tdf#124116 Correct Writer text shaping across formatting changes

Previously, Writer performed shaping for each span of text separately.
In certain situations, this caused incorrect glyph use, or incorrect
glyph positioning. This change updates Writer so it will also consider
neighboring text while performing shaping.

This change resolves the outstanding duplicates filed against tdf#61444.
As a side effect, this change also fixes tdf#134226.

In addition to the shaping fix, this change implements rendering for
individually-styled glyphs, which is required to fix tdf#71956. However,
this change does not implement diacritic selection, which is also
required for that issue.

Change-Id: Iab4774ffaab5ad6113778c54d02cb260a70c1010
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/167699
Reviewed-by: Jonathan Clark <jonathan@libreoffice.org>
Tested-by: Jenkins

6 files changed, 41 insertions, 19 deletions

diff --git a/include/vcl/glyphitemcache.hxx b/include/vcl/glyphitemcache.hxx
index ffe9bb7eb0c4..79f05e606550 100644
--- a/include/vcl/glyphitemcache.hxx
+++ b/include/vcl/glyphitemcache.hxx
@@ -53,6 +53,11 @@ public:
                                            const OUString& text, sal_Int32 nIndex, sal_Int32 nLen,
                                            tools::Long nLogicWidth = 0,
                                            const vcl::text::TextLayoutCache* layoutCache = nullptr);
+    const SalLayoutGlyphs* GetLayoutGlyphs(const VclPtr<const OutputDevice>& outputDevice,
+                                           const OUString& text, sal_Int32 nIndex, sal_Int32 nLen,
+                                           sal_Int32 nDrawMinCharPos, sal_Int32 nDrawEndCharPos,
+                                           tools::Long nLogicWidth = 0,
+                                           const vcl::text::TextLayoutCache* layoutCache = nullptr);
     void clear();
 
     /// Normally, we cannot cache glyphs when doing font fallback, because the font fallbacks
diff --git a/include/vcl/metaact.hxx b/include/vcl/metaact.hxx
index 71869689dc55..79a91a629783 100644
--- a/include/vcl/metaact.hxx
+++ b/include/vcl/metaact.hxx
@@ -510,6 +510,8 @@ private:
     std::vector<sal_Bool> maKashidaAry;
     sal_Int32   mnIndex;
     sal_Int32   mnLen;
+    sal_Int32 mnLayoutContextIndex = -1;
+    sal_Int32 mnLayoutContextLen = -1;
 
     SAL_DLLPRIVATE virtual             ~MetaTextArrayAction() override;
 
@@ -526,6 +528,9 @@ public:
                          std::span<const sal_Bool> pKashidaAry,
                          sal_Int32 nIndex,
                          sal_Int32 nLen );
+    MetaTextArrayAction(const Point& rStartPt, OUString aStr, KernArraySpan pDXAry,
+                        std::span<const sal_Bool> pKashidaAry, sal_Int32 nIndex, sal_Int32 nLen,
+                        sal_Int32 nLayoutContextIndex, sal_Int32 nLayoutContextLen);
 
     SAL_DLLPRIVATE virtual void        Execute( OutputDevice* pOut ) override;
 
@@ -538,12 +543,22 @@ public:
     const OUString& GetText() const { return maStr; }
     sal_Int32       GetIndex() const { return mnIndex; }
     sal_Int32       GetLen() const { return mnLen; }
+    sal_Int32 GetLayoutContextIndex() const { return mnLayoutContextIndex; }
+    sal_Int32 GetLayoutContextLen() const { return mnLayoutContextLen; }
     const KernArray& GetDXArray() const { return maDXAry; }
     const std::vector<sal_Bool> & GetKashidaArray() const { return maKashidaAry; }
     void            SetPoint(const Point& rPt) { maStartPt = rPt; }
     void            SetText(const OUString& rStr) { maStr = rStr; }
     void            SetIndex(sal_Int32 rIndex) { mnIndex = rIndex; }
     void            SetLen(sal_Int32 rLen) { mnLen = rLen; }
+    void SetLayoutContextIndex(sal_Int32 nLayoutContextIndex)
+    {
+        mnLayoutContextIndex = nLayoutContextIndex;
+    }
+    void SetLayoutContextLen(sal_Int32 nLayoutContextLen)
+    {
+        mnLayoutContextLen = nLayoutContextLen;
+    }
     SAL_DLLPRIVATE void            SetDXArray(KernArray aArray);
     SAL_DLLPRIVATE void            SetKashidaArray(std::vector<sal_Bool> aArray);
 };
diff --git a/include/vcl/outdev.hxx b/include/vcl/outdev.hxx
index 6dbb9acf7f32..347d5bb82226 100644
--- a/include/vcl/outdev.hxx
+++ b/include/vcl/outdev.hxx
@@ -1160,11 +1160,12 @@ public:
     // i60594
     // validate kashida positions against the current font
     // returns count of invalid kashida positions
-    sal_Int32                   ValidateKashidas( const OUString& rTxt, sal_Int32 nIdx, sal_Int32 nLen,
-                                                  sal_Int32 nKashCount, // number of suggested kashida positions (in)
-                                                  const sal_Int32* pKashidaPos, // suggested kashida positions (in)
-                                                  sal_Int32* pKashidaPosDropped // invalid kashida positions (out)
-                                                ) const;
+    sal_Int32
+    ValidateKashidas(const OUString& rTxt, sal_Int32 nIdx, sal_Int32 nLen, sal_Int32 nPartIdx,
+                     sal_Int32 nPartLen,
+                     std::span<const sal_Int32> pKashidaPos, // suggested kashida positions (in)
+                     std::vector<sal_Int32>* pKashidaPosDropped // invalid kashida positions (out)
+    ) const;
 
     static void                 BeginFontSubstitution();
     static void                 EndFontSubstitution();
@@ -1235,14 +1236,14 @@ public:
     SAL_DLLPRIVATE void         ReMirror( vcl::Region &rRegion ) const;
     SAL_DLLPRIVATE bool         ImplIsRecordLayout() const;
     virtual bool                HasMirroredGraphics() const;
-    std::unique_ptr<SalLayout>
-                                ImplLayout( const OUString&, sal_Int32 nIndex, sal_Int32 nLen,
-                                            const Point& rLogicPos = Point(0,0), tools::Long nLogicWidth=0,
-                                            KernArraySpan aKernArray = KernArraySpan(),
-                                            std::span<const sal_Bool> pKashidaArray={},
-                                            SalLayoutFlags flags = SalLayoutFlags::NONE,
-                                            vcl::text::TextLayoutCache const* = nullptr,
-                                            const SalLayoutGlyphs* pGlyphs = nullptr) const;
+    std::unique_ptr<SalLayout> ImplLayout(
+        const OUString&, sal_Int32 nIndex, sal_Int32 nLen, const Point& rLogicPos = Point(0, 0),
+        tools::Long nLogicWidth = 0, KernArraySpan aKernArray = KernArraySpan(),
+        std::span<const sal_Bool> pKashidaArray = {}, SalLayoutFlags flags = SalLayoutFlags::NONE,
+        vcl::text::TextLayoutCache const* = nullptr, const SalLayoutGlyphs* pGlyphs = nullptr,
+        std::optional<sal_Int32> nDrawOriginCluster = std::nullopt,
+        std::optional<sal_Int32> nDrawMinCharPos = std::nullopt,
+        std::optional<sal_Int32> nDrawEndCharPos = std::nullopt) const;
 
     SAL_DLLPRIVATE vcl::text::ImplLayoutArgs ImplPrepareLayoutArgs( OUString&, const sal_Int32 nIndex, const sal_Int32 nLen,
                                                          double nPixelWidth,
diff --git a/include/vcl/pdfwriter.hxx b/include/vcl/pdfwriter.hxx
index f4599154e465..34d44525b4d4 100644
--- a/include/vcl/pdfwriter.hxx
+++ b/include/vcl/pdfwriter.hxx
@@ -790,11 +790,9 @@ The following structure describes the permissions used in PDF security
                                       FontStrikeout eStrikeout,
                                       FontLineStyle eUnderline,
                                       FontLineStyle eOverline );
-    void                DrawTextArray( const Point& rStartPt, const OUString& rStr,
-                                       KernArraySpan aKernArray,
-                                       std::span<const sal_Bool> pKashidaAry,
-                                       sal_Int32 nIndex,
-                                       sal_Int32 nLen );
+    void DrawTextArray(const Point& rStartPt, const OUString& rStr, KernArraySpan aKernArray,
+                       std::span<const sal_Bool> pKashidaAry, sal_Int32 nIndex, sal_Int32 nLen,
+                       sal_Int32 nLayoutContextIndex, sal_Int32 nLayoutContextLen);
     void                DrawStretchText( const Point& rStartPt, sal_Int32 nWidth,
                                          const OUString& rStr,
                                          sal_Int32 nIndex, sal_Int32 nLen );
diff --git a/include/vcl/rendercontext/SalLayoutFlags.hxx b/include/vcl/rendercontext/SalLayoutFlags.hxx
index 576a4abd8fbd..3424fa2a1de4 100644
--- a/include/vcl/rendercontext/SalLayoutFlags.hxx
+++ b/include/vcl/rendercontext/SalLayoutFlags.hxx
@@ -33,10 +33,11 @@ enum class SalLayoutFlags
     DisableLigatures = 0x0200,
     ForFallback = 0x2000,
     GlyphItemsOnly = 0x4000,
+    UnclusteredGlyphs = 0x8000,
 };
 namespace o3tl
 {
-template <> struct typed_flags<SalLayoutFlags> : is_typed_flags<SalLayoutFlags, 0x6277>
+template <> struct typed_flags<SalLayoutFlags> : is_typed_flags<SalLayoutFlags, 0xE277>
 {
 };
 }
diff --git a/include/vcl/vcllayout.hxx b/include/vcl/vcllayout.hxx
index 9370c69ded2e..58ca11b876ef 100644
--- a/include/vcl/vcllayout.hxx
+++ b/include/vcl/vcllayout.hxx
@@ -137,6 +137,8 @@ private:
 protected:
     int             mnMinCharPos;
     int             mnEndCharPos;
+    int mnDrawMinCharPos = std::numeric_limits<int>::min();
+    int mnDrawEndCharPos = std::numeric_limits<int>::max();
     LanguageTag     maLanguageTag;
 
     Degree10        mnOrientation;