| /***************************************************************************/ |
| /* */ |
| /* cf2font.c */ |
| /* */ |
| /* Adobe's code for font instances (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 <ft2build.h> |
| #include FT_INTERNAL_CALC_H |
| |
| #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, |
| FT_Int* darkenParams ) |
| { |
| /* |
| * Total darkening amount is computed in 1000 unit character space |
| * using the modified 5 part curve as Adobe's Avalon rasterizer. |
| * The darkening amount is smaller for thicker stems. |
| * It becomes zero when the stem is thicker than 2.333 pixels. |
| * |
| * By default, we use |
| * |
| * darkenAmount = 0.4 pixels if scaledStem <= 0.5 pixels, |
| * darkenAmount = 0.275 pixels if 1 <= scaledStem <= 1.667 pixels, |
| * darkenAmount = 0 pixel if scaledStem >= 2.333 pixels, |
| * |
| * and piecewise linear in-between: |
| * |
| * |
| * darkening |
| * ^ |
| * | |
| * | (x1,y1) |
| * |--------+ |
| * | \ |
| * | \ |
| * | \ (x3,y3) |
| * | +----------+ |
| * | (x2,y2) \ |
| * | \ |
| * | \ |
| * | +----------------- |
| * | (x4,y4) |
| * +---------------------------------------------> stem |
| * thickness |
| * |
| * |
| * This corresponds to the following values for the |
| * `darkening-parameters' property: |
| * |
| * (x1, y1) = (500, 400) |
| * (x2, y2) = (1000, 275) |
| * (x3, y3) = (1667, 275) |
| * (x4, y4) = (2333, 0) |
| * |
| */ |
| |
| /* Internal calculations are done in units per thousand for */ |
| /* convenience. The x axis is scaled stem width in */ |
| /* thousandths of a pixel. That is, 1000 is 1 pixel. */ |
| /* The y axis is darkening amount in thousandths of a pixel.*/ |
| /* In the code, below, dividing by ppem and */ |
| /* adjusting for emRatio converts darkenAmount to character */ |
| /* space (font units). */ |
| CF2_Fixed stemWidthPer1000, scaledStem; |
| FT_Int logBase2; |
| |
| |
| *darkenAmount = 0; |
| |
| if ( boldenAmount == 0 && !stemDarkened ) |
| return; |
| |
| /* protect against range problems and divide by zero */ |
| if ( emRatio < cf2_floatToFixed( .01 ) ) |
| return; |
| |
| if ( stemDarkened ) |
| { |
| FT_Int x1 = darkenParams[0]; |
| FT_Int y1 = darkenParams[1]; |
| FT_Int x2 = darkenParams[2]; |
| FT_Int y2 = darkenParams[3]; |
| FT_Int x3 = darkenParams[4]; |
| FT_Int y3 = darkenParams[5]; |
| FT_Int x4 = darkenParams[6]; |
| FT_Int y4 = darkenParams[7]; |
| |
| |
| /* convert from true character space to 1000 unit character space; */ |
| /* add synthetic emboldening effect */ |
| |
| /* `stemWidthPer1000' will not overflow for a legitimate font */ |
| |
| stemWidthPer1000 = FT_MulFix( stemWidth + boldenAmount, emRatio ); |
| |
| /* `scaledStem' can easily overflow, so we must clamp its maximum */ |
| /* value; the test doesn't need to be precise, but must be */ |
| /* conservative. The clamp value (default 2333) where */ |
| /* `darkenAmount' is zero is well below the overflow value of */ |
| /* 32767. */ |
| /* */ |
| /* FT_MSB computes the integer part of the base 2 logarithm. The */ |
| /* number of bits for the product is 1 or 2 more than the sum of */ |
| /* logarithms; remembering that the 16 lowest bits of the fraction */ |
| /* are dropped this is correct to within a factor of almost 4. */ |
| /* For example, 0x80.0000 * 0x80.0000 = 0x4000.0000 is 23+23 and */ |
| /* is flagged as possible overflow because 0xFF.FFFF * 0xFF.FFFF = */ |
| /* 0xFFFF.FE00 is also 23+23. */ |
| |
| logBase2 = FT_MSB( (FT_UInt32)stemWidthPer1000 ) + |
| FT_MSB( (FT_UInt32)ppem ); |
| |
| if ( logBase2 >= 46 ) |
| /* possible overflow */ |
| scaledStem = cf2_intToFixed( x4 ); |
| else |
| scaledStem = FT_MulFix( stemWidthPer1000, ppem ); |
| |
| /* now apply the darkening parameters */ |
| |
| if ( scaledStem < cf2_intToFixed( x1 ) ) |
| *darkenAmount = FT_DivFix( cf2_intToFixed( y1 ), ppem ); |
| |
| else if ( scaledStem < cf2_intToFixed( x2 ) ) |
| { |
| FT_Int xdelta = x2 - x1; |
| FT_Int ydelta = y2 - y1; |
| FT_Int x = stemWidthPer1000 - |
| FT_DivFix( cf2_intToFixed( x1 ), ppem ); |
| |
| |
| if ( !xdelta ) |
| goto Try_x3; |
| |
| *darkenAmount = FT_MulDiv( x, ydelta, xdelta ) + |
| FT_DivFix( cf2_intToFixed( y1 ), ppem ); |
| } |
| |
| else if ( scaledStem < cf2_intToFixed( x3 ) ) |
| { |
| Try_x3: |
| { |
| FT_Int xdelta = x3 - x2; |
| FT_Int ydelta = y3 - y2; |
| FT_Int x = stemWidthPer1000 - |
| FT_DivFix( cf2_intToFixed( x2 ), ppem ); |
| |
| |
| if ( !xdelta ) |
| goto Try_x4; |
| |
| *darkenAmount = FT_MulDiv( x, ydelta, xdelta ) + |
| FT_DivFix( cf2_intToFixed( y2 ), ppem ); |
| } |
| } |
| |
| else if ( scaledStem < cf2_intToFixed( x4 ) ) |
| { |
| Try_x4: |
| { |
| FT_Int xdelta = x4 - x3; |
| FT_Int ydelta = y4 - y3; |
| FT_Int x = stemWidthPer1000 - |
| FT_DivFix( cf2_intToFixed( x3 ), ppem ); |
| |
| |
| if ( !xdelta ) |
| goto Use_y4; |
| |
| *darkenAmount = FT_MulDiv( x, ydelta, xdelta ) + |
| FT_DivFix( cf2_intToFixed( y3 ), ppem ); |
| } |
| } |
| |
| else |
| { |
| Use_y4: |
| *darkenAmount = FT_DivFix( cf2_intToFixed( y4 ), ppem ); |
| } |
| |
| /* 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 = FALSE; |
| |
| /* character space units */ |
| CF2_Fixed boldenX = font->syntheticEmboldeningAmountX; |
| CF2_Fixed boldenY = font->syntheticEmboldeningAmountY; |
| |
| CFF_SubFont subFont; |
| CF2_Fixed ppem; |
| |
| |
| /* clear previous error */ |
| font->error = FT_Err_Ok; |
| |
| /* if a CID fontDict has changed, we need to recompute some cached */ |
| /* data */ |
| subFont = cf2_getSubfont( decoder ); |
| if ( font->lastSubfont != subFont ) |
| { |
| font->lastSubfont = subFont; |
| needExtraSetup = TRUE; |
| } |
| |
| /* 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 = (FT_Bool)( 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 = |
| (FT_Bool)( 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, |
| font->darkenParams ); |
| } |
| else |
| cf2_computeDarkening( emRatio, |
| ppem, |
| font->stdVW, |
| &font->darkenX, |
| 0, |
| font->stemDarkened, |
| font->darkenParams ); |
| |
| #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, |
| font->darkenParams ); |
| |
| 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 */ |
