decompose_nil (hb_unicode_funcs_t *ufuncs HB_UNUSED,
} }
static unsigned int
hb_unicode_decompose_compatibility_nil (hb_unicode_funcs_t *ufuncs HB_UNUSED,
hb_codepoint_t u HB_UNUSED,
hb_codepoint_t *decomposed HB_UNUSED,
void *user_data HB_UNUSED)
{
return 0;
}
hb_unicode_funcs_t * hb_unicode_funcs_t *
hb_unicode_funcs_get_default (void) hb_unicode_funcs_get_default (void)
@ -312,6 +321,23 @@ hb_unicode_decompose (hb_unicode_funcs_t *ufuncs,
return ufuncs->func.decompose (ufuncs, ab, a, b, ufuncs->user_data.decompose); return ufuncs->func.decompose (ufuncs, ab, a, b, ufuncs->user_data.decompose);
} }
unsigned int
hb_unicode_decompose_compatibility (hb_unicode_funcs_t *ufuncs,
hb_codepoint_t u,
hb_codepoint_t *decomposed)
{
unsigned int ret = ufuncs->func.decompose_compatibility (ufuncs, u,
decomposed,
ufuncs->user_data.decompose_compatibility);
if (ret == 1 && u == decomposed[0]) {
decomposed[0] = 0;
return 0;
}
decomposed[ret] = 0;
return ret;
}
unsigned int unsigned int
@ -380,4 +406,3 @@ _hb_unicode_modified_combining_class (hb_unicode_funcs_t *ufuncs,
return c; return c;
} }

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@ -1,7 +1,7 @@
/* /*
* Copyright © 2009 Red Hat, Inc. * Copyright © 2009 Red Hat, Inc.
* Copyright © 2011 Codethink Limited * Copyright © 2011 Codethink Limited
* Copyright © 2011 Google, Inc. * Copyright © 2011,2012 Google, Inc.
* *
* This is part of HarfBuzz, a text shaping library. * This is part of HarfBuzz, a text shaping library.
* *
@ -122,6 +122,32 @@ typedef hb_bool_t (*hb_unicode_decompose_func_t) (hb_unicode_funcs_t *ufuncs,
hb_codepoint_t *b, hb_codepoint_t *b,
void *user_data); void *user_data);
/**
* hb_unicode_decompose_compatibility_func_t:
* @ufuncs: Unicode function structure
* @u: codepoint to decompose
* @decomposed: address of codepoint array (of length %HB_UNICODE_MAX_DECOMPOSITION_LEN) to write decomposition into
* @user_data: user data pointer as passed to hb_unicode_funcs_set_decompose_compatibility_func()
*
* Fully decompose @u to its Unicode compatibility decomposition. The codepoints of the decomposition will be written to @decomposed.
* The complete length of the decomposition will be returned.
*
* If @u has no compatibility decomposition, zero should be returned.
*
* The Unicode standard guarantees that a buffer of length %HB_UNICODE_MAX_DECOMPOSITION_LEN codepoints will always be sufficient for any
* compatibility decomposition plus an terminating value of 0. Consequently, @decompose must be allocated by the caller to be at least this length. Implementations
* of this function type must ensure that they do not write past the provided array.
*
* Return value: number of codepoints in the full compatibility decomposition of @u, or 0 if no decomposition available.
*/
typedef unsigned int (*hb_unicode_decompose_compatibility_func_t) (hb_unicode_funcs_t *ufuncs,
hb_codepoint_t u,
hb_codepoint_t *decomposed,
void *user_data);
/* See Unicode 6.1 for details on the maximum decomposition length. */
#define HB_UNICODE_MAX_DECOMPOSITION_LEN (18+1) /* codepoints */
/* setters */ /* setters */
void void
@ -159,6 +185,10 @@ hb_unicode_funcs_set_decompose_func (hb_unicode_funcs_t *ufuncs,
hb_unicode_decompose_func_t decompose_func, hb_unicode_decompose_func_t decompose_func,
void *user_data, hb_destroy_func_t destroy); void *user_data, hb_destroy_func_t destroy);
void
hb_unicode_funcs_set_decompose_compatibility_func (hb_unicode_funcs_t *ufuncs,
hb_unicode_decompose_compatibility_func_t decompose_compatibility_func,
void *user_data, hb_destroy_func_t destroy);
/* accessors */ /* accessors */
@ -193,6 +223,11 @@ hb_unicode_decompose (hb_unicode_funcs_t *ufuncs,
hb_codepoint_t *a, hb_codepoint_t *a,
hb_codepoint_t *b); hb_codepoint_t *b);
unsigned int
hb_unicode_decompose_compatibility (hb_unicode_funcs_t *ufuncs,
hb_codepoint_t u,
hb_codepoint_t *decomposed);
HB_END_DECLS HB_END_DECLS
#endif /* HB_UNICODE_H */ #endif /* HB_UNICODE_H */

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@ -33,6 +33,7 @@
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
#include <stdio.h>
HB_BEGIN_DECLS HB_BEGIN_DECLS

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@ -786,6 +786,7 @@ test_unicode_normalization (gconstpointer user_data)
{ {
hb_unicode_funcs_t *uf = (hb_unicode_funcs_t *) user_data; hb_unicode_funcs_t *uf = (hb_unicode_funcs_t *) user_data;
gunichar a, b, ab; gunichar a, b, ab;
hb_codepoint_t decomposed[HB_UNICODE_MAX_DECOMPOSITION_LEN];
/* Test compose() */ /* Test compose() */
@ -849,6 +850,55 @@ test_unicode_normalization (gconstpointer user_data)
g_assert (hb_unicode_decompose (uf, 0xCE31, &a, &b) && a == 0xCE20 && b == 0x11B8); g_assert (hb_unicode_decompose (uf, 0xCE31, &a, &b) && a == 0xCE20 && b == 0x11B8);
g_assert (hb_unicode_decompose (uf, 0xCE20, &a, &b) && a == 0x110E && b == 0x1173); g_assert (hb_unicode_decompose (uf, 0xCE20, &a, &b) && a == 0x110E && b == 0x1173);
/* Test decompose_compatibility() */
/* Not decomposable */
g_assert (hb_unicode_decompose_compatibility (uf, 0x0041, decomposed) == 0);
g_assert (hb_unicode_decompose_compatibility (uf, 0x1F632, decomposed) == 0);
/* Singletons */
g_assert (hb_unicode_decompose_compatibility (uf, 0x00B5, decomposed) == 1 && decomposed[0] == 0x03BC);
g_assert (hb_unicode_decompose_compatibility (uf, 0x03D6, decomposed) == 1 && decomposed[0] == 0x03C0);
/* Arabic compatibility */
g_assert (hb_unicode_decompose_compatibility (uf, 0xFB54, decomposed) == 1 && decomposed[0] == 0x067B);
/* Longest decomposition ever */
g_assert (18 <= HB_UNICODE_MAX_DECOMPOSITION_LEN);
g_assert (hb_unicode_decompose_compatibility (uf, 0xFDFA, decomposed) == 18 && decomposed[17] == 0x0645);
/* Note: we deliberately don't test characters that have canonical decompositions but no
* compatibility decomposition against the decompose_compatibility() function as that we
* leave up to implementations (for now). */
/* Spaces */
g_assert (hb_unicode_decompose_compatibility (uf, 0x2002, decomposed) == 1 && decomposed[0] == 0x0020);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2003, decomposed) == 1 && decomposed[0] == 0x0020);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2004, decomposed) == 1 && decomposed[0] == 0x0020);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2005, decomposed) == 1 && decomposed[0] == 0x0020);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2006, decomposed) == 1 && decomposed[0] == 0x0020);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2008, decomposed) == 1 && decomposed[0] == 0x0020);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2009, decomposed) == 1 && decomposed[0] == 0x0020);
g_assert (hb_unicode_decompose_compatibility (uf, 0x200A, decomposed) == 1 && decomposed[0] == 0x0020);
/* Pairs */
g_assert (hb_unicode_decompose_compatibility (uf, 0x0587, decomposed) == 2 &&
decomposed[0] == 0x0565 && decomposed[1] == 0x0582);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2017, decomposed) == 2 &&
decomposed[0] == 0x0020 && decomposed[1] == 0x0333);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2025, decomposed) == 2 &&
decomposed[0] == 0x002E && decomposed[1] == 0x002E);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2033, decomposed) == 2 &&
decomposed[0] == 0x2032 && decomposed[1] == 0x2032);
/* Triples */
g_assert (hb_unicode_decompose_compatibility (uf, 0x2026, decomposed) == 3 &&
decomposed[0] == 0x002E && decomposed[1] == 0x002E && decomposed[2] == 0x002E);
g_assert (hb_unicode_decompose_compatibility (uf, 0x2034, decomposed) == 3 &&
decomposed[0] == 0x2032 && decomposed[1] == 0x2032 && decomposed[2] == 0x2032);
g_assert (hb_unicode_decompose_compatibility (uf, 0x213B, decomposed) == 3 &&
decomposed[0] == 0x0046 && decomposed[1] == 0x0041 && decomposed[2] == 0x0058);
} }