/* * @(#)loengine.h 1.0 00/12/11 * * (C) Copyright IBM Corp. 1998, 1999, 2000 - All Rights Reserved * */ #ifndef __LOENGINE_H #define __LOENGINE_H #include "unicode/utypes.h" #include "unicode/uscript.h" #include "unicode/unistr.h" #include "layout/LETypes.h" #include "layout/LayoutEngine.h" U_NAMESPACE_BEGIN /** * This is a wrapper class designed to allow ICU clients to * use LayoutEngine in a way that is consistent with the rest * of ICU. * * (LayoutEngine was developed seperately from ICU and * the same source is used in non-ICU environments, so it cannot * be changed to match ICU coding conventions). * * This class is designed for clients who wish to use LayoutEngine * to layout complex text. If you need to subclass LayoutEngine, * you'll need to use the LayoutEngine interfaces directly. * * Basically, it creates an instance of LayoutEngine, stashes * it in fLayoutEngine, and uses it to implement the layout * functionality. * * Use the createInstance method to create an ICULayoutEngine. Use * delete to destroy it. The layoutChars method computes the glyphs * and positions, and saves them in the ICULayoutEngine object. * Use getGlyphs, getPositions and getCharIndices to retreive this * data. * * You'll also need an implementation of LEFontInstance for your platform. * * @see LayoutEngine.h * @see LEFontInstance.h */ class U_LAYOUT_API ICULayoutEngine { private: /** * This holds the instance of LayoutEngine that does all * the work. */ LayoutEngine *fLayoutEngine; /** * This no argument constructor is private so that clients * can't envoke it. Clients should use createInstance. * * @see createInstance */ ICULayoutEngine(); /** * The main constructor. It is defined as private to * stop clients from invoking it. Clients should use * createInstance. * * @param layoutEngine - the LayoutEngine that this instance wraps. * * @see createInstance */ ICULayoutEngine(LayoutEngine *layoutEngine); public: /** * The destructor. At least on Windows it needs to be * virtual to ensure that it deletes the object from the * same heap that createInstance will allocate it from. We * don't know why this is... * * @see createInstance */ virtual ~ICULayoutEngine(); /** * This method computes the glyph, character index and position arrays * for the input characters. * * @param chars - the input character context * @param startOffset - the starting offset of the characters to process * @param endOffset - the ending offset of the characters to process * @param max - the number of characters in the input context * @param rightToLeft - true if the characers are in a right to left directional run * @param x - the initial X position * @param y - the initial Y position * @param success - output parameter set to an error code if the operation fails * * @return the number of glyphs in the glyph array * * Note; the glyph, character index and position array can be accessed * using the getter method below. */ int32_t layoutChars(const UChar chars[], int32_t startOffset, int32_t endOffset, int32_t maxOffset, UBool rightToLeft, float x, float y, UErrorCode &success); /** * This method computes the glyph, character index and position arrays * for the input characters. * * @param str - the input character context * @param startOffset - the starting offset of the characters to process * @param endOffset - the ending offset of the characters to process * @param rightToLeft - true if the characers are in a right to left directional run * @param x - the initial X position * @param y - the initial Y position * @param success - output parameter set to an error code if the operation fails * * @return the number of glyphs in the glyph array * * Note; the glyph, character index and position array can be accessed * using the getter method below. */ int32_t layoutString(const UnicodeString &str, int32_t startOffset, int32_t endOffset, UBool rightToLeft, float x, float y, UErrorCode &success); /** * This method returns the number of glyphs in the glyph array. Note * that the number of glyphs will be greater than or equal to the number * of characters used to create the LayoutEngine. * * @return the number of glyphs in the glyph array */ int32_t countGlyphs() const; /** * This method copies the glyph array into a caller supplied array. * The caller must ensure that the array is large enough to hold all * the glyphs. * * @param glyphs - the destiniation glyph array * @param success - output parameter set to an error code if the operation fails */ void getGlyphs(uint16_t glyphs[], UErrorCode &success); /** * This method copies the character index array into a caller supplied array. * The caller must ensure that the array is large enough to hold a character * index for each glyph. * * @param charIndices - the destiniation character index array * @param success - output parameter set to an error code if the operation fails */ void getCharIndices(int32_t charIndices[], UErrorCode &success); /** * This method copies the character index array into a caller supplied array. * The caller must ensure that the array is large enough to hold a character * index for each glyph. * * @param charIndices - the destiniation character index array * @param indexBase - an offset which will be added to each index * @param success - output parameter set to an error code if the operation fails */ void getCharIndices(int32_t charIndices[], int32_t indexBase, UErrorCode &success); /** * This method copies the position array into a caller supplied array. * The caller must ensure that the array is large enough to hold an * X and Y position for each glyph, plus an extra X and Y for the * advance of the last glyph. * * @param glyphs - the destiniation position array * @param success - output parameter set to an error code if the operation fails */ void getGlyphPositions(float positions[], UErrorCode &success); /** * This method returns the X and Y position of the glyph at the * given index. * * Input parameters: * @param glyphIndex - the index of the glyph * * Output parameters: * @param x - the glyph's X position * @param y - the glyph's Y position * @param success - output parameter set to an error code if the operation fails * */ void getGlyphPosition(int32_t glyphIndex, float &x, float &y, UErrorCode &success); /** * This method returns an ICULayoutEngine capable of laying out text * in the given font, script and langauge. * * @param fontInstance - the font of the text * @param scriptCode - the script of the text * @param locale - used to determine the language of the text * @param success - output parameter set to an error code if the operation fails * * @return an ICULayoutEngine which can layout text in the given font. * * NOTE: currently, locale is ignored... * * @see LEFontInstance */ static ICULayoutEngine *createInstance(const LEFontInstance *fontInstance, UScriptCode script, Locale &locale, UErrorCode &success); }; inline ICULayoutEngine::ICULayoutEngine() { // nothing at all... } inline ICULayoutEngine::ICULayoutEngine(LayoutEngine *layoutEngine) : fLayoutEngine(layoutEngine) { // nothing else to do } inline ICULayoutEngine::~ICULayoutEngine() { delete fLayoutEngine; fLayoutEngine = 0; } inline int32_t ICULayoutEngine::layoutChars(const UChar chars[], int32_t startOffset, int32_t endOffset, int32_t maxOffset, UBool rightToLeft, float x, float y, UErrorCode &success) { // NOTE: call reset() so that clients can safely reuse fLayoutEngine->reset(); return fLayoutEngine->layoutChars(chars, startOffset, endOffset - startOffset, maxOffset, rightToLeft, x, y, (LEErrorCode &) success); } inline int32_t ICULayoutEngine::layoutString(const UnicodeString &str, int32_t startOffset, int32_t endOffset, UBool rightToLeft, float x, float y, UErrorCode &success) { int32_t glyphCount = 0; int32_t max = str.length(); UChar *chars = new UChar[max]; str.extract(0, max, chars); // NOTE: call reset() so that clients can safely reuse fLayoutEngine->reset(); glyphCount = fLayoutEngine->layoutChars(chars, startOffset, endOffset - startOffset, max, rightToLeft, x, y, (LEErrorCode &) success); delete[] chars; return glyphCount; } inline int32_t ICULayoutEngine::countGlyphs() const { return fLayoutEngine->getGlyphCount(); } inline void ICULayoutEngine::getGlyphs(uint16_t glyphs[], UErrorCode &success) { fLayoutEngine->getGlyphs(glyphs, (LEErrorCode &) success); } inline void ICULayoutEngine::getCharIndices(int32_t charIndices[], UErrorCode &success) { fLayoutEngine->getCharIndices(charIndices, (LEErrorCode &) success); } inline void ICULayoutEngine::getCharIndices(int32_t charIndices[], int32_t indexBase, UErrorCode &success) { fLayoutEngine->getCharIndices(charIndices, indexBase, (LEErrorCode &) success); } inline void ICULayoutEngine::getGlyphPositions(float positions[], UErrorCode &success) { fLayoutEngine->getGlyphPositions(positions, (LEErrorCode &) success); } inline void ICULayoutEngine::getGlyphPosition(int32_t glyphIndex, float &x, float &y, UErrorCode &success) { fLayoutEngine->getGlyphPosition(glyphIndex, x, y, (LEErrorCode &) success); } inline ICULayoutEngine *ICULayoutEngine::createInstance(const LEFontInstance *fontInstance, UScriptCode script, Locale &locale, UErrorCode &success) { LayoutEngine *engine = LayoutEngine::layoutEngineFactory(fontInstance, (le_int32) script, 0, (LEErrorCode &) success); return new ICULayoutEngine(engine); } U_NAMESPACE_END #endif