stb_truetype: GPOS handling formatting changes

Was using 4-character spaces and otherwise formatted unlike the
rest of the code, fix this. Also get rid of the outer switch in
GetGlyphGPOSInfoAdvance with just one case; just use an if.
No behavioral changes.

stb_truetype.h

@@ -2353,7 +2353,7 @@ STBTT_DEF int stbtt_GetKerningTable(const stbtt_fontinfo *info, stbtt_kerningent
    return length;
 }
 
-static int  stbtt__GetGlyphKernInfoAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2)
+static int stbtt__GetGlyphKernInfoAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2)
 {
    stbtt_uint8 *data = info->data + info->kern;
    stbtt_uint32 needle, straw;
@@ -2383,232 +2383,223 @@ static int  stbtt__GetGlyphKernInfoAdvance(const stbtt_fontinfo *info, int glyph
    return 0;
 }
 
-static stbtt_int32  stbtt__GetCoverageIndex(stbtt_uint8 *coverageTable, int glyph)
-{
-    stbtt_uint16 coverageFormat = ttUSHORT(coverageTable);
-    switch(coverageFormat) {
-        case 1: {
-            stbtt_uint16 glyphCount = ttUSHORT(coverageTable + 2);
-
-            // Binary search.
-            stbtt_int32 l=0, r=glyphCount-1, m;
-            int straw, needle=glyph;
-            while (l <= r) {
-                stbtt_uint8 *glyphArray = coverageTable + 4;
-                stbtt_uint16 glyphID;
-                m = (l + r) >> 1;
-                glyphID = ttUSHORT(glyphArray + 2 * m);
-                straw = glyphID;
-                if (needle < straw)
-                    r = m - 1;
-                else if (needle > straw)
-                    l = m + 1;
-                else {
-                     return m;
-                }
+static stbtt_int32 stbtt__GetCoverageIndex(stbtt_uint8 *coverageTable, int glyph)
+{
+   stbtt_uint16 coverageFormat = ttUSHORT(coverageTable);
+   switch (coverageFormat) {
+      case 1: {
+         stbtt_uint16 glyphCount = ttUSHORT(coverageTable + 2);
+
+         // Binary search.
+         stbtt_int32 l=0, r=glyphCount-1, m;
+         int straw, needle=glyph;
+         while (l <= r) {
+            stbtt_uint8 *glyphArray = coverageTable + 4;
+            stbtt_uint16 glyphID;
+            m = (l + r) >> 1;
+            glyphID = ttUSHORT(glyphArray + 2 * m);
+            straw = glyphID;
+            if (needle < straw)
+               r = m - 1;
+            else if (needle > straw)
+               l = m + 1;
+            else {
+               return m;
             }
-        } break;
-
-        case 2: {
-            stbtt_uint16 rangeCount = ttUSHORT(coverageTable + 2);
-            stbtt_uint8 *rangeArray = coverageTable + 4;
-
-            // Binary search.
-            stbtt_int32 l=0, r=rangeCount-1, m;
-            int strawStart, strawEnd, needle=glyph;
-            while (l <= r) {
-                stbtt_uint8 *rangeRecord;
-                m = (l + r) >> 1;
-                rangeRecord = rangeArray + 6 * m;
-                strawStart = ttUSHORT(rangeRecord);
-                strawEnd = ttUSHORT(rangeRecord + 2);
-                if (needle < strawStart)
-                    r = m - 1;
-                else if (needle > strawEnd)
-                    l = m + 1;
-                else {
-                    stbtt_uint16 startCoverageIndex = ttUSHORT(rangeRecord + 4);
-                    return startCoverageIndex + glyph - strawStart;
-                }
+         }
+         break;
+      }
+
+      case 2: {
+         stbtt_uint16 rangeCount = ttUSHORT(coverageTable + 2);
+         stbtt_uint8 *rangeArray = coverageTable + 4;
+
+         // Binary search.
+         stbtt_int32 l=0, r=rangeCount-1, m;
+         int strawStart, strawEnd, needle=glyph;
+         while (l <= r) {
+            stbtt_uint8 *rangeRecord;
+            m = (l + r) >> 1;
+            rangeRecord = rangeArray + 6 * m;
+            strawStart = ttUSHORT(rangeRecord);
+            strawEnd = ttUSHORT(rangeRecord + 2);
+            if (needle < strawStart)
+               r = m - 1;
+            else if (needle > strawEnd)
+               l = m + 1;
+            else {
+               stbtt_uint16 startCoverageIndex = ttUSHORT(rangeRecord + 4);
+               return startCoverageIndex + glyph - strawStart;
             }
-        } break;
+         }
+         break;
+      }
 
-        default: {
-            // There are no other cases.
-            STBTT_assert(0);
-        } break;
-    }
+      default: return -1; // unsupported
+   }
 
-    return -1;
+   return -1;
 }
 
 static stbtt_int32  stbtt__GetGlyphClass(stbtt_uint8 *classDefTable, int glyph)
 {
-    stbtt_uint16 classDefFormat = ttUSHORT(classDefTable);
-    switch(classDefFormat)
-    {
-        case 1: {
-            stbtt_uint16 startGlyphID = ttUSHORT(classDefTable + 2);
-            stbtt_uint16 glyphCount = ttUSHORT(classDefTable + 4);
-            stbtt_uint8 *classDef1ValueArray = classDefTable + 6;
-
-            if (glyph >= startGlyphID && glyph < startGlyphID + glyphCount)
-                return (stbtt_int32)ttUSHORT(classDef1ValueArray + 2 * (glyph - startGlyphID));
-        } break;
-
-        case 2: {
-            stbtt_uint16 classRangeCount = ttUSHORT(classDefTable + 2);
-            stbtt_uint8 *classRangeRecords = classDefTable + 4;
-
-            // Binary search.
-            stbtt_int32 l=0, r=classRangeCount-1, m;
-            int strawStart, strawEnd, needle=glyph;
-            while (l <= r) {
-                stbtt_uint8 *classRangeRecord;
-                m = (l + r) >> 1;
-                classRangeRecord = classRangeRecords + 6 * m;
-                strawStart = ttUSHORT(classRangeRecord);
-                strawEnd = ttUSHORT(classRangeRecord + 2);
-                if (needle < strawStart)
-                    r = m - 1;
-                else if (needle > strawEnd)
-                    l = m + 1;
-                else
-                    return (stbtt_int32)ttUSHORT(classRangeRecord + 4);
-            }
-        } break;
+   stbtt_uint16 classDefFormat = ttUSHORT(classDefTable);
+   switch (classDefFormat)
+   {
+      case 1: {
+         stbtt_uint16 startGlyphID = ttUSHORT(classDefTable + 2);
+         stbtt_uint16 glyphCount = ttUSHORT(classDefTable + 4);
+         stbtt_uint8 *classDef1ValueArray = classDefTable + 6;
 
-        default: {
-            // Unsupported defition type; return an error.
-            return -1;
-        } break;
-    }
+         if (glyph >= startGlyphID && glyph < startGlyphID + glyphCount)
+            return (stbtt_int32)ttUSHORT(classDef1ValueArray + 2 * (glyph - startGlyphID));
+         break;
+      }
 
-    // "All glyphs not assigned to a class fall into class 0". (OpenType spec)
-    return 0;
+      case 2: {
+         stbtt_uint16 classRangeCount = ttUSHORT(classDefTable + 2);
+         stbtt_uint8 *classRangeRecords = classDefTable + 4;
+
+         // Binary search.
+         stbtt_int32 l=0, r=classRangeCount-1, m;
+         int strawStart, strawEnd, needle=glyph;
+         while (l <= r) {
+            stbtt_uint8 *classRangeRecord;
+            m = (l + r) >> 1;
+            classRangeRecord = classRangeRecords + 6 * m;
+            strawStart = ttUSHORT(classRangeRecord);
+            strawEnd = ttUSHORT(classRangeRecord + 2);
+            if (needle < strawStart)
+               r = m - 1;
+            else if (needle > strawEnd)
+               l = m + 1;
+            else
+               return (stbtt_int32)ttUSHORT(classRangeRecord + 4);
+         }
+         break;
+      }
+
+      default:
+         return -1; // Unsupported definition type, return an error.
+   }
+
+   // "All glyphs not assigned to a class fall into class 0". (OpenType spec)
+   return 0;
 }
 
 // Define to STBTT_assert(x) if you want to break on unimplemented formats.
 #define STBTT_GPOS_TODO_assert(x)
 
-static stbtt_int32  stbtt__GetGlyphGPOSInfoAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2)
-{
-    stbtt_uint16 lookupListOffset;
-    stbtt_uint8 *lookupList;
-    stbtt_uint16 lookupCount;
-    stbtt_uint8 *data;
-    stbtt_int32 i;
-
-    if (!info->gpos) return 0;
-
-    data = info->data + info->gpos;
-
-    if (ttUSHORT(data+0) != 1) return 0; // Major version 1
-    if (ttUSHORT(data+2) != 0) return 0; // Minor version 0
-
-    lookupListOffset = ttUSHORT(data+8);
-    lookupList = data + lookupListOffset;
-    lookupCount = ttUSHORT(lookupList);
-
-    for (i=0; i<lookupCount; ++i) {
-        stbtt_uint16 lookupOffset = ttUSHORT(lookupList + 2 + 2 * i);
-        stbtt_uint8 *lookupTable = lookupList + lookupOffset;
-
-        stbtt_uint16 lookupType = ttUSHORT(lookupTable);
-        stbtt_uint16 subTableCount = ttUSHORT(lookupTable + 4);
-        stbtt_uint8 *subTableOffsets = lookupTable + 6;
-        switch(lookupType) {
-            case 2: { // Pair Adjustment Positioning Subtable
-                stbtt_int32 sti;
-                for (sti=0; sti<subTableCount; sti++) {
-                    stbtt_uint16 subtableOffset = ttUSHORT(subTableOffsets + 2 * sti);
-                    stbtt_uint8 *table = lookupTable + subtableOffset;
-                    stbtt_uint16 posFormat = ttUSHORT(table);
-                    stbtt_uint16 coverageOffset = ttUSHORT(table + 2);
-                    stbtt_int32 coverageIndex = stbtt__GetCoverageIndex(table + coverageOffset, glyph1);
-                    if (coverageIndex == -1) continue;
-
-                    switch (posFormat) {
-                        case 1: {
-                            stbtt_int32 l, r, m;
-                            int straw, needle;
-                            stbtt_uint16 valueFormat1 = ttUSHORT(table + 4);
-                            stbtt_uint16 valueFormat2 = ttUSHORT(table + 6);
-                            if (valueFormat1 == 4 && valueFormat2 == 0) { // Support more formats?
-                                stbtt_int32 valueRecordPairSizeInBytes = 2;
-                                stbtt_uint16 pairSetCount = ttUSHORT(table + 8);
-                                stbtt_uint16 pairPosOffset = ttUSHORT(table + 10 + 2 * coverageIndex);
-                                stbtt_uint8 *pairValueTable = table + pairPosOffset;
-                                stbtt_uint16 pairValueCount = ttUSHORT(pairValueTable);
-                                stbtt_uint8 *pairValueArray = pairValueTable + 2;
-
-                                if (coverageIndex >= pairSetCount) return 0;
-
-                                needle=glyph2;
-                                r=pairValueCount-1;
-                                l=0;
-
-                                // Binary search.
-                                while (l <= r) {
-                                    stbtt_uint16 secondGlyph;
-                                    stbtt_uint8 *pairValue;
-                                    m = (l + r) >> 1;
-                                    pairValue = pairValueArray + (2 + valueRecordPairSizeInBytes) * m;
-                                    secondGlyph = ttUSHORT(pairValue);
-                                    straw = secondGlyph;
-                                    if (needle < straw)
-                                        r = m - 1;
-                                    else if (needle > straw)
-                                        l = m + 1;
-                                    else {
-                                        stbtt_int16 xAdvance = ttSHORT(pairValue + 2);
-                                        return xAdvance;
-                                    }
-                                }
-                            } else
-                                return 0;
-                        } break;
-
-                        case 2: {
-                            stbtt_uint16 valueFormat1 = ttUSHORT(table + 4);
-                            stbtt_uint16 valueFormat2 = ttUSHORT(table + 6);
-                            if (valueFormat1 == 4 && valueFormat2 == 0) { // Support more formats?
-                                stbtt_uint16 classDef1Offset = ttUSHORT(table + 8);
-                                stbtt_uint16 classDef2Offset = ttUSHORT(table + 10);
-                                int glyph1class = stbtt__GetGlyphClass(table + classDef1Offset, glyph1);
-                                int glyph2class = stbtt__GetGlyphClass(table + classDef2Offset, glyph2);
-
-                                stbtt_uint16 class1Count = ttUSHORT(table + 12);
-                                stbtt_uint16 class2Count = ttUSHORT(table + 14);
-
-                                if (glyph1class < 0 || glyph1class >= class1Count) return 0; // malformed
-                                if (glyph2class < 0 || glyph2class >= class2Count) return 0; // malformed
-
-                                stbtt_uint8 *class1Records = table + 16;
-                                stbtt_uint8 *class2Records = class1Records + 2 * (glyph1class * class2Count);
-                                stbtt_int16 xAdvance = ttSHORT(class2Records + 2 * glyph2class);
-                                return xAdvance;
-                            } else
-                                return 0;
-                        } break;
-
-                        default: {
-                            // Unsupported definition type
-                            return 0;
-                            break;
-                        };
-                    }
-                }
-                break;
-            };
+static stbtt_int32 stbtt__GetGlyphGPOSInfoAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2)
+{
+   stbtt_uint16 lookupListOffset;
+   stbtt_uint8 *lookupList;
+   stbtt_uint16 lookupCount;
+   stbtt_uint8 *data;
+   stbtt_int32 i, sti;
+
+   if (!info->gpos) return 0;
+
+   data = info->data + info->gpos;
+
+   if (ttUSHORT(data+0) != 1) return 0; // Major version 1
+   if (ttUSHORT(data+2) != 0) return 0; // Minor version 0
+
+   lookupListOffset = ttUSHORT(data+8);
+   lookupList = data + lookupListOffset;
+   lookupCount = ttUSHORT(lookupList);
+
+   for (i=0; i<lookupCount; ++i) {
+      stbtt_uint16 lookupOffset = ttUSHORT(lookupList + 2 + 2 * i);
+      stbtt_uint8 *lookupTable = lookupList + lookupOffset;
+
+      stbtt_uint16 lookupType = ttUSHORT(lookupTable);
+      stbtt_uint16 subTableCount = ttUSHORT(lookupTable + 4);
+      stbtt_uint8 *subTableOffsets = lookupTable + 6;
+      if (lookupType != 2) // Pair Adjustment Positioning Subtable
+         continue;
+
+      for (sti=0; sti<subTableCount; sti++) {
+         stbtt_uint16 subtableOffset = ttUSHORT(subTableOffsets + 2 * sti);
+         stbtt_uint8 *table = lookupTable + subtableOffset;
+         stbtt_uint16 posFormat = ttUSHORT(table);
+         stbtt_uint16 coverageOffset = ttUSHORT(table + 2);
+         stbtt_int32 coverageIndex = stbtt__GetCoverageIndex(table + coverageOffset, glyph1);
+         if (coverageIndex == -1) continue;
+
+         switch (posFormat) {
+            case 1: {
+               stbtt_int32 l, r, m;
+               int straw, needle;
+               stbtt_uint16 valueFormat1 = ttUSHORT(table + 4);
+               stbtt_uint16 valueFormat2 = ttUSHORT(table + 6);
+               if (valueFormat1 == 4 && valueFormat2 == 0) { // Support more formats?
+                  stbtt_int32 valueRecordPairSizeInBytes = 2;
+                  stbtt_uint16 pairSetCount = ttUSHORT(table + 8);
+                  stbtt_uint16 pairPosOffset = ttUSHORT(table + 10 + 2 * coverageIndex);
+                  stbtt_uint8 *pairValueTable = table + pairPosOffset;
+                  stbtt_uint16 pairValueCount = ttUSHORT(pairValueTable);
+                  stbtt_uint8 *pairValueArray = pairValueTable + 2;
+
+                  if (coverageIndex >= pairSetCount) return 0;
+
+                  needle=glyph2;
+                  r=pairValueCount-1;
+                  l=0;
+
+                  // Binary search.
+                  while (l <= r) {
+                     stbtt_uint16 secondGlyph;
+                     stbtt_uint8 *pairValue;
+                     m = (l + r) >> 1;
+                     pairValue = pairValueArray + (2 + valueRecordPairSizeInBytes) * m;
+                     secondGlyph = ttUSHORT(pairValue);
+                     straw = secondGlyph;
+                     if (needle < straw)
+                        r = m - 1;
+                     else if (needle > straw)
+                        l = m + 1;
+                     else {
+                        stbtt_int16 xAdvance = ttSHORT(pairValue + 2);
+                        return xAdvance;
+                     }
+                  }
+               } else
+                  return 0;
+               break;
+            }
+
+            case 2: {
+               stbtt_uint16 valueFormat1 = ttUSHORT(table + 4);
+               stbtt_uint16 valueFormat2 = ttUSHORT(table + 6);
+               if (valueFormat1 == 4 && valueFormat2 == 0) { // Support more formats?
+                  stbtt_uint16 classDef1Offset = ttUSHORT(table + 8);
+                  stbtt_uint16 classDef2Offset = ttUSHORT(table + 10);
+                  int glyph1class = stbtt__GetGlyphClass(table + classDef1Offset, glyph1);
+                  int glyph2class = stbtt__GetGlyphClass(table + classDef2Offset, glyph2);
+
+                  stbtt_uint16 class1Count = ttUSHORT(table + 12);
+                  stbtt_uint16 class2Count = ttUSHORT(table + 14);
+
+                  if (glyph1class < 0 || glyph1class >= class1Count) return 0; // malformed
+                  if (glyph2class < 0 || glyph2class >= class2Count) return 0; // malformed
+
+                  stbtt_uint8 *class1Records = table + 16;
+                  stbtt_uint8 *class2Records = class1Records + 2 * (glyph1class * class2Count);
+                  stbtt_int16 xAdvance = ttSHORT(class2Records + 2 * glyph2class);
+                  return xAdvance;
+               } else
+                  return 0;
+               break;
+            }
 
             default:
-                // TODO: Implement other stuff.
-                break;
-        }
-    }
+               return 0; // Unsupported position format
+         }
+      }
+   }
 
-    return 0;
+   return 0;
 }
 
 STBTT_DEF int  stbtt_GetGlyphKernAdvance(const stbtt_fontinfo *info, int g1, int g2)