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# Fixed numbers in intybasic v1.2.9

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Apart the bug spotted elsewhere that leads this kind of expressions #ex(0) = -1.0+.#ex(0) to fail, it seems that it is missing a proper support to multiplications/divisions.

I was trying to multiply a fixed point number by a constant, but due to the fact that the fractional part in in the high byte, normal multiplication fails...

Is there a dedicated multiplication for 8.8 fixed point numbers ? BTW what is the reason for this inversion (high/low byte)?

Am I missing something or the support for fixed point numbers is just immature in v1.2.9 ?

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Apart the bug spotted elsewhere that leads this kind of expressions #ex(0) = -1.0+.#ex(0) to fail, it seems that it is missing a proper support to multiplications/divisions.

I was trying to multiply a fixed point number by a constant, but due to the fact that the fractional part in in the high byte, normal multiplication fails...

Is there a dedicated multiplication for 8.8 fixed point numbers ? BTW what is the reason for this inversion (high/low byte)?

Am I missing something or the support for fixed point numbers is just immature in v1.2.9 ?

Perhaps the multiplication by constant uses the macro Joe Z. and I worked on which assumed 16-bit integers.

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I'm afraid I forgot completely about the fixed point number support in IntyBASIC.

Supposedly it would have helped to integrate fractions to ease writing of Asteroids-like game but the support come with far too many bugs because it was too early.

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Well, once you fix addition and subtraction by constants, product of two 8.8 numbers is just a 32 bit multiplication where you keep the upper 16 bits as result.

You need

+.

-.

*.

/.

But, why the up/down bytes inversion? Does it help somehow?

Edited by artrag
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Actually if you keep the same convention used for usual integers you should end up with this

+. = +

-. = -

/. = /

*. = * on 32 bits >>16

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