scuffed-code/icu4c/source/layout/HangulLayoutEngine.cpp
2008-12-02 17:17:15 +00:00

339 lines
10 KiB
C++

/*
* HangulLayoutEngine.cpp: OpenType processing for Han fonts.
*
* (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved.
*/
#include "LETypes.h"
#include "LEScripts.h"
#include "LELanguages.h"
#include "LayoutEngine.h"
#include "OpenTypeLayoutEngine.h"
#include "HangulLayoutEngine.h"
#include "ScriptAndLanguageTags.h"
#include "LEGlyphStorage.h"
#include "OpenTypeTables.h"
U_NAMESPACE_BEGIN
UOBJECT_DEFINE_RTTI_IMPLEMENTATION(HangulOpenTypeLayoutEngine)
#define FEATURE_MAP(name) {name ## FeatureTag, name ## FeatureMask}
#define LJMO_FIRST 0x1100
#define LJMO_LAST 0x1159
#define LJMO_FILL 0x115F
#define LJMO_COUNT 19
#define VJMO_FIRST 0x1161
#define VJMO_LAST 0x11A2
#define VJMO_FILL 0x1160
#define VJMO_COUNT 21
#define TJMO_FIRST 0x11A7
#define TJMO_LAST 0x11F9
#define TJMO_COUNT 28
#define HSYL_FIRST 0xAC00
#define HSYL_COUNT 11172
#define HSYL_LVCNT (VJMO_COUNT * TJMO_COUNT)
// Character classes
enum
{
CC_L = 0,
CC_V,
CC_T,
CC_LV,
CC_LVT,
CC_X,
CC_COUNT
};
// Action flags
#define AF_L 1
#define AF_V 2
#define AF_T 4
// Actions
#define a_N 0
#define a_L (AF_L)
#define a_V (AF_V)
#define a_T (AF_T)
#define a_VT (AF_V | AF_T)
#define a_LV (AF_L | AF_V)
#define a_LVT (AF_L | AF_V | AF_T)
typedef struct
{
int32_t newState;
int32_t actionFlags;
} StateTransition;
static const StateTransition stateTable[][CC_COUNT] =
{
// L V T LV LVT X
{ {1, a_L}, {2, a_LV}, {3, a_LVT}, {2, a_LV}, {3, a_LVT}, {4, a_T}}, // 0 - start
{ {1, a_L}, {2, a_V}, {3, a_VT}, {2, a_LV}, {3, a_LVT}, {-1, a_V}}, // 1 - L+
{{-1, a_N}, {2, a_V}, {3, a_T}, {-1, a_N}, {-1, a_N}, {-1, a_N}}, // 2 - L+V+
{{-1, a_N}, {-1, a_N}, {3, a_T}, {-1, a_N}, {-1, a_N}, {-1, a_N}}, // 3 - L+V+T*
{{-1, a_N}, {-1, a_N}, {-1, a_N}, {-1, a_N}, {-1, a_N}, {4, a_T}} // 4 - X+
};
#define ccmpFeatureTag LE_CCMP_FEATURE_TAG
#define ljmoFeatureTag LE_LJMO_FEATURE_TAG
#define vjmoFeatureTag LE_VJMO_FEATURE_TAG
#define tjmoFeatureTag LE_TJMO_FEATURE_TAG
#define ccmpFeatureMask 0x80000000UL
#define ljmoFeatureMask 0x40000000UL
#define vjmoFeatureMask 0x20000000UL
#define tjmoFeatureMask 0x10000000UL
static const FeatureMap featureMap[] =
{
{ccmpFeatureTag, ccmpFeatureMask},
{ljmoFeatureTag, ljmoFeatureMask},
{vjmoFeatureTag, vjmoFeatureMask},
{tjmoFeatureTag, tjmoFeatureMask}
};
static const le_int32 featureMapCount = LE_ARRAY_SIZE(featureMap);
#define nullFeatures 0
#define ljmoFeatures (ccmpFeatureMask | ljmoFeatureMask)
#define vjmoFeatures (ccmpFeatureMask | vjmoFeatureMask | ljmoFeatureMask | tjmoFeatureMask)
#define tjmoFeatures (ccmpFeatureMask | tjmoFeatureMask | ljmoFeatureMask | vjmoFeatureMask)
static le_int32 compose(LEUnicode lead, LEUnicode vowel, LEUnicode trail, LEUnicode &syllable)
{
le_int32 lIndex = lead - LJMO_FIRST;
le_int32 vIndex = vowel - VJMO_FIRST;
le_int32 tIndex = trail - TJMO_FIRST;
le_int32 result = 3;
if ((lIndex < 0 || lIndex >= LJMO_COUNT ) || (vIndex < 0 || vIndex >= VJMO_COUNT)) {
return 0;
}
if (tIndex <= 0 || tIndex >= TJMO_COUNT) {
tIndex = 0;
result = 2;
}
syllable = (LEUnicode) ((lIndex * VJMO_COUNT + vIndex) * TJMO_COUNT + tIndex + HSYL_FIRST);
return result;
}
static le_int32 decompose(LEUnicode syllable, LEUnicode &lead, LEUnicode &vowel, LEUnicode &trail)
{
le_int32 sIndex = syllable - HSYL_FIRST;
if (sIndex < 0 || sIndex >= HSYL_COUNT) {
return 0;
}
lead = LJMO_FIRST + (sIndex / HSYL_LVCNT);
vowel = VJMO_FIRST + (sIndex % HSYL_LVCNT) / TJMO_COUNT;
trail = TJMO_FIRST + (sIndex % TJMO_COUNT);
if (trail == TJMO_FIRST) {
return 2;
}
return 3;
}
static le_int32 getCharClass(LEUnicode ch, LEUnicode &lead, LEUnicode &vowel, LEUnicode &trail)
{
lead = LJMO_FILL;
vowel = VJMO_FILL;
trail = TJMO_FIRST;
if (ch >= LJMO_FIRST && ch <= LJMO_LAST) {
lead = ch;
return CC_L;
}
if (ch >= VJMO_FIRST && ch <= VJMO_LAST) {
vowel = ch;
return CC_V;
}
if (ch > TJMO_FIRST && ch <= TJMO_LAST) {
trail = ch;
return CC_T;
}
le_int32 c = decompose(ch, lead, vowel, trail);
if (c == 2) {
return CC_LV;
}
if (c == 3) {
return CC_LVT;
}
trail = ch;
return CC_X;
}
HangulOpenTypeLayoutEngine::HangulOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 /*languageCode*/,
le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTable, LEErrorCode &success)
: OpenTypeLayoutEngine(fontInstance, scriptCode, korLanguageCode, typoFlags, gsubTable, success)
{
fFeatureMap = featureMap;
fFeatureMapCount = featureMapCount;
fFeatureOrder = TRUE;
}
HangulOpenTypeLayoutEngine::HangulOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 /*languageCode*/,
le_int32 typoFlags, LEErrorCode &success)
: OpenTypeLayoutEngine(fontInstance, scriptCode, korLanguageCode, typoFlags, success)
{
fFeatureMap = featureMap;
fFeatureMapCount = featureMapCount;
fFeatureOrder = TRUE;
}
HangulOpenTypeLayoutEngine::~HangulOpenTypeLayoutEngine()
{
// nothing to do
}
le_int32 HangulOpenTypeLayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success)
{
if (LE_FAILURE(success)) {
return 0;
}
if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
success = LE_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
le_int32 worstCase = count * 3;
outChars = LE_NEW_ARRAY(LEUnicode, worstCase);
if (outChars == NULL) {
success = LE_MEMORY_ALLOCATION_ERROR;
return 0;
}
glyphStorage.allocateGlyphArray(worstCase, rightToLeft, success);
glyphStorage.allocateAuxData(success);
if (LE_FAILURE(success)) {
LE_DELETE_ARRAY(outChars);
return 0;
}
le_int32 outCharCount = 0;
le_int32 limit = offset + count;
le_int32 i = offset;
while (i < limit) {
le_int32 state = 0;
le_int32 inStart = i;
le_int32 outStart = outCharCount;
while( i < limit) {
LEUnicode lead = 0;
LEUnicode vowel = 0;
LEUnicode trail = 0;
int32_t chClass = getCharClass(chars[i], lead, vowel, trail);
const StateTransition transition = stateTable[state][chClass];
if (chClass == CC_X) {
/* Any character of type X will be stored as a trail jamo */
if ((transition.actionFlags & AF_T) != 0) {
outChars[outCharCount] = trail;
glyphStorage.setCharIndex(outCharCount, i-offset, success);
glyphStorage.setAuxData(outCharCount++, nullFeatures, success);
}
} else {
/* Any Hangul will be fully decomposed. Output the decomposed characters. */
if ((transition.actionFlags & AF_L) != 0) {
outChars[outCharCount] = lead;
glyphStorage.setCharIndex(outCharCount, i-offset, success);
glyphStorage.setAuxData(outCharCount++, ljmoFeatures, success);
}
if ((transition.actionFlags & AF_V) != 0) {
outChars[outCharCount] = vowel;
glyphStorage.setCharIndex(outCharCount, i-offset, success);
glyphStorage.setAuxData(outCharCount++, vjmoFeatures, success);
}
if ((transition.actionFlags & AF_T) != 0) {
outChars[outCharCount] = trail;
glyphStorage.setCharIndex(outCharCount, i-offset, success);
glyphStorage.setAuxData(outCharCount++, tjmoFeatures, success);
}
}
state = transition.newState;
/* Negative next state means stop. */
if (state < 0) {
break;
}
i += 1;
}
le_int32 inLength = i - inStart;
le_int32 outLength = outCharCount - outStart;
/*
* See if the syllable can be composed into a single character. There are 5
* possible cases:
*
* Input Decomposed to Compose to
* LV L, V LV
* LVT L, V, T LVT
* L, V L, V LV, DEL
* LV, T L, V, T LVT, DEL
* L, V, T L, V, T LVT, DEL, DEL
*/
if ((inLength >= 1 && inLength <= 3) && (outLength == 2 || outLength == 3)) {
LEUnicode syllable = 0x0000;
LEUnicode lead = outChars[outStart];
LEUnicode vowel = outChars[outStart + 1];
LEUnicode trail = outLength == 3? outChars[outStart + 2] : TJMO_FIRST;
/*
* If the composition consumes the whole decomposed syllable,
* we can use it.
*/
if (compose(lead, vowel, trail, syllable) == outLength) {
outCharCount = outStart;
outChars[outCharCount] = syllable;
glyphStorage.setCharIndex(outCharCount, inStart-offset, success);
glyphStorage.setAuxData(outCharCount++, nullFeatures, success);
/*
* Replace the rest of the input characters with DEL.
*/
for(le_int32 d = inStart + 1; d < i; d += 1) {
outChars[outCharCount] = 0xFFFF;
glyphStorage.setCharIndex(outCharCount, d - offset, success);
glyphStorage.setAuxData(outCharCount++, nullFeatures, success);
}
}
}
}
glyphStorage.adoptGlyphCount(outCharCount);
return outCharCount;
}
U_NAMESPACE_END