ref: 0b429b609c4a5fec8568dc9716e920533e13ab74
dir: /src/psaux/pshints.c/
/****************************************************************************
*
* pshints.c
*
* Adobe's code for handling CFF hints (body).
*
* Copyright 2007-2014 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.
*
*/
#include "psft.h"
#include <freetype/internal/ftdebug.h>
#include "psglue.h"
#include "psfont.h"
#include "pshints.h"
#include "psintrp.h"
/**************************************************************************
*
* The macro FT_COMPONENT is used in trace mode. It is an implicit
* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
* messages during execution.
*/
#undef FT_COMPONENT
#define FT_COMPONENT cf2hints
typedef struct CF2_HintMoveRec_
{
size_t j; /* index of upper hint map edge */
CF2_Fixed moveUp; /* adjustment to optimum position */
} CF2_HintMoveRec, *CF2_HintMove;
/* Compute angular momentum for winding order detection. It is called */
/* for all lines and curves, but not necessarily in element order. */
static CF2_Int
cf2_getWindingMomentum( CF2_Fixed x1,
CF2_Fixed y1,
CF2_Fixed x2,
CF2_Fixed y2 )
{
/* cross product of pt1 position from origin with pt2 position from */
/* pt1; we reduce the precision so that the result fits into 32 bits */
return ( x1 >> 16 ) * ( SUB_INT32( y2, y1 ) >> 16 ) -
( y1 >> 16 ) * ( SUB_INT32( x2, x1 ) >> 16 );
}
/*
* Construct from a StemHint; this is used as a parameter to
* `cf2_blues_capture'.
* `hintOrigin' is the character space displacement of a seac accent.
* Adjust stem hint for darkening here.
*
*/
static void
cf2_hint_init( CF2_Hint hint,
const CF2_ArrStack stemHintArray,
size_t indexStemHint,
const CF2_Font font,
CF2_Fixed hintOrigin,
CF2_Fixed scale,
FT_Bool bottom )
{
CF2_Fixed width;
const CF2_StemHintRec* stemHint;
FT_ZERO( hint );
stemHint = (const CF2_StemHintRec*)cf2_arrstack_getPointer(
stemHintArray,
indexStemHint );
width = SUB_INT32( stemHint->max, stemHint->min );
if ( width == cf2_intToFixed( -21 ) )
{
/* ghost bottom */
if ( bottom )
{
hint->csCoord = stemHint->max;
hint->flags = CF2_GhostBottom;
}
else
hint->flags = 0;
}
else if ( width == cf2_intToFixed( -20 ) )
{
/* ghost top */
if ( bottom )
hint->flags = 0;
else
{
hint->csCoord = stemHint->min;
hint->flags = CF2_GhostTop;
}
}
else if ( width < 0 )
{
/* inverted pair */
/*
* Hints with negative widths were produced by an early version of a
* non-Adobe font tool. The Type 2 spec allows edge (ghost) hints
* with negative widths, but says
*
* All other negative widths have undefined meaning.
*
* CoolType has a silent workaround that negates the hint width; for
* permissive mode, we do the same here.
*
* Note: Such fonts cannot use ghost hints, but should otherwise work.
* Note: Some poor hints in our faux fonts can produce negative
* widths at some blends. For example, see a light weight of
* `u' in ASerifMM.
*
*/
if ( bottom )
{
hint->csCoord = stemHint->max;
hint->flags = CF2_PairBottom;
}
else
{
hint->csCoord = stemHint->min;
hint->flags = CF2_PairTop;
}
}
else
{
/* normal pair */
if ( bottom )
{
hint->csCoord = stemHint->min;
hint->flags = CF2_PairBottom;
}
else
{
hint->csCoord = stemHint->max;
hint->flags = CF2_PairTop;
}
}
/* Now that ghost hints have been detected, adjust this edge for */
/* darkening. Bottoms are not changed; tops are incremented by twice */
/* `darkenY'. */
if ( cf2_hint_isTop( hint ) )
hint->csCoord = ADD_INT32( hint->csCoord, 2 * font->darkenY );
hint->csCoord = ADD_INT32( hint->csCoord, hintOrigin );
hint->scale = scale;
hint->index = indexStemHint; /* index in original stem hint array */
/* if original stem hint has been used, use the same position */
if ( hint->flags != 0 && stemHint->used )
{
if ( cf2_hint_isTop( hint ) )
hint->dsCoord = stemHint->maxDS;
else
hint->dsCoord = stemHint->minDS;
cf2_hint_lock( hint );
}
else
hint->dsCoord = FT_MulFix( hint->csCoord, scale );
}
/* initialize an invalid hint map element */
static void
cf2_hint_initZero( CF2_Hint hint )
{
FT_ZERO( hint );
}
FT_LOCAL_DEF( FT_Bool )
cf2_hint_isValid( const CF2_Hint hint )
{
return FT_BOOL( hint->flags );
}
static FT_Bool
cf2_hint_isPair( const CF2_Hint hint )
{
return FT_BOOL( hint->flags & ( CF2_PairBottom | CF2_PairTop ) );
}
static FT_Bool
cf2_hint_isPairTop( const CF2_Hint hint )
{
return FT_BOOL( hint->flags & CF2_PairTop );
}
FT_LOCAL_DEF( FT_Bool )
cf2_hint_isTop( const CF2_Hint hint )
{
return FT_BOOL( hint->flags & ( CF2_PairTop | CF2_GhostTop ) );
}
FT_LOCAL_DEF( FT_Bool )
cf2_hint_isBottom( const CF2_Hint hint )
{
return FT_BOOL( hint->flags & ( CF2_PairBottom | CF2_GhostBottom ) );
}
static FT_Bool
cf2_hint_isLocked( const CF2_Hint hint )
{
return FT_BOOL( hint->flags & CF2_Locked );
}
static FT_Bool
cf2_hint_isSynthetic( const CF2_Hint hint )
{
return FT_BOOL( hint->flags & CF2_Synthetic );
}
FT_LOCAL_DEF( void )
cf2_hint_lock( CF2_Hint hint )
{
hint->flags |= CF2_Locked;
}
FT_LOCAL_DEF( void )
cf2_hintmap_init( CF2_HintMap hintmap,
CF2_Font font,
CF2_HintMap initialMap,
CF2_ArrStack hintMoves,
CF2_Fixed scale )
{
FT_ZERO( hintmap );
/* copy parameters from font instance */
hintmap->hinted = font->hinted;
hintmap->scale = scale;
hintmap->font = font;
hintmap->initialHintMap = initialMap;
/* will clear in `cf2_hintmap_adjustHints' */
hintmap->hintMoves = hintMoves;
}
static FT_Bool
cf2_hintmap_isValid( const CF2_HintMap hintmap )
{
return hintmap->isValid;
}
static void
cf2_hintmap_dump( CF2_HintMap hintmap )
{
#ifdef FT_DEBUG_LEVEL_TRACE
CF2_UInt i;
FT_TRACE6(( " index csCoord dsCoord scale flags\n" ));
for ( i = 0; i < hintmap->count; i++ )
{
CF2_Hint hint = &hintmap->edge[i];
FT_TRACE6(( " %3ld %7.2f %7.2f %5d %s%s%s%s\n",
hint->index,
hint->csCoord / 65536.0,
hint->dsCoord / ( hint->scale * 1.0 ),
hint->scale,
( cf2_hint_isPair( hint ) ? "p" : "g" ),
( cf2_hint_isTop( hint ) ? "t" : "b" ),
( cf2_hint_isLocked( hint ) ? "L" : ""),
( cf2_hint_isSynthetic( hint ) ? "S" : "" ) ));
}
#else
FT_UNUSED( hintmap );
#endif
}
/* transform character space coordinate to device space using hint map */
static CF2_Fixed
cf2_hintmap_map( CF2_HintMap hintmap,
CF2_Fixed csCoord )
{
if ( hintmap->count == 0 || !hintmap->hinted )
{
/* there are no hints; use uniform scale and zero offset */
return FT_MulFix( csCoord, hintmap->scale );
}
else
{
/* start linear search from last hit */
CF2_UInt i = hintmap->lastIndex;
FT_ASSERT( hintmap->lastIndex < CF2_MAX_HINT_EDGES );
/* search up */
while ( i < hintmap->count - 1 &&
csCoord >= hintmap->edge[i + 1].csCoord )
i += 1;
/* search down */
while ( i > 0 && csCoord < hintmap->edge[i].csCoord )
i -= 1;
hintmap->lastIndex = i;
if ( i == 0 && csCoord < hintmap->edge[0].csCoord )
{
/* special case for points below first edge: use uniform scale */
return ADD_INT32( FT_MulFix( SUB_INT32( csCoord,
hintmap->edge[0].csCoord ),
hintmap->scale ),
hintmap->edge[0].dsCoord );
}
else
{
/*
* Note: entries with duplicate csCoord are allowed.
* Use edge[i], the highest entry where csCoord >= entry[i].csCoord
*/
return ADD_INT32( FT_MulFix( SUB_INT32( csCoord,
hintmap->edge[i].csCoord ),
hintmap->edge[i].scale ),
hintmap->edge[i].dsCoord );
}
}
}
/*
* This hinting policy moves a hint pair in device space so that one of
* its two edges is on a device pixel boundary (its fractional part is
* zero). `cf2_hintmap_insertHint' guarantees no overlap in CS
* space. Ensure here that there is no overlap in DS.
*
* In the first pass, edges are adjusted relative to adjacent hints.
* Those that are below have already been adjusted. Those that are
* above have not yet been adjusted. If a hint above blocks an
* adjustment to an optimal position, we will try again in a second
* pass. The second pass is top-down.
*
*/
static void
cf2_hintmap_adjustHints( CF2_HintMap hintmap )
{
size_t i, j;
cf2_arrstack_clear( hintmap->hintMoves ); /* working storage */
/*
* First pass is bottom-up (font hint order) without look-ahead.
* Locked edges are already adjusted.
* Unlocked edges begin with dsCoord from `initialHintMap'.
* Save edges that are not optimally adjusted in `hintMoves' array,
* and process them in second pass.
*/
for ( i = 0; i < hintmap->count; i++ )
{
FT_Bool isPair = cf2_hint_isPair( &hintmap->edge[i] );
/* final amount to move edge or edge pair */
CF2_Fixed move = 0;
CF2_Fixed dsCoord_i;
CF2_Fixed dsCoord_j;
/* index of upper edge (same value for ghost hint) */
j = isPair ? i + 1 : i;
FT_ASSERT( j < hintmap->count );
FT_ASSERT( cf2_hint_isValid( &hintmap->edge[i] ) );
FT_ASSERT( cf2_hint_isValid( &hintmap->edge[j] ) );
FT_ASSERT( cf2_hint_isLocked( &hintmap->edge[i] ) ==
cf2_hint_isLocked( &hintmap->edge[j] ) );
dsCoord_i = hintmap->edge[i].dsCoord;
dsCoord_j = hintmap->edge[j].dsCoord;
if ( !cf2_hint_isLocked( &hintmap->edge[i] ) )
{
/* hint edge is not locked, we can adjust it */
CF2_Fixed fracDown = cf2_fixedFraction( dsCoord_i );
CF2_Fixed fracUp = cf2_fixedFraction( dsCoord_j );
/* calculate all four possibilities; moves down are negative */
CF2_Fixed downMoveDown = 0 - fracDown;
CF2_Fixed upMoveDown = 0 - fracUp;
CF2_Fixed downMoveUp = ( fracDown == 0 )
? 0
: cf2_intToFixed( 1 ) - fracDown;
CF2_Fixed upMoveUp = ( fracUp == 0 )
? 0
: cf2_intToFixed( 1 ) - fracUp;
/* smallest move up */
CF2_Fixed moveUp = FT_MIN( downMoveUp, upMoveUp );
/* smallest move down */
CF2_Fixed moveDown = FT_MAX( downMoveDown, upMoveDown );
CF2_Fixed downMinCounter = CF2_MIN_COUNTER;
CF2_Fixed upMinCounter = CF2_MIN_COUNTER;
FT_Bool saveEdge = FALSE;
/* minimum counter constraint doesn't apply when adjacent edges */
/* are synthetic */
/* TODO: doesn't seem a big effect; for now, reduce the code */
#if 0
if ( i == 0 ||
cf2_hint_isSynthetic( &hintmap->edge[i - 1] ) )
downMinCounter = 0;
if ( j >= hintmap->count - 1 ||
cf2_hint_isSynthetic( &hintmap->edge[j + 1] ) )
upMinCounter = 0;
#endif
/* is there room to move up? */
/* there is if we are at top of array or the next edge is at or */
/* beyond proposed move up? */
if ( j >= hintmap->count - 1 ||
hintmap->edge[j + 1].dsCoord >=
ADD_INT32( dsCoord_j, moveUp + upMinCounter ) )
{
/* there is room to move up; is there also room to move down? */
if ( i == 0 ||
hintmap->edge[i - 1].dsCoord <=
ADD_INT32( dsCoord_i, moveDown - downMinCounter ) )
{
/* move smaller absolute amount */
move = ( -moveDown < moveUp ) ? moveDown : moveUp; /* optimum */
}
else
move = moveUp;
}
else
{
/* is there room to move down? */
if ( i == 0 ||
hintmap->edge[i - 1].dsCoord <=
ADD_INT32( dsCoord_i, moveDown - downMinCounter ) )
{
move = moveDown;
/* true if non-optimum move */
saveEdge = FT_BOOL( moveUp < -moveDown );
}
else
{
/* no room to move either way without overlapping or reducing */
/* the counter too much */
move = 0;
saveEdge = TRUE;
}
}
/* Identify non-moves and moves down that aren't optimal, and save */
/* them for second pass. */
/* Do this only if there is an unlocked edge above (which could */
/* possibly move). */
if ( saveEdge &&
j < hintmap->count - 1 &&
!cf2_hint_isLocked( &hintmap->edge[j + 1] ) )
{
CF2_HintMoveRec savedMove;
savedMove.j = j;
/* desired adjustment in second pass */
savedMove.moveUp = moveUp - move;
cf2_arrstack_push( hintmap->hintMoves, &savedMove );
}
/* move the edge(s) */
hintmap->edge[i].dsCoord = ADD_INT32( dsCoord_i, move );
if ( isPair )
hintmap->edge[j].dsCoord = ADD_INT32( dsCoord_j, move );
}
/* assert there are no overlaps in device space; */
/* ignore tests if there was overflow (that is, if */
/* operands have the same sign but the sum does not) */
FT_ASSERT( i == 0 ||
( ( dsCoord_i ^ move ) >= 0 &&
( dsCoord_i ^ hintmap->edge[i].dsCoord ) < 0 ) ||
hintmap->edge[i - 1].dsCoord <= hintmap->edge[i].dsCoord );
FT_ASSERT( i < j ||
( ( dsCoord_j ^ move ) >= 0 &&
( dsCoord_j ^ hintmap->edge[j].dsCoord ) < 0 ) ||
hintmap->edge[i].dsCoord <= hintmap->edge[j].dsCoord );
/* adjust the scales, avoiding divide by zero */
if ( i > 0 )
{
if ( hintmap->edge[i].csCoord != hintmap->edge[i - 1].csCoord )
hintmap->edge[i - 1].scale =
FT_DivFix( SUB_INT32( hintmap->edge[i].dsCoord,
hintmap->edge[i - 1].dsCoord ),
SUB_INT32( hintmap->edge[i].csCoord,
hintmap->edge[i - 1].csCoord ) );
}
if ( isPair )
{
if ( hintmap->edge[j].csCoord != hintmap->edge[j - 1].csCoord )
hintmap->edge[j - 1].scale =
FT_DivFix( SUB_INT32( hintmap->edge[j].dsCoord,
hintmap->edge[j - 1].dsCoord ),
SUB_INT32( hintmap->edge[j].csCoord,
hintmap->edge[j - 1].csCoord ) );
i += 1; /* skip upper edge on next loop */
}
}
/* second pass tries to move non-optimal hints up, in case there is */
/* room now */
for ( i = cf2_arrstack_size( hintmap->hintMoves ); i > 0; i-- )
{
CF2_HintMove hintMove = (CF2_HintMove)
cf2_arrstack_getPointer( hintmap->hintMoves, i - 1 );
j = hintMove->j;
/* this was tested before the push, above */
FT_ASSERT( j < hintmap->count - 1 );
/* is there room to move up? */
if ( hintmap->edge[j + 1].dsCoord >=
ADD_INT32( hintmap->edge[j].dsCoord,
hintMove->moveUp + CF2_MIN_COUNTER ) )
{
/* there is more room now, move edge up */
hintmap->edge[j].dsCoord = ADD_INT32( hintmap->edge[j].dsCoord,
hintMove->moveUp );
if ( cf2_hint_isPair( &hintmap->edge[j] ) )
{
FT_ASSERT( j > 0 );
hintmap->edge[j - 1].dsCoord =
ADD_INT32( hintmap->edge[j - 1].dsCoord, hintMove->moveUp );
}
}
}
}
/* insert hint edges into map, sorted by csCoord */
static void
cf2_hintmap_insertHint( CF2_HintMap hintmap,
CF2_Hint bottomHintEdge,
CF2_Hint topHintEdge )
{
CF2_UInt indexInsert;
/* set default values, then check for edge hints */
FT_Bool isPair = TRUE;
CF2_Hint firstHintEdge = bottomHintEdge;
CF2_Hint secondHintEdge = topHintEdge;
/* one or none of the input params may be invalid when dealing with */
/* edge hints; at least one edge must be valid */
FT_ASSERT( cf2_hint_isValid( bottomHintEdge ) ||
cf2_hint_isValid( topHintEdge ) );
/* determine how many and which edges to insert */
if ( !cf2_hint_isValid( bottomHintEdge ) )
{
/* insert only the top edge */
firstHintEdge = topHintEdge;
isPair = FALSE;
}
else if ( !cf2_hint_isValid( topHintEdge ) )
{
/* insert only the bottom edge */
isPair = FALSE;
}
/* paired edges must be in proper order */
if ( isPair &&
topHintEdge->csCoord < bottomHintEdge->csCoord )
return;
/* linear search to find index value of insertion point */
indexInsert = 0;
for ( ; indexInsert < hintmap->count; indexInsert++ )
{
if ( hintmap->edge[indexInsert].csCoord >= firstHintEdge->csCoord )
break;
}
FT_TRACE7(( " Got hint at %.2f (%.2f)\n",
firstHintEdge->csCoord / 65536.0,
firstHintEdge->dsCoord / 65536.0 ));
if ( isPair )
FT_TRACE7(( " Got hint at %.2f (%.2f)\n",
secondHintEdge->csCoord / 65536.0,
secondHintEdge->dsCoord / 65536.0 ));
/*
* Discard any hints that overlap in character space. Most often, this
* is while building the initial map, where captured hints from all
* zones are combined. Define overlap to include hints that `touch'
* (overlap zero). Hiragino Sans/Gothic fonts have numerous hints that
* touch. Some fonts have non-ideographic glyphs that overlap our
* synthetic hints.
*
* Overlap also occurs when darkening stem hints that are close.
*
*/
if ( indexInsert < hintmap->count )
{
/* we are inserting before an existing edge: */
/* verify that an existing edge is not the same */
if ( hintmap->edge[indexInsert].csCoord == firstHintEdge->csCoord )
return; /* ignore overlapping stem hint */
/* verify that a new pair does not straddle the next edge */
if ( isPair &&
hintmap->edge[indexInsert].csCoord <= secondHintEdge->csCoord )
return; /* ignore overlapping stem hint */
/* verify that we are not inserting between paired edges */
if ( cf2_hint_isPairTop( &hintmap->edge[indexInsert] ) )
return; /* ignore overlapping stem hint */
}
/* recompute device space locations using initial hint map */
if ( cf2_hintmap_isValid( hintmap->initialHintMap ) &&
!cf2_hint_isLocked( firstHintEdge ) )
{
if ( isPair )
{
/* Use hint map to position the center of stem, and nominal scale */
/* to position the two edges. This preserves the stem width. */
CF2_Fixed midpoint =
cf2_hintmap_map(
hintmap->initialHintMap,
ADD_INT32( secondHintEdge->csCoord,
firstHintEdge->csCoord ) / 2 );
CF2_Fixed halfWidth =
FT_MulFix( SUB_INT32( secondHintEdge->csCoord,
firstHintEdge->csCoord ) / 2,
hintmap->scale );
firstHintEdge->dsCoord = SUB_INT32( midpoint, halfWidth );
secondHintEdge->dsCoord = ADD_INT32( midpoint, halfWidth );
}
else
firstHintEdge->dsCoord = cf2_hintmap_map( hintmap->initialHintMap,
firstHintEdge->csCoord );
}
/*
* Discard any hints that overlap in device space; this can occur
* because locked hints have been moved to align with blue zones.
*
* TODO: Although we might correct this later during adjustment, we
* don't currently have a way to delete a conflicting hint once it has
* been inserted. See v2.030 MinionPro-Regular, 12 ppem darkened,
* initial hint map for second path, glyph 945 (the perispomeni (tilde)
* in U+1F6E, Greek omega with psili and perispomeni). Darkening is
* 25. Pair 667,747 initially conflicts in design space with top edge
* 660. This is because 667 maps to 7.87, and the top edge was
* captured by a zone at 8.0. The pair is later successfully inserted
* in a zone without the top edge. In this zone it is adjusted to 8.0,
* and no longer conflicts with the top edge in design space. This
* means it can be included in yet a later zone which does have the top
* edge hint. This produces a small mismatch between the first and
* last points of this path, even though the hint masks are the same.
* The density map difference is tiny (1/256).
*
*/
if ( indexInsert > 0 )
{
/* we are inserting after an existing edge */
if ( firstHintEdge->dsCoord < hintmap->edge[indexInsert - 1].dsCoord )
return;
}
if ( indexInsert < hintmap->count )
{
/* we are inserting before an existing edge */
if ( isPair )
{
if ( secondHintEdge->dsCoord > hintmap->edge[indexInsert].dsCoord )
return;
}
else
{
if ( firstHintEdge->dsCoord > hintmap->edge[indexInsert].dsCoord )
return;
}
}
/* make room to insert */
{
CF2_UInt iSrc = hintmap->count - 1;
CF2_UInt iDst = isPair ? hintmap->count + 1 : hintmap->count;
CF2_UInt count = hintmap->count - indexInsert;
if ( iDst >= CF2_MAX_HINT_EDGES )
{
FT_TRACE4(( "cf2_hintmap_insertHint: too many hintmaps\n" ));
return;
}
while ( count-- )
hintmap->edge[iDst--] = hintmap->edge[iSrc--];
/* insert first edge */
hintmap->edge[indexInsert] = *firstHintEdge; /* copy struct */
hintmap->count += 1;
FT_TRACE7(( " Inserting hint %.2f (%.2f)\n",
firstHintEdge->csCoord / 65536.0,
firstHintEdge->dsCoord / 65536.0 ));
if ( isPair )
{
/* insert second edge */
hintmap->edge[indexInsert + 1] = *secondHintEdge; /* copy struct */
hintmap->count += 1;
FT_TRACE7(( " Inserting hint %.2f (%.2f)\n",
secondHintEdge->csCoord / 65536.0,
secondHintEdge->dsCoord / 65536.0 ));
}
}
return;
}
/*
* Build a map from hints and mask.
*
* This function may recur one level if `hintmap->initialHintMap' is not yet
* valid.
* If `initialMap' is true, simply build initial map.
*
* Synthetic hints are used in two ways. A hint at zero is inserted, if
* needed, in the initial hint map, to prevent translations from
* propagating across the origin. If synthetic em box hints are enabled
* for ideographic dictionaries, then they are inserted in all hint
* maps, including the initial one.
*
*/
FT_LOCAL_DEF( void )
cf2_hintmap_build( CF2_HintMap hintmap,
CF2_ArrStack hStemHintArray,
CF2_ArrStack vStemHintArray,
CF2_HintMask hintMask,
CF2_Fixed hintOrigin,
FT_Bool initialMap )
{
FT_Byte* maskPtr;
CF2_Font font = hintmap->font;
CF2_HintMaskRec tempHintMask;
size_t bitCount, i;
FT_Byte maskByte;
/* check whether initial map is constructed */
if ( !initialMap && !cf2_hintmap_isValid( hintmap->initialHintMap ) )
{
/* make recursive call with initialHintMap and temporary mask; */
/* temporary mask will get all bits set, below */
cf2_hintmask_init( &tempHintMask, hintMask->error );
cf2_hintmap_build( hintmap->initialHintMap,
hStemHintArray,
vStemHintArray,
&tempHintMask,
hintOrigin,
TRUE );
}
if ( !cf2_hintmask_isValid( hintMask ) )
{
/* without a hint mask, assume all hints are active */
cf2_hintmask_setAll( hintMask,
cf2_arrstack_size( hStemHintArray ) +
cf2_arrstack_size( vStemHintArray ) );
if ( !cf2_hintmask_isValid( hintMask ) )
{
if ( font->isT1 )
{
/* no error, just continue unhinted */
*hintMask->error = FT_Err_Ok;
hintmap->hinted = FALSE;
}
return; /* too many stem hints */
}
}
/* begin by clearing the map */
hintmap->count = 0;
hintmap->lastIndex = 0;
/* make a copy of the hint mask so we can modify it */
tempHintMask = *hintMask;
maskPtr = cf2_hintmask_getMaskPtr( &tempHintMask );
/* use the hStem hints only, which are first in the mask */
bitCount = cf2_arrstack_size( hStemHintArray );
/* Defense-in-depth. Should never return here. */
if ( bitCount > hintMask->bitCount )
return;
/* synthetic embox hints get highest priority */
if ( font->blues.doEmBoxHints )
{
CF2_HintRec dummy;
cf2_hint_initZero( &dummy ); /* invalid hint map element */
/* ghost bottom */
cf2_hintmap_insertHint( hintmap,
&font->blues.emBoxBottomEdge,
&dummy );
/* ghost top */
cf2_hintmap_insertHint( hintmap,
&dummy,
&font->blues.emBoxTopEdge );
}
/* insert hints captured by a blue zone or already locked (higher */
/* priority) */
for ( i = 0, maskByte = 0x80; i < bitCount; i++ )
{
if ( maskByte & *maskPtr )
{
/* expand StemHint into two `CF2_Hint' elements */
CF2_HintRec bottomHintEdge, topHintEdge;
cf2_hint_init( &bottomHintEdge,
hStemHintArray,
i,
font,
hintOrigin,
hintmap->scale,
TRUE /* bottom */ );
cf2_hint_init( &topHintEdge,
hStemHintArray,
i,
font,
hintOrigin,
hintmap->scale,
FALSE /* top */ );
if ( cf2_hint_isLocked( &bottomHintEdge ) ||
cf2_hint_isLocked( &topHintEdge ) ||
cf2_blues_capture( &font->blues,
&bottomHintEdge,
&topHintEdge ) )
{
/* insert captured hint into map */
cf2_hintmap_insertHint( hintmap, &bottomHintEdge, &topHintEdge );
*maskPtr &= ~maskByte; /* turn off the bit for this hint */
}
}
if ( ( i & 7 ) == 7 )
{
/* move to next mask byte */
maskPtr++;
maskByte = 0x80;
}
else
maskByte >>= 1;
}
/* initial hint map includes only captured hints plus maybe one at 0 */
/*
* TODO: There is a problem here because we are trying to build a
* single hint map containing all captured hints. It is
* possible for there to be conflicts between captured hints,
* either because of darkening or because the hints are in
* separate hint zones (we are ignoring hint zones for the
* initial map). An example of the latter is MinionPro-Regular
* v2.030 glyph 883 (Greek Capital Alpha with Psili) at 15ppem.
* A stem hint for the psili conflicts with the top edge hint
* for the base character. The stem hint gets priority because
* of its sort order. In glyph 884 (Greek Capital Alpha with
* Psili and Oxia), the top of the base character gets a stem
* hint, and the psili does not. This creates different initial
* maps for the two glyphs resulting in different renderings of
* the base character. Will probably defer this either as not
* worth the cost or as a font bug. I don't think there is any
* good reason for an accent to be captured by an alignment
* zone. -darnold 2/12/10
*/
if ( initialMap )
{
/* Apply a heuristic that inserts a point for (0,0), unless it's */
/* already covered by a mapping. This locks the baseline for glyphs */
/* that have no baseline hints. */
if ( hintmap->count == 0 ||
hintmap->edge[0].csCoord > 0 ||
hintmap->edge[hintmap->count - 1].csCoord < 0 )
{
/* all edges are above 0 or all edges are below 0; */
/* construct a locked edge hint at 0 */
CF2_HintRec edge, invalid;
cf2_hint_initZero( &edge );
edge.flags = CF2_GhostBottom |
CF2_Locked |
CF2_Synthetic;
edge.scale = hintmap->scale;
cf2_hint_initZero( &invalid );
cf2_hintmap_insertHint( hintmap, &edge, &invalid );
}
}
else
{
/* insert remaining hints */
maskPtr = cf2_hintmask_getMaskPtr( &tempHintMask );
for ( i = 0, maskByte = 0x80; i < bitCount; i++ )
{
if ( maskByte & *maskPtr )
{
CF2_HintRec bottomHintEdge, topHintEdge;
cf2_hint_init( &bottomHintEdge,
hStemHintArray,
i,
font,
hintOrigin,
hintmap->scale,
TRUE /* bottom */ );
cf2_hint_init( &topHintEdge,
hStemHintArray,
i,
font,
hintOrigin,
hintmap->scale,
FALSE /* top */ );
cf2_hintmap_insertHint( hintmap, &bottomHintEdge, &topHintEdge );
}
if ( ( i & 7 ) == 7 )
{
/* move to next mask byte */
maskPtr++;
maskByte = 0x80;
}
else
maskByte >>= 1;
}
}
#ifdef FT_DEBUG_LEVEL_TRACE
if ( initialMap )
{
FT_TRACE6(( "flags: [p]air [g]host [t]op"
" [b]ottom [L]ocked [S]ynthetic\n" ));
FT_TRACE6(( "Initial hintmap" ));
}
else
FT_TRACE6(( "Hints:" ));
#endif
cf2_hintmap_dump( hintmap );
/*
* Note: The following line is a convenient place to break when
* debugging hinting. Examine `hintmap->edge' for the list of
* enabled hints, then step over the call to see the effect of
* adjustment. We stop here first on the recursive call that
* creates the initial map, and then on each counter group and
* hint zone.
*/
/* adjust positions of hint edges that are not locked to blue zones */
cf2_hintmap_adjustHints( hintmap );
FT_TRACE6(( "(adjusted)\n" ));
cf2_hintmap_dump( hintmap );
/* save the position of all hints that were used in this hint map; */
/* if we use them again, we'll locate them in the same position */
if ( !initialMap )
{
for ( i = 0; i < hintmap->count; i++ )
{
if ( !cf2_hint_isSynthetic( &hintmap->edge[i] ) )
{
/* Note: include both valid and invalid edges */
/* Note: top and bottom edges are copied back separately */
CF2_StemHint stemhint = (CF2_StemHint)
cf2_arrstack_getPointer( hStemHintArray,
hintmap->edge[i].index );
if ( cf2_hint_isTop( &hintmap->edge[i] ) )
stemhint->maxDS = hintmap->edge[i].dsCoord;
else
stemhint->minDS = hintmap->edge[i].dsCoord;
stemhint->used = TRUE;
}
}
}
/* hint map is ready to use */
hintmap->isValid = TRUE;
/* remember this mask has been used */
cf2_hintmask_setNew( hintMask, FALSE );
}
FT_LOCAL_DEF( void )
cf2_glyphpath_init( CF2_GlyphPath glyphpath,
CF2_Font font,
CF2_OutlineCallbacks callbacks,
CF2_Fixed scaleY,
/* CF2_Fixed hShift, */
CF2_ArrStack hStemHintArray,
CF2_ArrStack vStemHintArray,
CF2_HintMask hintMask,
CF2_Fixed hintOriginY,
const CF2_Blues blues,
const FT_Vector* fractionalTranslation )
{
FT_ZERO( glyphpath );
glyphpath->font = font;
glyphpath->callbacks = callbacks;
cf2_arrstack_init( &glyphpath->hintMoves,
font->memory,
&font->error,
sizeof ( CF2_HintMoveRec ) );
cf2_hintmap_init( &glyphpath->initialHintMap,
font,
&glyphpath->initialHintMap,
&glyphpath->hintMoves,
scaleY );
cf2_hintmap_init( &glyphpath->firstHintMap,
font,
&glyphpath->initialHintMap,
&glyphpath->hintMoves,
scaleY );
cf2_hintmap_init( &glyphpath->hintMap,
font,
&glyphpath->initialHintMap,
&glyphpath->hintMoves,
scaleY );
glyphpath->scaleX = font->innerTransform.a;
glyphpath->scaleC = font->innerTransform.c;
glyphpath->scaleY = font->innerTransform.d;
glyphpath->fractionalTranslation = *fractionalTranslation;
#if 0
glyphpath->hShift = hShift; /* for fauxing */
#endif
glyphpath->hStemHintArray = hStemHintArray;
glyphpath->vStemHintArray = vStemHintArray;
glyphpath->hintMask = hintMask; /* ptr to current mask */
glyphpath->hintOriginY = hintOriginY;
glyphpath->blues = blues;
glyphpath->darken = font->darkened; /* TODO: should we make copies? */
glyphpath->xOffset = font->darkenX;
glyphpath->yOffset = font->darkenY;
glyphpath->miterLimit = 2 * FT_MAX(
cf2_fixedAbs( glyphpath->xOffset ),
cf2_fixedAbs( glyphpath->yOffset ) );
/* .1 character space unit */
glyphpath->snapThreshold = cf2_doubleToFixed( 0.1 );
glyphpath->moveIsPending = TRUE;
glyphpath->pathIsOpen = FALSE;
glyphpath->pathIsClosing = FALSE;
glyphpath->elemIsQueued = FALSE;
}
FT_LOCAL_DEF( void )
cf2_glyphpath_finalize( CF2_GlyphPath glyphpath )
{
cf2_arrstack_finalize( &glyphpath->hintMoves );
}
/*
* Hint point in y-direction and apply outerTransform.
* Input `current' hint map (which is actually delayed by one element).
* Input x,y point in Character Space.
* Output x,y point in Device Space, including translation.
*/
static void
cf2_glyphpath_hintPoint( CF2_GlyphPath glyphpath,
CF2_HintMap hintmap,
FT_Vector* ppt,
CF2_Fixed x,
CF2_Fixed y )
{
FT_Vector pt; /* hinted point in upright DS */
pt.x = ADD_INT32( FT_MulFix( glyphpath->scaleX, x ),
FT_MulFix( glyphpath->scaleC, y ) );
pt.y = cf2_hintmap_map( hintmap, y );
ppt->x = ADD_INT32(
FT_MulFix( glyphpath->font->outerTransform.a, pt.x ),
ADD_INT32(
FT_MulFix( glyphpath->font->outerTransform.c, pt.y ),
glyphpath->fractionalTranslation.x ) );
ppt->y = ADD_INT32(
FT_MulFix( glyphpath->font->outerTransform.b, pt.x ),
ADD_INT32(
FT_MulFix( glyphpath->font->outerTransform.d, pt.y ),
glyphpath->fractionalTranslation.y ) );
}
/*
* From two line segments, (u1,u2) and (v1,v2), compute a point of
* intersection on the corresponding lines.
* Return false if no intersection is found, or if the intersection is
* too far away from the ends of the line segments, u2 and v1.
*
*/
static FT_Bool
cf2_glyphpath_computeIntersection( CF2_GlyphPath glyphpath,
const FT_Vector* u1,
const FT_Vector* u2,
const FT_Vector* v1,
const FT_Vector* v2,
FT_Vector* intersection )
{
/*
* Let `u' be a zero-based vector from the first segment, `v' from the
* second segment.
* Let `w 'be the zero-based vector from `u1' to `v1'.
* `perp' is the `perpendicular dot product'; see
* https://mathworld.wolfram.com/PerpDotProduct.html.
* `s' is the parameter for the parametric line for the first segment
* (`u').
*
* See notation in
* http://geomalgorithms.com/a05-_intersect-1.html.
* Calculations are done in 16.16, but must handle the squaring of
* line lengths in character space. We scale all vectors by 1/32 to
* avoid overflow. This allows values up to 4095 to be squared. The
* scale factor cancels in the divide.
*
* TODO: the scale factor could be computed from UnitsPerEm.
*
*/
#define cf2_perp( a, b ) \
( FT_MulFix( a.x, b.y ) - FT_MulFix( a.y, b.x ) )
/* round and divide by 32 */
#define CF2_CS_SCALE( x ) \
( ( (x) + 0x10 ) >> 5 )
FT_Vector u, v, w; /* scaled vectors */
CF2_Fixed denominator, s;
u.x = CF2_CS_SCALE( SUB_INT32( u2->x, u1->x ) );
u.y = CF2_CS_SCALE( SUB_INT32( u2->y, u1->y ) );
v.x = CF2_CS_SCALE( SUB_INT32( v2->x, v1->x ) );
v.y = CF2_CS_SCALE( SUB_INT32( v2->y, v1->y ) );
w.x = CF2_CS_SCALE( SUB_INT32( v1->x, u1->x ) );
w.y = CF2_CS_SCALE( SUB_INT32( v1->y, u1->y ) );
denominator = cf2_perp( u, v );
if ( denominator == 0 )
return FALSE; /* parallel or coincident lines */
s = FT_DivFix( cf2_perp( w, v ), denominator );
intersection->x = ADD_INT32( u1->x,
FT_MulFix( s, SUB_INT32( u2->x, u1->x ) ) );
intersection->y = ADD_INT32( u1->y,
FT_MulFix( s, SUB_INT32( u2->y, u1->y ) ) );
/*
* Special case snapping for horizontal and vertical lines.
* This cleans up intersections and reduces problems with winding
* order detection.
* Sample case is sbc cd KozGoPr6N-Medium.otf 20 16685.
* Note: these calculations are in character space.
*
*/
if ( u1->x == u2->x &&
cf2_fixedAbs( SUB_INT32( intersection->x,
u1->x ) ) < glyphpath->snapThreshold )
intersection->x = u1->x;
if ( u1->y == u2->y &&
cf2_fixedAbs( SUB_INT32( intersection->y,
u1->y ) ) < glyphpath->snapThreshold )
intersection->y = u1->y;
if ( v1->x == v2->x &&
cf2_fixedAbs( SUB_INT32( intersection->x,
v1->x ) ) < glyphpath->snapThreshold )
intersection->x = v1->x;
if ( v1->y == v2->y &&
cf2_fixedAbs( SUB_INT32( intersection->y,
v1->y ) ) < glyphpath->snapThreshold )
intersection->y = v1->y;
/* limit the intersection distance from midpoint of u2 and v1 */
if ( cf2_fixedAbs( intersection->x - ADD_INT32( u2->x, v1->x ) / 2 ) >
glyphpath->miterLimit ||
cf2_fixedAbs( intersection->y - ADD_INT32( u2->y, v1->y ) / 2 ) >
glyphpath->miterLimit )
return FALSE;
return TRUE;
}
/*
* Push the cached element (glyphpath->prevElem*) to the outline
* consumer. When a darkening offset is used, the end point of the
* cached element may be adjusted to an intersection point or we may
* synthesize a connecting line to the current element. If we are
* closing a subpath, we may also generate a connecting line to the start
* point.
*
* This is where Character Space (CS) is converted to Device Space (DS)
* using a hint map. This calculation must use a HintMap that was valid
* at the time the element was saved. For the first point in a subpath,
* that is a saved HintMap. For most elements, it just means the caller
* has delayed building a HintMap from the current HintMask.
*
* Transform each point with outerTransform and call the outline
* callbacks. This is a general 3x3 transform:
*
* x' = a*x + c*y + tx, y' = b*x + d*y + ty
*
* but it uses 4 elements from CF2_Font and the translation part
* from CF2_GlyphPath.
*
*/
static void
cf2_glyphpath_pushPrevElem( CF2_GlyphPath glyphpath,
CF2_HintMap hintmap,
FT_Vector* nextP0,
FT_Vector nextP1,
FT_Bool close )
{
CF2_CallbackParamsRec params;
FT_Vector* prevP0;
FT_Vector* prevP1;
FT_Vector intersection = { 0, 0 };
FT_Bool useIntersection = FALSE;
FT_ASSERT( glyphpath->prevElemOp == CF2_PathOpLineTo ||
glyphpath->prevElemOp == CF2_PathOpCubeTo );
if ( glyphpath->prevElemOp == CF2_PathOpLineTo )
{
prevP0 = &glyphpath->prevElemP0;
prevP1 = &glyphpath->prevElemP1;
}
else
{
prevP0 = &glyphpath->prevElemP2;
prevP1 = &glyphpath->prevElemP3;
}
/* optimization: if previous and next elements are offset by the same */
/* amount, then there will be no gap, and no need to compute an */
/* intersection. */
if ( prevP1->x != nextP0->x || prevP1->y != nextP0->y )
{
/* previous element does not join next element: */
/* adjust end point of previous element to the intersection */
useIntersection = cf2_glyphpath_computeIntersection( glyphpath,
prevP0,
prevP1,
nextP0,
&nextP1,
&intersection );
if ( useIntersection )
{
/* modify the last point of the cached element (either line or */
/* curve) */
*prevP1 = intersection;
}
}
params.pt0 = glyphpath->currentDS;
switch( glyphpath->prevElemOp )
{
case CF2_PathOpLineTo:
params.op = CF2_PathOpLineTo;
/* note: pt2 and pt3 are unused */
if ( close )
{
/* use first hint map if closing */
cf2_glyphpath_hintPoint( glyphpath,
&glyphpath->firstHintMap,
¶ms.pt1,
glyphpath->prevElemP1.x,
glyphpath->prevElemP1.y );
}
else
{
cf2_glyphpath_hintPoint( glyphpath,
hintmap,
¶ms.pt1,
glyphpath->prevElemP1.x,
glyphpath->prevElemP1.y );
}
/* output only non-zero length lines */
if ( params.pt0.x != params.pt1.x || params.pt0.y != params.pt1.y )
{
glyphpath->callbacks->lineTo( glyphpath->callbacks, ¶ms );
glyphpath->currentDS = params.pt1;
}
break;
case CF2_PathOpCubeTo:
params.op = CF2_PathOpCubeTo;
/* TODO: should we intersect the interior joins (p1-p2 and p2-p3)? */
cf2_glyphpath_hintPoint( glyphpath,
hintmap,
¶ms.pt1,
glyphpath->prevElemP1.x,
glyphpath->prevElemP1.y );
cf2_glyphpath_hintPoint( glyphpath,
hintmap,
¶ms.pt2,
glyphpath->prevElemP2.x,
glyphpath->prevElemP2.y );
cf2_glyphpath_hintPoint( glyphpath,
hintmap,
¶ms.pt3,
glyphpath->prevElemP3.x,
glyphpath->prevElemP3.y );
glyphpath->callbacks->cubeTo( glyphpath->callbacks, ¶ms );
glyphpath->currentDS = params.pt3;
break;
}
if ( !useIntersection || close )
{
/* insert connecting line between end of previous element and start */
/* of current one */
/* note: at the end of a subpath, we might do both, so use `nextP0' */
/* before we change it, below */
if ( close )
{
/* if we are closing the subpath, then nextP0 is in the first */
/* hint zone */
cf2_glyphpath_hintPoint( glyphpath,
&glyphpath->firstHintMap,
¶ms.pt1,
nextP0->x,
nextP0->y );
}
else
{
cf2_glyphpath_hintPoint( glyphpath,
hintmap,
¶ms.pt1,
nextP0->x,
nextP0->y );
}
if ( params.pt1.x != glyphpath->currentDS.x ||
params.pt1.y != glyphpath->currentDS.y )
{
/* length is nonzero */
params.op = CF2_PathOpLineTo;
params.pt0 = glyphpath->currentDS;
/* note: pt2 and pt3 are unused */
glyphpath->callbacks->lineTo( glyphpath->callbacks, ¶ms );
glyphpath->currentDS = params.pt1;
}
}
if ( useIntersection )
{
/* return intersection point to caller */
*nextP0 = intersection;
}
}
/* push a MoveTo element based on current point and offset of current */
/* element */
static void
cf2_glyphpath_pushMove( CF2_GlyphPath glyphpath,
FT_Vector start )
{
CF2_CallbackParamsRec params;
params.op = CF2_PathOpMoveTo;
params.pt0 = glyphpath->currentDS;
/* Test if move has really happened yet; it would have called */
/* `cf2_hintmap_build' to set `isValid'. */
if ( !cf2_hintmap_isValid( &glyphpath->hintMap ) )
{
/* we are here iff first subpath is missing a moveto operator: */
/* synthesize first moveTo to finish initialization of hintMap */
cf2_glyphpath_moveTo( glyphpath,
glyphpath->start.x,
glyphpath->start.y );
}
cf2_glyphpath_hintPoint( glyphpath,
&glyphpath->hintMap,
¶ms.pt1,
start.x,
start.y );
/* note: pt2 and pt3 are unused */
glyphpath->callbacks->moveTo( glyphpath->callbacks, ¶ms );
glyphpath->currentDS = params.pt1;
glyphpath->offsetStart0 = start;
}
/*
* All coordinates are in character space.
* On input, (x1, y1) and (x2, y2) give line segment.
* On output, (x, y) give offset vector.
* We use a piecewise approximation to trig functions.
*
* TODO: Offset true perpendicular and proper length
* supply the y-translation for hinting here, too,
* that adds yOffset unconditionally to *y.
*/
static void
cf2_glyphpath_computeOffset( CF2_GlyphPath glyphpath,
CF2_Fixed x1,
CF2_Fixed y1,
CF2_Fixed x2,
CF2_Fixed y2,
CF2_Fixed* x,
CF2_Fixed* y )
{
CF2_Fixed dx = SUB_INT32( x2, x1 );
CF2_Fixed dy = SUB_INT32( y2, y1 );
/* note: negative offsets don't work here; negate deltas to change */
/* quadrants, below */
if ( glyphpath->font->reverseWinding )
{
dx = NEG_INT32( dx );
dy = NEG_INT32( dy );
}
*x = *y = 0;
if ( !glyphpath->darken )
return;
/* add momentum for this path element */
glyphpath->callbacks->windingMomentum =
ADD_INT32( glyphpath->callbacks->windingMomentum,
cf2_getWindingMomentum( x1, y1, x2, y2 ) );
/* note: allow mixed integer and fixed multiplication here */
if ( dx >= 0 )
{
if ( dy >= 0 )
{
/* first quadrant, +x +y */
if ( dx > MUL_INT32( 2, dy ) )
{
/* +x */
*x = 0;
*y = 0;
}
else if ( dy > MUL_INT32( 2, dx ) )
{
/* +y */
*x = glyphpath->xOffset;
*y = glyphpath->yOffset;
}
else
{
/* +x +y */
*x = FT_MulFix( cf2_doubleToFixed( 0.7 ),
glyphpath->xOffset );
*y = FT_MulFix( cf2_doubleToFixed( 1.0 - 0.7 ),
glyphpath->yOffset );
}
}
else
{
/* fourth quadrant, +x -y */
if ( dx > MUL_INT32( -2, dy ) )
{
/* +x */
*x = 0;
*y = 0;
}
else if ( NEG_INT32( dy ) > MUL_INT32( 2, dx ) )
{
/* -y */
*x = NEG_INT32( glyphpath->xOffset );
*y = glyphpath->yOffset;
}
else
{
/* +x -y */
*x = FT_MulFix( cf2_doubleToFixed( -0.7 ),
glyphpath->xOffset );
*y = FT_MulFix( cf2_doubleToFixed( 1.0 - 0.7 ),
glyphpath->yOffset );
}
}
}
else
{
if ( dy >= 0 )
{
/* second quadrant, -x +y */
if ( NEG_INT32( dx ) > MUL_INT32( 2, dy ) )
{
/* -x */
*x = 0;
*y = MUL_INT32( 2, glyphpath->yOffset );
}
else if ( dy > MUL_INT32( -2, dx ) )
{
/* +y */
*x = glyphpath->xOffset;
*y = glyphpath->yOffset;
}
else
{
/* -x +y */
*x = FT_MulFix( cf2_doubleToFixed( 0.7 ),
glyphpath->xOffset );
*y = FT_MulFix( cf2_doubleToFixed( 1.0 + 0.7 ),
glyphpath->yOffset );
}
}
else
{
/* third quadrant, -x -y */
if ( NEG_INT32( dx ) > MUL_INT32( -2, dy ) )
{
/* -x */
*x = 0;
*y = MUL_INT32( 2, glyphpath->yOffset );
}
else if ( NEG_INT32( dy ) > MUL_INT32( -2, dx ) )
{
/* -y */
*x = NEG_INT32( glyphpath->xOffset );
*y = glyphpath->yOffset;
}
else
{
/* -x -y */
*x = FT_MulFix( cf2_doubleToFixed( -0.7 ),
glyphpath->xOffset );
*y = FT_MulFix( cf2_doubleToFixed( 1.0 + 0.7 ),
glyphpath->yOffset );
}
}
}
}
/*
* The functions cf2_glyphpath_{moveTo,lineTo,curveTo,closeOpenPath} are
* called by the interpreter with Character Space (CS) coordinates. Each
* path element is placed into a queue of length one to await the
* calculation of the following element. At that time, the darkening
* offset of the following element is known and joins can be computed,
* including possible modification of this element, before mapping to
* Device Space (DS) and passing it on to the outline consumer.
*
*/
FT_LOCAL_DEF( void )
cf2_glyphpath_moveTo( CF2_GlyphPath glyphpath,
CF2_Fixed x,
CF2_Fixed y )
{
cf2_glyphpath_closeOpenPath( glyphpath );
/* save the parameters of the move for later, when we'll know how to */
/* offset it; */
/* also save last move point */
glyphpath->currentCS.x = glyphpath->start.x = x;
glyphpath->currentCS.y = glyphpath->start.y = y;
glyphpath->moveIsPending = TRUE;
/* ensure we have a valid map with current mask */
if ( !cf2_hintmap_isValid( &glyphpath->hintMap ) ||
cf2_hintmask_isNew( glyphpath->hintMask ) )
cf2_hintmap_build( &glyphpath->hintMap,
glyphpath->hStemHintArray,
glyphpath->vStemHintArray,
glyphpath->hintMask,
glyphpath->hintOriginY,
FALSE );
/* save a copy of current HintMap to use when drawing initial point */
glyphpath->firstHintMap = glyphpath->hintMap; /* structure copy */
}
FT_LOCAL_DEF( void )
cf2_glyphpath_lineTo( CF2_GlyphPath glyphpath,
CF2_Fixed x,
CF2_Fixed y )
{
CF2_Fixed xOffset, yOffset;
FT_Vector P0, P1;
FT_Bool newHintMap;
/*
* New hints will be applied after cf2_glyphpath_pushPrevElem has run.
* In case this is a synthesized closing line, any new hints should be
* delayed until this path is closed (`cf2_hintmask_isNew' will be
* called again before the next line or curve).
*/
/* true if new hint map not on close */
newHintMap = cf2_hintmask_isNew( glyphpath->hintMask ) &&
!glyphpath->pathIsClosing;
/*
* Zero-length lines may occur in the charstring. Because we cannot
* compute darkening offsets or intersections from zero-length lines,
* it is best to remove them and avoid artifacts. However, zero-length
* lines in CS at the start of a new hint map can generate non-zero
* lines in DS due to hint substitution. We detect a change in hint
* map here and pass those zero-length lines along.
*/
/*
* Note: Find explicitly closed paths here with a conditional
* breakpoint using
*
* !gp->pathIsClosing && gp->start.x == x && gp->start.y == y
*
*/
if ( glyphpath->currentCS.x == x &&
glyphpath->currentCS.y == y &&
!newHintMap )
/*
* Ignore zero-length lines in CS where the hint map is the same
* because the line in DS will also be zero length.
*
* Ignore zero-length lines when we synthesize a closing line because
* the close will be handled in cf2_glyphPath_pushPrevElem.
*/
return;
cf2_glyphpath_computeOffset( glyphpath,
glyphpath->currentCS.x,
glyphpath->currentCS.y,
x,
y,
&xOffset,
&yOffset );
/* construct offset points */
P0.x = ADD_INT32( glyphpath->currentCS.x, xOffset );
P0.y = ADD_INT32( glyphpath->currentCS.y, yOffset );
P1.x = ADD_INT32( x, xOffset );
P1.y = ADD_INT32( y, yOffset );
if ( glyphpath->moveIsPending )
{
/* emit offset 1st point as MoveTo */
cf2_glyphpath_pushMove( glyphpath, P0 );
glyphpath->moveIsPending = FALSE; /* adjust state machine */
glyphpath->pathIsOpen = TRUE;
glyphpath->offsetStart1 = P1; /* record second point */
}
if ( glyphpath->elemIsQueued )
{
FT_ASSERT( cf2_hintmap_isValid( &glyphpath->hintMap ) ||
glyphpath->hintMap.count == 0 );
cf2_glyphpath_pushPrevElem( glyphpath,
&glyphpath->hintMap,
&P0,
P1,
FALSE );
}
/* queue the current element with offset points */
glyphpath->elemIsQueued = TRUE;
glyphpath->prevElemOp = CF2_PathOpLineTo;
glyphpath->prevElemP0 = P0;
glyphpath->prevElemP1 = P1;
/* update current map */
if ( newHintMap )
cf2_hintmap_build( &glyphpath->hintMap,
glyphpath->hStemHintArray,
glyphpath->vStemHintArray,
glyphpath->hintMask,
glyphpath->hintOriginY,
FALSE );
glyphpath->currentCS.x = x; /* pre-offset current point */
glyphpath->currentCS.y = y;
}
FT_LOCAL_DEF( void )
cf2_glyphpath_curveTo( CF2_GlyphPath glyphpath,
CF2_Fixed x1,
CF2_Fixed y1,
CF2_Fixed x2,
CF2_Fixed y2,
CF2_Fixed x3,
CF2_Fixed y3 )
{
CF2_Fixed xOffset1, yOffset1, xOffset3, yOffset3;
FT_Vector P0, P1, P2, P3;
/* TODO: ignore zero length portions of curve?? */
cf2_glyphpath_computeOffset( glyphpath,
glyphpath->currentCS.x,
glyphpath->currentCS.y,
x1,
y1,
&xOffset1,
&yOffset1 );
cf2_glyphpath_computeOffset( glyphpath,
x2,
y2,
x3,
y3,
&xOffset3,
&yOffset3 );
/* add momentum from the middle segment */
glyphpath->callbacks->windingMomentum =
ADD_INT32( glyphpath->callbacks->windingMomentum,
cf2_getWindingMomentum( x1, y1, x2, y2 ) );
/* construct offset points */
P0.x = ADD_INT32( glyphpath->currentCS.x, xOffset1 );
P0.y = ADD_INT32( glyphpath->currentCS.y, yOffset1 );
P1.x = ADD_INT32( x1, xOffset1 );
P1.y = ADD_INT32( y1, yOffset1 );
/* note: preserve angle of final segment by using offset3 at both ends */
P2.x = ADD_INT32( x2, xOffset3 );
P2.y = ADD_INT32( y2, yOffset3 );
P3.x = ADD_INT32( x3, xOffset3 );
P3.y = ADD_INT32( y3, yOffset3 );
if ( glyphpath->moveIsPending )
{
/* emit offset 1st point as MoveTo */
cf2_glyphpath_pushMove( glyphpath, P0 );
glyphpath->moveIsPending = FALSE;
glyphpath->pathIsOpen = TRUE;
glyphpath->offsetStart1 = P1; /* record second point */
}
if ( glyphpath->elemIsQueued )
{
FT_ASSERT( cf2_hintmap_isValid( &glyphpath->hintMap ) ||
glyphpath->hintMap.count == 0 );
cf2_glyphpath_pushPrevElem( glyphpath,
&glyphpath->hintMap,
&P0,
P1,
FALSE );
}
/* queue the current element with offset points */
glyphpath->elemIsQueued = TRUE;
glyphpath->prevElemOp = CF2_PathOpCubeTo;
glyphpath->prevElemP0 = P0;
glyphpath->prevElemP1 = P1;
glyphpath->prevElemP2 = P2;
glyphpath->prevElemP3 = P3;
/* update current map */
if ( cf2_hintmask_isNew( glyphpath->hintMask ) )
cf2_hintmap_build( &glyphpath->hintMap,
glyphpath->hStemHintArray,
glyphpath->vStemHintArray,
glyphpath->hintMask,
glyphpath->hintOriginY,
FALSE );
glyphpath->currentCS.x = x3; /* pre-offset current point */
glyphpath->currentCS.y = y3;
}
FT_LOCAL_DEF( void )
cf2_glyphpath_closeOpenPath( CF2_GlyphPath glyphpath )
{
if ( glyphpath->pathIsOpen )
{
/*
* A closing line in Character Space line is always generated below
* with `cf2_glyphPath_lineTo'. It may be ignored later if it turns
* out to be zero length in Device Space.
*/
glyphpath->pathIsClosing = TRUE;
cf2_glyphpath_lineTo( glyphpath,
glyphpath->start.x,
glyphpath->start.y );
/* empty the final element from the queue and close the path */
if ( glyphpath->elemIsQueued )
cf2_glyphpath_pushPrevElem( glyphpath,
&glyphpath->hintMap,
&glyphpath->offsetStart0,
glyphpath->offsetStart1,
TRUE );
/* reset state machine */
glyphpath->moveIsPending = TRUE;
glyphpath->pathIsOpen = FALSE;
glyphpath->pathIsClosing = FALSE;
glyphpath->elemIsQueued = FALSE;
}
}
/* END */