cogl-texture: Avoid premult conversion if the dst format has no alpha

The _cogl_texture_needs_premult_conversion function was already
checking whether the source format had an alpha channel before
returning TRUE, but it also doesn't make sense to do the premult
conversion if the destination format has no alpha. This patch adds
that check in too.
This commit is contained in:
Neil Roberts 2010-06-01 13:32:57 +01:00
parent 31b5beb2c0
commit 6ad668c76b

View File

@ -125,8 +125,9 @@ static gboolean
_cogl_texture_needs_premult_conversion (CoglPixelFormat src_format,
CoglPixelFormat dst_format)
{
return ((src_format & COGL_A_BIT) &&
return ((src_format & dst_format & COGL_A_BIT) &&
src_format != COGL_PIXEL_FORMAT_A_8 &&
dst_format != COGL_PIXEL_FORMAT_A_8 &&
(src_format & COGL_PREMULT_BIT) !=
(dst_format & COGL_PREMULT_BIT));
}