Add Harfbuzz to third_party and Skia support for such.

Harfbuzz is an open source library which is a unification of the Qt
and Pango shaping engines. We'll be using it on Chromium Linux to
perform complex text shaping.

Additionally, we add support for Harfbuzz into Skia, guarded by
SKIA_HARFBUZZ.

http://codereview.chromium.org/63035/show


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@13214 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 188 insertions, 0 deletions

diff --git a/third_party/harfbuzz/src/harfbuzz-hebrew.c b/third_party/harfbuzz/src/harfbuzz-hebrew.c
new file mode 100644
index 0000000..533a063
--- /dev/null
+++ b/third_party/harfbuzz/src/harfbuzz-hebrew.c
@@ -0,0 +1,188 @@
+/*
+ * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
+ *
+ * This is part of HarfBuzz, an OpenType Layout engine 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.
+ */
+
+#include "harfbuzz-shaper.h"
+#include "harfbuzz-shaper-private.h"
+#include <assert.h>
+
+/*
+// Uniscribe also defines dlig for Hebrew, but we leave this out for now, as it's mostly
+// ligatures one does not want in modern Hebrew (as lam-alef ligatures).
+*/
+#ifndef NO_OPENTYPE
+static const HB_OpenTypeFeature hebrew_features[] = {
+    { HB_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },
+    {0, 0}
+};
+#endif
+
+/* Hebrew shaping. In the non opentype case we try to use the
+   presentation forms specified for Hebrew. Especially for the
+   ligatures with Dagesh this gives much better results than we could
+   achieve manually.
+*/
+HB_Bool HB_HebrewShape(HB_ShaperItem *shaper_item)
+{
+    enum {
+        Dagesh = 0x5bc,
+        ShinDot = 0x5c1,
+        SinDot = 0x5c2,
+        Patah = 0x5b7,
+        Qamats = 0x5b8,
+        Holam = 0x5b9,
+        Rafe = 0x5bf
+    };
+
+    assert(shaper_item->item.script == HB_Script_Hebrew);
+
+#ifndef NO_OPENTYPE
+    if (HB_SelectScript(shaper_item, hebrew_features)) {
+
+        const int availableGlyphs = shaper_item->num_glyphs;
+        if (!HB_ConvertStringToGlyphIndices(shaper_item))
+            return FALSE;
+
+
+        HB_HeuristicSetGlyphAttributes(shaper_item);
+        HB_OpenTypeShape(shaper_item, /*properties*/0);
+        return HB_OpenTypePosition(shaper_item, availableGlyphs, /*doLogClusters*/TRUE);
+    }
+#endif
+
+    {
+        const HB_UChar16 *uc = shaper_item->string + shaper_item->item.pos;
+        unsigned short *logClusters = shaper_item->log_clusters;
+        HB_GlyphAttributes *attributes = shaper_item->attributes;
+
+        HB_Bool haveGlyphs;
+        int slen = 1;
+        int cluster_start = 0;
+        hb_uint32 i;
+
+        HB_STACKARRAY(HB_UChar16, shapedChars, 2 * shaper_item->item.length);
+        *shapedChars = *uc;
+        logClusters[0] = 0;
+
+        for (i = 1; i < shaper_item->item.length; ++i) {
+            hb_uint16 base = shapedChars[slen-1];
+            hb_uint16 shaped = 0;
+            HB_Bool invalid = FALSE;
+            if (uc[i] == Dagesh) {
+                if (base >= 0x5d0
+                    && base <= 0x5ea
+                    && base != 0x5d7
+                    && base != 0x5dd
+                    && base != 0x5df
+                    && base != 0x5e2
+                    && base != 0x5e5) {
+                    shaped = base - 0x5d0 + 0xfb30;
+                } else if (base == 0xfb2a || base == 0xfb2b /* Shin with Shin or Sin dot */) {
+                    shaped = base + 2;
+                } else {
+                    invalid = TRUE;
+                }
+            } else if (uc[i] == ShinDot) {
+                if (base == 0x05e9)
+                    shaped = 0xfb2a;
+                else if (base == 0xfb49)
+                    shaped = 0xfb2c;
+                else
+                    invalid = TRUE;
+            } else if (uc[i] == SinDot) {
+                if (base == 0x05e9)
+                    shaped = 0xfb2b;
+                else if (base == 0xfb49)
+                    shaped = 0xfb2d;
+                else
+                    invalid = TRUE;
+            } else if (uc[i] == Patah) {
+                if (base == 0x5d0)
+                    shaped = 0xfb2e;
+            } else if (uc[i] == Qamats) {
+                if (base == 0x5d0)
+                    shaped = 0xfb2f;
+            } else if (uc[i] == Holam) {
+                if (base == 0x5d5)
+                    shaped = 0xfb4b;
+            } else if (uc[i] == Rafe) {
+                if (base == 0x5d1)
+                    shaped = 0xfb4c;
+                else if (base == 0x5db)
+                    shaped = 0xfb4d;
+                else if (base == 0x5e4)
+                    shaped = 0xfb4e;
+            }
+
+            if (invalid) {
+                shapedChars[slen] = 0x25cc;
+                attributes[slen].clusterStart = TRUE;
+                attributes[slen].mark = FALSE;
+                attributes[slen].combiningClass = 0;
+                cluster_start = slen;
+                ++slen;
+            }
+            if (shaped) {
+                if (shaper_item->font->klass->canRender(shaper_item->font, (HB_UChar16 *)&shaped, 1)) {
+                    shapedChars[slen-1] = shaped;
+                } else
+                    shaped = 0;
+            }
+            if (!shaped) {
+                HB_CharCategory category;
+                int cmb;
+                shapedChars[slen] = uc[i];
+                HB_GetUnicodeCharProperties(uc[i], &category, &cmb);
+                if (category != HB_Mark_NonSpacing) {
+                    attributes[slen].clusterStart = TRUE;
+                    attributes[slen].mark = FALSE;
+                    attributes[slen].combiningClass = 0;
+                    attributes[slen].dontPrint = HB_IsControlChar(uc[i]);
+                    cluster_start = slen;
+                } else {
+                    attributes[slen].clusterStart = FALSE;
+                    attributes[slen].mark = TRUE;
+                    attributes[slen].combiningClass = cmb;
+                }
+                ++slen;
+            }
+            logClusters[i] = cluster_start;
+        }
+
+        haveGlyphs = shaper_item->font->klass
+            ->convertStringToGlyphIndices(shaper_item->font,
+                                          shapedChars, slen,
+                                          shaper_item->glyphs, &shaper_item->num_glyphs,
+                                          shaper_item->item.bidiLevel % 2);
+
+        HB_FREE_STACKARRAY(shapedChars);
+
+        if (!haveGlyphs)
+            return FALSE;
+
+        HB_HeuristicPosition(shaper_item);
+    }
+
+    return TRUE;
+}
+