trying to fix TrueType rendering glitches

This commit is contained in:
David Turner 2003-03-14 07:31:35 +00:00
parent b280537b6d
commit 562731d487
2 changed files with 21 additions and 9 deletions

View File

@ -1,3 +1,8 @@
2003-03-14 David Turner <david@freetype.org>
* src/truetype/ttdriver.c: fixing the small TrueType native rendering
glitches, they came from a small rounding error.
2003-03-13 David Turner <david@freetype.org>
* src/base/ftdbgmem.c, docs/DEBUG.TXT: added new environment variables

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@ -193,6 +193,7 @@
FT_Size_Metrics* metrics = &size->root.metrics;
FT_Size_Metrics* metrics2 = &size->metrics;
TT_Face face = (TT_Face)size->root.face;
FT_Long dim_x, dim_y;
*metrics2 = *metrics;
@ -203,19 +204,25 @@
/* */
if ( ( face->header.Flags & 8 ) != 0 )
{
FT_Long dim_x, dim_y;
/* we need to use rounding in the following computations. Otherwise,
* the resulting hinted outlines will be very slightly distorted
*/
dim_x = ( char_width * horz_resolution + 36 ) / 72;
dim_y = ( char_height * vert_resolution + 36 ) / 72;
metrics2->x_ppem = (FT_UShort)( dim_x >> 6 );
metrics2->y_ppem = (FT_UShort)( dim_y >> 6 );
metrics2->x_scale = FT_DivFix( dim_x, face->root.units_per_EM );
metrics2->y_scale = FT_DivFix( dim_y, face->root.units_per_EM );
dim_x = ( ( ( char_width * horz_resolution ) / 72 ) + 32 ) & -64;
dim_y = ( ( ( char_height * vert_resolution ) / 72 ) + 32 ) & -64;
}
else
{
dim_x = ( ( char_width * horz_resolution + 36 ) / 72 );
dim_y = ( ( char_height * vert_resolution + 36 ) / 72 );
}
/* we only modify "metrics2", not "metrics", so these changes have */
/* no effect on the result of the auto-hinter when it is used */
/* */
metrics2->x_ppem = (FT_UShort)( dim_x >> 6 );
metrics2->y_ppem = (FT_UShort)( dim_y >> 6 );
metrics2->x_scale = FT_DivFix( dim_x, face->root.units_per_EM );
metrics2->y_scale = FT_DivFix( dim_y, face->root.units_per_EM );
size->ttmetrics.valid = FALSE;
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS