diff --git a/ChangeLog b/ChangeLog index abcb6d723..82ce4f5bc 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,47 @@ +2009-09-02 Bram Tassyns + + Improve vertical metrics calculation (Savannah bug #27364). + + The calculation of `vertBearingX' is not defined in the OTF font + spec so FreeType does a `best effort' attempt. However, this value + is defined in the PDF and PostScript specs, and that algorithm is + better than the one FreeType currently uses: + + FreeType: Use the middle of the bounding box as the X coordinate + of the vertical origin. + + Adobe PDF spec: Use the middle of the horizontal advance vector as + the X coordinate of the vertical origin. + + FreeType's algorithm goes wrong if you have a really small glyph + (like the full-width, circle-like dot at the end of the sentence, as + used in CJK scripts) with large bearings. With the FreeType + algorithm this dot gets centered on the baseline; with the PDF + algorithm it gets the correct location (in the top right). Note + that this is a serious issue, it's like printing the dot at the end + of a Roman sentence at the center of the textline instead of on the + baseline like it should. So i believe the PDF spec's algorithm + should be used in FreeType as well. + + The `vertBearingY' value for such small glyphs is also very strange + if no `vmtx' information is present, since the height of the bbox is + not representable for the height of the glyph visually (the + whitespace up to the baseline is part of the glyph). The fix also + includes some code for a better estimate of `vertBearingY'. + + * src/base/ftobjs.c (ft_synthesize_vertical_metrics): `vertBearingX' + is now calculated as described by the Adobe PDF Spec. Estimate for + `vertBearingY' now works better for small glyphs completely above or + below the baseline into account. + + * src/cff/cffgload.c (cff_slot_load): `vertBearingX' is now + calculated as described by the Adobe PDF Spec. Vertical metrics + information was always ignored when FT_CONFIG_OPTION_OLD_INTERNALS + was not defined. + + * src/truetype/ttgload.c (compute_glyph_metrics): `vertBearingX' is + now calculated as described by the Adobe PDF Spec. + 2009-09-01 John Tytgat Fix custom cmap for empty Type 1 font (Savannah bug #27294). diff --git a/src/base/ftobjs.c b/src/base/ftobjs.c index dead68e31..421540c8d 100644 --- a/src/base/ftobjs.c +++ b/src/base/ftobjs.c @@ -2404,12 +2404,24 @@ ft_synthesize_vertical_metrics( FT_Glyph_Metrics* metrics, FT_Pos advance ) { + FT_Pos height = metrics->height; + + + /* compensate for glyph with bbox above/below the baseline */ + if ( metrics->horiBearingY < 0 ) + { + if ( height < metrics->horiBearingY ) + height = metrics->horiBearingY; + } + else if ( metrics->horiBearingY > 0 ) + height -= metrics->horiBearingY; + /* the factor 1.2 is a heuristical value */ if ( !advance ) - advance = metrics->height * 12 / 10; + advance = height * 12 / 10; - metrics->vertBearingX = -( metrics->width / 2 ); - metrics->vertBearingY = ( advance - metrics->height ) / 2; + metrics->vertBearingX = metrics->horiBearingX - metrics->horiAdvance / 2; + metrics->vertBearingY = ( advance - height ) / 2; metrics->vertAdvance = advance; } diff --git a/src/cff/cffgload.c b/src/cff/cffgload.c index e132ab781..a5b3e8413 100644 --- a/src/cff/cffgload.c +++ b/src/cff/cffgload.c @@ -2726,9 +2726,14 @@ glyph->root.linearHoriAdvance = decoder.glyph_width; glyph->root.internal->glyph_transformed = 0; +#ifdef FT_CONFIG_OPTION_OLD_INTERNALS has_vertical_info = FT_BOOL( face->vertical_info && face->vertical.number_Of_VMetrics > 0 && face->vertical.long_metrics ); +#else + has_vertical_info = FT_BOOL( face->vertical_info && + face->vertical.number_Of_VMetrics > 0 ); +#endif /* get the vertical metrics from the vtmx table if we have one */ if ( has_vertical_info ) @@ -2819,7 +2824,8 @@ metrics->horiBearingY = cbox.yMax; if ( has_vertical_info ) - metrics->vertBearingX = -metrics->width / 2; + metrics->vertBearingX = metrics->horiBearingX - + metrics->horiAdvance / 2; else ft_synthesize_vertical_metrics( metrics, metrics->vertAdvance ); diff --git a/src/truetype/ttgload.c b/src/truetype/ttgload.c index b0f6810f0..32cb523ae 100644 --- a/src/truetype/ttgload.c +++ b/src/truetype/ttgload.c @@ -1594,10 +1594,28 @@ glyph->metrics.horiBearingY = bbox.yMax; glyph->metrics.horiAdvance = loader->pp2.x - loader->pp1.x; - /* Now take care of vertical metrics. In the case where there is */ - /* no vertical information within the font (relatively common), make */ - /* up some metrics by `hand'... */ + /* adjust advance width to the value contained in the hdmx table */ + if ( !face->postscript.isFixedPitch && + IS_HINTED( loader->load_flags ) ) + { + FT_Byte* widthp; + + widthp = tt_face_get_device_metrics( face, + size->root.metrics.x_ppem, + glyph_index ); + + if ( widthp ) + glyph->metrics.horiAdvance = *widthp << 6; + } + + /* set glyph dimensions */ + glyph->metrics.width = bbox.xMax - bbox.xMin; + glyph->metrics.height = bbox.yMax - bbox.yMin; + + /* Now take care of vertical metrics. In the case where there is */ + /* no vertical information within the font (relatively common), */ + /* create some metrics manually */ { FT_Pos top; /* scaled vertical top side bearing */ FT_Pos advance; /* scaled vertical advance height */ @@ -1686,30 +1704,12 @@ /* XXX: for now, we have no better algorithm for the lsb, but it */ /* should work fine. */ /* */ - glyph->metrics.vertBearingX = ( bbox.xMin - bbox.xMax ) / 2; + glyph->metrics.vertBearingX = glyph->metrics.horiBearingX - + glyph->metrics.horiAdvance / 2; glyph->metrics.vertBearingY = top; glyph->metrics.vertAdvance = advance; } - /* adjust advance width to the value contained in the hdmx table */ - if ( !face->postscript.isFixedPitch && - IS_HINTED( loader->load_flags ) ) - { - FT_Byte* widthp; - - - widthp = tt_face_get_device_metrics( face, - size->root.metrics.x_ppem, - glyph_index ); - - if ( widthp ) - glyph->metrics.horiAdvance = *widthp << 6; - } - - /* set glyph dimensions */ - glyph->metrics.width = bbox.xMax - bbox.xMin; - glyph->metrics.height = bbox.yMax - bbox.yMin; - return 0; } @@ -2013,7 +2013,7 @@ break; } } - else + else glyph->outline.flags |= FT_OUTLINE_IGNORE_DROPOUTS; }