RE: [Flightgear-devel] New texture draw method

[Norman V. <nh...@ca...>]

Julian Foad writes:
>
>Norman Vine wrote:
>> 
>> To exploit this means we need to determine the furthest
>> point in each tile from the tile's center point and then
>> scale it to be 2**23
>
>No.  You are thinking of integer (or maybe fixed-point) 
>arithmetic.  We are using floating-point arithmetic, which 
>does the scaling automatically so that there are 23 bits of 
>precision whatever the magnitude of numbers.  That's what the 
>8-bit exponent field does.

YES I understand this.

However this 23 bits of precision and another 23 bits of precision
are not necessarily the same thing !  
Only by scaling all the numbers to occupy the same range 
< I could have used 1.0 > will the 'resolution' of the floating point 
format of two numbers be identical and thus have the same property 
of repeatability as that of fixed or integer representation.

I agree that this differentation between 'precision' and 'resolution'
of floating point representation is an obscure point that I have a hard 
time expressing.

but as I said in my earlier post
"Now all we need is for someone to test this"

FWIW
I allready have in other similar problems :-)

Cheers

Norman