minhngoc25a
/
freetype2
mirror of git://git.savannah.gnu.org/freetype/freetype2.git
2
1
Fork 2
Code Issues 4 Releases Wiki Activity

[base] Build outlines in amortized constant time. 

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.
This commit is contained in:
Ben Wagner 2022-07-22 16:22:19 -04:00 committed by Werner Lemberg
parent 275b116b40
commit 0417e54bec
1 changed files with 15 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/base/ftgloadr.c
View File

@ -212,7 +212,7 @@
FT_Outline* current = &loader->current.outline;
FT_Bool adjust = 0;
FT_UInt new_max, old_max;
FT_UInt new_max, old_max, min_new_max;
error = FT_GlyphLoader_CreateExtra( loader );
@ -226,14 +226,19 @@
if ( new_max > old_max )
{
new_max = FT_PAD_CEIL( new_max, 8 );
if ( new_max > FT_OUTLINE_POINTS_MAX )
{
error = FT_THROW( Array_Too_Large );
goto Exit;
}
min_new_max = old_max + ( old_max >> 1 );
if ( new_max < min_new_max )
new_max = min_new_max;
new_max = FT_PAD_CEIL( new_max, 8 );
if ( new_max > FT_OUTLINE_POINTS_MAX )
new_max = FT_OUTLINE_POINTS_MAX;
if ( FT_RENEW_ARRAY( base->points, old_max, new_max ) ||
FT_RENEW_ARRAY( base->tags, old_max, new_max ) )
goto Exit;
@ -265,14 +270,19 @@
n_contours;
if ( new_max > old_max )
{
new_max = FT_PAD_CEIL( new_max, 4 );
if ( new_max > FT_OUTLINE_CONTOURS_MAX )
{
error = FT_THROW( Array_Too_Large );
goto Exit;
}
min_new_max = old_max + ( old_max >> 1 );
if ( new_max < min_new_max )
new_max = min_new_max;
new_max = FT_PAD_CEIL( new_max, 4 );
if ( new_max > FT_OUTLINE_CONTOURS_MAX )
new_max = FT_OUTLINE_CONTOURS_MAX;
if ( FT_RENEW_ARRAY( base->contours, old_max, new_max ) )
goto Exit;