[try 2] [1/3] dsound: Add support for 32-bit IEEE float buffers

[Owen Rudge]

On 08/09/2010 15:41, Chris Robinson wrote:
> Is it safe to call le32 on a float? Especially one that's going to be used
> more? If the system is big-endian, the float/integer will need to be in big-
> endian to be processed.

The raw data should be in a little-endian format. But you're right that 
it would probably have to be converted to big-endian to be processed, 
and then converted back to be stored.

> I'm also not sure that the conversion math is correct. In this case, -1.0
> would get converted to -126.5 (or -32766.5, etc), instead of -128 (or -32768,
> etc). As well, I don't think the rules for converting a negative float value
> to an unsigned integer are that straight forward. I seem to recall mention
> that some systems will actually give 0 in that case.

I realise now that I actually made a mistake in using WORD, DWORD, etc, 
as - with the exception of 8-bit audio - all of the destination buffers 
are signed. So hopefully we shouldn't have an issue with negative values 
being multiplied incorrectly.

I'll have a poke around and produce a revised patch.

Cheers,

-- 
Owen Rudge
http://www.owenrudge.net/