/* * * (C) Copyright IBM Corp. 1998-2014 - All Rights Reserved * */ #ifndef __THAILAYOUTENGINE_H #define __THAILAYOUTENGINE_H #include "LETypes.h" #include "LEFontInstance.h" #include "LayoutEngine.h" #include "ThaiShaping.h" U_NAMESPACE_BEGIN class LEGlyphStorage; /** * This class implements layout for the Thai script, using the ThaiShapingClass. * All existing Thai fonts use an encoding which assigns character codes to all * the variant forms needed to display accents and tone marks correctly in context. * This class can deal with fonts using the Microsoft, Macintosh, and WorldType encodings. * * @internal */ class ThaiLayoutEngine : public LayoutEngine { public: /** * This constructs an instance of ThaiLayoutEngine for the given font, script and * language. It examines the font, using LEFontInstance::canDisplay, to set fGlyphSet * and fErrorChar. (see below) * * @param fontInstance - the font * @param scriptCode - the script * @param languageCode - the language * @param success - set to an error code if the operation fails * * @see LEFontInstance * @see ScriptAndLanguageTags.h for script and language codes * * @internal */ ThaiLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags, LEErrorCode &success); /** * The destructor, virtual for correct polymorphic invocation. * * @internal */ virtual ~ThaiLayoutEngine(); /** * ICU "poor man's RTTI", returns a UClassID for the actual class. * * @deprecated ICU 54. See {@link icu::LayoutEngine} */ virtual UClassID getDynamicClassID() const; /** * ICU "poor man's RTTI", returns a UClassID for this class. * * @deprecated ICU 54. See {@link icu::LayoutEngine} */ static UClassID getStaticClassID(); protected: /** * A small integer indicating which Thai encoding * the font uses. * * @see ThaiShaping * * @internal */ le_uint8 fGlyphSet; /** * The character used as a base for vowels and * tone marks that are out of sequence. Usually * this will be Unicode 0x25CC, if the font can * display it. * * @see ThaiShaping * * @internal */ LEUnicode fErrorChar; /** * This method performs Thai layout. It calls ThaiShaping::compose to * generate the correct contextual character codes, and then calls * mapCharsToGlyphs to generate the glyph indices. * * Input parameters: * @param chars - the input character context * @param offset - the index of the first character to process * @param count - the number of characters to process * @param max - the number of characters in the input context * @param rightToLeft - <code>TRUE</code> if the text is in a right to left directional run * @param glyphStorage - the glyph storage object. The glyph and char index arrays will be set. * * Output parameters: * @param success - set to an error code if the operation fails * * @return the number of glyphs in the glyph index array * * @see ThaiShaping * * @internal */ virtual le_int32 computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft, LEGlyphStorage &glyphStorage, LEErrorCode &success); /** * This method does positioning adjustments like accent positioning and * kerning. The default implementation does nothing. Subclasses needing * position adjustments must override this method. * * Note that this method has both characters and glyphs as input so that * it can use the character codes to determine glyph types if that information * isn't directly available. (e.g. Some Arabic OpenType fonts don't have a GDEF * table) * * @param chars - the input character context * @param offset - the offset of the first character to process * @param count - the number of characters to process * @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered * @param glyphStorage - the object which holds the per-glyph storage. The glyph positions will be * adjusted as needed. * @param success - output parameter set to an error code if the operation fails * * @internal */ virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success); }; U_NAMESPACE_END #endif