Add m-esr52 at 52.6.0

1 files changed, 438 insertions, 0 deletions

diff --git a/gfx/thebes/gfxGraphiteShaper.cpp b/gfx/thebes/gfxGraphiteShaper.cpp
new file mode 100644
index 000000000..aeebf30f2
--- /dev/null
+++ b/gfx/thebes/gfxGraphiteShaper.cpp
@@ -0,0 +1,438 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gfxGraphiteShaper.h"
+#include "nsString.h"
+#include "gfxContext.h"
+#include "gfxFontConstants.h"
+#include "gfxTextRun.h"
+
+#include "graphite2/Font.h"
+#include "graphite2/Segment.h"
+
+#include "harfbuzz/hb.h"
+
+#define FloatToFixed(f) (65536 * (f))
+#define FixedToFloat(f) ((f) * (1.0 / 65536.0))
+// Right shifts of negative (signed) integers are undefined, as are overflows
+// when converting unsigned to negative signed integers.
+// (If speed were an issue we could make some 2's complement assumptions.)
+#define FixedToIntRound(f) ((f) > 0 ?  ((32768 + (f)) >> 16) \
+                                    : -((32767 - (f)) >> 16))
+
+using namespace mozilla; // for AutoSwap_* types
+
+/*
+ * Creation and destruction; on deletion, release any font tables we're holding
+ */
+
+gfxGraphiteShaper::gfxGraphiteShaper(gfxFont *aFont)
+    : gfxFontShaper(aFont),
+      mGrFace(mFont->GetFontEntry()->GetGrFace()),
+      mGrFont(nullptr), mFallbackToSmallCaps(false)
+{
+    mCallbackData.mFont = aFont;
+}
+
+gfxGraphiteShaper::~gfxGraphiteShaper()
+{
+    if (mGrFont) {
+        gr_font_destroy(mGrFont);
+    }
+    mFont->GetFontEntry()->ReleaseGrFace(mGrFace);
+}
+
+/*static*/ float
+gfxGraphiteShaper::GrGetAdvance(const void* appFontHandle, uint16_t glyphid)
+{
+    const CallbackData *cb =
+        static_cast<const CallbackData*>(appFontHandle);
+    return FixedToFloat(cb->mFont->GetGlyphWidth(*cb->mDrawTarget, glyphid));
+}
+
+static inline uint32_t
+MakeGraphiteLangTag(uint32_t aTag)
+{
+    uint32_t grLangTag = aTag;
+    // replace trailing space-padding with NULs for graphite
+    uint32_t mask = 0x000000FF;
+    while ((grLangTag & mask) == ' ') {
+        grLangTag &= ~mask;
+        mask <<= 8;
+    }
+    return grLangTag;
+}
+
+struct GrFontFeatures {
+    gr_face        *mFace;
+    gr_feature_val *mFeatures;
+};
+
+static void
+AddFeature(const uint32_t& aTag, uint32_t& aValue, void *aUserArg)
+{
+    GrFontFeatures *f = static_cast<GrFontFeatures*>(aUserArg);
+
+    const gr_feature_ref* fref = gr_face_find_fref(f->mFace, aTag);
+    if (fref) {
+        gr_fref_set_feature_value(fref, aValue, f->mFeatures);
+    }
+}
+
+bool
+gfxGraphiteShaper::ShapeText(DrawTarget      *aDrawTarget,
+                             const char16_t *aText,
+                             uint32_t         aOffset,
+                             uint32_t         aLength,
+                             Script           aScript,
+                             bool             aVertical,
+                             gfxShapedText   *aShapedText)
+{
+    // some font back-ends require this in order to get proper hinted metrics
+    if (!mFont->SetupCairoFont(aDrawTarget)) {
+        return false;
+    }
+
+    mCallbackData.mDrawTarget = aDrawTarget;
+
+    const gfxFontStyle *style = mFont->GetStyle();
+
+    if (!mGrFont) {
+        if (!mGrFace) {
+            return false;
+        }
+
+        if (mFont->ProvidesGlyphWidths()) {
+            gr_font_ops ops = {
+                sizeof(gr_font_ops),
+                &GrGetAdvance,
+                nullptr // vertical text not yet implemented
+            };
+            mGrFont = gr_make_font_with_ops(mFont->GetAdjustedSize(),
+                                            &mCallbackData, &ops, mGrFace);
+        } else {
+            mGrFont = gr_make_font(mFont->GetAdjustedSize(), mGrFace);
+        }
+
+        if (!mGrFont) {
+            return false;
+        }
+
+        // determine whether petite-caps falls back to small-caps
+        if (style->variantCaps != NS_FONT_VARIANT_CAPS_NORMAL) {
+            switch (style->variantCaps) {
+                case NS_FONT_VARIANT_CAPS_ALLPETITE:
+                case NS_FONT_VARIANT_CAPS_PETITECAPS:
+                    bool synLower, synUpper;
+                    mFont->SupportsVariantCaps(aScript, style->variantCaps,
+                                               mFallbackToSmallCaps, synLower,
+                                               synUpper);
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    gfxFontEntry *entry = mFont->GetFontEntry();
+    uint32_t grLang = 0;
+    if (style->languageOverride) {
+        grLang = MakeGraphiteLangTag(style->languageOverride);
+    } else if (entry->mLanguageOverride) {
+        grLang = MakeGraphiteLangTag(entry->mLanguageOverride);
+    } else if (style->explicitLanguage) {
+        nsAutoCString langString;
+        style->language->ToUTF8String(langString);
+        grLang = GetGraphiteTagForLang(langString);
+    }
+    gr_feature_val *grFeatures = gr_face_featureval_for_lang(mGrFace, grLang);
+
+    // insert any merged features into Graphite feature list
+    GrFontFeatures f = {mGrFace, grFeatures};
+    MergeFontFeatures(style,
+                      mFont->GetFontEntry()->mFeatureSettings,
+                      aShapedText->DisableLigatures(),
+                      mFont->GetFontEntry()->FamilyName(),
+                      mFallbackToSmallCaps,
+                      AddFeature,
+                      &f);
+
+    // Graphite shaping doesn't map U+00a0 (nbsp) to space if it is missing
+    // from the font, so check for that possibility. (Most fonts double-map
+    // the space glyph to both 0x20 and 0xA0, so this won't often be needed;
+    // so we don't copy the text until we know it's required.)
+    nsAutoString transformed;
+    const char16_t NO_BREAK_SPACE = 0x00a0;
+    if (!entry->HasCharacter(NO_BREAK_SPACE)) {
+        nsDependentSubstring src(aText, aLength);
+        if (src.FindChar(NO_BREAK_SPACE) != kNotFound) {
+            transformed = src;
+            transformed.ReplaceChar(NO_BREAK_SPACE, ' ');
+            aText = transformed.BeginReading();
+        }
+    }
+
+    size_t numChars = gr_count_unicode_characters(gr_utf16,
+                                                  aText, aText + aLength,
+                                                  nullptr);
+    gr_bidirtl grBidi = gr_bidirtl(aShapedText->IsRightToLeft()
+                                   ? (gr_rtl | gr_nobidi) : gr_nobidi);
+    gr_segment *seg = gr_make_seg(mGrFont, mGrFace, 0, grFeatures,
+                                  gr_utf16, aText, numChars, grBidi);
+
+    gr_featureval_destroy(grFeatures);
+
+    if (!seg) {
+        return false;
+    }
+
+    nsresult rv = SetGlyphsFromSegment(aDrawTarget, aShapedText, aOffset, aLength,
+                                       aText, seg);
+
+    gr_seg_destroy(seg);
+
+    return NS_SUCCEEDED(rv);
+}
+
+#define SMALL_GLYPH_RUN 256 // avoid heap allocation of per-glyph data arrays
+                            // for short (typical) runs up to this length
+
+struct Cluster {
+    uint32_t baseChar; // in UTF16 code units, not Unicode character indices
+    uint32_t baseGlyph;
+    uint32_t nChars; // UTF16 code units
+    uint32_t nGlyphs;
+    Cluster() : baseChar(0), baseGlyph(0), nChars(0), nGlyphs(0) { }
+};
+
+nsresult
+gfxGraphiteShaper::SetGlyphsFromSegment(DrawTarget      *aDrawTarget,
+                                        gfxShapedText   *aShapedText,
+                                        uint32_t         aOffset,
+                                        uint32_t         aLength,
+                                        const char16_t *aText,
+                                        gr_segment      *aSegment)
+{
+    int32_t dev2appUnits = aShapedText->GetAppUnitsPerDevUnit();
+    bool rtl = aShapedText->IsRightToLeft();
+
+    uint32_t glyphCount = gr_seg_n_slots(aSegment);
+
+    // identify clusters; graphite may have reordered/expanded/ligated glyphs.
+    AutoTArray<Cluster,SMALL_GLYPH_RUN> clusters;
+    AutoTArray<uint16_t,SMALL_GLYPH_RUN> gids;
+    AutoTArray<float,SMALL_GLYPH_RUN> xLocs;
+    AutoTArray<float,SMALL_GLYPH_RUN> yLocs;
+
+    if (!clusters.SetLength(aLength, fallible) ||
+        !gids.SetLength(glyphCount, fallible) ||
+        !xLocs.SetLength(glyphCount, fallible) ||
+        !yLocs.SetLength(glyphCount, fallible))
+    {
+        return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    // walk through the glyph slots and check which original character
+    // each is associated with
+    uint32_t gIndex = 0; // glyph slot index
+    uint32_t cIndex = 0; // current cluster index
+    for (const gr_slot *slot = gr_seg_first_slot(aSegment);
+         slot != nullptr;
+         slot = gr_slot_next_in_segment(slot), gIndex++)
+    {
+        uint32_t before =
+            gr_cinfo_base(gr_seg_cinfo(aSegment, gr_slot_before(slot)));
+        uint32_t after =
+            gr_cinfo_base(gr_seg_cinfo(aSegment, gr_slot_after(slot)));
+        gids[gIndex] = gr_slot_gid(slot);
+        xLocs[gIndex] = gr_slot_origin_X(slot);
+        yLocs[gIndex] = gr_slot_origin_Y(slot);
+
+        // if this glyph has a "before" character index that precedes the
+        // current cluster's char index, we need to merge preceding
+        // clusters until it gets included
+        while (before < clusters[cIndex].baseChar && cIndex > 0) {
+            clusters[cIndex-1].nChars += clusters[cIndex].nChars;
+            clusters[cIndex-1].nGlyphs += clusters[cIndex].nGlyphs;
+            --cIndex;
+        }
+
+        // if there's a gap between the current cluster's base character and
+        // this glyph's, extend the cluster to include the intervening chars
+        if (gr_slot_can_insert_before(slot) && clusters[cIndex].nChars &&
+            before >= clusters[cIndex].baseChar + clusters[cIndex].nChars)
+        {
+            NS_ASSERTION(cIndex < aLength - 1, "cIndex at end of word");
+            Cluster& c = clusters[cIndex + 1];
+            c.baseChar = clusters[cIndex].baseChar + clusters[cIndex].nChars;
+            c.nChars = before - c.baseChar;
+            c.baseGlyph = gIndex;
+            c.nGlyphs = 0;
+            ++cIndex;
+        }
+
+        // increment cluster's glyph count to include current slot
+        NS_ASSERTION(cIndex < aLength, "cIndex beyond word length");
+        ++clusters[cIndex].nGlyphs;
+
+        // bump |after| index if it falls in the middle of a surrogate pair
+        if (NS_IS_HIGH_SURROGATE(aText[after]) && after < aLength - 1 &&
+            NS_IS_LOW_SURROGATE(aText[after + 1])) {
+            after++;
+        }
+        // extend cluster if necessary to reach the glyph's "after" index
+        if (clusters[cIndex].baseChar + clusters[cIndex].nChars < after + 1) {
+            clusters[cIndex].nChars = after + 1 - clusters[cIndex].baseChar;
+        }
+    }
+
+    bool roundX, roundY;
+    GetRoundOffsetsToPixels(aDrawTarget, &roundX, &roundY);
+
+    gfxShapedText::CompressedGlyph *charGlyphs =
+        aShapedText->GetCharacterGlyphs() + aOffset;
+
+    // now put glyphs into the textrun, one cluster at a time
+    for (uint32_t i = 0; i <= cIndex; ++i) {
+        const Cluster& c = clusters[i];
+
+        float adv; // total advance of the cluster
+        if (rtl) {
+            if (i == 0) {
+                adv = gr_seg_advance_X(aSegment) - xLocs[c.baseGlyph];
+            } else {
+                adv = xLocs[clusters[i-1].baseGlyph] - xLocs[c.baseGlyph];
+            }
+        } else {
+            if (i == cIndex) {
+                adv = gr_seg_advance_X(aSegment) - xLocs[c.baseGlyph];
+            } else {
+                adv = xLocs[clusters[i+1].baseGlyph] - xLocs[c.baseGlyph];
+            }
+        }
+
+        // Check for default-ignorable char that didn't get filtered, combined,
+        // etc by the shaping process, and skip it.
+        uint32_t offs = c.baseChar;
+        NS_ASSERTION(offs < aLength, "unexpected offset");
+        if (c.nGlyphs == 1 && c.nChars == 1 &&
+            aShapedText->FilterIfIgnorable(aOffset + offs, aText[offs])) {
+            continue;
+        }
+
+        uint32_t appAdvance = roundX ? NSToIntRound(adv) * dev2appUnits :
+                                       NSToIntRound(adv * dev2appUnits);
+        if (c.nGlyphs == 1 &&
+            gfxShapedText::CompressedGlyph::IsSimpleGlyphID(gids[c.baseGlyph]) &&
+            gfxShapedText::CompressedGlyph::IsSimpleAdvance(appAdvance) &&
+            charGlyphs[offs].IsClusterStart() &&
+            yLocs[c.baseGlyph] == 0)
+        {
+            charGlyphs[offs].SetSimpleGlyph(appAdvance, gids[c.baseGlyph]);
+        } else {
+            // not a one-to-one mapping with simple metrics: use DetailedGlyph
+            AutoTArray<gfxShapedText::DetailedGlyph,8> details;
+            float clusterLoc;
+            for (uint32_t j = c.baseGlyph; j < c.baseGlyph + c.nGlyphs; ++j) {
+                gfxShapedText::DetailedGlyph* d = details.AppendElement();
+                d->mGlyphID = gids[j];
+                d->mYOffset = roundY ? NSToIntRound(-yLocs[j]) * dev2appUnits :
+                              -yLocs[j] * dev2appUnits;
+                if (j == c.baseGlyph) {
+                    d->mXOffset = 0;
+                    d->mAdvance = appAdvance;
+                    clusterLoc = xLocs[j];
+                } else {
+                    float dx = rtl ? (xLocs[j] - clusterLoc) :
+                                     (xLocs[j] - clusterLoc - adv);
+                    d->mXOffset = roundX ? NSToIntRound(dx) * dev2appUnits :
+                                           dx * dev2appUnits;
+                    d->mAdvance = 0;
+                }
+            }
+            gfxShapedText::CompressedGlyph g;
+            g.SetComplex(charGlyphs[offs].IsClusterStart(),
+                         true, details.Length());
+            aShapedText->SetGlyphs(aOffset + offs, g, details.Elements());
+        }
+
+        for (uint32_t j = c.baseChar + 1; j < c.baseChar + c.nChars; ++j) {
+            NS_ASSERTION(j < aLength, "unexpected offset");
+            gfxShapedText::CompressedGlyph &g = charGlyphs[j];
+            NS_ASSERTION(!g.IsSimpleGlyph(), "overwriting a simple glyph");
+            g.SetComplex(g.IsClusterStart(), false, 0);
+        }
+    }
+
+    return NS_OK;
+}
+
+#undef SMALL_GLYPH_RUN
+
+// for language tag validation - include list of tags from the IANA registry
+#include "gfxLanguageTagList.cpp"
+
+nsTHashtable<nsUint32HashKey> *gfxGraphiteShaper::sLanguageTags;
+
+/*static*/ uint32_t
+gfxGraphiteShaper::GetGraphiteTagForLang(const nsCString& aLang)
+{
+    int len = aLang.Length();
+    if (len < 2) {
+        return 0;
+    }
+
+    // convert primary language subtag to a left-packed, NUL-padded integer
+    // for the Graphite API
+    uint32_t grLang = 0;
+    for (int i = 0; i < 4; ++i) {
+        grLang <<= 8;
+        if (i < len) {
+            uint8_t ch = aLang[i];
+            if (ch == '-') {
+                // found end of primary language subtag, truncate here
+                len = i;
+                continue;
+            }
+            if (ch < 'a' || ch > 'z') {
+                // invalid character in tag, so ignore it completely
+                return 0;
+            }
+            grLang += ch;
+        }
+    }
+
+    // valid tags must have length = 2 or 3
+    if (len < 2 || len > 3) {
+        return 0;
+    }
+
+    if (!sLanguageTags) {
+        // store the registered IANA tags in a hash for convenient validation
+        sLanguageTags = new nsTHashtable<nsUint32HashKey>(ArrayLength(sLanguageTagList));
+        for (const uint32_t *tag = sLanguageTagList; *tag != 0; ++tag) {
+            sLanguageTags->PutEntry(*tag);
+        }
+    }
+
+    // only accept tags known in the IANA registry
+    if (sLanguageTags->GetEntry(grLang)) {
+        return grLang;
+    }
+
+    return 0;
+}
+
+/*static*/ void
+gfxGraphiteShaper::Shutdown()
+{
+#ifdef NS_FREE_PERMANENT_DATA
+    if (sLanguageTags) {
+        sLanguageTags->Clear();
+        delete sLanguageTags;
+        sLanguageTags = nullptr;
+    }
+#endif
+}