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/****************************************************************************
*
* psblues.h
*
* Adobe's code for handling Blue Zones (specification).
*
* Copyright 2009-2013 Adobe Systems Incorporated.
*
* This software, and all works of authorship, whether in source or
* object code form as indicated by the copyright notice(s) included
* herein (collectively, the "Work") is made available, and may only be
* used, modified, and distributed under the FreeType Project License,
* LICENSE.TXT. Additionally, subject to the terms and conditions of the
* FreeType Project License, each contributor to the Work hereby grants
* to any individual or legal entity exercising permissions granted by
* the FreeType Project License and this section (hereafter, "You" or
* "Your") a perpetual, worldwide, non-exclusive, no-charge,
* royalty-free, irrevocable (except as stated in this section) patent
* license to make, have made, use, offer to sell, sell, import, and
* otherwise transfer the Work, where such license applies only to those
* patent claims licensable by such contributor that are necessarily
* infringed by their contribution(s) alone or by combination of their
* contribution(s) with the Work to which such contribution(s) was
* submitted. If You institute patent litigation against any entity
* (including a cross-claim or counterclaim in a lawsuit) alleging that
* the Work or a contribution incorporated within the Work constitutes
* direct or contributory patent infringement, then any patent licenses
* granted to You under this License for that Work shall terminate as of
* the date such litigation is filed.
*
* By using, modifying, or distributing the Work you indicate that you
* have read and understood the terms and conditions of the
* FreeType Project License as well as those provided in this section,
* and you accept them fully.
*
*/
/*
* A `CF2_Blues' object stores the blue zones (horizontal alignment
* zones) of a font. These are specified in the CFF private dictionary
* by `BlueValues', `OtherBlues', `FamilyBlues', and `FamilyOtherBlues'.
* Each zone is defined by a top and bottom edge in character space.
* Further, each zone is either a top zone or a bottom zone, as recorded
* by `bottomZone'.
*
* The maximum number of `BlueValues' and `FamilyBlues' is 7 each.
* However, these are combined to produce a total of 7 zones.
* Similarly, the maximum number of `OtherBlues' and `FamilyOtherBlues'
* is 5 and these are combined to produce an additional 5 zones.
*
* Blue zones are used to `capture' hints and force them to a common
* alignment point. This alignment is recorded in device space in
* `dsFlatEdge'. Except for this value, a `CF2_Blues' object could be
* constructed independently of scaling. Construction may occur once
* the matrix is known. Other features implemented in the Capture
* method are overshoot suppression, overshoot enforcement, and Blue
* Boost.
*
* Capture is determined by `BlueValues' and `OtherBlues', but the
* alignment point may be adjusted to the scaled flat edge of
* `FamilyBlues' or `FamilyOtherBlues'. No alignment is done to the
* curved edge of a zone.
*
*/
#ifndef PSBLUES_H_
#define PSBLUES_H_
#include "psglue.h"
FT_BEGIN_HEADER
/*
* `CF2_Hint' is shared by `cf2hints.h' and
* `cf2blues.h', but `cf2blues.h' depends on
* `cf2hints.h', so define it here. Note: The typedef is in
* `cf2glue.h'.
*
*/
enum
{
CF2_GhostBottom = 0x1, /* a single bottom edge */
CF2_GhostTop = 0x2, /* a single top edge */
CF2_PairBottom = 0x4, /* the bottom edge of a stem hint */
CF2_PairTop = 0x8, /* the top edge of a stem hint */
CF2_Locked = 0x10, /* this edge has been aligned */
/* by a blue zone */
CF2_Synthetic = 0x20 /* this edge was synthesized */
};
/*
* Default value for OS/2 typoAscender/Descender when their difference
* is not equal to `unitsPerEm'. The default is based on -250 and 1100
* in `CF2_Blues', assuming 1000 units per em here.
*
*/
enum
{
CF2_ICF_Top = cf2_intToFixed( 880 ),
CF2_ICF_Bottom = cf2_intToFixed( -120 )
};
/*
* Constant used for hint adjustment and for synthetic em box hint
* placement.
*/
#define CF2_MIN_COUNTER cf2_doubleToFixed( 0.5 )
/* shared typedef is in cf2glue.h */
struct CF2_HintRec_
{
CF2_UInt flags; /* attributes of the edge */
size_t index; /* index in original stem hint array */
/* (if not synthetic) */
CF2_Fixed csCoord;
CF2_Fixed dsCoord;
CF2_Fixed scale;
};
typedef struct CF2_BlueRec_
{
CF2_Fixed csBottomEdge;
CF2_Fixed csTopEdge;
CF2_Fixed csFlatEdge; /* may be from either local or Family zones */
CF2_Fixed dsFlatEdge; /* top edge of bottom zone or bottom edge */
/* of top zone (rounded) */
FT_Bool bottomZone;
} CF2_BlueRec;
/* max total blue zones is 12 */
enum
{
CF2_MAX_BLUES = 7,
CF2_MAX_OTHERBLUES = 5
};
typedef struct CF2_BluesRec_
{
CF2_Fixed scale;
CF2_UInt count;
FT_Bool suppressOvershoot;
FT_Bool doEmBoxHints;
CF2_Fixed blueScale;
CF2_Fixed blueShift;
CF2_Fixed blueFuzz;
CF2_Fixed boost;
CF2_HintRec emBoxTopEdge;
CF2_HintRec emBoxBottomEdge;
CF2_BlueRec zone[CF2_MAX_BLUES + CF2_MAX_OTHERBLUES];
} CF2_BluesRec, *CF2_Blues;
FT_LOCAL( void )
cf2_blues_init( CF2_Blues blues,
CF2_Font font );
FT_LOCAL( FT_Bool )
cf2_blues_capture( const CF2_Blues blues,
CF2_Hint bottomHintEdge,
CF2_Hint topHintEdge );
FT_END_HEADER
#endif /* PSBLUES_H_ */
/* END */