| |
| /* |
| * |
| * (C) Copyright IBM Corp. 1998-2008 - 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. |
| * |
| * @stable ICU 2.8 |
| */ |
| virtual UClassID getDynamicClassID() const; |
| |
| /** |
| * ICU "poor man's RTTI", returns a UClassID for this class. |
| * |
| * @stable ICU 2.8 |
| */ |
| 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 |
| |