scuffed-code/icu4c/source/layout/ThaiShaping.cpp
2002-10-04 19:27:01 +00:00

357 lines
10 KiB
C++

/*
* @(#)ThaiShaping.cpp 1.13 00/03/15
*
* (C) Copyright IBM Corp. 1998, 1999, 2000 - All Rights Reserved
*
*/
#include "LETypes.h"
#include "LEGlyphFilter.h"
#include "OpenTypeTables.h"
#include "ThaiShaping.h"
U_NAMESPACE_BEGIN
enum {
CH_SPACE = 0x0020,
CH_YAMAKKAN = 0x0E4E,
CH_MAI_HANAKAT = 0x0E31,
CH_SARA_AA = 0x0E32,
CH_SARA_AM = 0x0E33,
CH_SARA_UEE = 0x0E37,
CH_MAITAIKHU = 0x0E47,
CH_NIKHAHIT = 0x0E4D,
CH_SARA_U = 0x0E38,
CH_PHINTHU = 0x0E3A,
CH_YO_YING = 0x0E0D,
CH_THO_THAN = 0x0E10,
CH_DOTTED_CIRCLE = 0x25CC
};
le_uint8 ThaiShaping::getCharClass(LEUnicode ch)
{
le_uint8 charClass = NON;
if (ch >= 0x0E00 && ch <= 0x0E5B) {
charClass = classTable[ch - 0x0E00];
}
return charClass;
}
LEUnicode ThaiShaping::leftAboveVowel(LEUnicode vowel, le_uint8 glyphSet)
{
static LEUnicode leftAboveVowels[][7] = {
{0x0E61, 0x0E32, 0x0E33, 0x0E64, 0x0E65, 0x0E66, 0x0E67},
{0xF710, 0x0E32, 0x0E33, 0xF701, 0xF702, 0xF703, 0xF704},
{0xF884, 0x0E32, 0x0E33, 0xF885, 0xF886, 0xF887, 0xF788},
{0x0E31, 0x0E32, 0x0E33, 0x0E34, 0x0E35, 0x0E36, 0x0E37}
};
if (vowel >= CH_MAI_HANAKAT && vowel <= CH_SARA_UEE) {
return leftAboveVowels[glyphSet][vowel - CH_MAI_HANAKAT];
}
if (vowel == CH_YAMAKKAN && glyphSet == 0) {
return 0x0E7E;
}
return vowel;
}
LEUnicode ThaiShaping::lowerRightTone(LEUnicode tone, le_uint8 glyphSet)
{
static LEUnicode lowerRightTones[][7] = {
{0x0E68, 0x0E69, 0x0E6A, 0x0E6B, 0x0E6C, 0x0E6D, 0x0E6E},
{0x0E47, 0xF70A, 0xF70B, 0xF70C, 0xF70D, 0xF70E, 0x0E4D},
{0x0E47, 0xF88B, 0xF88E, 0xF891, 0xF894, 0xF897, 0x0E4D},
{0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}
};
if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {
return lowerRightTones[glyphSet][tone - CH_MAITAIKHU];
}
return tone;
}
LEUnicode ThaiShaping::lowerLeftTone(LEUnicode tone, le_uint8 glyphSet)
{
static LEUnicode lowerLeftTones[][7] = {
{0x0E76, 0x0E77, 0x0E78, 0x0E79, 0x0E7A, 0x0E7B, 0x0E7C},
{0xF712, 0xF705, 0xF706, 0xF707, 0xF708, 0xF709, 0xF711},
{0xF889, 0xF88C, 0xF88F, 0xF892, 0xF895, 0xF898, 0xF899},
{0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}
};
if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {
return lowerLeftTones[glyphSet][tone - CH_MAITAIKHU];
}
return tone;
}
LEUnicode ThaiShaping::upperLeftTone(LEUnicode tone, le_uint8 glyphSet)
{
static LEUnicode upperLeftTones[][7] = {
{0x0E6F, 0x0E70, 0x0E71, 0x0E72, 0x0E73, 0x0E74, 0x0E75},
{0xF712, 0xF713, 0xF714, 0xF715, 0xF716, 0xF717, 0xF711},
{0xF889, 0xF88A, 0xF88D, 0xF890, 0xF893, 0xF896, 0xF899},
{0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B, 0x0E4C, 0x0E4D}
};
if (tone >= CH_MAITAIKHU && tone <= CH_NIKHAHIT) {
return upperLeftTones[glyphSet][tone - CH_MAITAIKHU];
}
return tone;
}
LEUnicode ThaiShaping::lowerBelowVowel(LEUnicode vowel, le_uint8 glyphSet)
{
static LEUnicode lowerBelowVowels[][3] = {
{0x0E3C, 0x0E3D, 0x0E3E},
{0xF718, 0xF719, 0xF71A},
{0x0E38, 0x0E39, 0x0E3A},
{0x0E38, 0x0E39, 0x0E3A}
};
if (vowel >= CH_SARA_U && vowel <= CH_PHINTHU) {
return lowerBelowVowels[glyphSet][vowel - CH_SARA_U];
}
return vowel;
}
LEUnicode ThaiShaping::noDescenderCOD(LEUnicode cod, le_uint8 glyphSet)
{
static LEUnicode noDescenderCODs[][4] = {
{0x0E60, 0x0E0E, 0x0E0F, 0x0E63},
{0xF70F, 0x0E0E, 0x0E0F, 0xF700},
{0x0E0D, 0x0E0E, 0x0E0F, 0x0E10},
{0x0E0D, 0x0E0E, 0x0E0F, 0x0E10}
};
if (cod >= CH_YO_YING && cod <= CH_THO_THAN) {
return noDescenderCODs[glyphSet][cod - CH_YO_YING];
}
return cod;
}
le_uint8 ThaiShaping::doTransition (StateTransition transition, LEUnicode currChar, le_int32 inputIndex, le_uint8 glyphSet,
LEUnicode errorChar, LEUnicode *outputBuffer, le_int32 *charIndicies, le_int32 &outputIndex)
{
switch (transition.action) {
case _A:
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = currChar;
break;
case _C:
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = currChar;
break;
case _D:
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = leftAboveVowel(currChar, glyphSet);
break;
case _E:
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = lowerRightTone(currChar, glyphSet);
break;
case _F:
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = lowerLeftTone(currChar, glyphSet);
break;
case _G:
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = upperLeftTone(currChar, glyphSet);
break;
case _H:
{
LEUnicode cod = outputBuffer[outputIndex - 1];
LEUnicode coa = noDescenderCOD(cod, glyphSet);
if (cod != coa) {
outputBuffer[outputIndex - 1] = coa;
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = currChar;
break;
}
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = lowerBelowVowel(currChar, glyphSet);
break;
}
case _R:
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = errorChar;
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = currChar;
break;
case _S:
if (currChar == CH_SARA_AM) {
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = errorChar;
}
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = currChar;
break;
default:
// FIXME: if we get here, there's an error
// in the state table!
charIndicies[outputIndex] = inputIndex;
outputBuffer[outputIndex++] = currChar;
break;
}
return transition.nextState;
}
le_uint8 ThaiShaping::getNextState(LEUnicode ch, le_uint8 prevState, le_int32 inputIndex, le_uint8 glyphSet, LEUnicode errorChar,
le_uint8 &charClass, LEUnicode *output, le_int32 *charIndicies, le_int32 &outputIndex)
{
StateTransition transition;
charClass = getCharClass(ch);
transition = getTransition(prevState, charClass);
return doTransition(transition, ch, inputIndex, glyphSet, errorChar, output, charIndicies, outputIndex);
}
le_bool ThaiShaping::isLegalHere(LEUnicode ch, le_uint8 prevState)
{
le_uint8 charClass = getCharClass(ch);
StateTransition transition = getTransition(prevState, charClass);
switch (transition.action) {
case _A:
case _C:
case _D:
case _E:
case _F:
case _G:
case _H:
return true;
case _R:
case _S:
return false;
default:
// FIXME: if we get here, there's an error
// in the state table!
return false;
}
}
le_int32 ThaiShaping::compose(const LEUnicode *input, le_int32 offset, le_int32 charCount, le_uint8 glyphSet,
LEUnicode errorChar, LEUnicode *output, le_int32 *charIndicies)
{
le_uint8 state = 0;
le_int32 inputIndex;
le_int32 outputIndex = 0;
le_uint8 conState = 0xFF;
le_int32 conInput = -1;
le_int32 conOutput = -1;
for (inputIndex = 0; inputIndex < charCount; inputIndex += 1) {
LEUnicode ch = input[inputIndex + offset];
le_uint8 charClass;
// Decompose SARA AM into NIKHAHIT + SARA AA
if (ch == CH_SARA_AM && isLegalHere(ch, state)) {
outputIndex = conOutput;
state = getNextState(CH_NIKHAHIT, conState, inputIndex, glyphSet, errorChar, charClass,
output, charIndicies, outputIndex);
for (int j = conInput + 1; j < inputIndex; j += 1) {
ch = input[j + offset];
state = getNextState(ch, state, j, glyphSet, errorChar, charClass,
output, charIndicies, outputIndex);
}
ch = CH_SARA_AA;
}
state = getNextState(ch, state, inputIndex, glyphSet, errorChar, charClass,
output, charIndicies, outputIndex);
if (charClass >= CON && charClass <= COD) {
conState = state;
conInput = inputIndex;
conOutput = outputIndex;
}
}
return outputIndex;
}
ThaiMarkFilter::ThaiMarkFilter(le_uint8 glyphSet)
: rangeList(NULL)
{
static MarkRange glyphSet0MarkRanges[] =
{
{0x0E31, 0x0E31}, {0x0E34, 0x0E3A}, {0x0E47, 0x0E4E}, {0x0E61, 0x0E61}, {0x0E64, 0x0E7C}, {0xFFFF, 0xFFFF}
};
static MarkRange glyphSet1MarkRanges[] =
{
{0x0E31, 0x0E31}, {0x0E34, 0x0E3A}, {0x0E47, 0x0E4E}, {0xF701, 0xF70E}, {0xF710, 0xF71A}, {0xFFFF, 0xFFFF}
};
static MarkRange glyphSet2MarkRanges[] =
{
{0x0E31, 0x0E31}, {0x0E34, 0x0E3A}, {0x0E47, 0x0E4E}, {0xF884, 0xF899}, {0xFFFF, 0xFFFF}
};
static MarkRange glyphSet3MarkRanges[] =
{
{0x0E31, 0x0E31}, {0x0E34, 0x0E3A}, {0x0E47, 0x0E4E}, {0xFFFF, 0xFFFF}
};
static MarkRange *rangeTable[] =
{glyphSet0MarkRanges, glyphSet1MarkRanges, glyphSet2MarkRanges, glyphSet3MarkRanges};
if (glyphSet <= 3) {
rangeList = rangeTable[glyphSet];
}
}
ThaiMarkFilter::~ThaiMarkFilter()
{
// nothing to do here...
}
le_bool ThaiMarkFilter::filter(LEGlyphID glyph)
{
le_int32 i;
if (rangeList != NULL) {
for (i = 0; rangeList[i].first <= glyph; i += 1) {
if (rangeList[i].last >= glyph) {
return true;
}
}
}
return false;
}
U_NAMESPACE_END