| [AD] bug in create_trans_table() |
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I committed the attached patch, fixing a bug that I introduced when I
supposedly improved accuracy in create_trans_table() the other month.
The function has to interpolate between two colors, e.g.,
r = (a*r0 + (1-a)*r1) / max
The problem was that the two terms were calculated separately as
a*r0/max and (1-a)*r1/max, and then added. When I made the division be
rounded, both terms were sometimes rounded upwards so summing them
caused overflow. The new version is more robust because it postpones the
division until after summing a*r0 and (1-a)*r1.
Sven