ICU 52.1  52.1
LEFontInstance.h
Go to the documentation of this file.
1 
2 /*
3  *
4  * (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved
5  *
6  */
7 
8 #ifndef __LEFONTINSTANCE_H
9 #define __LEFONTINSTANCE_H
10 
11 #include "LETypes.h"
18 
28 class LECharMapper /* not : public UObject because this is an interface/mixin class */
29 {
30 public:
35  virtual ~LECharMapper();
36 
46  virtual LEUnicode32 mapChar(LEUnicode32 ch) const = 0;
47 };
48 
55 class LEGlyphStorage;
56 
82 {
83 public:
84 
91  virtual ~LEFontInstance();
92 
144  virtual const LEFontInstance *getSubFont(const LEUnicode chars[], le_int32 *offset, le_int32 limit, le_int32 script, LEErrorCode &success) const;
145 
146  //
147  // Font file access
148  //
149 
170  virtual const void *getFontTable(LETag tableTag) const = 0;
171 
191  virtual const void* getFontTable(LETag tableTag, size_t &length) const { length=-1; return getFontTable(tableTag); } /* -1 = unknown length */
192 
209  virtual le_bool canDisplay(LEUnicode32 ch) const;
210 
219  virtual le_int32 getUnitsPerEM() const = 0;
220 
244  virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, const LECharMapper *mapper, le_bool filterZeroWidth, LEGlyphStorage &glyphStorage) const;
245 
261  virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper, le_bool filterZeroWidth) const;
262 
277  virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper) const;
278 
291  virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch) const = 0;
292 
293  //
294  // Metrics
295  //
296 
305  virtual void getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const = 0;
306 
319  virtual le_bool getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const = 0;
320 
329  virtual float getXPixelsPerEm() const = 0;
330 
339  virtual float getYPixelsPerEm() const = 0;
340 
351  virtual float xUnitsToPoints(float xUnits) const;
352 
363  virtual float yUnitsToPoints(float yUnits) const;
364 
373  virtual void unitsToPoints(LEPoint &units, LEPoint &points) const;
374 
385  virtual float xPixelsToUnits(float xPixels) const;
386 
397  virtual float yPixelsToUnits(float yPixels) const;
398 
407  virtual void pixelsToUnits(LEPoint &pixels, LEPoint &units) const;
408 
420  virtual float getScaleFactorX() const = 0;
421 
432  virtual float getScaleFactorY() const = 0;
433 
449  virtual void transformFunits(float xFunits, float yFunits, LEPoint &pixels) const;
450 
461  static inline float fixedToFloat(le_int32 fixed);
462 
473  static inline le_int32 floatToFixed(float theFloat);
474 
475  //
476  // These methods won't ever be called by the LayoutEngine,
477  // but are useful for clients of <code>LEFontInstance</code> who
478  // need to render text.
479  //
480 
489  virtual le_int32 getAscent() const = 0;
490 
499  virtual le_int32 getDescent() const = 0;
500 
509  virtual le_int32 getLeading() const = 0;
510 
521  virtual le_int32 getLineHeight() const;
522 
528  virtual UClassID getDynamicClassID() const;
529 
535  static UClassID getStaticClassID();
536 
537 };
538 
539 inline float LEFontInstance::fixedToFloat(le_int32 fixed)
540 {
541  return (float) (fixed / 65536.0);
542 }
543 
544 inline le_int32 LEFontInstance::floatToFixed(float theFloat)
545 {
546  return (le_int32) (theFloat * 65536.0);
547 }
548 
550 #endif
UChar32 LEUnicode32
Used to represent 32-bit Unicode code points.
Definition: LETypes.h:230
le_uint32 LETag
Used for four character tags.
Definition: LETypes.h:93
virtual UClassID getDynamicClassID() const
ICU4C "poor man's RTTI", returns a UClassID for the actual ICU class.
virtual const void * getFontTable(LETag tableTag, size_t &length) const
This method reads a table from the font.
Instances of this class are used by LEFontInstance::mapCharsToGlyphs and LEFontInstance::mapCharToGly...
#define U_LAYOUT_API
Set to export library symbols from inside the layout engine library, and to import them from outside...
Definition: utypes.h:359
void * UClassID
UClassID is used to identify classes without using the compiler's RTTI.
Definition: uobject.h:91
C API: Basic definitions for the ICU LayoutEngine.
int32_t le_int32
A type used for signed, 32-bit integers.
Definition: LETypes.h:34
UBool le_bool
A type used for boolean values.
Definition: LETypes.h:77
#define U_NAMESPACE_BEGIN
This is used to begin a declaration of a public ICU C++ API.
Definition: uversion.h:129
LEErrorCode
Error codes returned by the LayoutEngine.
Definition: LETypes.h:687
#define U_NAMESPACE_END
This is used to end a declaration of a public ICU C++ API.
Definition: uversion.h:130
UChar LEUnicode
Used to represent 16-bit Unicode code points.
Definition: LETypes.h:238
This is a virtual base class that serves as the interface between a LayoutEngine and the platform fon...
This class encapsulates the per-glyph storage used by the ICU LayoutEngine.
le_uint32 LEGlyphID
Used for glyph indices.
Definition: LETypes.h:112
UObject is the common ICU "boilerplate" class.
Definition: uobject.h:221
Used to hold a pair of (x, y) values which represent a point.
Definition: LETypes.h:246