LEFontInstance.h

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/*
 *
 * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
 *
 */

#ifndef __LEFONTINSTANCE_H
#define __LEFONTINSTANCE_H

#include "LETypes.h"
U_NAMESPACE_BEGIN

class LECharMapper /* not : public UObject because this is an interface/mixin class */
{
public:
    virtual inline ~LECharMapper() {};

    virtual LEUnicode32 mapChar(LEUnicode32 ch) const = 0;
};

class LEGlyphStorage;

class U_LAYOUT_API LEFontInstance : public UObject
{
public:

    virtual inline ~LEFontInstance() {};

    virtual const LEFontInstance *getSubFont(const LEUnicode chars[], le_int32 *offset, le_int32 limit, le_int32 script, LEErrorCode &success) const;

    //
    // Font file access
    //

    virtual const void *getFontTable(LETag tableTag) const = 0;

    virtual inline le_bool canDisplay(LEUnicode32 ch) const;

    virtual le_int32 getUnitsPerEM() const = 0;

    virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, const LECharMapper *mapper, LEGlyphStorage &glyphStorage) const;

    virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper) const;

    virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch) const = 0;

    //
    // Metrics
    //

    virtual void getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const = 0;

    virtual le_bool getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const = 0;

    virtual float getXPixelsPerEm() const = 0;

    virtual float getYPixelsPerEm() const = 0;

    virtual inline float xUnitsToPoints(float xUnits) const;

    virtual inline float yUnitsToPoints(float yUnits) const;

    virtual inline void unitsToPoints(LEPoint &units, LEPoint &points) const;

    virtual inline float xPixelsToUnits(float xPixels) const;

    virtual inline float yPixelsToUnits(float yPixels) const;

    virtual inline void pixelsToUnits(LEPoint &pixels, LEPoint &units) const;

    virtual float getScaleFactorX() const = 0;

    virtual float getScaleFactorY() const = 0;

    virtual inline void transformFunits(float xFunits, float yFunits, LEPoint &pixels) const;

    static inline float fixedToFloat(le_int32 fixed);

    static inline le_int32 floatToFixed(float theFloat);

    //
    // These methods won't ever be called by the LayoutEngine,
    // but are useful for clients of <code>LEFontInstance</code> who
    // need to render text.
    //

    virtual le_int32 getAscent() const = 0;

    virtual le_int32 getDescent() const = 0;

    virtual le_int32 getLeading() const = 0;

    virtual le_int32 getLineHeight() const;

    virtual UClassID getDynamicClassID() const;

    static UClassID getStaticClassID();

};

inline le_bool LEFontInstance::canDisplay(LEUnicode32 ch) const
{
    return LE_GET_GLYPH(mapCharToGlyph(ch)) != 0;
}

inline float LEFontInstance::xUnitsToPoints(float xUnits) const
{
    return (xUnits * getXPixelsPerEm()) / (float) getUnitsPerEM();
}

inline float LEFontInstance::yUnitsToPoints(float yUnits) const
{
    return (yUnits * getYPixelsPerEm()) / (float) getUnitsPerEM();
}

inline void LEFontInstance::unitsToPoints(LEPoint &units, LEPoint &points) const
{
    points.fX = xUnitsToPoints(units.fX);
    points.fY = yUnitsToPoints(units.fY);
}

inline float LEFontInstance::xPixelsToUnits(float xPixels) const
{
    return (xPixels * getUnitsPerEM()) / (float) getXPixelsPerEm();
}

inline float LEFontInstance::yPixelsToUnits(float yPixels) const
{
    return (yPixels * getUnitsPerEM()) / (float) getYPixelsPerEm();
}

inline void LEFontInstance::pixelsToUnits(LEPoint &pixels, LEPoint &units) const
{
    units.fX = xPixelsToUnits(pixels.fX);
    units.fY = yPixelsToUnits(pixels.fY);
}

inline void LEFontInstance::transformFunits(float xFunits, float yFunits, LEPoint &pixels) const
{
    pixels.fX = xUnitsToPoints(xFunits) * getScaleFactorX();
    pixels.fY = yUnitsToPoints(yFunits) * getScaleFactorY();
}

inline float LEFontInstance::fixedToFloat(le_int32 fixed)
{
    return (float) (fixed / 65536.0);
}

inline le_int32 LEFontInstance::floatToFixed(float theFloat)
{
    return (le_int32) (theFloat * 65536.0);
}

inline le_int32 LEFontInstance::getLineHeight() const
{
    return getAscent() + getDescent() + getLeading();
}

U_NAMESPACE_END
#endif

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