[PATCH v3 0/1] MR10704: Display invalid Indic syllables

[Aric Stewart (＠aricstewart)]

Use the U+25CC DOTTED CIRCLE as the base glyph for invalid Indic
syllables

https://bugs.winehq.org/show_bug.cgi?id=27637

--
  v3: Display invalid Indic syllables
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10704

[PATCH v3 1/1] Display invalid Indic syllables

[Aric Stewart]

From: Aric Stewart <[e-mail]>

Use the U+25CC DOTTED CIRCLE as the base glyph for invalid Indic
syllables

https://bugs.winehq.org/show_bug.cgi?id=27637
---
 dlls/gdi32/uniscribe/indic.c          | 38 ++++++++++--------
 dlls/gdi32/uniscribe/shape.c          | 55 +++++++++++++++++++++++++++
 dlls/gdi32/uniscribe/usp10_internal.h |  1 +
 3 files changed, 78 insertions(+), 16 deletions(-)

diff --git a/dlls/gdi32/uniscribe/indic.c b/dlls/gdi32/uniscribe/indic.c
index 2d527ddbd1a..bae638ced63 100644
--- a/dlls/gdi32/uniscribe/indic.c
+++ b/dlls/gdi32/uniscribe/indic.c
@@ -326,6 +326,7 @@ void Indic_ParseSyllables(HDC hdc, SCRIPT_ANALYSIS *psa, ScriptCache *psc, const
     unsigned int center = 0;
     int index = 0;
     int next = 0;
+    BOOL valid;
 
     *syllable_count = 0;
 
@@ -344,24 +345,29 @@ void Indic_ParseSyllables(HDC hdc, SCRIPT_ANALYSIS *psa, ScriptCache *psc, const
         if (next >= cChar)
             break;
         next = Indic_process_next_syllable(input, cChar, 0, ¢er, index, lex);
-        if (next != -1)
-        {
-            *syllables = realloc(*syllables, sizeof(IndicSyllable)*(*syllable_count+1));
-            (*syllables)[*syllable_count].start = index;
-            (*syllables)[*syllable_count].base = center;
-            (*syllables)[*syllable_count].ralf = -1;
-            (*syllables)[*syllable_count].blwf = -1;
-            (*syllables)[*syllable_count].pref = -1;
-            (*syllables)[*syllable_count].end = next-1;
-            FindBaseConsonant(hdc, psa, psc, input, &(*syllables)[*syllable_count], lex, modern);
-            index = next;
-            *syllable_count = (*syllable_count)+1;
-        }
-        else if (index < cChar)
-        {
+        valid = (next != -1);
+        if (index < cChar && !valid) {
             TRACE("Processing failed at %i\n",index);
-            next = ++index;
+            center = index;
+            next = index + 1;
         }
+        *syllables = realloc(*syllables, sizeof(IndicSyllable)*(*syllable_count+1));
+        if (!*syllables) {
+            ERR("Allocation failure of syllables\n");
+            *syllable_count = 0;
+            return;
+        }
+        (*syllables)[*syllable_count].valid = valid;
+        (*syllables)[*syllable_count].start = index;
+        (*syllables)[*syllable_count].base = center;
+        (*syllables)[*syllable_count].ralf = -1;
+        (*syllables)[*syllable_count].blwf = -1;
+        (*syllables)[*syllable_count].pref = -1;
+        (*syllables)[*syllable_count].end = next-1;
+        if (valid)
+            FindBaseConsonant(hdc, psa, psc, input, &(*syllables)[*syllable_count], lex, modern);
+        index = next;
+        *syllable_count = (*syllable_count)+1;
     }
     TRACE("Processed %i of %i characters into %i syllables\n",index,cChar,*syllable_count);
 }
diff --git a/dlls/gdi32/uniscribe/shape.c b/dlls/gdi32/uniscribe/shape.c
index b0bd0c5a473..f9ef619e95e 100644
--- a/dlls/gdi32/uniscribe/shape.c
+++ b/dlls/gdi32/uniscribe/shape.c
@@ -2209,6 +2209,50 @@ static void ShapeIndicSyllables(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *psa,
     }
 }
 
+static void mark_invalid_syllables(HDC hdc, const WCHAR* pwcChars, INT cChars, WORD *pwGlyphs, INT *pcGlyphs, INT cMaxGlyphs, WORD *pwLogClust, IndicSyllable *syllables, int syllable_count, lexical_function lexical)
+{
+    int i;
+    WCHAR invalid = 0x25cc;
+    WORD invalid_glyph;
+    int offset = 0;
+
+    if (!hdc || !pwcChars || !pwGlyphs || !pcGlyphs || !pwLogClust || !syllables || syllable_count <= 0) {
+        ERR("Invalid parameters in mark_invalid_syllables\n");
+        return;
+    }
+    if (cChars <= 0 || cMaxGlyphs <= 0) {
+        ERR("Invalid size parameters\n");
+        return;
+    }
+    if (NtGdiGetGlyphIndicesW(hdc, &invalid, 1, &invalid_glyph, 0) == GDI_ERROR || invalid_glyph == 0x0000) {
+        TRACE("Invalid glyph 0x25cc not found in font, using placeholder\n");
+        invalid_glyph = 0x0020; // Use space as fallback
+    }
+
+    for (i = 0; i < syllable_count; i++)
+        if (!syllables[i].valid) break;
+
+    if (i >= syllable_count) {
+        /* Everything valid */
+        return;
+    }
+
+    /* Mark invalid combinations */
+    for (i = 0; i < syllable_count; i++)
+    {
+        if (!syllables[i].valid) {
+            if (*pcGlyphs + 1 > cMaxGlyphs) {
+                ERR("Number of glyphs exceed buffer(%i, %i)\n", *pcGlyphs, cMaxGlyphs);
+                pwGlyphs[syllables[i].start] = invalid_glyph;
+            } else {
+                int dir = (lexical(pwcChars[syllables[i].start]) == lex_Matra_pre)?1:0;
+                insert_glyph(pwGlyphs, pcGlyphs, cChars, 1, invalid_glyph, syllables[i].start+dir+offset, pwLogClust);
+                offset++;
+            }
+        }
+    }
+}
+
 static inline int unicode_lex(WCHAR c)
 {
     int type;
@@ -2325,6 +2369,7 @@ static void ContextualShape_Sinhala(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, sinhala_lex, NULL, TRUE);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, sinhala_lex);
     free(syllables);
 }
 
@@ -2383,6 +2428,7 @@ static void ContextualShape_Devanagari(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSI
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, devanagari_lex, NULL, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, devanagari_lex);
     free(syllables);
 }
 
@@ -2453,6 +2499,7 @@ static void ContextualShape_Bengali(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, bengali_lex, NULL, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, bengali_lex);
     free(syllables);
 }
 
@@ -2503,6 +2550,7 @@ static void ContextualShape_Gurmukhi(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, gurmukhi_lex, NULL, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, gurmukhi_lex);
     free(syllables);
 }
 
@@ -2543,6 +2591,7 @@ static void ContextualShape_Gujarati(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, gujarati_lex, NULL, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, gujarati_lex);
     free(syllables);
 }
 
@@ -2599,6 +2648,7 @@ static void ContextualShape_Oriya(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *ps
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, oriya_lex, NULL, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, oriya_lex);
     free(syllables);
 }
 
@@ -2649,6 +2699,7 @@ static void ContextualShape_Tamil(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *ps
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, tamil_lex, SecondReorder_Like_Tamil, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, tamil_lex);
     free(syllables);
 }
 
@@ -2698,6 +2749,7 @@ static void ContextualShape_Telugu(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *p
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, telugu_lex, SecondReorder_Like_Telugu, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, telugu_lex);
     free(syllables);
 }
 
@@ -2750,6 +2802,7 @@ static void ContextualShape_Kannada(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, kannada_lex, SecondReorder_Like_Telugu, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, kannada_lex);
     free(syllables);
 }
 
@@ -2795,6 +2848,7 @@ static void ContextualShape_Malayalam(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, malayalam_lex, SecondReorder_Like_Tamil, modern);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, malayalam_lex);
     free(syllables);
 }
 
@@ -2829,6 +2883,7 @@ static void ContextualShape_Khmer(HDC hdc, ScriptCache *psc, SCRIPT_ANALYSIS *ps
     ShapeIndicSyllables(hdc, psc, psa, input, cChars, syllables, syllable_count, pwOutGlyphs, pcGlyphs, pwLogClust, khmer_lex, NULL, FALSE);
 
     free(input);
+    mark_invalid_syllables(hdc, pwcChars, cChars, pwOutGlyphs, pcGlyphs, cMaxGlyphs, pwLogClust, syllables, syllable_count, khmer_lex);
     free(syllables);
 }
 
diff --git a/dlls/gdi32/uniscribe/usp10_internal.h b/dlls/gdi32/uniscribe/usp10_internal.h
index b8ae1fb1a57..aa24df22308 100644
--- a/dlls/gdi32/uniscribe/usp10_internal.h
+++ b/dlls/gdi32/uniscribe/usp10_internal.h
@@ -218,6 +218,7 @@ typedef struct _scriptData
 } scriptData;
 
 typedef struct {
+    BOOL valid;
     INT start;
     INT base;
     INT ralf;
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10704

[Aric Stewart (＠aricstewart)]

Ok thank you! I have improved the logic here and it appear to be placing the invalid character in the correct location.

I am still having a problem where if we have an invalid `lex_Matra_pre` combination at the beginning of a string: `ि`  the initial character is not being displayed. Adding something as simple as a space before causes it to display properly.    Looking at the string and glyph string that all looks correct so I think it is a different bug.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10704#note_137746

[समीरसिंह Sameer Singh (＠ss141309)]

AFAICT, this is because the dotted circle is inserted in `pwGlyphs`  but not in `pwcChars`, so it has no entry in `pwLogClust`. `UpdateClusters` does not know this, it pushes every glyph in `pwLogClust` forward at or beyond the insertion point. This pushes the matra's cluster entry forward to point at the dotted circle's glyph slot.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10704#note_137758