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Fix fvi sqrt

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A previous optimization restructured the code in a way that lost the
>>16 normally applied to the product of two fix values.

Fixes: 707b69220d ("Skip sqrt,square in check_vector_to_sphere_1")
This commit is contained in:
Kp 2016-01-03 20:21:36 +00:00
parent 0a2ef79242
commit 0c0dff9def
1 changed files with 3 additions and 1 deletions
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4
similar/main/fvi.cpp
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@ -442,7 +442,9 @@ static vm_distance_squared check_vector_to_sphere_1(vms_vector &intp,const vms_v
const vm_distance_squared sphere_rad_squared{sphere_rad64 * sphere_rad64};
if (dist2 < sphere_rad_squared)
{
const auto shorten = fix_sqrt(static_cast<fix64>(sphere_rad_squared) - static_cast<fix64>(dist2));
const fix64 delta_squared = static_cast<fix64>(sphere_rad_squared) - static_cast<fix64>(dist2);
const fix delta = static_cast<fix>(delta_squared >> 16);
const auto shorten = fix_sqrt(delta);
const auto int_dist = w_dist-shorten;
if (int_dist > mag_d || int_dist < 0) //past one or the other end of vector, which means we're inside