Index: src/cff/cf2blues.c |
diff --git a/src/cff/cf2blues.c b/src/cff/cf2blues.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..5b348398af857728271a646328a8521d1bfc5da3 |
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+++ b/src/cff/cf2blues.c |
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+/***************************************************************************/ |
+/* */ |
+/* cf2blues.c */ |
+/* */ |
+/* Adobe's code for handling Blue Zones (body). */ |
+/* */ |
+/* 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. */ |
+/* */ |
+/***************************************************************************/ |
+ |
+ |
+#include "cf2ft.h" |
+#include FT_INTERNAL_DEBUG_H |
+ |
+#include "cf2blues.h" |
+#include "cf2hints.h" |
+#include "cf2font.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 trace_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 */ |
+ CFF_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; |
+ |
+ CF2_Int unitsPerEm = font->unitsPerEm; |
+ |
+ |
+ if ( unitsPerEm == 0 ) |
+ unitsPerEm = 1000; |
+ |
+ 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 = 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 = 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( 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( 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( 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 = FT_MulFix( |
+ cf2_floatToFixed( .6 ), |
+ ( cf2_intToFixed( 1 ) - |
+ FT_DivFix( 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 ( ( blues->zone[i].csBottomEdge - csFuzz ) <= |
+ bottomHintEdge->csCoord && |
+ bottomHintEdge->csCoord <= |
+ ( blues->zone[i].csTopEdge + csFuzz ) ) |
+ { |
+ /* bottom edge captured by bottom zone */ |
+ |
+ if ( blues->suppressOvershoot ) |
+ dsNew = blues->zone[i].dsFlatEdge; |
+ |
+ else if ( ( blues->zone[i].csTopEdge - bottomHintEdge->csCoord ) >= |
+ blues->blueShift ) |
+ { |
+ /* guarantee minimum of 1 pixel overshoot */ |
+ dsNew = FT_MIN( |
+ cf2_fixedRound( bottomHintEdge->dsCoord ), |
+ blues->zone[i].dsFlatEdge - cf2_intToFixed( 1 ) ); |
+ } |
+ |
+ else |
+ { |
+ /* simply round captured edge */ |
+ dsNew = cf2_fixedRound( bottomHintEdge->dsCoord ); |
+ } |
+ |
+ dsMove = dsNew - bottomHintEdge->dsCoord; |
+ captured = TRUE; |
+ |
+ break; |
+ } |
+ } |
+ |
+ if ( !blues->zone[i].bottomZone && cf2_hint_isTop( topHintEdge ) ) |
+ { |
+ if ( ( blues->zone[i].csBottomEdge - csFuzz ) <= |
+ topHintEdge->csCoord && |
+ topHintEdge->csCoord <= |
+ ( blues->zone[i].csTopEdge + csFuzz ) ) |
+ { |
+ /* top edge captured by top zone */ |
+ |
+ if ( blues->suppressOvershoot ) |
+ dsNew = blues->zone[i].dsFlatEdge; |
+ |
+ else if ( ( 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 = dsNew - topHintEdge->dsCoord; |
+ captured = TRUE; |
+ |
+ break; |
+ } |
+ } |
+ } |
+ |
+ if ( captured ) |
+ { |
+ /* move both edges and flag them `locked' */ |
+ if ( cf2_hint_isValid( bottomHintEdge ) ) |
+ { |
+ bottomHintEdge->dsCoord += dsMove; |
+ cf2_hint_lock( bottomHintEdge ); |
+ } |
+ |
+ if ( cf2_hint_isValid( topHintEdge ) ) |
+ { |
+ topHintEdge->dsCoord += dsMove; |
+ cf2_hint_lock( topHintEdge ); |
+ } |
+ } |
+ |
+ return captured; |
+ } |
+ |
+ |
+/* END */ |