1 /*

     2  *

     3  * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved

     4  *

     5  */

     6 

     7 #include "LETypes.h"

     8 #include "LEFontInstance.h"

     9 #include "OpenTypeTables.h"

    10 #include "AnchorTables.h"

    11 #include "MarkArrays.h"

    12 #include "GlyphPositioningTables.h"

    13 #include "AttachmentPosnSubtables.h"

    14 #include "MarkToBasePosnSubtables.h"

    15 #include "GlyphIterator.h"

    16 #include "LESwaps.h"

    17 

    18 U_NAMESPACE_BEGIN

    19 

    20 LEGlyphID MarkToBasePositioningSubtable::findBaseGlyph(GlyphIterator *glyphIterator) const

    21 {

    22     if (glyphIterator->prev()) {

    23         return glyphIterator->getCurrGlyphID();

    24     }

    25 

    26     return 0xFFFF;

    27 }

    28 

    29 le_int32 MarkToBasePositioningSubtable::process(GlyphIterator *glyphIterator, const LEFontInstance *fontInstance) const

    30 {

    31     LEGlyphID markGlyph = glyphIterator->getCurrGlyphID();

    32     le_int32 markCoverage = getGlyphCoverage((LEGlyphID) markGlyph);

    33 

    34     if (markCoverage < 0) {

    35         // markGlyph isn't a covered mark glyph

    36         return 0;

    37     }

    38 

    39     LEPoint markAnchor;

    40     const MarkArray *markArray = (const MarkArray *) ((char *) this + SWAPW(markArrayOffset));

    41     le_int32 markClass = markArray->getMarkClass(markGlyph, markCoverage, fontInstance, markAnchor);

    42     le_uint16 mcCount = SWAPW(classCount);

    43 

    44     if (markClass < 0 || markClass >= mcCount) {

    45         // markGlyph isn't in the mark array or its

    46         // mark class is too big. The table is mal-formed!

    47         return 0;

    48     }

    49 

    50     // FIXME: We probably don't want to find a base glyph before a previous ligature... 

    51     GlyphIterator baseIterator(*glyphIterator, (le_uint16) (lfIgnoreMarks /*| lfIgnoreLigatures*/));

    52     LEGlyphID baseGlyph = findBaseGlyph(&baseIterator);

    53     le_int32 baseCoverage = getBaseCoverage((LEGlyphID) baseGlyph);

    54     const BaseArray *baseArray = (const BaseArray *) ((char *) this + SWAPW(baseArrayOffset));

    55     le_uint16 baseCount = SWAPW(baseArray->baseRecordCount);

    56 

    57     if (baseCoverage < 0 || baseCoverage >= baseCount) {

    58         // The base glyph isn't covered, or the coverage

    59         // index is too big. The latter means that the

    60         // table is mal-formed...

    61         return 0;

    62     }

    63 

    64     const BaseRecord *baseRecord = &baseArray->baseRecordArray[baseCoverage * mcCount];

    65     Offset anchorTableOffset = SWAPW(baseRecord->baseAnchorTableOffsetArray[markClass]);

    66     const AnchorTable *anchorTable = (const AnchorTable *) ((char *) baseArray + anchorTableOffset);

    67     LEPoint baseAnchor, markAdvance, pixels;

    68 

    69     if (anchorTableOffset == 0) {

    70         // this means the table is mal-formed...

    71         glyphIterator->setCurrGlyphBaseOffset(baseIterator.getCurrStreamPosition());

    72         return 0;

    73     }

    74 

    75     anchorTable->getAnchor(baseGlyph, fontInstance, baseAnchor);

    76 

    77     fontInstance->getGlyphAdvance(markGlyph, pixels);

    78     fontInstance->pixelsToUnits(pixels, markAdvance);

    79 

    80     float anchorDiffX = baseAnchor.fX - markAnchor.fX;

    81     float anchorDiffY = baseAnchor.fY - markAnchor.fY;

    82 

    83     glyphIterator->setCurrGlyphBaseOffset(baseIterator.getCurrStreamPosition());

    84 

    85     if (glyphIterator->isRightToLeft()) {

    86         glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX, anchorDiffY, -markAdvance.fX, -markAdvance.fY);

    87     } else {

    88         LEPoint baseAdvance;

    89 

    90         fontInstance->getGlyphAdvance(baseGlyph, pixels);

    91         fontInstance->pixelsToUnits(pixels, baseAdvance);

    92 

    93         glyphIterator->setCurrGlyphPositionAdjustment(anchorDiffX - baseAdvance.fX, anchorDiffY - baseAdvance.fY, -markAdvance.fX, -markAdvance.fY);

    94     }

    95 

    96     return 1;

    97 }

    98 

    99 U_NAMESPACE_END