If the distance of the current pixel to the edge is less than or equal
to 0.5, skip further neighbor comparisons to avoid unnecessary
calculations. When the `USE_SQUARED_DISTANCES` macro is defined,
compare to 0.25 instead.
* src/sdf/ftbsdf.c (compare_neighbor): Add early return for pixels
close to edges to avoid unnecessary neighbor checks.
This doubles the number or allowed points, see
https://github.com/harfbuzz/harfbuzz/issues/4752
Although it is hardly practical to use more than 32767 points,
other font engines seem to support it.
* docs/CHANGES: Announce it.
* include/freetype/ftimage.h (FT_Outline): Do it and update limits.
* src/*: Update `FT_Outline` users.
FT_SqrtFixed (95b0fe2a6d) is faster and does not overflow.
* src/sdf/ftsdfcommin.h (square_root): Replace with a macro.
* src/sdf/ftsdfcommin.c (square_root): Remove function.
This is a refinement of commit 7b3ebb9.
* src/sdf/ftsdfrend.c (ft_sdf_render): Goto 'Exit' instead of directly
returning.
(fd_bsdf_render): Ditto, also taking care of setting `FT_GLYPH_OWN_BITMAP`
correctly.
Modern compilers get more insistent on that...
* include/freetype/internal/compiler-macros.h (FALL_THROUGH): Define.
* src/*: Use it instead of `/* fall through */` comments.
* src/sdf/ftsdfcommon.h (FT_16D16, FT_26D6): Use 32-bit integers
instead of `FT_Fixed` for internal data types. `FT_Fixed` i.e.
`signed long` is 64-bit on some architectures.
* src/sdf/ftsdfrend.c (ft_sdf_render, ft_bsdf_render): Return `FT_Err_Ok` if
width or height is zero, since some glyphs do not generate visible bitmaps.
Fixes#1150.
* src/sdf/ftsdf.c (sdf_generate_bounding_box): Always check for a corner if
two distances (for different curves) are very close.
(sdf_conic_to): Check whether the conic curve can be treated as a line
(which happens if the control point coincides with any end point).
* src/sdf/ftsdf.c (split_sdf_cubic, split_sdf_shape): Add checks to figure
out the deviation of Bezier curves and stop splitting if the curve is flat
enough.
* src/sdf/ftsdfcommon.h (ONE_PIXEL): New macro.
Function `map_fixed_to_sdf` expects spread to be absolute
and not squared.
* src/sdf/ftbsdf.c (finalize_sdf): Pass absolute spread
while `map_fixed_to_sdf`.
* src/sdf/ftsdf.c (sdf_generate_bounding_box): Ditto.
* src/base/ftobjs.c (FT_Get_Paint): Operator has equivalent nested operands.
* src/bdf/bdflib.c (_bdf_add_property): Value stored to `fp` is never read.
* src/sdf/ftbsdf.c (bsdf_init_distance_map): Value stored to `pixel` is
never read.
* src/sdf/ftsdf.c (split_sdf_shape): Value stored to `error` is never read.
* src/sdf/ftbsdf.c (first_pass, second_pass): Fix range during forward pass.
Otherwise the index goes out of range for the last column.
Fixes issue #1077.
Do not generate SDF from bitmap if the `FT_GLYPH_OWN_BITMAP` flag is not
set. In some cases the bitmap buffer is freed but still points to a valid
address; to handle those cases check the flag before accessing the memory.
* src/sdf/ftsdfrend.c (ft_bsdf_render): Handle the above case.
Also, return an error message if the bitmap's rows/pitch is invalid,
otherwise `slot->buffer` might be assigned to some invalid memory location.
(ft_sdf_render): Same as above.
Plus, move the outline back to original state after rasterization and not if
any error occurs.
Signed-off-by: Anuj Verma <anujv@iitbhilai.ac.in>
* src/sdf/ftsdf.c: Include `ftbitmap.h`.
* src/sdf/ftsdfcommon.h: Move function bodies to `ftsdfcommon.c`.
Include `ftobjs.h` to get definitions of `FT_LOCAL` and friends.
* src/sdf/ftsdfcommon.c: New file.
* src/sdf/rules.mk, src/sdf/sdf.c: Updated.
Since 8-bits is enough to represent SDF data we no longer require
16-bits for this purpose. Also, we now normalize the output data
to use the entire 8-bit range efficiently. For example: if we use
3.5 format with a spread of 1 we basically only use the starting
5-bits. By normalizing we can use the entire 8-bit range.
* include/freetype/freetype.h (FT_Render_Mode): Updated description
for `FT_RENDER_MODE_SDF` regarding this change.
* include/freetype/ftimage.h (FT_Pixel_Mode): Removed
`FT_PIXEL_MODE_GRAY16` since no longer required.
* include/freetype/fttypes.h (FT_F6Dot10): Removed since no longer
required.
* src/sdf/ftsdfrend.c (ft_sdf_render, ft_bsdf_render): Allocate 8-bit
bitmap instead of 16-bit buffer.
* src/sdf/ftsdfcommon.h (map_fixed_to_sdf): Added function to convert
16.16 distance value to our desired format.
* src/sdf/ftsdf.c (sdf_generate_with_overlaps,
sdf_generate_bounding_box): Use the new `map_fixed_to_sdf` function
and also use 8-bit output buffer.
* src/sdf/ftbsdf.c (finalize_sdf): Output to a 8-bit buffer instead
of 16-bit buffer.
