| |
| /* |
| * @(#)LEFontInstance.h 1.3 00/03/15 |
| * |
| * (C) Copyright IBM Corp. 1998, 1999, 2000, 2001, 2002 - All Rights Reserved |
| * |
| */ |
| |
| #ifndef __LEFONTINSTANCE_H |
| #define __LEFONTINSTANCE_H |
| |
| #include "LETypes.h" |
| |
| U_NAMESPACE_BEGIN |
| |
| /** |
| * Instances of this class are used by LEFontInstance::mapCharsToGlyphs and |
| * LEFontInstance::mapCharToGlyph to adjust character codes before the character |
| * to glyph mapping process. Examples of this are filtering out control charcters |
| * and character mirroring - replacing a character which has both a left and a right |
| * hand form with the opposite form. |
| * |
| * @draft ICU 2.2 |
| */ |
| class LECharMapper /* not : public UObject because this is an interface/mixin class */ { |
| public: |
| /** |
| * This method does the adjustments. |
| * |
| * @param ch - the input charcter |
| * |
| * @return the adjusted character |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual LEUnicode32 mapChar(LEUnicode32 ch) const = 0; |
| }; |
| |
| /** |
| * This is a pure virtual base class that servers as the interface between a LayoutEngine |
| * and the platform font environment. It allows a LayoutEngine to access font tables, do |
| * character to glyph mapping, and obtain metrics information without knowing any platform |
| * specific details. There are also a few utility methods for converting between points, |
| * pixels and funits. (font design units) |
| * |
| * Each instance of an LEFontInstance represents a renerable instance of a font. (i.e. a |
| * single font at a particular point size, with a particular transform) |
| * |
| * @draft ICU 2.2 |
| */ |
| class LEFontInstance /* not : public UObject because this is an interface/mixin class */ { |
| public: |
| |
| /** |
| * This virtual destructor is here so that the subclass |
| * destructors can be invoked through the base class. |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual ~LEFontInstance() { }; |
| |
| // |
| // Font file access |
| // |
| |
| /** |
| * This method reads a table from the font. |
| * |
| * @param tableTag - the four byte table tag |
| * |
| * @return the address of the table in memory |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual const void *getFontTable(LETag tableTag) const = 0; |
| |
| /** |
| * This method is used to determine if the font can |
| * render the given character. This can usually be done |
| * by looking the character up in the font's character |
| * to glyph mapping. |
| * |
| * @param ch - the character to be tested |
| * |
| * @return true if the font can render ch. |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual le_bool canDisplay(LEUnicode32 ch) const = 0; |
| |
| /** |
| * This method returns the number of design units in |
| * the font's EM square. |
| * |
| * @return the number of design units pre EM. |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual le_int32 getUnitsPerEM() const = 0; |
| |
| /** |
| * This method maps an array of charcter codes to an array of glyph |
| * indices, using the font's character to glyph map. |
| * |
| * @param chars - the character array |
| * @param offset - the index of the first charcter |
| * @param count - the number of charcters |
| * @param reverse - if true, store the glyph indices in reverse order. |
| * @param mapper - the character mapper. |
| * @param glyphs - the output glyph array |
| * |
| * @see LECharMapper |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, const LECharMapper *mapper, LEGlyphID glyphs[]) const = 0; |
| |
| /** |
| * This method maps a single character to a glyph index, using the |
| * font's charcter to glyph map. |
| * |
| * @param ch - the character |
| * @param mapper - the character mapper |
| * |
| * @return the glyph index |
| * |
| * @see LECharMapper |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper) const = 0; |
| |
| /** |
| * This method gets a name from the font. (e.g. the family name) The encoding |
| * of the name is specified by the platform, the script, and the language. |
| * |
| * @param platformID - the platform id |
| * @param scriptID - the script id |
| * @param langaugeID - the language id |
| * @param name - the destination character array (can be null) |
| * |
| * @return the number of characters in the name |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual le_int32 getName(le_uint16 platformID, le_uint16 scriptID, le_uint16 languageID, le_uint16 nameID, LEUnicode *name) const = 0; |
| |
| // |
| // Metrics |
| // |
| |
| /** |
| * This method gets the X and Y advance of a particular glyph, in pixels. |
| * |
| * @param glyph - the glyph index |
| * @param advance - the X and Y pixel values will be stored here |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual void getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const = 0; |
| |
| /** |
| * This method gets the hinted X and Y pixel coordinates of a particular |
| * point in the outline of the given glyph. |
| * |
| * @param glyph - the glyph index |
| * @param pointNumber - the number of the point |
| * @param point - the point's X and Y pixel values will be stored here |
| * |
| * @return true if the point coordinates could be stored. |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual le_bool getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const = 0; |
| |
| /** |
| * This method returns the width of the font's EM square |
| * in pixels. |
| * |
| * @return the pixel width of the EM square |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual float getXPixelsPerEm() const = 0; |
| |
| /** |
| * This method returns the height of the font's EM square |
| * in pixels. |
| * |
| * @return the pixel height of the EM square |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual float getYPixelsPerEm() const = 0; |
| |
| /** |
| * This method converts font design units in the |
| * X direction to points. |
| * |
| * @param xUnits - design units in the X direction |
| * |
| * @return points in the X direction |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual float xUnitsToPoints(float xUnits) const = 0; |
| |
| /** |
| * This method converts font design units in the |
| * Y direction to points. |
| * |
| * @param yUnits - design units in the Y direction |
| * |
| * @return points in the Y direction |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual float yUnitsToPoints(float yUunits) const = 0; |
| |
| /** |
| * This method converts font design units to points. |
| * |
| * @param units - X and Y design units |
| * @param points - set to X and Y points |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual void unitsToPoints(LEPoint &units, LEPoint &points) const = 0; |
| |
| /** |
| * This method converts pixels in the |
| * X direction to font design units. |
| * |
| * @param xPixels - pixels in the X direction |
| * |
| * @return font design units in the X direction |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual float xPixelsToUnits(float xPixels) const = 0; |
| |
| /** |
| * This method converts pixels in the |
| * Y direction to font design units. |
| * |
| * @param yPixels - pixels in the Y direction |
| * |
| * @return font design units in the Y direction |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual float yPixelsToUnits(float yPixels) const = 0; |
| |
| /** |
| * This method converts pixels to font design units. |
| * |
| * @param pixels - X and Y pixel |
| * @param units - set to X and Y font design units |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual void pixelsToUnits(LEPoint &pixels, LEPoint &units) const = 0; |
| |
| /** |
| * This method transforms an X, Y point in font design units to a |
| * pixel coordinate, applying the font's transform. |
| * |
| * @param xFunits - the X coordinate in font design units |
| * @param yFunits - the Y coordinate in font design units |
| * @param pixels - the tranformed co-ordinate in pixels |
| * |
| * @draft ICU 2.2 |
| */ |
| virtual void transformFunits(float xFunits, float yFunits, LEPoint &pixels) const = 0; |
| |
| /** |
| * This is a convenience method used to convert |
| * values in a 16.16 fixed point format to floating point. |
| * |
| * @param fixed - the fixed point value |
| * |
| * @return the floating point value |
| * |
| * @draft ICU 2.2 |
| */ |
| static float fixedToFloat(le_int32 fixed) |
| { |
| return (float) (fixed / 65536.0); |
| }; |
| |
| /** |
| * This is a convenience method used to convert |
| * floating point values to 16.16 fixed point format. |
| * |
| * @param theFloat - the floating point value |
| * |
| * @return the fixed point value |
| */ |
| static le_int32 floatToFixed(float theFloat) |
| { |
| return (le_int32) (theFloat * 65536.0); |
| }; |
| }; |
| |
| U_NAMESPACE_END |
| #endif |
| |
| |