The optional 'COLR' v1 glyph-specific clip box helps upstream graphics
libraries allocate a sufficiently large bitmap for a glyph without having to
traverse the glyph graph for that. See
https://github.com/googlefonts/colr-gradients-spec/issues/251
for background on the introduction of this specification change.
* include/freetype/ftcolor.h (FT_ClipBox): New structure.
(FT_Get_Color_Glyph_ClipBox): New function declaration.
* include/freetype/internal/sfnt.h (TT_Get_Color_Glyph_ClipBox_Func):
New function type.
(SFNT_Interface, FT_DEFINE_SFNT_INTERFACE): Use it.
* src/base/ftobjs.c (FT_Get_Color_Glyph_ClipBox): New function to link API
with SFNT implementation.
* src/sfnt/sfdriver.c (sfnt_interface): Updated.
* src/sfnt/ttcolr.c (Colr): New field `clip_list`.
(tt_face_load_colr): Parse global clip list offset.
(tt_face_get_color_glyph_clipbox): New function to find the clip box for a
glyph id from the clip list array.
* src/sfnt/ttcolr.h: Updated.
* src/sfnt/ttcolr.c (read_paint): PaintSweepGradient follows other
spec changes and now has the angles specified as F2DOT14, reflect
that in the implementation.
* include/freetype/ftcolor.h (FT_PaintSweepGradient): Update
documentation.
* src/sfnt/ttcolr.c (read_paint): Implement spec change where
affine transform matrix is now referenced by offset instead of
being placed inline in the PaintTransform table.
* src/sfnt/ttcolr.c (read_paint): Implement spec changes around
PaintSkew, PaintSkewAroundCenter. Update parsing to read shorter
values as changed in the spec.
* include/freetype/ftcolor.h (FT_PaintSkew): Update documentation.
* src/sfnt/ttcolr.c (read_paint): Implement spec change where
PaintRotate and PaintRotateAroundCenter were split for a more
compact format definition. Update parsing to read shorter values
as changed in the spec.
* include/freetype/ftcolor.h (FT_PaintRotate): Update documentation.
'COLR' v1 fonts do not necessarily need to have a layer list; for
this reason, 'fontTools' recently started generating fonts in a way
that drops the layer list if there are no layers in it. This
results in the layer list offset becoming zero, which FreeType
treated as an invalid table. Fix that and handle the case for layer
list offset being 0. This slightly changes how we need to calculate
the starting offset for paints.
* src/sfnt/ttcolr.c (tt_face_load_colr): Handle case of layer list
offset being zero without outright rejecting table.
Paint tables can appear before the `base_glyphs_v1` offset if the
font is produced with the layer list before the base glyph list. In
this case paint tables can occur after the layer list but before the
base glyph list. Checks in the 'COLR' v1 code were rejecting fonts
with this layout. Improve these checks by calculating a minimum
offset after which paint tables can occur and use that in safety
checks.
* src/sfnt/ttcolr.c (Colr, tt_face_load_colr): Declare
`paint_start_v1` and calculate that as the minimum of the end of
layer list and base glyph list.
(get_child_table_pointer, read_paint, tt_face_get_paint_layers):
Use that in safety checks.
* include/freetype/ftcolor.h (FT_PaintTransformed, FT_PaintFormat,
FT_COLR_Paint): Do it to make it harmonize with other names such as
'PaintTranslate'.
* src/sfnt/ttcolr.c (read_paint, tt_face_get_paint): Ditto.
* src/sfnt/ttcolr.c (tt_face_get_paint_layers): In addition to the
existing sanity checks, ensure that the pointer to the layer to be
read is within the 'COLR' v1 table.
* src/sfnt/ttcolr.c (tt_face_get_paint_layers): Do not output
layer pointer to iterator if it is outside the 'COLR' table.
(read_paint): Do not attempt to read layers that are outside the
table.
* src/sfnt/ttcolr.c (get_child_table_pointer): New function to fetch
child table pointer early for all paint formats that compute a child
table pointer.
(read_color_line, read_paint): Updated.
(tt_face_get_colorline_stops): Check `colr->table`.
* freetype.h (FT_PaintFormat): Update paint format identifiers after
a specification change. The specification was updated to have
sibling formats, variable and non-variable variants for each.
Reflect that here.
* sfnt/ttcolr.c (read_paint): Remove parsing of variable indices as
the non-variable formats no longer have them.
* include/freetype/freetype.h (FT_Get_Color_Glyph_Paint):
Additional function argument root_transform to control whether
root transform should be returned.
(FT_OpaquePaint): Additional tracking field to denote whether
root transform is to be returned.
* include/freetype/internal/sfnt.h
(TT_Get_Color_Glyph_Paint_Func): Propagate additional argument.
* src/base/ftobjs.c (FT_Get_Color_Glyph_Paint): Ditto.
* src/sfnt/ttcolr.c (tt_face_get_colr_glyph_paint): Return root
transform reflecting the size and tranform configured on
FT_Face.
(read_paint): Initialize and track status of insert_root_transform
flag.
* sfnt/ttcolr.c (tt_face_get_colr_glyph_paint,
tt_face_get_colorline_stops, tt_face_get_paint): Additional checks
for whether colr table is present. Prevents crashes when these
methods are called on non-COLR fonts.
* src/sfnt/ttcolr.c (tt_face_get_paint_layers): New function to get
the layers of a `PaintColrLayers` table in the font, using an
`FT_LayerIterator` from an `FT_PaintColrLayers` object retrieved via
`tt_face_get_paint`.
* src/sfnt/ttcolr.h: Updated.
* src/sfnt/ttcolr.c (tt_face_get_colorline_stops): New function to
return the current `FT_ColorStop` object from `FT_ColorStopIterator`.
Also increment the iterator.
* src/sfnt/ttcolr.h: Updated.
* src/sfnt/ttcolr.c (tt_face_get_paint): New function to resolve an
`FT_OpaquePaint` paint reference into an `FT_COLR_Paint` object of a
certain format, which contains the detailed information stored in a
paint of the respective format.
(read_paint): New function to provide the format specific parsing
and to populate the data members of each specific `FT_COLR_Paint`
subtype.
(read_color_line): New function to parse retrieved color line
information into an `FT_ColorLine` object, which has information
about the color line extend mode as well as an
`FT_ColorStopIterator` object.
* src/sfnt/ttcolr.h: Updated.
* src/sfnt/ttcolr.c (BaseGlyphV1Record): New structure.
(tt_face_load_colr): Handle version 1 table header.
(find_base_glyph_v1_record): New auxiliary function.
(tt_face_get_colr_glyph_paint): New function to find the root
`FT_OpaquePaint` object for a given glyph ID.
* src/sfnt/ttcolr.h: Updated.
We no longer have to take care of the 8.3 file name limit; this
allows us (a) to introduce longer, meaningful file names, and (b) to
avoid macro names in `#include' lines altogether since some
compilers (most notably Visual C++) doesn't support this properly.
*/*: Replace
#include FOO_H
with
#include <freetype/foo.h>
or something similar. Also update the documentation.
Reported by Alexei.
* src/sfnt/ttcolr.c (tt_face_get_colr_layer): Return immediately if
`colr' is NULL.
* src/sfnt/ttcpal.c (tt_face_palette_set): Return immediately, if
`cpal' is NULL.
Werner Lemberg