rgraves
/
freetype2
forked from minhngoc25a/freetype2
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[base] Clean up bitmap conversion. 

* src/base/ftbitmap.c (ft_gray_for_premultiplied_srgb_bgra): Use
appropriate FT_DivFix and remove superfluous upscaling.
This commit is contained in:
Alexei Podtelezhnikov 2014-07-11 22:40:34 -04:00
parent 2f52df4a0d
commit 35576bf067
2 changed files with 12 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
ChangeLog
View File

@ -1,3 +1,10 @@
2014-07-11 Alexei Podtelezhnikov <apodtele@gmail.com>
[base] Clean up bitmap conversion.
* src/base/ftbitmap.c (ft_gray_for_premultiplied_srgb_bgra): Use
appropriate FT_DivFix and remove superfluous upscaling.
2014-07-04 Alexei Podtelezhnikov <apodtele@gmail.com>
[base] Small optimization of the ancient code.

11
src/base/ftbitmap.c
View File

@ -401,10 +401,9 @@
*/
/* Undo premultification, get the number in a 16.16 form. */
b = FT_MulDiv( b, 65536, a );
g = FT_MulDiv( g, 65536, a );
r = FT_MulDiv( r, 65536, a );
a = a * 256;
b = FT_DivFix( b, a );
g = FT_DivFix( g, a );
r = FT_DivFix( r, a );
/* Apply gamma of 2.0 instead of 2.2. */
b = FT_MulFix( b, b );
@ -425,10 +424,10 @@
* - If alpha is zero and luminosity is zero, we want 255.
* - If alpha is zero and luminosity is one, we want 0.
*
* So the formula is a * (1 - l).
* So the formula is a * (1 - l) = a - l * a.
*/
return (FT_Byte)( FT_MulFix( 65535 - l, a ) >> 8 );
return a - (FT_Byte)FT_MulFix( l, a );
}