diff -r 000000000000 -r bde4ae8d615e os/textandloc/fontservices/textshaperplugin/IcuSource/layout/LEFontInstance.h
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/os/textandloc/fontservices/textshaperplugin/IcuSource/layout/LEFontInstance.h Fri Jun 15 03:10:57 2012 +0200
@@ -0,0 +1,557 @@
+
+/*
+ *
+ * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
+ *
+ */
+
+#ifndef __LEFONTINSTANCE_H
+#define __LEFONTINSTANCE_H
+
+#include "LETypes.h"
+/**
+ * \file
+ * \brief C++ API: Layout Engine Font Instance object
+ */
+
+U_NAMESPACE_BEGIN
+
+/**
+ * Instances of this class are used by <code>LEFontInstance::mapCharsToGlyphs</code> and
+ * <code>LEFontInstance::mapCharToGlyph</code> to adjust character codes before the character
+ * to glyph mapping process. Examples of this are filtering out control characters
+ * and character mirroring - replacing a character which has both a left and a right
+ * hand form with the opposite form.
+ *
+ * @stable ICU 3.2
+ */
+class LECharMapper /* not : public UObject because this is an interface/mixin class */
+{
+public:
+ /**
+ * Destructor.
+ * @stable ICU 3.2
+ */
+ virtual inline ~LECharMapper() {};
+
+ /**
+ * This method does the adjustments.
+ *
+ * @param ch - the input character
+ *
+ * @return the adjusted character
+ *
+ * @stable ICU 2.8
+ */
+ virtual LEUnicode32 mapChar(LEUnicode32 ch) const = 0;
+};
+
+/**
+ * This is a forward reference to the class which holds the per-glyph
+ * storage.
+ *
+ * @draft ICU 3.0
+ */
+class LEGlyphStorage;
+
+/**
+ * This is a virtual base class that serves 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)
+ *
+ * An instance of an <code>LEFontInstance</code> represents a font at a particular point
+ * size. Each instance can represent either a single physical font, or a composite font.
+ * A composite font is a collection of physical fonts, each of which contains a subset of
+ * the characters contained in the composite font.
+ *
+ * Note: with the exception of <code>getSubFont</code>, the methods in this class only
+ * make sense for a physical font. If you have an <code>LEFontInstance</code> which
+ * represents a composite font you should only call the methods below which have
+ * an <code>LEGlyphID</code>, an <code>LEUnicode</code> or an <code>LEUnicode32</code>
+ * as one of the arguments because these can be used to select a particular subfont.
+ *
+ * Subclasses which implement composite fonts should supply an implementation of these
+ * methods with some default behavior such as returning constant values, or using the
+ * values from the first subfont.
+ *
+ * @draft ICU 3.0
+ */
+class U_LAYOUT_API LEFontInstance : public UObject
+{
+public:
+
+ /**
+ * This virtual destructor is here so that the subclass
+ * destructors can be invoked through the base class.
+ *
+ * @stable ICU 2.8
+ */
+ virtual inline ~LEFontInstance() {};
+
+ /**
+ * Get a physical font which can render the given text. For composite fonts,
+ * if there is no single physical font which can render all of the text,
+ * return a physical font which can render an initial substring of the text,
+ * and set the <code>offset</code> parameter to the end of that substring.
+ *
+ * Internally, the LayoutEngine works with runs of text all in the same
+ * font and script, so it is best to call this method with text which is
+ * in a single script, passing the script code in as a hint. If you don't
+ * know the script of the text, you can use zero, which is the script code
+ * for characters used in more than one script.
+ *
+ * The default implementation of this method is intended for instances of
+ * <code>LEFontInstance</code> which represent a physical font. It returns
+ * <code>this</code> and indicates that the entire string can be rendered.
+ *
+ * This method will return a valid <code>LEFontInstance</code> unless you
+ * have passed illegal parameters, or an internal error has been encountered.
+ * For composite fonts, it may return the warning <code>LE_NO_SUBFONT_WARNING</code>
+ * to indicate that the returned font may not be able to render all of
+ * the text. Whenever a valid font is returned, the <code>offset</code> parameter
+ * will be advanced by at least one.
+ *
+ * Subclasses which implement composite fonts must override this method.
+ * Where it makes sense, they should use the script code as a hint to render
+ * characters from the COMMON script in the font which is used for the given
+ * script. For example, if the input text is a series of Arabic words separated
+ * by spaces, and the script code passed in is <code>arabScriptCode</code> you
+ * should return the font used for Arabic characters for all of the input text,
+ * including the spaces. If, on the other hand, the input text contains characters
+ * which cannot be rendered by the font used for Arabic characters, but which can
+ * be rendered by another font, you should return that font for those characters.
+ *
+ * @param chars - the array of Unicode characters.
+ * @param offset - a pointer to the starting offset in the text. On exit this
+ * will be set the the limit offset of the text which can be
+ * rendered using the returned font.
+ * @param limit - the limit offset for the input text.
+ * @param script - the script hint.
+ * @param success - set to an error code if the arguments are illegal, or no font
+ * can be returned for some reason. May also be set to
+ * <code>LE_NO_SUBFONT_WARNING</code> if the subfont which
+ * was returned cannot render all of the text.
+ *
+ * @return an <code>LEFontInstance</code> for the sub font which can render the characters, or
+ * <code>NULL</code> if there is an error.
+ *
+ * @see LEScripts.h
+ *
+ * @stable ICU 3.2
+ */
+ virtual const LEFontInstance *getSubFont(const LEUnicode chars[], le_int32 *offset, le_int32 limit, le_int32 script, LEErrorCode &success) const;
+
+ //
+ // Font file access
+ //
+
+ /**
+ * This method reads a table from the font. Note that in general,
+ * it only makes sense to call this method on an <code>LEFontInstance</code>
+ * which represents a physical font - i.e. one which has been returned by
+ * <code>getSubFont()</code>. This is because each subfont in a composite font
+ * will have different tables, and there's no way to know which subfont to access.
+ *
+ * Subclasses which represent composite fonts should always return <code>NULL</code>.
+ *
+ * @param tableTag - the four byte table tag. (e.g. 'cmap')
+ *
+ * @return the address of the table in memory, or <code>NULL</code>
+ * if the table doesn't exist.
+ *
+ * @stable ICU 2.8
+ */
+ 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.
+ *
+ * The default implementation of this method will return
+ * <code>TRUE</code> if <code>mapCharToGlyph(ch)</code>
+ * returns a non-zero value.
+ *
+ * @param ch - the character to be tested
+ *
+ * @return <code>TRUE</code> if the font can render ch.
+ *
+ * @stable ICU 3.2
+ */
+ virtual inline 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.
+ *
+ * @stable ICU 2.8
+ */
+ 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.
+ *
+ * The default implementation iterates over all of the characters and calls
+ * <code>mapCharToGlyph(ch, mapper)</code> on each one. It also handles surrogate
+ * characters, storing the glyph ID for the high surrogate, and a deleted glyph (0xFFFF)
+ * for the low surrogate.
+ *
+ * Most sublcasses will not need to implement this method.
+ *
+ * @param chars - the character array
+ * @param offset - the index of the first character
+ * @param count - the number of characters
+ * @param reverse - if <code>TRUE</code>, store the glyph indices in reverse order.
+ * @param mapper - the character mapper.
+ * @param glyphStorage - the object which contains the output glyph array
+ *
+ * @see LECharMapper
+ *
+ * @draft ICU 3.0
+ */
+ virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, const LECharMapper *mapper, LEGlyphStorage &glyphStorage) const;
+
+ /**
+ * This method maps a single character to a glyph index, using the
+ * font's character 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
+ *
+ * @see LECharMapper
+ *
+ * @stable ICU 3.2
+ */
+ virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch, const LECharMapper *mapper) const;
+
+ /**
+ * This method maps a single character to a glyph index, using the
+ * font's character to glyph map. There is no default implementation
+ * of this method because it requires information about the platform
+ * font implementation.
+ *
+ * @param ch - the character
+ *
+ * @return the glyph index
+ *
+ * @stable ICU 3.2
+ */
+ virtual LEGlyphID mapCharToGlyph(LEUnicode32 ch) 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
+ *
+ * @stable ICU 3.2
+ */
+ 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 <code>TRUE</code> if the point coordinates could be stored.
+ *
+ * @stable ICU 2.8
+ */
+ 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
+ *
+ * @stable ICU 2.8
+ */
+ 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
+ *
+ * @stable ICU 2.8
+ */
+ 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
+ *
+ * @stable ICU 3.2
+ */
+ virtual inline 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
+ *
+ * @stable ICU 3.2
+ */
+ virtual inline 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
+ *
+ * @stable ICU 3.2
+ */
+ virtual inline 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
+ *
+ * @stable ICU 3.2
+ */
+ virtual inline 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
+ *
+ * @stable ICU 3.2
+ */
+ virtual inline 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
+ *
+ * @stable ICU 3.2
+ */
+ virtual inline 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
+ *
+ * @stable ICU 3.2
+ */
+ 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
+ *
+ * @stable ICU 3.2
+ */
+ 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
+ *
+ * @stable ICU 3.2
+ */
+ virtual inline 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
+ *
+ * @stable ICU 2.8
+ */
+ static inline 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
+ *
+ * @stable ICU 2.8
+ */
+ 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.
+ //
+
+ /**
+ * Get the font's ascent.
+ *
+ * @return the font's ascent, in points. This value
+ * will always be positive.
+ *
+ * @stable ICU 3.2
+ */
+ virtual le_int32 getAscent() const = 0;
+
+ /**
+ * Get the font's descent.
+ *
+ * @return the font's descent, in points. This value
+ * will always be positive.
+ *
+ * @stable ICU 3.2
+ */
+ virtual le_int32 getDescent() const = 0;
+
+ /**
+ * Get the font's leading.
+ *
+ * @return the font's leading, in points. This value
+ * will always be positive.
+ *
+ * @stable ICU 3.2
+ */
+ virtual le_int32 getLeading() const = 0;
+
+ /**
+ * Get the line height required to display text in
+ * this font. The default implementation of this method
+ * returns the sum of the ascent, descent, and leading.
+ *
+ * @return the line height, in points. This vaule will
+ * always be positive.
+ *
+ * @stable ICU 3.2
+ */
+ virtual le_int32 getLineHeight() const;
+
+ /**
+ * ICU "poor man's RTTI", returns a UClassID for the actual class.
+ *
+ * @stable ICU 3.2
+ */
+ virtual UClassID getDynamicClassID() const;
+
+ /**
+ * ICU "poor man's RTTI", returns a UClassID for this class.
+ *
+ * @stable ICU 3.2
+ */
+ 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
+
+