ICU 4.0.1: LEFontInstance.h Source File

00001 
00002 /*
00003  *
00004  * (C) Copyright IBM Corp. 1998-2007 - All Rights Reserved
00005  *
00006  */
00007 
00008 #ifndef __LEFONTINSTANCE_H
00009 #define __LEFONTINSTANCE_H
00010 
00011 #include "LETypes.h"
00017 U_NAMESPACE_BEGIN
00018 
00028 class LECharMapper /* not : public UObject because this is an interface/mixin class */
00029 {
00030 public:
00035     virtual ~LECharMapper();
00036 
00046     virtual LEUnicode32 mapChar(LEUnicode32 ch) const = 0;
00047 };
00048 
00055 class LEGlyphStorage;
00056 
00081 class U_LAYOUT_API LEFontInstance : public UObject
00082 {
00083 public:
00084 
00091     virtual ~LEFontInstance();
00092 
00144     virtual const LEFontInstance *getSubFont(const LEUnicode chars[], le_int32 *offset, le_int32 limit, le_int32 script, LEErrorCode &success) const;
00145 
00146     //
00147     // Font file access
00148     //
00149 
00166     virtual const void *getFontTable(LETag tableTag) const = 0;
00167 
00184     virtual le_bool canDisplay(LEUnicode32 ch) const;
00185 
00194     virtual le_int32 getUnitsPerEM() const = 0;
00195 
00219     virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, const LECharMapper *mapper, le_bool filterZeroWidth, LEGlyphStorage &glyphStorage) const;
00220 
00236     virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper, le_bool filterZeroWidth) const;
00237 
00252     virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper) const;
00253 
00266     virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch) const = 0;
00267 
00268     //
00269     // Metrics
00270     //
00271 
00280     virtual void getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const = 0;
00281 
00294     virtual le_bool getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const = 0;
00295 
00304     virtual float getXPixelsPerEm() const = 0;
00305 
00314     virtual float getYPixelsPerEm() const = 0;
00315 
00326     virtual float xUnitsToPoints(float xUnits) const;
00327 
00338     virtual float yUnitsToPoints(float yUnits) const;
00339 
00348     virtual void unitsToPoints(LEPoint &units, LEPoint &points) const;
00349 
00360     virtual float xPixelsToUnits(float xPixels) const;
00361 
00372     virtual float yPixelsToUnits(float yPixels) const;
00373 
00382     virtual void pixelsToUnits(LEPoint &pixels, LEPoint &units) const;
00383 
00395     virtual float getScaleFactorX() const = 0;
00396 
00407     virtual float getScaleFactorY() const = 0;
00408 
00424     virtual void transformFunits(float xFunits, float yFunits, LEPoint &pixels) const;
00425 
00436     static inline float fixedToFloat(le_int32 fixed);
00437 
00448     static inline le_int32 floatToFixed(float theFloat);
00449 
00450     //
00451     // These methods won't ever be called by the LayoutEngine,
00452     // but are useful for clients of <code>LEFontInstance</code> who
00453     // need to render text.
00454     //
00455 
00464     virtual le_int32 getAscent() const = 0;
00465 
00474     virtual le_int32 getDescent() const = 0;
00475 
00484     virtual le_int32 getLeading() const = 0;
00485 
00496     virtual le_int32 getLineHeight() const;
00497 
00503     virtual UClassID getDynamicClassID() const;
00504 
00510     static UClassID getStaticClassID();
00511 
00512 };
00513 
00514 inline float LEFontInstance::fixedToFloat(le_int32 fixed)
00515 {
00516     return (float) (fixed / 65536.0);
00517 }
00518 
00519 inline le_int32 LEFontInstance::floatToFixed(float theFloat)
00520 {
00521     return (le_int32) (theFloat * 65536.0);
00522 }
00523 
00524 U_NAMESPACE_END
00525 #endif
00526 
00527