This implements oversampling to metigate artifacts in pixels partially
covered by overlapping contours. It turns out that the 4x4
oversampling is sufficient but, at least, quadruples the rendering
time. The outline has to set FT_OUTLINE_OVERLAP to use this method.
* include/freetype/ftimage.h (FT_OUTLINE_OVERLAP): New flag.
* src/smooth/ftsmooth.c (ft_smooth_render): Check it to...
(ft_smooth_raster_overlap): ... inflate outline and set up direct
rendering for oversampling with...
(ft_smooth_overlap_spans): ... new span function that integrates them.
This second and final monster commit was created by applying Nikhil's
scripts `docconverter.py' and `markify.py' to all C header and source files,
followed up by minor manual clean-up.
No change in functionality, of course.
I used commit f7419907bc6044b9b7057f9789866426c804ba82 from
https://github.com/nikramakrishnan/freetype-docs.git.
This removes unnecessary complexity of span merging and buffering.
Instead, the spans are rendered as they come, speeding up the
rendering by about 5% percents as a result.
* src/smooth/ftgrays.c [FT_MAX_GRAY_SPANS]: Macro removed.
(gray_TWorker): Remove span buffer and related fields.
(gray_sweep, gray_hline): Updated.
* include/freetype/ftimage.h: Remove documentation note about
`FT_MAX_GRAY_SPANS', which was never in `ftoption.h' and is now gone.
Such macro names are reserved for both C and C++.
* include/freetype/ftimage.h, src/raster/ftraster.c,
src/smooth/ftgrays.c, src/smooth/ftgrays.h:
s/_STANDALONE_/STANDALONE_/.
This change is a result of a discussion thread on freetype-devel
http://lists.nongnu.org/archive/html/freetype-devel/2015-06/msg00041.html
Re-introduce the `freetype2' subdirectory for all FreeType header
files after installation, and rename the `freetype2' subdirectory in
the git repository to `freetype'.
* include/freetype2: Renamed to...
* include/freetype: This.
* CMakeLists.txt (PUBLIC_HEADERS, PUBLIC_CONFIG_HEADERS,
PRIVATE_HEADERS): Updated.
Update creation of `ftconfig.h'.
Install generated `ftconfig.h'.
* Jamfile (HDRMACRO, RefDoc), autogen.sh: Updated.
* builds/amiga/include/config/ftconfig.h, builds/freetype.mk
(PUBLIC_DIR), builds/symbian/bld.inf, builds/toplevel.mk (work),
builds/unix/freetype2.in: Updated.
* builds/unix/freetype-config.in: Updated.
* builds/unix/configure.raw: Don't check for `rmdir'.
* builds/unix/unix-def.in (DELDIR): Use `rm -rf', which is portable
according to the autoconf info manual.
* builds/unix/install.mk (install, uninstall,
distclean_project_unix): Update and simplify.
* builds/wince/*, builds/windows/*: Updated.
* devel/ft2build.h, include/ft2build.h: Updated.
* include/freetype2/config/ftheader.h,
include/freetype2/internal/ftserv.h,
include/freetype2/internal/internal.h: Update all header file
macros.
* src/tools/chktrcmp.py (TRACE_DEF_FILES): Updated.
* docs/*: Updated.
This large patch changes the header file directory layout from
`include/freetype/...' to `include/...', effectively removing one
level. Since the file `ft2build.h' is also located in `include'
(and it stays there even after installation), all FreeType header
files are now in a single directory.
Applications that use (a) `freetype-config' or FreeType's
`pkg-config' file to get the include directory for the compiler, and
(b) the documented way for header inclusion like
#include <ft2build.h>
#include FT_FREETYPE_H
...
don't need any change to the source code.
* include/freetype/*: Move up to...
* include/*: ... this directory.
* builds/amiga/include/freetype/*: Move up to...
* builds/amiga/include/*: ... this directory.
*/*: Essentially do `s@/freetype/@/@' where appropriate.
* CMakeList.txt: Simplify.
* builds/unix/freetype-config.in, builds/unix/freetype2.in: For
`--cflags', return a single directory.
* builds/unix/install.mk (install): No longer try to remove `cache'
and `internal' subdirectories; instead, remove the `freetype'
subdirectory.
A new load flag, FT_LOAD_COLOR, makes FreeType load color
embedded-bitmaps, following this draft specification
https://color-emoji.googlecode.com/git/specification/v1.html
which defines two new SFNT tables, `CBDT' and `CBLC' (named and
modeled after `EBDT' and `EBLC', respectively). The color bitmaps
are stored in the new FT_PIXEL_MODE_BGRA format to represent BGRA
pre-multiplied sRGB images. If PNG support is available, PNG color
images as defined in the same proposed specification are supported
also.
Note that color bitmaps are converted to grayscale if client didn't
ask for color.
* builds/unix/configure.raw: Search for libpng.
Add `--without-png' option.
* devel/ftoption.h, include/freetype/config/ftoption.h
(FT_CONFIG_OPTION_USE_PNG): New macro.
* include/freetype/freetype.h (FT_LOAD_COLOR): New load flag.
* include/freetype/ftimage.h (FT_Pixel_Mode): Add
`FT_PIXEL_MODE_BGRA'.
* include/freetype/tttags.h (TTAG_CBDT, TTAG_CBLC): New tags.
* src/base/ftbitmap.c (FT_Bitmap_Embolden): Updated.
(ft_gray_for_premultiplied_srgb_bgra): New function.
(FT_Bitmap_Convert): Handle FT_PIXEL_MODE_BGRA.
* src/sfnt/pngshim.c, src/sfnt/pngshim.h: New files.
* src/sfnt/sfnt.c: Include `pngshim.c'.
* src/sfnt/ttsbit.c: Include FT_BITMAP_H and `pngshim.h'
(tt_face_load_eblc): Load `CBLC'.
(tt_sbit_decoder_init): Load `CBDT'.
(tt_sbit_decoder_alloc_bitmap): Pass load flags to select between
color and grayscale bitmaps.
Set `num_grays'. This is used by `ftview' to choose the blending
algorithm.
(tt_sbit_decoder_load_byte_aligned,
tt_sbit_decoder_load_bit_aligned, tt_sbit_decoder_load_compound,
tt_sbit_decoder_load_image): Pass load flag.
s/write/pwrite/.
Don't call `tt_sbit_decoder_alloc_bitmap'.
Updated.
(tt_sbit_decoder_load_png) [FT_CONFIG_OPTION_USE_PNG]: New function.
(tt_sbit_decoder_load_bitmap): Pass load flag.
Handle new glyph formats 17, 18, and 19.
Call `tt_sbit_decoder_alloc_bitmap'.
Flatten color bitmaps if necessary.
(tt_face_load_sbit_image): Updated.
* src/sfnt/rules.mk (SFNT_DRV_SRC): Add `pngshim.c'.
* docs/CHANGES: Updated.
Normally, the SCANMODE instruction (if present) to set the drop-out
mode in a TrueType font is located in the `prep' table only and thus
valid for all glyphs. However, there are fonts like `pala.ttf'
which additionally contain this instruction in the hinting code of
some glyphs (but not all). As a result it can happen that a
composite glyph needs multiple drop-out modes for its subglyphs
since the rendering state gets reset for each subglyph.
FreeType collects the hinted outlines from all subglyphs, then it
sends the data to the rasterizer. It also sends the drop-out mode
-- after hinting has been applied -- and here is the error: It sends
the drop-out mode of the last subglyph only; drop-out modes of all
other subglyphs are lost.
This patch fixes the problem; it adds a second, alternative
mechanism to pass the drop-out mode: For each contour, the
rasterizer now checks the first `tags' array element. If bit 2 is
set, bits 5-7 contain the contour's drop-out mode, overriding the
global drop-out mode.
* include/freetype/ftimage.h (FT_CURVE_TAG_HAS_SCANMODE): New macro.
* src/truetype/ttgload.c (TT_Hint_Glyph): Store drop-out mode in
`tags[0]'.
* src/raster/ftraster.c (Flow_Up, Overshoot_Top, Overshoot_Bottom):
Use bits 3-5 instead of 0-2.
(New_Profile): Set the drop-out mode in the profile's `flags' field.
(Decompose_Curve): Check `tags[0]' and set `dropOutControl' if
necessary.
(Vertical_Sweep_Drop, Horizontal_Sweep_Drop,
Horizontal_Gray_Sweep_Drop, Draw_Sweep): Use the profile's drop-out
mode.
Pass dropout rules from the TT bytecode interpreter to the
rasterizer; temporarily this is enabled only if
`USE_SCAN_CONVERSION_RULES' is defined.
* include/freetype/ftimage.h (FT_OUTLINE_SMART_DROPOUTS,
FT_OUTLINE_EXCLUDE_STUBS): New flags for for FT_Outline.
* src/raster/ftraster.c (Vertical_Sweep_Drop, Horizontal_Sweep_Drop,
Horizontal_Gray_Sweep_Drop): Use same mode numbers as given in the
OpenType specification.
Fix mode 4 computation.
(Render_Glyph, Render_Gray_Glyph): Handle new outline flags.
* src/truetype/ttgload.c (TT_Load_Glyph)
[USE_SCAN_CONVERSION_RULES]: Convert scan conversion mode to
FT_OUTLINE_XXX flags.
* src/truetype/ttinterp.c (Ins_SCANCTRL): Enable ppem check.
Alexei Podtelezhnikov