[CoreText] Add basic Core Text backend for comparison with our native shaping

Does not attempt to handle clusters in a Uniscribe- or HarfBuzz-compatible way;
just returns the original string indexes that CT maintains. These may even be
out-of-order in the case of reordrant glyphs.

configure.ac

@@ -186,6 +186,18 @@ AM_CONDITIONAL(HAVE_UNISCRIBE, $have_uniscribe)
 
 dnl ===========================================================================
 
+AC_CHECK_HEADERS(ApplicationServices/ApplicationServices.h, have_coretext=true, have_coretext=false)
+if $have_coretext; then
+	CORETEXT_CFLAGS=
+	CORETEXT_LIBS=
+	AC_SUBST(CORETEXT_CFLAGS)
+	AC_SUBST(CORETEXT_LIBS)
+	AC_DEFINE(HAVE_CORETEXT, 1, [Have Core Text backend])
+fi
+AM_CONDITIONAL(HAVE_CORETEXT, $have_coretext)
+
+dnl ===========================================================================
+
 AC_CACHE_CHECK([for Intel atomic primitives], hb_cv_have_intel_atomic_primitives, [
 	hb_cv_have_intel_atomic_primitives=false
 	AC_TRY_LINK([

src/Makefile.am

@@ -138,6 +138,13 @@ HBSOURCES += hb-uniscribe.cc hb-uniscribe-private.hh
 HBHEADERS += hb-uniscribe.h
 endif
 
+if HAVE_CORETEXT
+HBCFLAGS += $(CORETEXT_CFLAGS)
+HBLIBS   += $(CORETEXT_LIBS)
+HBSOURCES += hb-coretext.cc hb-coretext-private.hh
+HBHEADERS += hb-coretext.h
+endif
+
 # Use a C linker, not C++; Don't link to libstdc++
 libharfbuzz_la_LINK = $(LINK) $(libharfbuzz_la_LDFLAGS)
 libharfbuzz_la_SOURCES = $(HBSOURCES) $(HBHEADERS)

src/hb-coretext-private.hh

@@ -0,0 +1,42 @@
+/*
+ * Copyright © 2012  Mozilla Foundation.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Mozilla Author(s): Jonathan Kew
+ */
+
+#ifndef HB_CORETEXT_PRIVATE_HH
+#define HB_CORETEXT_PRIVATE_HH
+
+#include "hb-private.hh"
+
+#include "hb-coretext.h"
+
+
+HB_INTERNAL hb_bool_t
+_hb_coretext_shape (hb_font_t          *font,
+		     hb_buffer_t        *buffer,
+		     const hb_feature_t *features,
+		     unsigned int        num_features);
+
+
+#endif /* HB_CORETEXT_PRIVATE_HH */

src/hb-coretext.cc

@@ -0,0 +1,323 @@
+/*
+ * Copyright © 2012  Mozilla Foundation.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Mozilla Author(s): Jonathan Kew
+ */
+
+#include "hb-private.hh"
+
+#define GlyphID GlyphID_mac
+#include <ApplicationServices/ApplicationServices.h>
+#undef GlyphID
+
+#include "hb-coretext.h"
+
+#include "hb-ot-name-table.hh"
+#include "hb-ot-tag.h"
+
+#include "hb-font-private.hh"
+#include "hb-buffer-private.hh"
+
+
+#ifndef HB_DEBUG_CORETEXT
+#define HB_DEBUG_CORETEXT (HB_DEBUG+0)
+#endif
+
+
+static hb_user_data_key_t hb_coretext_data_key;
+
+static struct hb_coretext_face_data_t {
+  CGFontRef  cg_font;
+} _hb_coretext_face_data_nil = {0};
+
+static void
+_hb_coretext_face_data_destroy (hb_coretext_face_data_t *data)
+{
+  if (data->cg_font)
+    CFRelease (data->cg_font);
+  free (data);
+}
+
+static void
+release_data (void *info, const void *data, size_t size)
+{
+  assert (hb_blob_get_length ((hb_blob_t *) info) == size &&
+          hb_blob_get_data ((hb_blob_t *) info, NULL) == data);
+
+  hb_blob_destroy ((hb_blob_t *) info);
+}
+
+static hb_coretext_face_data_t *
+_hb_coretext_face_get_data (hb_face_t *face)
+{
+  hb_coretext_face_data_t *data = (hb_coretext_face_data_t *) hb_face_get_user_data (face, &hb_coretext_data_key);
+  if (likely (data)) return data;
+
+  data = (hb_coretext_face_data_t *) calloc (1, sizeof (hb_coretext_face_data_t));
+  if (unlikely (!data))
+    return &_hb_coretext_face_data_nil;
+
+
+  hb_blob_t *blob = hb_face_reference_blob (face);
+  unsigned int blob_length;
+  const char *blob_data = hb_blob_get_data (blob, &blob_length);
+  if (unlikely (!blob_length))
+    DEBUG_MSG (CORETEXT, face, "Face has empty blob");
+
+  CGDataProviderRef provider = CGDataProviderCreateWithData (blob, blob_data, blob_length, &release_data);
+  data->cg_font = CGFontCreateWithDataProvider (provider);
+  CGDataProviderRelease (provider);
+
+  if (unlikely (!data->cg_font))
+    DEBUG_MSG (CORETEXT, face, "Face CGFontCreateWithDataProvider() failed");
+
+
+  if (unlikely (!hb_face_set_user_data (face, &hb_coretext_data_key, data,
+                                        (hb_destroy_func_t) _hb_coretext_face_data_destroy,
+                                        false)))
+  {
+    _hb_coretext_face_data_destroy (data);
+    data = (hb_coretext_face_data_t *) hb_face_get_user_data (face, &hb_coretext_data_key);
+    if (data)
+      return data;
+    else
+      return &_hb_coretext_face_data_nil;
+  }
+
+  return data;
+}
+
+
+static struct hb_coretext_font_data_t {
+  CTFontRef ct_font;
+} _hb_coretext_font_data_nil = {0};
+
+static void
+_hb_coretext_font_data_destroy (hb_coretext_font_data_t *data)
+{
+  if (data->ct_font)
+    CFRelease (data->ct_font);
+  free (data);
+}
+
+static hb_coretext_font_data_t *
+_hb_coretext_font_get_data (hb_font_t *font)
+{
+  hb_coretext_font_data_t *data = (hb_coretext_font_data_t *) hb_font_get_user_data (font, &hb_coretext_data_key);
+  if (likely (data)) return data;
+
+  data = (hb_coretext_font_data_t *) calloc (1, sizeof (hb_coretext_font_data_t));
+  if (unlikely (!data))
+    return &_hb_coretext_font_data_nil;
+
+  hb_coretext_face_data_t *face_data = _hb_coretext_face_get_data (font->face);
+
+  data->ct_font = CTFontCreateWithGraphicsFont (face_data->cg_font, font->y_scale, NULL, NULL);
+  if (unlikely (!data->ct_font))
+    DEBUG_MSG (CORETEXT, font, "Font CTFontCreateWithGraphicsFont() failed");
+
+  if (unlikely (!hb_font_set_user_data (font, &hb_coretext_data_key, data,
+                                        (hb_destroy_func_t) _hb_coretext_font_data_destroy,
+                                        false)))
+  {
+    _hb_coretext_font_data_destroy (data);
+    data = (hb_coretext_font_data_t *) hb_font_get_user_data (font, &hb_coretext_data_key);
+    if (data)
+      return data;
+    else
+      return &_hb_coretext_font_data_nil;
+  }
+
+  return data;
+}
+
+CTFontRef
+hb_coretext_font_get_ct_font (hb_font_t *font)
+{
+  hb_coretext_font_data_t *font_data = _hb_coretext_font_get_data (font);
+  if (unlikely (!font_data))
+    return 0;
+  return font_data->ct_font;
+}
+
+
+hb_bool_t
+_hb_coretext_shape (hb_font_t          *font,
+                    hb_buffer_t        *buffer,
+                    const hb_feature_t *features,
+                    unsigned int        num_features)
+{
+  buffer->guess_properties ();
+
+#define FAIL(...) \
+  HB_STMT_START { \
+    DEBUG_MSG (CORETEXT, NULL, __VA_ARGS__); \
+    return false; \
+  } HB_STMT_END;
+
+  hb_coretext_face_data_t *face_data = _hb_coretext_face_get_data (font->face);
+  if (unlikely (!face_data->cg_font))
+    FAIL ("Couldn't get face data");
+
+  hb_coretext_font_data_t *font_data = _hb_coretext_font_get_data (font);
+  if (unlikely (!font_data->ct_font))
+    FAIL ("Couldn't get font font");
+
+  if (unlikely (!buffer->len))
+    return true;
+
+  unsigned int scratch_size;
+  char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
+
+#define utf16_index() var1.u32
+
+  UniChar *pchars = (UniChar *) scratch;
+  unsigned int chars_len = 0;
+  for (unsigned int i = 0; i < buffer->len; i++) {
+    hb_codepoint_t c = buffer->info[i].codepoint;
+    buffer->info[i].utf16_index() = chars_len;
+    if (likely (c < 0x10000))
+      pchars[chars_len++] = c;
+    else if (unlikely (c >= 0x110000))
+      pchars[chars_len++] = 0xFFFD;
+    else {
+      pchars[chars_len++] = 0xD800 + ((c - 0x10000) >> 10);
+      pchars[chars_len++] = 0xDC00 + ((c - 0x10000) & ((1 << 10) - 1));
+    }
+  }
+
+#undef utf16_index
+
+  CFStringRef string_ref = CFStringCreateWithCharactersNoCopy (kCFAllocatorDefault,
+                                                               pchars, chars_len,
+                                                               kCFAllocatorNull);
+
+  CFDictionaryRef attrs = CFDictionaryCreate (kCFAllocatorDefault,
+                                              (const void**) &kCTFontAttributeName,
+                                              (const void**) &font_data->ct_font,
+                                              1, // count of attributes
+                                              &kCFTypeDictionaryKeyCallBacks,
+                                              &kCFTypeDictionaryValueCallBacks);
+
+  // TODO: support features
+
+  // Now we can create an attributed string
+  CFAttributedStringRef attr_string = CFAttributedStringCreate (kCFAllocatorDefault, string_ref, attrs);
+  CFRelease (string_ref);
+  CFRelease (attrs);
+
+  // Create the CoreText line from our string, then we're done with it
+  CTLineRef line = CTLineCreateWithAttributedString (attr_string);
+  CFRelease (attr_string);
+
+  // and finally retrieve the glyph data and store into the gfxTextRun
+  CFArrayRef glyph_runs = CTLineGetGlyphRuns (line);
+  unsigned int num_runs = CFArrayGetCount (glyph_runs);
+
+  // Iterate through the glyph runs.
+  bool success = true;
+  buffer->len = 0;
+
+  const CFRange range_all = CFRangeMake (0, 0);
+
+  for (unsigned int i = 0; i < num_runs; i++) {
+    CTRunRef run = (CTRunRef) CFArrayGetValueAtIndex (glyph_runs, i);
+
+    unsigned int num_glyphs = CTRunGetGlyphCount (run);
+    if (num_glyphs == 0)
+      continue;
+
+    buffer->ensure (buffer->len + num_glyphs);
+
+    // retrieve the laid-out glyph data from the CTRun
+
+    // Testing indicates that CTRunGetGlyphsPtr (almost?) always succeeds,
+    // and so copying data to our own buffer with CTRunGetGlyphs will be
+    // extremely rare.
+
+    unsigned int scratch_size;
+    char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
+
+#define ALLOCATE_ARRAY(Type, name, len) \
+  Type *name = (Type *) scratch; \
+  scratch += len * sizeof (name[0]); \
+  scratch_size -= len * sizeof (name[0]);
+
+    const CGGlyph* glyphs = CTRunGetGlyphsPtr (run);
+    if (!glyphs) {
+      ALLOCATE_ARRAY (CGGlyph, glyph_buf, num_glyphs);
+      CTRunGetGlyphs (run, range_all, glyph_buf);
+      glyphs = glyph_buf;
+    }
+
+    const CGPoint* positions = CTRunGetPositionsPtr (run);
+    if (!positions) {
+      ALLOCATE_ARRAY (CGPoint, position_buf, num_glyphs);
+      CTRunGetPositions (run, range_all, position_buf);
+      positions = position_buf;
+    }
+
+    const CFIndex* string_indices = CTRunGetStringIndicesPtr (run);
+    if (!string_indices) {
+      ALLOCATE_ARRAY (CFIndex, index_buf, num_glyphs);
+      CTRunGetStringIndices (run, range_all, index_buf);
+      string_indices = index_buf;
+    }
+
+#undef ALLOCATE_ARRAY
+
+    double run_width = CTRunGetTypographicBounds (run, range_all, NULL, NULL, NULL);
+
+    for (unsigned int j = 0; j < num_glyphs; j++) {
+      double advance = (j + 1 < num_glyphs ? positions[j + 1].x : positions[0].x + run_width) - positions[j].x;
+
+      hb_glyph_info_t *info = &buffer->info[buffer->len];
+      hb_glyph_position_t *pos = &buffer->pos[buffer->len];
+
+      info->codepoint = glyphs[j];
+      info->cluster = string_indices[j];
+
+      // currently, we do all x-positioning by setting the advance, we never use x-offset
+      info->mask = advance;
+      info->var1.u32 = 0;
+      info->var2.u32 = positions[j].y;
+
+      buffer->len++;
+    }
+  }
+
+  buffer->clear_positions ();
+
+  unsigned int count = buffer->len;
+  for (unsigned int i = 0; i < count; ++i) {
+    hb_glyph_info_t *info = &buffer->info[i];
+    hb_glyph_position_t *pos = &buffer->pos[i];
+
+    /* TODO vertical */
+    pos->x_advance = info->mask;
+    pos->x_offset = info->var1.u32;
+    pos->y_offset = info->var2.u32;
+  }
+
+  return true;
+}

src/hb-coretext.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright © 2012  Mozilla Foundation.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Mozilla Author(s): Jonathan Kew
+ */
+
+#ifndef HB_CORETEXT_H
+#define HB_CORETEXT_H
+
+#include "hb.h"
+
+#include <ApplicationServices/ApplicationServices.h>
+
+HB_BEGIN_DECLS
+
+
+CTFontRef
+hb_coretext_font_get_ct_font (hb_font_t *font);
+
+
+HB_END_DECLS
+
+#endif /* HB_CORETEXT_H */

src/hb-shape.cc

@@ -36,6 +36,9 @@
 #ifdef HAVE_UNISCRIBE
 # include "hb-uniscribe-private.hh"
 #endif
+#ifdef HAVE_CORETEXT
+# include "hb-coretext-private.hh"
+#endif
 #ifdef HAVE_OT
 # include "hb-ot-shape-private.hh"
 #endif
@@ -58,6 +61,9 @@ static const struct hb_shaper_pair_t {
 #ifdef HAVE_UNISCRIBE
   HB_SHAPER_IMPLEMENT (uniscribe),
 #endif
+#ifdef HAVE_CORETEXT
+  HB_SHAPER_IMPLEMENT (coretext),
+#endif
 #ifdef HAVE_OT
   HB_SHAPER_IMPLEMENT (ot),
 #endif