fontservices/textshaperplugin/source/cmaps.cpp
changeset 0 1fb32624e06b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/fontservices/textshaperplugin/source/cmaps.cpp	Tue Feb 02 02:02:46 2010 +0200
@@ -0,0 +1,200 @@
+/***************************************************************************
+*
+*   Copyright (C) 1998-2003, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+************************************************************************/
+
+#include "LETypes.h"
+#include "LESwaps.h"
+
+#include "sfnt.h"
+#include "cmaps.h"
+
+#define SWAPU16(code) ((LEUnicode16) SWAPW(code))
+#define SWAPU32(code) ((LEUnicode32) SWAPL(code))
+
+//
+// Finds the high bit by binary searching
+// through the bits in value.
+//
+le_int8 highBit(le_uint32 value)
+{
+    le_uint8 bit = 0;
+
+    if (value >= 1 << 16) {
+        value >>= 16;
+        bit += 16;
+    }
+
+    if (value >= 1 << 8) {
+        value >>= 8;
+        bit += 8;
+    }
+
+    if (value >= 1 << 4) {
+        value >>= 4;
+        bit += 4;
+    }
+
+    if (value >= 1 << 2) {
+        value >>= 2;
+        bit += 2;
+    }
+
+    if (value >= 1 << 1) {
+        value >>= 1;
+        bit += 1;
+    }
+
+    return bit;
+}
+
+CMAPMapper *CMAPMapper::createUnicodeMapper(const CMAPTable *cmap)
+{
+    le_uint16 i;
+    le_uint16 nSubtables = SWAPW(cmap->numberSubtables);
+    const CMAPEncodingSubtable *subtable = NULL;
+    le_uint32 offset1 = 0, offset10 = 0;
+
+    for (i = 0; i < nSubtables; i += 1) {
+        const CMAPEncodingSubtableHeader *esh = &cmap->encodingSubtableHeaders[i];
+
+        if (SWAPW(esh->platformID) == 3) {
+            switch (SWAPW(esh->platformSpecificID)) {
+            case 1:
+                offset1 = SWAPL(esh->encodingOffset);
+                break;
+
+            case 10:
+                offset10 = SWAPL(esh->encodingOffset);
+                break;
+            }
+        }
+    }
+
+
+    if (offset10 != 0)
+    {
+        subtable = (const CMAPEncodingSubtable *) ((const char *) cmap + offset10);
+    } else if (offset1 != 0) {
+        subtable = (const CMAPEncodingSubtable *) ((const char *) cmap + offset1);
+    } else {
+        return NULL;
+    }
+
+    switch (SWAPW(subtable->format)) {
+    case 4:
+        return new CMAPFormat4Mapper(cmap, (const CMAPFormat4Encoding *) subtable);
+
+    case 12:
+    {
+        const CMAPFormat12Encoding *encoding = (const CMAPFormat12Encoding *) subtable;
+
+        return new CMAPGroupMapper(cmap, encoding->groups, SWAPL(encoding->nGroups));
+    }
+
+    default:
+        break;
+    }
+
+    return NULL;
+}
+
+CMAPFormat4Mapper::CMAPFormat4Mapper(const CMAPTable *cmap, const CMAPFormat4Encoding *header)
+    : CMAPMapper(cmap)
+{
+    le_uint16 segCount = SWAPW(header->segCountX2) / 2;
+
+    fEntrySelector = SWAPW(header->entrySelector);
+    fRangeShift = SWAPW(header->rangeShift) / 2;
+    fEndCodes = &header->endCodes[0];
+    fStartCodes = &header->endCodes[segCount + 1]; // + 1 for reservedPad...
+    fIdDelta = &fStartCodes[segCount];
+    fIdRangeOffset = &fIdDelta[segCount];
+}
+
+LEGlyphID CMAPFormat4Mapper::unicodeToGlyph(LEUnicode32 unicode32) const
+{
+    if (unicode32 >= 0x10000) {
+        return 0;
+    }
+
+    LEUnicode16 unicode = (LEUnicode16) unicode32;
+    le_uint16 index = 0;
+    le_uint16 probe = 1 << fEntrySelector;
+    TTGlyphID result = 0;
+
+    if (SWAPU16(fStartCodes[fRangeShift]) <= unicode) {
+        index = fRangeShift;
+    }
+
+    while (probe > (1 << 0)) {
+        probe >>= 1;
+
+        if (SWAPU16(fStartCodes[index + probe]) <= unicode) {
+            index += probe;
+        }
+    }
+
+    if (unicode >= SWAPU16(fStartCodes[index]) && unicode <= SWAPU16(fEndCodes[index])) {
+        if (fIdRangeOffset[index] == 0) {
+            result = (TTGlyphID) unicode;
+        } else {
+            le_uint16 offset = unicode - SWAPU16(fStartCodes[index]);
+            le_uint16 rangeOffset = SWAPW(fIdRangeOffset[index]);
+            le_uint16 *glyphIndexTable = (le_uint16 *) ((char *) &fIdRangeOffset[index] + rangeOffset);
+
+            result = SWAPW(glyphIndexTable[offset]);
+        }
+
+        result += SWAPW(fIdDelta[index]);
+    } else {
+        result = 0;
+    }
+
+    return LE_SET_GLYPH(0, result);
+}
+
+CMAPFormat4Mapper::~CMAPFormat4Mapper()
+{
+    // parent destructor does it all
+}
+
+CMAPGroupMapper::CMAPGroupMapper(const CMAPTable *cmap, const CMAPGroup *groups, le_uint32 nGroups)
+    : CMAPMapper(cmap), fGroups(groups)
+{
+    le_uint8 bit = highBit(nGroups);
+    fPower = 1 << bit;
+    fRangeOffset = nGroups - fPower;
+}
+
+LEGlyphID CMAPGroupMapper::unicodeToGlyph(LEUnicode32 unicode32) const
+{
+    le_int32 probe = fPower;
+    le_int32 range = 0;
+
+    if (SWAPU32(fGroups[fRangeOffset].startCharCode) <= unicode32) {
+        range = fRangeOffset;
+    }
+
+    while (probe > (1 << 0)) {
+        probe >>= 1;
+
+        if (SWAPU32(fGroups[range + probe].startCharCode) <= unicode32) {
+            range += probe;
+        }
+    }
+
+    if (SWAPU32(fGroups[range].startCharCode) <= unicode32 && SWAPU32(fGroups[range].endCharCode) >= unicode32) {
+        return (LEGlyphID) (SWAPU32(fGroups[range].startGlyphCode) + unicode32 - SWAPU32(fGroups[range].startCharCode));
+    }
+
+    return 0;
+}
+
+CMAPGroupMapper::~CMAPGroupMapper()
+{
+    // parent destructor does it all
+}
+