Index: src/cff/cf2font.c |
diff --git a/src/cff/cf2font.c b/src/cff/cf2font.c |
new file mode 100644 |
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+/***************************************************************************/ |
+/* */ |
+/* cf2font.c */ |
+/* */ |
+/* Adobe's code for font instances (body). */ |
+/* */ |
+/* Copyright 2007-2013 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 "cf2glue.h" |
+#include "cf2font.h" |
+#include "cf2error.h" |
+#include "cf2intrp.h" |
+ |
+ |
+ /* Compute a stem darkening amount in character space. */ |
+ static void |
+ cf2_computeDarkening( CF2_Fixed emRatio, |
+ CF2_Fixed ppem, |
+ CF2_Fixed stemWidth, |
+ CF2_Fixed* darkenAmount, |
+ CF2_Fixed boldenAmount, |
+ FT_Bool stemDarkened ) |
+ { |
+ /* Internal calculations are done in units per thousand for */ |
+ /* convenience. */ |
+ CF2_Fixed stemWidthPer1000, scaledStem; |
+ |
+ |
+ *darkenAmount = 0; |
+ |
+ if ( boldenAmount == 0 && !stemDarkened ) |
+ return; |
+ |
+ /* protect against range problems and divide by zero */ |
+ if ( emRatio < cf2_floatToFixed( .01 ) ) |
+ return; |
+ |
+ if ( stemDarkened ) |
+ { |
+ /* convert from true character space to 1000 unit character space; */ |
+ /* add synthetic emboldening effect */ |
+ |
+ /* we have to assure that the computation of `scaledStem' */ |
+ /* and `stemWidthPer1000' don't overflow */ |
+ |
+ stemWidthPer1000 = FT_MulFix( stemWidth + boldenAmount, emRatio ); |
+ |
+ if ( emRatio > CF2_FIXED_ONE && |
+ stemWidthPer1000 <= ( stemWidth + boldenAmount ) ) |
+ { |
+ stemWidthPer1000 = 0; /* to pacify compiler */ |
+ scaledStem = cf2_intToFixed( 2333 ); |
+ } |
+ else |
+ { |
+ scaledStem = FT_MulFix( stemWidthPer1000, ppem ); |
+ |
+ if ( ppem > CF2_FIXED_ONE && |
+ scaledStem <= stemWidthPer1000 ) |
+ scaledStem = cf2_intToFixed( 2333 ); |
+ } |
+ |
+ /* |
+ * Total darkening amount is computed in 1000 unit character space |
+ * using the modified 5 part curve as Avalon rasterizer. |
+ * The darkening amount is smaller for thicker stems. |
+ * It becomes zero when the stem is thicker than 2.333 pixels. |
+ * |
+ * In Avalon rasterizer, |
+ * |
+ * darkenAmount = 0.5 pixels if scaledStem <= 0.5 pixels, |
+ * darkenAmount = 0.333 pixels if 1 <= scaledStem <= 1.667 pixels, |
+ * darkenAmount = 0 pixel if scaledStem >= 2.333 pixels, |
+ * |
+ * and piecewise linear in-between. |
+ * |
+ */ |
+ if ( scaledStem < cf2_intToFixed( 500 ) ) |
+ *darkenAmount = FT_DivFix( cf2_intToFixed( 400 ), ppem ); |
+ |
+ else if ( scaledStem < cf2_intToFixed( 1000 ) ) |
+ *darkenAmount = FT_DivFix( cf2_intToFixed( 525 ), ppem ) - |
+ FT_MulFix( stemWidthPer1000, |
+ cf2_floatToFixed( .25 ) ); |
+ |
+ else if ( scaledStem < cf2_intToFixed( 1667 ) ) |
+ *darkenAmount = FT_DivFix( cf2_intToFixed( 275 ), ppem ); |
+ |
+ else if ( scaledStem < cf2_intToFixed( 2333 ) ) |
+ *darkenAmount = FT_DivFix( cf2_intToFixed( 963 ), ppem ) - |
+ FT_MulFix( stemWidthPer1000, |
+ cf2_floatToFixed( .413 ) ); |
+ |
+ /* use half the amount on each side and convert back to true */ |
+ /* character space */ |
+ *darkenAmount = FT_DivFix( *darkenAmount, 2 * emRatio ); |
+ } |
+ |
+ /* add synthetic emboldening effect in character space */ |
+ *darkenAmount += boldenAmount / 2; |
+ } |
+ |
+ |
+ /* set up values for the current FontDict and matrix */ |
+ |
+ /* caller's transform is adjusted for subpixel positioning */ |
+ static void |
+ cf2_font_setup( CF2_Font font, |
+ const CF2_Matrix* transform ) |
+ { |
+ /* pointer to parsed font object */ |
+ CFF_Decoder* decoder = font->decoder; |
+ |
+ FT_Bool needExtraSetup; |
+ |
+ /* character space units */ |
+ CF2_Fixed boldenX = font->syntheticEmboldeningAmountX; |
+ CF2_Fixed boldenY = font->syntheticEmboldeningAmountY; |
+ |
+ CF2_Fixed ppem; |
+ |
+ |
+ /* clear previous error */ |
+ font->error = FT_Err_Ok; |
+ |
+ /* if a CID fontDict has changed, we need to recompute some cached */ |
+ /* data */ |
+ needExtraSetup = font->lastSubfont != cf2_getSubfont( decoder ); |
+ |
+ /* if ppem has changed, we need to recompute some cached data */ |
+ /* note: because of CID font matrix concatenation, ppem and transform */ |
+ /* do not necessarily track. */ |
+ ppem = cf2_getPpemY( decoder ); |
+ if ( font->ppem != ppem ) |
+ { |
+ font->ppem = ppem; |
+ needExtraSetup = TRUE; |
+ } |
+ |
+ /* copy hinted flag on each call */ |
+ font->hinted = font->renderingFlags & CF2_FlagsHinted; |
+ |
+ /* determine if transform has changed; */ |
+ /* include Fontmatrix but ignore translation */ |
+ if ( ft_memcmp( transform, |
+ &font->currentTransform, |
+ 4 * sizeof ( CF2_Fixed ) ) != 0 ) |
+ { |
+ /* save `key' information for `cache of one' matrix data; */ |
+ /* save client transform, without the translation */ |
+ font->currentTransform = *transform; |
+ font->currentTransform.tx = |
+ font->currentTransform.ty = cf2_intToFixed( 0 ); |
+ |
+ /* TODO: FreeType transform is simple scalar; for now, use identity */ |
+ /* for outer */ |
+ font->innerTransform = *transform; |
+ font->outerTransform.a = |
+ font->outerTransform.d = cf2_intToFixed( 1 ); |
+ font->outerTransform.b = |
+ font->outerTransform.c = cf2_intToFixed( 0 ); |
+ |
+ needExtraSetup = TRUE; |
+ } |
+ |
+ /* |
+ * font->darkened is set to true if there is a stem darkening request or |
+ * the font is synthetic emboldened. |
+ * font->darkened controls whether to adjust blue zones, winding order, |
+ * and hinting. |
+ * |
+ */ |
+ if ( font->stemDarkened != ( font->renderingFlags & CF2_FlagsDarkened ) ) |
+ { |
+ font->stemDarkened = font->renderingFlags & CF2_FlagsDarkened; |
+ |
+ /* blue zones depend on darkened flag */ |
+ needExtraSetup = TRUE; |
+ } |
+ |
+ /* recompute variables that are dependent on transform or FontDict or */ |
+ /* darken flag */ |
+ if ( needExtraSetup ) |
+ { |
+ /* StdVW is found in the private dictionary; */ |
+ /* recompute darkening amounts whenever private dictionary or */ |
+ /* transform change */ |
+ /* Note: a rendering flag turns darkening on or off, so we want to */ |
+ /* store the `on' amounts; */ |
+ /* darkening amount is computed in character space */ |
+ /* TODO: testing size-dependent darkening here; */ |
+ /* what to do for rotations? */ |
+ |
+ CF2_Fixed emRatio; |
+ CF2_Fixed stdHW; |
+ CF2_Int unitsPerEm = font->unitsPerEm; |
+ |
+ |
+ if ( unitsPerEm == 0 ) |
+ unitsPerEm = 1000; |
+ |
+ ppem = FT_MAX( cf2_intToFixed( 4 ), |
+ font->ppem ); /* use minimum ppem of 4 */ |
+ |
+#if 0 |
+ /* since vstem is measured in the x-direction, we use the `a' member */ |
+ /* of the fontMatrix */ |
+ emRatio = cf2_fixedFracMul( cf2_intToFixed( 1000 ), fontMatrix->a ); |
+#endif |
+ |
+ /* Freetype does not preserve the fontMatrix when parsing; use */ |
+ /* unitsPerEm instead. */ |
+ /* TODO: check precision of this */ |
+ emRatio = cf2_intToFixed( 1000 ) / unitsPerEm; |
+ font->stdVW = cf2_getStdVW( decoder ); |
+ |
+ if ( font->stdVW <= 0 ) |
+ font->stdVW = FT_DivFix( cf2_intToFixed( 75 ), emRatio ); |
+ |
+ if ( boldenX > 0 ) |
+ { |
+ /* Ensure that boldenX is at least 1 pixel for synthetic bold font */ |
+ /* (similar to what Avalon does) */ |
+ boldenX = FT_MAX( boldenX, |
+ FT_DivFix( cf2_intToFixed( unitsPerEm ), ppem ) ); |
+ |
+ /* Synthetic emboldening adds at least 1 pixel to darkenX, while */ |
+ /* stem darkening adds at most half pixel. Since the purpose of */ |
+ /* stem darkening (readability at small sizes) is met with */ |
+ /* synthetic emboldening, no need to add stem darkening for a */ |
+ /* synthetic bold font. */ |
+ cf2_computeDarkening( emRatio, |
+ ppem, |
+ font->stdVW, |
+ &font->darkenX, |
+ boldenX, |
+ FALSE ); |
+ } |
+ else |
+ cf2_computeDarkening( emRatio, |
+ ppem, |
+ font->stdVW, |
+ &font->darkenX, |
+ 0, |
+ font->stemDarkened ); |
+ |
+#if 0 |
+ /* since hstem is measured in the y-direction, we use the `d' member */ |
+ /* of the fontMatrix */ |
+ /* TODO: use the same units per em as above; check this */ |
+ emRatio = cf2_fixedFracMul( cf2_intToFixed( 1000 ), fontMatrix->d ); |
+#endif |
+ |
+ /* set the default stem width, because it must be the same for all */ |
+ /* family members; */ |
+ /* choose a constant for StdHW that depends on font contrast */ |
+ stdHW = cf2_getStdHW( decoder ); |
+ |
+ if ( stdHW > 0 && font->stdVW > 2 * stdHW ) |
+ font->stdHW = FT_DivFix( cf2_intToFixed( 75 ), emRatio ); |
+ else |
+ { |
+ /* low contrast font gets less hstem darkening */ |
+ font->stdHW = FT_DivFix( cf2_intToFixed( 110 ), emRatio ); |
+ } |
+ |
+ cf2_computeDarkening( emRatio, |
+ ppem, |
+ font->stdHW, |
+ &font->darkenY, |
+ boldenY, |
+ font->stemDarkened ); |
+ |
+ if ( font->darkenX != 0 || font->darkenY != 0 ) |
+ font->darkened = TRUE; |
+ else |
+ font->darkened = FALSE; |
+ |
+ font->reverseWinding = FALSE; /* initial expectation is CCW */ |
+ |
+ /* compute blue zones for this instance */ |
+ cf2_blues_init( &font->blues, font ); |
+ } |
+ } |
+ |
+ |
+ /* equivalent to AdobeGetOutline */ |
+ FT_LOCAL_DEF( FT_Error ) |
+ cf2_getGlyphOutline( CF2_Font font, |
+ CF2_Buffer charstring, |
+ const CF2_Matrix* transform, |
+ CF2_F16Dot16* glyphWidth ) |
+ { |
+ FT_Error lastError = FT_Err_Ok; |
+ |
+ FT_Vector translation; |
+ |
+#if 0 |
+ FT_Vector advancePoint; |
+#endif |
+ |
+ CF2_Fixed advWidth = 0; |
+ FT_Bool needWinding; |
+ |
+ |
+ /* Note: use both integer and fraction for outlines. This allows bbox */ |
+ /* to come out directly. */ |
+ |
+ translation.x = transform->tx; |
+ translation.y = transform->ty; |
+ |
+ /* set up values based on transform */ |
+ cf2_font_setup( font, transform ); |
+ if ( font->error ) |
+ goto exit; /* setup encountered an error */ |
+ |
+ /* reset darken direction */ |
+ font->reverseWinding = FALSE; |
+ |
+ /* winding order only affects darkening */ |
+ needWinding = font->darkened; |
+ |
+ while ( 1 ) |
+ { |
+ /* reset output buffer */ |
+ cf2_outline_reset( &font->outline ); |
+ |
+ /* build the outline, passing the full translation */ |
+ cf2_interpT2CharString( font, |
+ charstring, |
+ (CF2_OutlineCallbacks)&font->outline, |
+ &translation, |
+ FALSE, |
+ 0, |
+ 0, |
+ &advWidth ); |
+ |
+ if ( font->error ) |
+ goto exit; |
+ |
+ if ( !needWinding ) |
+ break; |
+ |
+ /* check winding order */ |
+ if ( font->outline.root.windingMomentum >= 0 ) /* CFF is CCW */ |
+ break; |
+ |
+ /* invert darkening and render again */ |
+ /* TODO: this should be a parameter to getOutline-computeOffset */ |
+ font->reverseWinding = TRUE; |
+ |
+ needWinding = FALSE; /* exit after next iteration */ |
+ } |
+ |
+ /* finish storing client outline */ |
+ cf2_outline_close( &font->outline ); |
+ |
+ exit: |
+ /* FreeType just wants the advance width; there is no translation */ |
+ *glyphWidth = advWidth; |
+ |
+ /* free resources and collect errors from objects we've used */ |
+ cf2_setError( &font->error, lastError ); |
+ |
+ return font->error; |
+ } |
+ |
+ |
+/* END */ |