scuffed-code/icu4c/source/layout/ArabicShaping.cpp
2004-10-17 20:31:34 +00:00

207 lines
7.8 KiB
C++

/*
*
* (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
*
*/
#include "LETypes.h"
#include "OpenTypeTables.h"
#include "ArabicShaping.h"
#include "LEGlyphStorage.h"
U_NAMESPACE_BEGIN
enum {
_c_ = ArabicShaping::ST_NOSHAPE_DUAL,
_d_ = ArabicShaping::ST_DUAL,
_n_ = ArabicShaping::ST_NONE,
_r_ = ArabicShaping::ST_RIGHT,
_t_ = ArabicShaping::ST_TRANSPARENT,
_x_ = ArabicShaping::ST_NOSHAPE_NONE
};
const ArabicShaping::ShapeType ArabicShaping::shapeTypes[] =
{
_t_, _t_, _t_, _t_, _t_, _t_, _x_, _x_, _x_, _x_, _x_, _n_, _x_, _x_, _x_, _n_, // 0x610 - 0x61f
_x_, _n_, _r_, _r_, _r_, _r_, _d_, _r_, _d_, _r_, _d_, _d_, _d_, _d_, _d_, _r_, // 0x620 - 0x62f
_r_, _r_, _r_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _x_, _x_, _x_, _x_, _x_, // 0x630 - 0x63f
_c_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _r_, _d_, _d_, _t_, _t_, _t_, _t_, _t_, // 0x640 - 0x64f
_t_, _t_, _t_, _t_, _t_, _t_, _t_, _t_, _t_, _x_, _x_, _x_, _x_, _x_, _x_, _x_, // 0x650 - 0x65f
_n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _d_, _d_, // 0x660 - 0x66f
_t_, _r_, _r_, _r_, _n_, _r_, _r_, _r_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, // 0x670 - 0x67f
_d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, // 0x680 - 0x68f
_r_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, _d_, _d_, _d_, _d_, _d_, _d_, // 0x690 - 0x69f
_d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, // 0x6a0 - 0x6af
_d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, _d_, // 0x6b0 - 0x6bf
_r_, _d_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, _r_, _d_, _r_, _d_, _r_, // 0x6c0 - 0x6cf
_d_, _d_, _r_, _r_, _n_, _r_, _t_, _t_, _t_, _t_, _t_, _t_, _t_, _x_, _t_, _t_, // 0x6d0 - 0x6df
_t_, _t_, _t_, _t_, _t_, _n_, _n_, _t_, _t_, _n_, _t_, _t_, _t_, _t_, _r_, _r_, // 0x6e0 - 0x6ef
_n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _n_, _d_, _d_, _d_, _n_, _n_, _d_ // 0x6f0 - 0x6ff
};
/*
shaping array holds types for Arabic chars between 0610 and 0700
other values are either unshaped, or transparent if a mark or format
code, except for format codes 200c (zero-width non-joiner) and 200d
(dual-width joiner) which are both unshaped and non_joining or
dual-joining, respectively.
*/
ArabicShaping::ShapeType ArabicShaping::getShapeType(LEUnicode c)
{
if (c >= 0x0610 && c <= 0x206f) {
if (c < 0x0700) {
return shapeTypes[c - 0x0610];
} else if (c == 0x200c) { // ZWNJ
return ST_NOSHAPE_NONE;
} else if (c == 0x200d) { // ZWJ
return ST_NOSHAPE_DUAL;
} else if (c >= 0x202a && c <= 0x202e) { // LRE - RLO
return ST_TRANSPARENT;
} else if (c >= 0x206a && c <= 0x206f) { // Inhibit Symmetric Swapping - Nominal Digit Shapes
return ST_TRANSPARENT;
}
}
return ST_NOSHAPE_NONE;
}
static const LETag isolFeatureTag = LE_ISOL_FEATURE_TAG;
static const LETag initFeatureTag = LE_INIT_FEATURE_TAG;
static const LETag mediFeatureTag = LE_MEDI_FEATURE_TAG;
static const LETag finaFeatureTag = LE_FINA_FEATURE_TAG;
static const LETag ligaFeatureTag = LE_LIGA_FEATURE_TAG;
static const LETag msetFeatureTag = LE_MSET_FEATURE_TAG;
static const LETag markFeatureTag = LE_MARK_FEATURE_TAG;
static const LETag ccmpFeatureTag = LE_CCMP_FEATURE_TAG;
static const LETag rligFeatureTag = LE_RLIG_FEATURE_TAG;
static const LETag caltFeatureTag = LE_CALT_FEATURE_TAG;
static const LETag dligFeatureTag = LE_DLIG_FEATURE_TAG;
static const LETag cswhFeatureTag = LE_CSWH_FEATURE_TAG;
static const LETag cursFeatureTag = LE_CURS_FEATURE_TAG;
static const LETag kernFeatureTag = LE_KERN_FEATURE_TAG;
static const LETag mkmkFeatureTag = LE_MKMK_FEATURE_TAG;
static const LETag emptyTag = 0x00000000; // ''
static const LETag featureOrder[] =
{
ccmpFeatureTag, isolFeatureTag, finaFeatureTag, mediFeatureTag, initFeatureTag, rligFeatureTag,
caltFeatureTag, ligaFeatureTag, dligFeatureTag, cswhFeatureTag, msetFeatureTag, cursFeatureTag,
kernFeatureTag, markFeatureTag, mkmkFeatureTag, emptyTag
};
const LETag ArabicShaping::tagArray[] =
{
isolFeatureTag, ligaFeatureTag, msetFeatureTag, markFeatureTag, ccmpFeatureTag, rligFeatureTag,
caltFeatureTag, dligFeatureTag, cswhFeatureTag, cursFeatureTag, kernFeatureTag, mkmkFeatureTag, emptyTag,
finaFeatureTag, ligaFeatureTag, msetFeatureTag, markFeatureTag, ccmpFeatureTag, rligFeatureTag,
caltFeatureTag, dligFeatureTag, cswhFeatureTag, cursFeatureTag, kernFeatureTag, mkmkFeatureTag, emptyTag,
initFeatureTag, ligaFeatureTag, msetFeatureTag, markFeatureTag, ccmpFeatureTag, rligFeatureTag,
caltFeatureTag, dligFeatureTag, cswhFeatureTag, cursFeatureTag, kernFeatureTag, mkmkFeatureTag, emptyTag,
mediFeatureTag, ligaFeatureTag, msetFeatureTag, markFeatureTag, ccmpFeatureTag, rligFeatureTag,
caltFeatureTag, dligFeatureTag, cswhFeatureTag, cursFeatureTag, kernFeatureTag, mkmkFeatureTag, emptyTag
};
#define TAGS_PER_GLYPH ((sizeof ArabicShaping::tagArray / sizeof ArabicShaping::tagArray[0]) / 4)
const LETag *ArabicShaping::getFeatureOrder()
{
return featureOrder;
}
void ArabicShaping::adjustTags(le_int32 outIndex, le_int32 shapeOffset, LEGlyphStorage &glyphStorage)
{
LEErrorCode success = LE_NO_ERROR;
const LETag *glyphTags = (const LETag *) glyphStorage.getAuxData(outIndex, success);
glyphStorage.setAuxData(outIndex, (void *) &glyphTags[TAGS_PER_GLYPH * shapeOffset], success);
}
void ArabicShaping::shape(const LEUnicode *chars, le_int32 offset, le_int32 charCount, le_int32 charMax,
le_bool rightToLeft, LEGlyphStorage &glyphStorage)
{
// iterate in logical order, store tags in visible order
//
// the effective right char is the most recently encountered
// non-transparent char
//
// four boolean states:
// the effective right char shapes
// the effective right char causes left shaping
// the current char shapes
// the current char causes right shaping
//
// if both cause shaping, then
// shaper.shape(errout, 2) (isolate to initial, or final to medial)
// shaper.shape(out, 1) (isolate to final)
ShapeType rightType = ST_NOSHAPE_NONE, leftType = ST_NOSHAPE_NONE;
LEErrorCode success = LE_NO_ERROR;
le_int32 i;
for (i = offset - 1; i >= 0; i -= 1) {
rightType = getShapeType(chars[i]);
if (rightType != ST_TRANSPARENT) {
break;
}
}
for (i = offset + charCount; i < charMax; i += 1) {
leftType = getShapeType(chars[i]);
if (leftType != ST_TRANSPARENT) {
break;
}
}
// erout is effective right logical index
le_int32 erout = -1;
le_bool rightShapes = FALSE;
le_bool rightCauses = (rightType & MASK_SHAPE_LEFT) != 0;
le_int32 in, e, out = 0, dir = 1;
if (rightToLeft) {
out = charCount - 1;
erout = charCount;
dir = -1;
}
for (in = offset, e = offset + charCount; in < e; in += 1, out += dir) {
LEUnicode c = chars[in];
ShapeType t = getShapeType(c);
glyphStorage.setAuxData(out, (void *) tagArray, success);
if ((t & MASK_TRANSPARENT) != 0) {
continue;
}
le_bool curShapes = (t & MASK_NOSHAPE) == 0;
le_bool curCauses = (t & MASK_SHAPE_RIGHT) != 0;
if (rightCauses && curCauses) {
if (rightShapes) {
adjustTags(erout, 2, glyphStorage);
}
if (curShapes) {
adjustTags(out, 1, glyphStorage);
}
}
rightShapes = curShapes;
rightCauses = (t & MASK_SHAPE_LEFT) != 0;
erout = out;
}
if (rightShapes && rightCauses && (leftType & MASK_SHAPE_RIGHT) != 0) {
adjustTags(erout, 2, glyphStorage);
}
}
U_NAMESPACE_END