507 lines
14 KiB
C++
507 lines
14 KiB
C++
|
|
/*
|
|
* @(#)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:
|
|
/**
|
|
* Destructor.
|
|
* @draft ICU 2.4
|
|
*/
|
|
virtual inline ~LECharMapper() {};
|
|
|
|
/**
|
|
* 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 U_LAYOUT_API 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 inline ~LEFontInstance() {};
|
|
|
|
/**
|
|
* This method is provided so that clients can tell if
|
|
* a given LEFontInstance is an instance of a composite
|
|
* font.
|
|
*
|
|
* @return <code>true</code> if the instance represents a composite font, <code>false</code> otherwise.
|
|
*
|
|
* @see LECompositeFont?
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual le_bool isComposite() const;
|
|
|
|
/**
|
|
* Get a sub-font for a run of text from a composite font. This method examines the
|
|
* given text, finding a run of text which can all be rendered
|
|
* using the same sub-font. Subclassers should try to keep all the text in a single
|
|
* sub-font if they can.
|
|
*
|
|
* @param chars - the array of unicode characters
|
|
* @param offset - a pointer to the starting offset in the text. This will be
|
|
* set to the limit offset of the run on exit.
|
|
* @param count - the number of characters in the array. Can be used as a hint for selecting a sub-font.
|
|
* @param script - the script of the characters.
|
|
*
|
|
* @return an <code>LEFontInstance</code> for the sub font which can render the characters.
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual const LEFontInstance *getSubFont(const LEUnicode chars[], le_int32 *offset, le_int32 count, le_int32 script) const;
|
|
|
|
//
|
|
// 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 2.6
|
|
*/
|
|
virtual le_bool canDisplay(LEUnicode32 ch) const;
|
|
|
|
/**
|
|
* 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 character 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 2.6
|
|
*/
|
|
virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, const LECharMapper *mapper, LEGlyphID glyphs[]) const;
|
|
|
|
/**
|
|
* This method maps a single character to a glyph index, using the
|
|
* font's charcter to glyph map. The default implementation of this
|
|
* method calls the mapper, and then calls <code>mapCharToGlyph(mappedCh)</code>.
|
|
*
|
|
* @param ch - the character
|
|
* @param mapper - the character mapper
|
|
*
|
|
* @return the glyph index
|
|
*
|
|
* @draft ICU 2.2
|
|
*/
|
|
virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper) const;
|
|
|
|
/**
|
|
* This method maps a single character to a glyph index, using the
|
|
* font's charcter to glyph map.
|
|
*
|
|
* @param ch - the character
|
|
*
|
|
* @return the glyph index
|
|
*
|
|
* @see LECharMapper
|
|
*
|
|
* @draft ICU 2.2
|
|
*/
|
|
virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch) 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;
|
|
|
|
//
|
|
// 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 2.6
|
|
*/
|
|
virtual float xUnitsToPoints(float xUnits) const;
|
|
|
|
/**
|
|
* 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 2.6
|
|
*/
|
|
virtual float yUnitsToPoints(float yUnits) const;
|
|
|
|
/**
|
|
* 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 2.6
|
|
*/
|
|
virtual void unitsToPoints(LEPoint &units, LEPoint &points) const;
|
|
|
|
/**
|
|
* 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 2.6
|
|
*/
|
|
virtual float xPixelsToUnits(float xPixels) const;
|
|
|
|
/**
|
|
* 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;
|
|
|
|
/**
|
|
* 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 2.6
|
|
*/
|
|
virtual void pixelsToUnits(LEPoint &pixels, LEPoint &units) const;
|
|
|
|
/**
|
|
* Get the X scale factor from the font's transform. The default
|
|
* implementation of <code>transformFunits()</code> will call this method.
|
|
*
|
|
* @return the X scale factor.
|
|
*
|
|
*
|
|
* @see transformFunits
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual float getScaleFactorX() const = 0;
|
|
|
|
/**
|
|
* Get the Y scale factor from the font's transform. The default
|
|
* implementation of <code>transformFunits()</code> will call this method.
|
|
*
|
|
* @return the Yscale factor.
|
|
*
|
|
* @see transformFunits
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual float getScaleFactorY() const = 0;
|
|
|
|
/**
|
|
* This method transforms an X, Y point in font design units to a
|
|
* pixel coordinate, applying the font's transform. The default
|
|
* implementation of this method calls <code>getScaleFactorX()</code>
|
|
* and <code>getScaleFactorY()</code>.
|
|
*
|
|
* @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
|
|
*
|
|
* @see getScaleFactorX
|
|
* @see getScaleFactorY
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual void transformFunits(float xFunits, float yFunits, LEPoint &pixels) const;
|
|
|
|
/**
|
|
* 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);
|
|
|
|
/**
|
|
* 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
|
|
*
|
|
* @draft ICU 2.2
|
|
*/
|
|
static le_int32 floatToFixed(float theFloat);
|
|
|
|
//
|
|
// These methods won't ever be called by the LayoutEngine,
|
|
// but are useful for cleints of <code>LEFontInstance</code> who
|
|
// need to render text.
|
|
//
|
|
|
|
/**
|
|
* Get the font's ascent.
|
|
*
|
|
* @return the font's ascent, in points.
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual le_int32 getAscent() const = 0;
|
|
|
|
/**
|
|
* Get the font's descent.
|
|
*
|
|
* @return the font's descent, in points.
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual le_int32 getDescent() const = 0;
|
|
|
|
/**
|
|
* Get the font's leading.
|
|
*
|
|
* @return the font's leading, in points.
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual le_int32 getLeading() const = 0;
|
|
|
|
/**
|
|
* Get the line height required to display text in
|
|
* this font. The value returned is just the sum of
|
|
* the ascent, descent, and leading.
|
|
*
|
|
* @return the line height, in points
|
|
*
|
|
* @draft ICU 2.6
|
|
*/
|
|
virtual le_int32 getLineHeight() const;
|
|
};
|
|
|
|
inline le_bool LEFontInstance::isComposite() const
|
|
{
|
|
return false;
|
|
}
|
|
|
|
inline const LEFontInstance *LEFontInstance::getSubFont(const LEUnicode chars[], le_int32 *offset, le_int32 count, le_int32 script) const
|
|
{
|
|
*offset += count;
|
|
return this;
|
|
}
|
|
|
|
inline le_bool LEFontInstance::canDisplay(LEUnicode32 ch) const
|
|
{
|
|
return mapCharToGlyph(ch) != 0;
|
|
}
|
|
|
|
inline le_int32 LEFontInstance::getName(le_uint16 platformID, le_uint16 scriptID, le_uint16 languageID, le_uint16 nameID, LEUnicode *name) const
|
|
{
|
|
if (name != NULL) {
|
|
*name = 0;
|
|
}
|
|
|
|
return 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
|
|
|
|
|