scuffed-code/icu4c/source/layout/ThaiLayoutEngine.cpp
2001-10-16 00:39:01 +00:00

92 lines
2.3 KiB
C++

/*
* @(#)ThaiLayoutEngine.cpp 1.2 00/03/15
*
* (C) Copyright IBM Corp. 1998, 1999, 2000 - All Rights Reserved
*
*/
#include "LETypes.h"
#include "LayoutEngine.h"
#include "ThaiLayoutEngine.h"
#include "ScriptAndLanguageTags.h"
#include "ThaiShaping.h"
U_NAMESPACE_BEGIN
ThaiLayoutEngine::ThaiLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode)
: LayoutEngine(fontInstance, scriptCode, languageCode)
{
fErrorChar = 0x25CC;
// Figure out which presentation forms the font uses
if (fontInstance->canDisplay(0x0E64)) {
// WorldType uses reserved space in Thai block
fGlyphSet = 0;
} else if (fontInstance->canDisplay(0xF701)) {
// Microsoft corporate zone
fGlyphSet = 1;
if (!fontInstance->canDisplay(fErrorChar)) {
fErrorChar = 0xF71B;
}
} else if (fontInstance->canDisplay(0xF885)) {
// Apple corporate zone
fGlyphSet = 2;
} else {
// no presentation forms in the font
fGlyphSet = 3;
}
}
ThaiLayoutEngine::~ThaiLayoutEngine()
{
// nothing to do
}
// Input: characters (0..max provided for context)
// Output: glyphs, char indices
// Returns: the glyph count
// NOTE: this assumes that ThaiShaping::compose will allocate the outChars array...
le_int32 ThaiLayoutEngine::computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft, LEGlyphID *&glyphs, le_int32 *&charIndices, 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;
}
LEUnicode *outChars;
le_int32 glyphCount;
// This is enough room for the worst-case expansion
// (it says here...)
outChars = new LEUnicode[count * 2];
if (outChars == NULL) {
success = LE_MEMORY_ALLOCATION_ERROR;
return 0;
}
charIndices = new le_int32[count * 2];
if (charIndices == NULL) {
delete[] outChars;
success = LE_MEMORY_ALLOCATION_ERROR;
return 0;
}
glyphCount = ThaiShaping::compose(chars, offset, count, fGlyphSet, fErrorChar, outChars, charIndices);
mapCharsToGlyphs(outChars, 0, glyphCount, false, false, glyphs, charIndices, success);
delete[] outChars;
return glyphCount;
}
U_NAMESPACE_END