Add m-esr52 at 52.6.0

1 files changed, 190 insertions, 0 deletions

diff --git a/gfx/thebes/gfxHarfBuzzShaper.h b/gfx/thebes/gfxHarfBuzzShaper.h
new file mode 100644
index 000000000..70d912cc0
--- /dev/null
+++ b/gfx/thebes/gfxHarfBuzzShaper.h
@@ -0,0 +1,190 @@
+/* -*- Mode: C++; tab-width: 20; 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/. */
+
+#ifndef GFX_HARFBUZZSHAPER_H
+#define GFX_HARFBUZZSHAPER_H
+
+#include "gfxFont.h"
+
+#include "harfbuzz/hb.h"
+#include "nsUnicodeProperties.h"
+#include "mozilla/gfx/2D.h"
+
+class gfxHarfBuzzShaper : public gfxFontShaper {
+public:
+    explicit gfxHarfBuzzShaper(gfxFont *aFont);
+    virtual ~gfxHarfBuzzShaper();
+
+    /*
+     * For HarfBuzz font callback functions, font_data is a ptr to a
+     * FontCallbackData struct
+     */
+    struct FontCallbackData {
+        gfxHarfBuzzShaper* mShaper;
+        mozilla::gfx::DrawTarget* mDrawTarget;
+    };
+
+    bool Initialize();
+    virtual bool ShapeText(DrawTarget      *aDrawTarget,
+                           const char16_t *aText,
+                           uint32_t         aOffset,
+                           uint32_t         aLength,
+                           Script           aScript,
+                           bool             aVertical,
+                           gfxShapedText   *aShapedText);
+
+    // get a given font table in harfbuzz blob form
+    hb_blob_t * GetFontTable(hb_tag_t aTag) const;
+
+    // map unicode character to glyph ID
+    hb_codepoint_t GetNominalGlyph(hb_codepoint_t unicode) const;
+    hb_codepoint_t GetVariationGlyph(hb_codepoint_t unicode,
+                                     hb_codepoint_t variation_selector) const;
+
+    // get harfbuzz glyph advance, in font design units
+    hb_position_t GetGlyphHAdvance(hb_codepoint_t glyph) const;
+
+    hb_position_t GetGlyphVAdvance(hb_codepoint_t glyph) const;
+
+    void GetGlyphVOrigin(hb_codepoint_t aGlyph,
+                         hb_position_t *aX, hb_position_t *aY) const;
+
+    // get harfbuzz horizontal advance in 16.16 fixed point format.
+    static hb_position_t
+    HBGetGlyphHAdvance(hb_font_t *font, void *font_data,
+                       hb_codepoint_t glyph, void *user_data);
+
+    // get harfbuzz vertical advance in 16.16 fixed point format.
+    static hb_position_t
+    HBGetGlyphVAdvance(hb_font_t *font, void *font_data,
+                       hb_codepoint_t glyph, void *user_data);
+
+    static hb_bool_t
+    HBGetGlyphVOrigin(hb_font_t *font, void *font_data,
+                      hb_codepoint_t glyph,
+                      hb_position_t *x, hb_position_t *y,
+                      void *user_data);
+
+    hb_position_t GetHKerning(uint16_t aFirstGlyph,
+                              uint16_t aSecondGlyph) const;
+
+    hb_bool_t GetGlyphExtents(hb_codepoint_t aGlyph,
+                              hb_glyph_extents_t *aExtents) const;
+
+    bool UseVerticalPresentationForms() const
+    {
+        return mUseVerticalPresentationForms;
+    }
+
+    static hb_script_t
+    GetHBScriptUsedForShaping(Script aScript) {
+        // Decide what harfbuzz script code will be used for shaping
+        hb_script_t hbScript;
+        if (aScript <= Script::INHERITED) {
+            // For unresolved "common" or "inherited" runs,
+            // default to Latin for now.
+            hbScript = HB_SCRIPT_LATIN;
+        } else {
+            hbScript =
+                hb_script_t(mozilla::unicode::GetScriptTagForCode(aScript));
+        }
+        return hbScript;
+    }
+
+protected:
+    nsresult SetGlyphsFromRun(DrawTarget     *aDrawTarget,
+                              gfxShapedText  *aShapedText,
+                              uint32_t        aOffset,
+                              uint32_t        aLength,
+                              const char16_t *aText,
+                              hb_buffer_t    *aBuffer,
+                              bool            aVertical);
+
+    // retrieve glyph positions, applying advance adjustments and attachments
+    // returns results in appUnits
+    nscoord GetGlyphPositions(gfxContext *aContext,
+                              hb_buffer_t *aBuffer,
+                              nsTArray<nsPoint>& aPositions,
+                              uint32_t aAppUnitsPerDevUnit);
+
+    bool InitializeVertical();
+    bool LoadHmtxTable();
+
+    struct Glyf { // we only need the bounding-box at the beginning
+                  // of the glyph record, not the actual outline data
+        AutoSwap_PRInt16 numberOfContours;
+        AutoSwap_PRInt16 xMin;
+        AutoSwap_PRInt16 yMin;
+        AutoSwap_PRInt16 xMax;
+        AutoSwap_PRInt16 yMax;
+    };
+
+    const Glyf *FindGlyf(hb_codepoint_t aGlyph, bool *aEmptyGlyf) const;
+
+    // harfbuzz face object: we acquire a reference from the font entry
+    // on shaper creation, and release it in our destructor
+    hb_face_t         *mHBFace;
+
+    // size-specific font object, owned by the gfxHarfBuzzShaper
+    hb_font_t         *mHBFont;
+
+    FontCallbackData   mCallbackData;
+
+    // Following table references etc are declared "mutable" because the
+    // harfbuzz callback functions take a const ptr to the shaper, but
+    // wish to cache tables here to avoid repeatedly looking them up
+    // in the font.
+
+    // Old-style TrueType kern table, if we're not doing GPOS kerning
+    mutable hb_blob_t *mKernTable;
+
+    // Cached copy of the hmtx table.
+    mutable hb_blob_t *mHmtxTable;
+
+    // For vertical fonts, cached vmtx and VORG table, if present.
+    mutable hb_blob_t *mVmtxTable;
+    mutable hb_blob_t *mVORGTable;
+    // And for vertical TrueType (not CFF) fonts that have vmtx,
+    // we also use loca and glyf to get glyph bounding boxes.
+    mutable hb_blob_t *mLocaTable;
+    mutable hb_blob_t *mGlyfTable;
+
+    // Cached pointer to cmap subtable to be used for char-to-glyph mapping.
+    // This comes from GetFontTablePtr; if it is non-null, our destructor
+    // must call ReleaseFontTablePtr to avoid permanently caching the table.
+    mutable hb_blob_t *mCmapTable;
+    mutable int32_t    mCmapFormat;
+    mutable uint32_t   mSubtableOffset;
+    mutable uint32_t   mUVSTableOffset;
+
+    // Cached copy of numLongMetrics field from the hhea table,
+    // for use when looking up glyph metrics; initialized to 0 by the
+    // constructor so we can tell it hasn't been set yet.
+    // This is a signed value so that we can use -1 to indicate
+    // an error (if the hhea table was not available).
+    mutable int32_t    mNumLongHMetrics;
+    // Similarly for vhea if it's a vertical font.
+    mutable int32_t    mNumLongVMetrics;
+
+    // Whether the font implements GetGlyph, or we should read tables
+    // directly
+    bool mUseFontGetGlyph;
+    // Whether the font implements GetGlyphWidth, or we should read tables
+    // directly to get ideal widths
+    bool mUseFontGlyphWidths;
+
+    bool mInitialized;
+    bool mVerticalInitialized;
+
+    // Whether to use vertical presentation forms for CJK characters
+    // when available (only set if the 'vert' feature is not available).
+    bool mUseVerticalPresentationForms;
+
+    // these are set from the FindGlyf callback on first use of the glyf data
+    mutable bool mLoadedLocaGlyf;
+    mutable bool mLocaLongOffsets;
+};
+
+#endif /* GFX_HARFBUZZSHAPER_H */