| /**************************************************************************** |
| * |
| * psblues.c |
| * |
| * Adobe's code for handling Blue Zones (body). |
| * |
| * Copyright 2009-2014 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 "psblues.h" |
| #include "pshints.h" |
| #include "psfont.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 cf2blues |
| |
| |
| /* |
| * For blue values, the FreeType parser produces an array of integers, |
| * while the Adobe CFF engine produces an array of fixed. |
| * Define a macro to convert FreeType to fixed. |
| */ |
| #define cf2_blueToFixed( x ) cf2_intToFixed( x ) |
| |
| |
| FT_LOCAL_DEF( void ) |
| cf2_blues_init( CF2_Blues blues, |
| CF2_Font font ) |
| { |
| /* pointer to parsed font object */ |
| PS_Decoder* decoder = font->decoder; |
| |
| CF2_Fixed zoneHeight; |
| CF2_Fixed maxZoneHeight = 0; |
| CF2_Fixed csUnitsPerPixel; |
| |
| size_t numBlueValues; |
| size_t numOtherBlues; |
| size_t numFamilyBlues; |
| size_t numFamilyOtherBlues; |
| |
| FT_Pos* blueValues; |
| FT_Pos* otherBlues; |
| FT_Pos* familyBlues; |
| FT_Pos* familyOtherBlues; |
| |
| size_t i; |
| CF2_Fixed emBoxBottom, emBoxTop; |
| |
| #if 0 |
| CF2_Int unitsPerEm = font->unitsPerEm; |
| |
| |
| if ( unitsPerEm == 0 ) |
| unitsPerEm = 1000; |
| #endif |
| |
| FT_ZERO( blues ); |
| blues->scale = font->innerTransform.d; |
| |
| cf2_getBlueMetrics( decoder, |
| &blues->blueScale, |
| &blues->blueShift, |
| &blues->blueFuzz ); |
| |
| cf2_getBlueValues( decoder, &numBlueValues, &blueValues ); |
| cf2_getOtherBlues( decoder, &numOtherBlues, &otherBlues ); |
| cf2_getFamilyBlues( decoder, &numFamilyBlues, &familyBlues ); |
| cf2_getFamilyOtherBlues( decoder, &numFamilyOtherBlues, &familyOtherBlues ); |
| |
| /* |
| * synthetic em box hint heuristic |
| * |
| * Apply this when ideographic dictionary (LanguageGroup 1) has no |
| * real alignment zones. Adobe tools generate dummy zones at -250 and |
| * 1100 for a 1000 unit em. Fonts with ICF-based alignment zones |
| * should not enable the heuristic. When the heuristic is enabled, |
| * the font's blue zones are ignored. |
| * |
| */ |
| |
| /* get em box from OS/2 typoAscender/Descender */ |
| /* TODO: FreeType does not parse these metrics. Skip them for now. */ |
| #if 0 |
| FCM_getHorizontalLineMetrics( &e, |
| font->font, |
| &ascender, |
| &descender, |
| &linegap ); |
| if ( ascender - descender == unitsPerEm ) |
| { |
| emBoxBottom = cf2_intToFixed( descender ); |
| emBoxTop = cf2_intToFixed( ascender ); |
| } |
| else |
| #endif |
| { |
| emBoxBottom = CF2_ICF_Bottom; |
| emBoxTop = CF2_ICF_Top; |
| } |
| |
| if ( cf2_getLanguageGroup( decoder ) == 1 && |
| ( numBlueValues == 0 || |
| ( numBlueValues == 4 && |
| cf2_blueToFixed( blueValues[0] ) < emBoxBottom && |
| cf2_blueToFixed( blueValues[1] ) < emBoxBottom && |
| cf2_blueToFixed( blueValues[2] ) > emBoxTop && |
| cf2_blueToFixed( blueValues[3] ) > emBoxTop ) ) ) |
| { |
| /* |
| * Construct hint edges suitable for synthetic ghost hints at top |
| * and bottom of em box. +-CF2_MIN_COUNTER allows for unhinted |
| * features above or below the last hinted edge. This also gives a |
| * net 1 pixel boost to the height of ideographic glyphs. |
| * |
| * Note: Adjust synthetic hints outward by epsilon (0x.0001) to |
| * avoid interference. E.g., some fonts have real hints at |
| * 880 and -120. |
| */ |
| |
| blues->emBoxBottomEdge.csCoord = emBoxBottom - CF2_FIXED_EPSILON; |
| blues->emBoxBottomEdge.dsCoord = cf2_fixedRound( |
| FT_MulFix( |
| blues->emBoxBottomEdge.csCoord, |
| blues->scale ) ) - |
| CF2_MIN_COUNTER; |
| blues->emBoxBottomEdge.scale = blues->scale; |
| blues->emBoxBottomEdge.flags = CF2_GhostBottom | |
| CF2_Locked | |
| CF2_Synthetic; |
| |
| blues->emBoxTopEdge.csCoord = emBoxTop + CF2_FIXED_EPSILON + |
| 2 * font->darkenY; |
| blues->emBoxTopEdge.dsCoord = cf2_fixedRound( |
| FT_MulFix( |
| blues->emBoxTopEdge.csCoord, |
| blues->scale ) ) + |
| CF2_MIN_COUNTER; |
| blues->emBoxTopEdge.scale = blues->scale; |
| blues->emBoxTopEdge.flags = CF2_GhostTop | |
| CF2_Locked | |
| CF2_Synthetic; |
| |
| blues->doEmBoxHints = TRUE; /* enable the heuristic */ |
| |
| return; |
| } |
| |
| /* copy `BlueValues' and `OtherBlues' to a combined array of top and */ |
| /* bottom zones */ |
| for ( i = 0; i < numBlueValues; i += 2 ) |
| { |
| blues->zone[blues->count].csBottomEdge = |
| cf2_blueToFixed( blueValues[i] ); |
| blues->zone[blues->count].csTopEdge = |
| cf2_blueToFixed( blueValues[i + 1] ); |
| |
| zoneHeight = SUB_INT32( blues->zone[blues->count].csTopEdge, |
| blues->zone[blues->count].csBottomEdge ); |
| |
| if ( zoneHeight < 0 ) |
| { |
| FT_TRACE4(( "cf2_blues_init: ignoring negative zone height\n" )); |
| continue; /* reject this zone */ |
| } |
| |
| if ( zoneHeight > maxZoneHeight ) |
| { |
| /* take maximum before darkening adjustment */ |
| /* so overshoot suppression point doesn't change */ |
| maxZoneHeight = zoneHeight; |
| } |
| |
| /* adjust both edges of top zone upward by twice darkening amount */ |
| if ( i != 0 ) |
| { |
| blues->zone[blues->count].csTopEdge += 2 * font->darkenY; |
| blues->zone[blues->count].csBottomEdge += 2 * font->darkenY; |
| } |
| |
| /* first `BlueValue' is bottom zone; others are top */ |
| if ( i == 0 ) |
| { |
| blues->zone[blues->count].bottomZone = |
| TRUE; |
| blues->zone[blues->count].csFlatEdge = |
| blues->zone[blues->count].csTopEdge; |
| } |
| else |
| { |
| blues->zone[blues->count].bottomZone = |
| FALSE; |
| blues->zone[blues->count].csFlatEdge = |
| blues->zone[blues->count].csBottomEdge; |
| } |
| |
| blues->count += 1; |
| } |
| |
| for ( i = 0; i < numOtherBlues; i += 2 ) |
| { |
| blues->zone[blues->count].csBottomEdge = |
| cf2_blueToFixed( otherBlues[i] ); |
| blues->zone[blues->count].csTopEdge = |
| cf2_blueToFixed( otherBlues[i + 1] ); |
| |
| zoneHeight = SUB_INT32( blues->zone[blues->count].csTopEdge, |
| blues->zone[blues->count].csBottomEdge ); |
| |
| if ( zoneHeight < 0 ) |
| { |
| FT_TRACE4(( "cf2_blues_init: ignoring negative zone height\n" )); |
| continue; /* reject this zone */ |
| } |
| |
| if ( zoneHeight > maxZoneHeight ) |
| { |
| /* take maximum before darkening adjustment */ |
| /* so overshoot suppression point doesn't change */ |
| maxZoneHeight = zoneHeight; |
| } |
| |
| /* Note: bottom zones are not adjusted for darkening amount */ |
| |
| /* all OtherBlues are bottom zone */ |
| blues->zone[blues->count].bottomZone = |
| TRUE; |
| blues->zone[blues->count].csFlatEdge = |
| blues->zone[blues->count].csTopEdge; |
| |
| blues->count += 1; |
| } |
| |
| /* Adjust for FamilyBlues */ |
| |
| /* Search for the nearest flat edge in `FamilyBlues' or */ |
| /* `FamilyOtherBlues'. According to the Black Book, any matching edge */ |
| /* must be within one device pixel */ |
| |
| csUnitsPerPixel = FT_DivFix( cf2_intToFixed( 1 ), blues->scale ); |
| |
| /* loop on all zones in this font */ |
| for ( i = 0; i < blues->count; i++ ) |
| { |
| size_t j; |
| CF2_Fixed minDiff; |
| CF2_Fixed flatFamilyEdge, diff; |
| /* value for this font */ |
| CF2_Fixed flatEdge = blues->zone[i].csFlatEdge; |
| |
| |
| if ( blues->zone[i].bottomZone ) |
| { |
| /* In a bottom zone, the top edge is the flat edge. */ |
| /* Search `FamilyOtherBlues' for bottom zones; look for closest */ |
| /* Family edge that is within the one pixel threshold. */ |
| |
| minDiff = CF2_FIXED_MAX; |
| |
| for ( j = 0; j < numFamilyOtherBlues; j += 2 ) |
| { |
| /* top edge */ |
| flatFamilyEdge = cf2_blueToFixed( familyOtherBlues[j + 1] ); |
| |
| diff = cf2_fixedAbs( SUB_INT32( flatEdge, flatFamilyEdge ) ); |
| |
| if ( diff < minDiff && diff < csUnitsPerPixel ) |
| { |
| blues->zone[i].csFlatEdge = flatFamilyEdge; |
| minDiff = diff; |
| |
| if ( diff == 0 ) |
| break; |
| } |
| } |
| |
| /* check the first member of FamilyBlues, which is a bottom zone */ |
| if ( numFamilyBlues >= 2 ) |
| { |
| /* top edge */ |
| flatFamilyEdge = cf2_blueToFixed( familyBlues[1] ); |
| |
| diff = cf2_fixedAbs( SUB_INT32( flatEdge, flatFamilyEdge ) ); |
| |
| if ( diff < minDiff && diff < csUnitsPerPixel ) |
| blues->zone[i].csFlatEdge = flatFamilyEdge; |
| } |
| } |
| else |
| { |
| /* In a top zone, the bottom edge is the flat edge. */ |
| /* Search `FamilyBlues' for top zones; skip first zone, which is a */ |
| /* bottom zone; look for closest Family edge that is within the */ |
| /* one pixel threshold */ |
| |
| minDiff = CF2_FIXED_MAX; |
| |
| for ( j = 2; j < numFamilyBlues; j += 2 ) |
| { |
| /* bottom edge */ |
| flatFamilyEdge = cf2_blueToFixed( familyBlues[j] ); |
| |
| /* adjust edges of top zone upward by twice darkening amount */ |
| flatFamilyEdge += 2 * font->darkenY; /* bottom edge */ |
| |
| diff = cf2_fixedAbs( SUB_INT32( flatEdge, flatFamilyEdge ) ); |
| |
| if ( diff < minDiff && diff < csUnitsPerPixel ) |
| { |
| blues->zone[i].csFlatEdge = flatFamilyEdge; |
| minDiff = diff; |
| |
| if ( diff == 0 ) |
| break; |
| } |
| } |
| } |
| } |
| |
| /* TODO: enforce separation of zones, including BlueFuzz */ |
| |
| /* Adjust BlueScale; similar to AdjustBlueScale() in coretype */ |
| /* `bcsetup.c'. */ |
| |
| if ( maxZoneHeight > 0 ) |
| { |
| if ( blues->blueScale > FT_DivFix( cf2_intToFixed( 1 ), |
| maxZoneHeight ) ) |
| { |
| /* clamp at maximum scale */ |
| blues->blueScale = FT_DivFix( cf2_intToFixed( 1 ), |
| maxZoneHeight ); |
| } |
| |
| /* |
| * TODO: Revisit the bug fix for 613448. The minimum scale |
| * requirement catches a number of library fonts. For |
| * example, with default BlueScale (.039625) and 0.4 minimum, |
| * the test below catches any font with maxZoneHeight < 10.1. |
| * There are library fonts ranging from 2 to 10 that get |
| * caught, including e.g., Eurostile LT Std Medium with |
| * maxZoneHeight of 6. |
| * |
| */ |
| #if 0 |
| if ( blueScale < .4 / maxZoneHeight ) |
| { |
| tetraphilia_assert( 0 ); |
| /* clamp at minimum scale, per bug 0613448 fix */ |
| blueScale = .4 / maxZoneHeight; |
| } |
| #endif |
| |
| } |
| |
| /* |
| * Suppress overshoot and boost blue zones at small sizes. Boost |
| * amount varies linearly from 0.5 pixel near 0 to 0 pixel at |
| * blueScale cutoff. |
| * Note: This boost amount is different from the coretype heuristic. |
| * |
| */ |
| |
| if ( blues->scale < blues->blueScale ) |
| { |
| blues->suppressOvershoot = TRUE; |
| |
| /* Change rounding threshold for `dsFlatEdge'. */ |
| /* Note: constant changed from 0.5 to 0.6 to avoid a problem with */ |
| /* 10ppem Arial */ |
| |
| blues->boost = cf2_doubleToFixed( .6 ) - |
| FT_MulDiv( cf2_doubleToFixed ( .6 ), |
| blues->scale, |
| blues->blueScale ); |
| if ( blues->boost > 0x7FFF ) |
| { |
| /* boost must remain less than 0.5, or baseline could go negative */ |
| blues->boost = 0x7FFF; |
| } |
| } |
| |
| /* boost and darkening have similar effects; don't do both */ |
| if ( font->stemDarkened ) |
| blues->boost = 0; |
| |
| /* set device space alignment for each zone; */ |
| /* apply boost amount before rounding flat edge */ |
| |
| for ( i = 0; i < blues->count; i++ ) |
| { |
| if ( blues->zone[i].bottomZone ) |
| blues->zone[i].dsFlatEdge = cf2_fixedRound( |
| FT_MulFix( |
| blues->zone[i].csFlatEdge, |
| blues->scale ) - |
| blues->boost ); |
| else |
| blues->zone[i].dsFlatEdge = cf2_fixedRound( |
| FT_MulFix( |
| blues->zone[i].csFlatEdge, |
| blues->scale ) + |
| blues->boost ); |
| } |
| } |
| |
| |
| /* |
| * Check whether `stemHint' is captured by one of the blue zones. |
| * |
| * Zero, one or both edges may be valid; only valid edges can be |
| * captured. For compatibility with CoolType, search top and bottom |
| * zones in the same pass (see `BlueLock'). If a hint is captured, |
| * return true and position the edge(s) in one of 3 ways: |
| * |
| * 1) If `BlueScale' suppresses overshoot, position the captured edge |
| * at the flat edge of the zone. |
| * 2) If overshoot is not suppressed and `BlueShift' requires |
| * overshoot, position the captured edge a minimum of 1 device pixel |
| * from the flat edge. |
| * 3) If overshoot is not suppressed or required, position the captured |
| * edge at the nearest device pixel. |
| * |
| */ |
| FT_LOCAL_DEF( FT_Bool ) |
| cf2_blues_capture( const CF2_Blues blues, |
| CF2_Hint bottomHintEdge, |
| CF2_Hint topHintEdge ) |
| { |
| /* TODO: validate? */ |
| CF2_Fixed csFuzz = blues->blueFuzz; |
| |
| /* new position of captured edge */ |
| CF2_Fixed dsNew; |
| |
| /* amount that hint is moved when positioned */ |
| CF2_Fixed dsMove = 0; |
| |
| FT_Bool captured = FALSE; |
| CF2_UInt i; |
| |
| |
| /* assert edge flags are consistent */ |
| FT_ASSERT( !cf2_hint_isTop( bottomHintEdge ) && |
| !cf2_hint_isBottom( topHintEdge ) ); |
| |
| /* TODO: search once without blue fuzz for compatibility with coretype? */ |
| for ( i = 0; i < blues->count; i++ ) |
| { |
| if ( blues->zone[i].bottomZone && |
| cf2_hint_isBottom( bottomHintEdge ) ) |
| { |
| if ( SUB_INT32( blues->zone[i].csBottomEdge, csFuzz ) <= |
| bottomHintEdge->csCoord && |
| bottomHintEdge->csCoord <= |
| ADD_INT32( blues->zone[i].csTopEdge, csFuzz ) ) |
| { |
| /* bottom edge captured by bottom zone */ |
| |
| if ( blues->suppressOvershoot ) |
| dsNew = blues->zone[i].dsFlatEdge; |
| |
| else if ( SUB_INT32( blues->zone[i].csTopEdge, |
| bottomHintEdge->csCoord ) >= |
| blues->blueShift ) |
| { |
| /* guarantee minimum of 1 pixel overshoot */ |
| dsNew = FT_MIN( |
| cf2_fixedRound( bottomHintEdge->dsCoord ), |
| SUB_INT32( blues->zone[i].dsFlatEdge, |
| cf2_intToFixed( 1 ) ) ); |
| } |
| |
| else |
| { |
| /* simply round captured edge */ |
| dsNew = cf2_fixedRound( bottomHintEdge->dsCoord ); |
| } |
| |
| dsMove = SUB_INT32( dsNew, bottomHintEdge->dsCoord ); |
| captured = TRUE; |
| |
| break; |
| } |
| } |
| |
| if ( !blues->zone[i].bottomZone && cf2_hint_isTop( topHintEdge ) ) |
| { |
| if ( SUB_INT32( blues->zone[i].csBottomEdge, csFuzz ) <= |
| topHintEdge->csCoord && |
| topHintEdge->csCoord <= |
| ADD_INT32( blues->zone[i].csTopEdge, csFuzz ) ) |
| { |
| /* top edge captured by top zone */ |
| |
| if ( blues->suppressOvershoot ) |
| dsNew = blues->zone[i].dsFlatEdge; |
| |
| else if ( SUB_INT32( topHintEdge->csCoord, |
| blues->zone[i].csBottomEdge ) >= |
| blues->blueShift ) |
| { |
| /* guarantee minimum of 1 pixel overshoot */ |
| dsNew = FT_MAX( |
| cf2_fixedRound( topHintEdge->dsCoord ), |
| blues->zone[i].dsFlatEdge + cf2_intToFixed( 1 ) ); |
| } |
| |
| else |
| { |
| /* simply round captured edge */ |
| dsNew = cf2_fixedRound( topHintEdge->dsCoord ); |
| } |
| |
| dsMove = SUB_INT32( dsNew, topHintEdge->dsCoord ); |
| captured = TRUE; |
| |
| break; |
| } |
| } |
| } |
| |
| if ( captured ) |
| { |
| /* move both edges and flag them `locked' */ |
| if ( cf2_hint_isValid( bottomHintEdge ) ) |
| { |
| bottomHintEdge->dsCoord = ADD_INT32( bottomHintEdge->dsCoord, |
| dsMove ); |
| cf2_hint_lock( bottomHintEdge ); |
| } |
| |
| if ( cf2_hint_isValid( topHintEdge ) ) |
| { |
| topHintEdge->dsCoord = ADD_INT32( topHintEdge->dsCoord, dsMove ); |
| cf2_hint_lock( topHintEdge ); |
| } |
| } |
| |
| return captured; |
| } |
| |
| |
| /* END */ |
