Fixes#1172.
* src/sfnt/sfobjs.c (sfnt_load_face): Tag font as Multiple Masters font if
`fvar` is present; do not require other tables to be present.
* src/truetype/ttgxvar.c (tt_set_mm_blend): Allow for a missing 'gvar' table
when setting variation coordinates. However, if a 'gvar' table is actually
present, do perform a sanity check and fail on malformedness.
(TT_Get_MM_Var): Don't assume 'fvar' needs 'gvar' or 'CFF2 tables in all
cases, which is an overly tight check.
This follows similar code in `cff_slot_done`.
* src/base/ftobjs.c (ft_glyphslot_done), src/type1/t1objs.c
(T1_GlyphSlot_Done): Check `internal` pointer.
The Type1 problems was reported as
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=50057.
Any array index must be strictly less then the array size. Therefore,
we must reject indexes that are equal to the array size. Alternatively,
we should move the bounds check before the index decrement but that
would be confusing.
In addition, it is ok to decrement zero (.notdef) and get UINT_MAX,
which is then automatically rejected in the bounds check.
* src/pfr/pfrobjs.c (pfr_face_get_kerning): Fix the bounds checking.
When resizing the loader's points and contours, resize them to at least 1.5
times their current size. The code currently only reserves as much space as
is currently required, leading to O(n^2) runtime when adding points one at a
time.
This change does not attempt to ever shrink the loader's point and contour
storage since this was not attempted previously either. The 1.5 multiple
was chosen as a trade-off between potentially unused space and the runtime.
* src/base/ftgloader.c (FT_GlyphLoader_CheckPoints): Implement it.
Fixes#1173.
* src/sfnt/ttcolr.c (FT_PaintFormat_Internal): New enumeration values
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_SKEW`,
`FT_COLR_PAINTFORMAT_INTERNAL_SKEW_CENTER`, and
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_SKEW_CENTER`.
(read_paint): Handle new enumeration values.
* src/sfnt/ttcolr.c (FT_PaintFormat_Internal): New enumeration values
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_ROTATE` and
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_ROTATE_CENTER`.
(read_paint): Handle new enumeration values.
* src/sfnt/ttcolr.c (FT_PaintFormat_Internal): New enumeration value
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_TRANSLATE`.
(read_paint): Handle new enumeration value.
* src/sfnt/ttcolr.c (FT_PaintFormat_Internal): New enumeration value
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_TRANSFORM`.
(read_paint): Handle new enumeration value.
* src/sfnt/ttcolr.c (read_paint) [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Read and
apply deltas to radial, linear, and sweep gradient coordinates such as 'p0',
'p1', 'p2', 'center', 'radii', and 'angles'.
* include/freetype/ftcolor.h (FT_ColorStopIterator): Add field
`read_variable` to indicate whether a variation index base should be read.
* src/sfnt/ttcolr.c: (FT_PaintFormat_Internal): New enumerations
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_LINEAR_GRADIENT`
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_RADIAL_GRADIENT`, and
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_SWEEP_GRADIENT`.
(read_color_line): New parameter `read_variable`; update callers.
(read_paint): Handle new enumerations.
* src/sfnt/ttcolr.c (FT_PaintFormat_Internal_): New enumeration
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_SOLID`.
(get_deltas_for_var_index_base) [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: New
function to retrieve an array of delta values, which will be used for most
of 'COLR' v1 variation formats (in follow-up commits).
(read_paint): Add `face` parameter; update caller.
Handle `FT_COLR_PAINTFORMAT_INTERNAL_VAR_SOLID`.
* src/sfnt/ttcolr.c: Include `ttobjs.h` temporarily.
(VARIABLE_COLRV1_ENABLED): New temporary macro to detect whether variable
COLRv1 is enabled.
(Colr): New fields `var_store` and `delta_set_idx_map`.
(tt_face_load_colr, tt_face_free_colr) [VARIABLE_COLRV1_ENABLED]: Load and
free variation store data using the functions from the Multiple Masters
service.
If `FT_GlyphLoader_CreateExtra` returns an error (and a couple of other
places), `FT_GlyphLoader_CheckPoints` would propagate the error immediately,
rather than cleaning up the partially set up `FT_GlyphLoader`. As a
consequence, a subsequent attempt to create a glyph could result in a crash.
* src/base/ftgloadr.c (FT_GlyphLoader_CheckPoints): Ensure all the error
conditions exits are consistent, eventually calling `FT_GlyphLoader_Reset`.
This avoids regressing Blink layout tests and makes `FT_MulAdd_Fix` delta
retrieval implementation consistent with the previous implementation, which
used `FT_fixedToInt` and included rounding.
* src/base/ftcalc.c (FT_MulAdd_Fix): Implement it.
Also fix remaining `temp` initialization compilation issue.
Fixes#1169.
* include/freetype/internal/ftmmtypes.h (FT_ItemVarDelta): Make type
explicitly 32-bit.
* include/freetype/internal/services/svmm.h
(FT_Var_Get_Item_Delta_Func): Change return type to `FT_ItemVarDelta`
* truetype/ttgxvar.h (tt_var_get_item_delta): Change return type to
`FT_ItemVarDelta`.
* truetype/ttgxvar.c (tt_var_get_item_delta): Store scalars and deltas
to intermediate array, perform computation using new method
`FT_MulAddFix`.
This function, based on the code of `FT_MulFix`, uses 64-bit precision
internally for intermediate computations.
* include/freetype/internal/ftcalc.h, base/ftcalc.c (FT_MulAddFix):
Implement it.
This formalizes that the phantom points appended in the outline
do not increase its point count, nor are they tagged or included
in any additional contours. Only their coordinates are stored.
They are counted in the glyph zone, however.
* src/truetype/ttgxvar.c (TT_Vary_Apply_Glyph_Deltas): Infer `n_points`
from the outline size plus four phantom points.
* src/truetype/ttgxvar.h (TT_Vary_Apply_Glyph_Deltas): Remove this
argument.
* src/truetype/ttgload.c (tt_prepare_zone): Add phantom four.
(TT_Process_Simple_Glyph, load_truetype_glyph): Update all callers.
This moves phantom point and advance variation adjustment next to
calculations. The logic stays the same, HVAR and VVAR take priority.
* src/truetype/ttgload.c (load_truetype_glyph): Move it from here...
* src/truetype/ttgxvar.c (TT_Vary_Apply_Glyph_Deltas): ... to here
and check for HVAR and VVAR presence outside the main loop.
`FT_READ_LONG`, `FT_GET_LONG`, and related macros did not return
negative values when `long` is more than 32 bits. `FT_Stream_ReadULong`
would read four bytes into the LSB of an `FT_ULong` and return that.
Since this can never set the MSb of the `FT_ULong` when `FT_ULong` is
more than 32 bits the cast to `FT_Long` never resulted in a negative
value.
Fix this by modifying `FT_Stream_Read*` to return a type of the same
size as the bytes it is reading and changing the `FT_READ_*` and
`FT_GET_*` macros to cast to the same type returned by `FT_Stream_Read*`
but with the correctly signed type (instead of casting to what is
assumed to be the type of `var` which will happen automatically anyway).
There exist a few cases like with the `OFF3` variants where there isn't
generally a type with the correct size. `FT_PEEK_OFF3` works around this
loading the bytes into the three most significant bits and then doing a
signed shift down. `FT_NEXT_OFF3` also already worked correctly by
casting this signed value to another signed type. `FT_Stream_GetUOffset`
works correctly but one must be careful not to attempt to cast the
returned value to a signed type. Fortunately there is only
`FT_GET_UOFF3` and no `FT_GET_OFF3`.
All of these cases are handled correctly when reading values through
`FT_Stream_ReadFields` since it generically computes the signed value
through an `FT_Int32`. This change is essentially doing the same for
these macros.
* include/freetype/internal/ftstream.h (FT_NEXT_*, FT_GET_*, FT_READ*):
Update macros and return types to use fixed size types for fixed size
values.
* src/base/ftstream.c (FT_StreamGet*, FT_StreamRead*): Dito.
Issue: #1161
Dominik Röttsches