[truetype/GX] Read stream more aggressively.

With ample checks against the table size, we should be able to use
macros without the limit checks and functional calls.

* src/truetype/ttgxvar.c (ft_var_readpacked{points,deltas}):
Use FT_NEXT_* instead of FT_GET_*.
This commit is contained in:
Alexei Podtelezhnikov 2024-07-29 20:26:00 -04:00
parent 3f8edd234d
commit 104f85448d

View File

@ -152,6 +152,7 @@
FT_UInt runcnt;
FT_UInt i, j;
FT_UShort first;
FT_Byte* p;
FT_Memory memory = stream->memory;
FT_Error error;
@ -183,21 +184,22 @@
*point_cnt = n;
p = stream->cursor;
first = 0;
i = 0;
while ( i < n )
{
runcnt = FT_GET_BYTE();
runcnt = FT_NEXT_BYTE( p );
if ( runcnt & GX_PT_POINTS_ARE_WORDS )
{
runcnt &= GX_PT_POINT_RUN_COUNT_MASK;
first += FT_GET_USHORT();
first += FT_NEXT_USHORT( p );
points[i++] = first;
/* first point not included in run count */
for ( j = 0; j < runcnt; j++ )
{
first += FT_GET_USHORT();
first += FT_NEXT_USHORT( p );
points[i++] = first;
if ( i >= n )
break;
@ -205,12 +207,12 @@
}
else
{
first += FT_GET_BYTE();
first += FT_NEXT_BYTE( p );
points[i++] = first;
for ( j = 0; j < runcnt; j++ )
{
first += FT_GET_BYTE();
first += FT_NEXT_BYTE( p );
points[i++] = first;
if ( i >= n )
break;
@ -218,6 +220,8 @@
}
}
stream->cursor = p;
return points;
}
@ -265,6 +269,7 @@
FT_UInt runcnt, cnt;
FT_UInt i, j;
FT_UInt bytes_used;
FT_Byte* p;
FT_Memory memory = stream->memory;
FT_Error error;
@ -272,12 +277,13 @@
if ( FT_QNEW_ARRAY( deltas, delta_cnt ) )
return NULL;
p = stream->cursor;
i = 0;
bytes_used = 0;
while ( i < delta_cnt && bytes_used < size )
{
runcnt = FT_GET_BYTE();
runcnt = FT_NEXT_BYTE( p );
cnt = runcnt & GX_DT_DELTA_RUN_COUNT_MASK;
bytes_used++;
@ -300,7 +306,7 @@
}
for ( j = 0; j <= cnt && i < delta_cnt; j++ )
deltas[i++] = FT_intToFixed( FT_GET_SHORT() );
deltas[i++] = FT_intToFixed( FT_NEXT_SHORT( p ) );
}
else
{
@ -314,7 +320,7 @@
}
for ( j = 0; j <= cnt && i < delta_cnt; j++ )
deltas[i++] = FT_intToFixed( FT_GET_CHAR() );
deltas[i++] = FT_intToFixed( FT_NEXT_CHAR( p ) );
}
if ( j <= cnt )
@ -331,6 +337,8 @@
goto Fail;
}
stream->cursor = p;
return deltas;
Fail: