With the hack in _cairo_pattern_acquire_surface to return a 2x2
surface for reflected patterns, we can now accept REFLECT surface
patterns natively in all backends. SVG was already doing that.
The PDF case needed some changes to go through
_cairo_pattern_acquire_surface. A similar change to the recent
change in SVG.
cairo-scaled-font-subsets stores two sets of subsets -
scaled and unscaled. The first time each glyph is mapped,
_cairo_scaled_glyph_lookup() is called to determine if
the glyph is bitmap or outline. Outline glyphs are put
in the unscaled subsets. Bitmap glyphs are put in the
scaled subsets. The unscaled subsets hash table keyed is
the scaled_font->font_face to ensure only one font for
each font face is created. The scaled subsets hash
table is keyed by scaled_font.
_cairo_scaled_font_subsets_create() now takes two arguments
to specify the maximum size of the scaled and unscaled subsets.
If the unscaled max size is set to 0 all glyphs are mapped
to scaled subsets.
A separate foreach function is provided for scaled and unscaled
subsets. The PDF and PS backends iterate over the unscaled
subsets to emit CFF, TrueType, and Type1 fonts. The scaled
subsets are iterated to emit Type3 bitmap fonts.
The function _cairo_pdf_surface_write_fonts is the
original PDF TrueType font embedding function that was
disabled in commit f500cef19f
shortly before Type3 font support was added.
TrueType font embedding was later reintroduced as new code
making this function obsolete.
- Add a to_unicode array to the scaled_font_subsets
for mapping glyphs to unicode characters
- Add a function to the TrueType subsetting for
performing a reverse cmap for mapping glyph indices
to unicode characters.
- Add a new scaled font backend function for mapping
glyph indices to unicode characters. Provide FreeType
and Win32 implementations of the font backend mapping
function.
- Modify the PDF backend to embed ToUnicode streams
into each font. The unicode mapping is obtained by
first trying the reverse cmap. If this fails the font
backend mapping function is called.
PDF backend sets /LastChar value in Type1C font dictionary incorrectly.
acroread then complains about incorrect /Widths in font.
The last char is numchars - 1, since it's zero-based.
The former workaround for the lack of non-repeating patterns in PDF
(as far as we can tell) was broken for a source pattern matrix that
resulted in scaling the source surface pattern down. This was
demonstrated by the failure of the scale-down-source-surface-paint
test which now passes.
The old code would have also allowed for bogus repeated pattern
instances to appear if the source surface pattern was translated
sufficiently far off the destination surface in just the right
direction. This bug is also fixed.
The rule is: cairo_glyph_t* is always passed as const for measurement
purposes. This was not reflected in our public api previously. Fixed
Showing glyphs used to have cairo_glyph_t* always as const. With this
changed, it is only const on cairo_t and cairo_gstate_t operations.
cairo_surface_t, cairo_scaled_font_t, and individual backends receive
cairo_glyph_t* as non-const. The desired semantics is that they may modify
the contents of the array as long as they do not return
CAIRO_STATUS_UNSUPPORTED. This makes it possible to avoid copying the glyph
array again and again, and edit it in-place. Backends are in fact free to use
the array as a generic buffer as they see fit.
This is a little simpler than the old idiom of calling
_cairo_output_stream_get_status just before calling
_cairo_output_stream_destroy.
I had hoped this technique would apply in more cases, but
many cases want to separate the two actions anyway to do
conditional assignment of the status value, (in order to
not overwrite an earlier error value).
This patch generates Type 1 fonts for the PS/PDF backends when TrueType
or Type 1 subsetting fails. This has the advantage over the current
Type 3 fallback of reduced font size and better quality rendering
in some PDF viewers. xpdf shows a large improvement in text display
quality with this patch.
PDF Files with Type 1 fonts fail to open in any version of
ghostscript prior to 8.54. The problem is the hex encoding of the
encrypted portion of the font. The PDF reference says this should
only be in binary.
There are still some problems in the resulting output:
PDF: Rotated font ends up being blurry in final PNG (not too important)
PS and SVG: There's an incorrect offset being applied somewhere.
This only affects the image fallback in those backends, and avoids getting
colored pixels there if user's fontconfig configuration turns subpixel on.
This doesn't quite fix that problem though, more changes are needed/coming.
Add a load_truetype_table function to cairo_scaled_font_backend_t and
use it to load the truetype sfnt tables. Implement this with freetype
for the freetype font backend and use GetFontData for win32. Atsui
remains unimplemented, and still falls back to type3 fonts.
