Re: [PATCH v2] msacm32: Rewrite PCM conversion functions.

[Andrew Eikum]

On Tue, Jun 13, 2017 at 04:35:52PM -0500, Zebediah Figura wrote:
> +#define PCM_CVT_CHANGE_FUNC(name)	static void name(DWORD srcRate, const unsigned char *src, DWORD *nsrc, \
> -
> 					 DWORD dstRate, unsigned char *dst, DWORD *ndst) \
> - { \
> - DWORD error = srcRate / 2; \
> - DWORD srcUsed = 0, dstUsed = 0; \
> - for (srcUsed = 0; srcUsed < *nsrc; srcUsed++) { \
> -
>    error += dstRate; \
> -
>    while (error > srcRate) { \
> -
>        if (dstUsed == *ndst) { \
> -
>            *nsrc = srcUsed; \
> -
>            *ndst = dstUsed; \
> -
>            return; \
> -
>        }
> -
> -
>        /* conversion is done here */
> -
>
> +#define PCM_CVT_CHANGE_FUNC_END(offset)	\
> -
>        dstUsed++; \
> -
>        error -= srcRate; \
> -
>    } \
> -
>    src += offset; \
> - } \
> - *nsrc = srcUsed; \
> - *ndst = dstUsed; \
>
> +}
> -
>
> +PCM_CVT_CHANGE_FUNC(cvtSS88C)
> - *dst++ = src[0];
> - *dst++ = src[1];
>
> +PCM_CVT_CHANGE_FUNC_END(2)
> -

I really dislike complicated preprocessor tricks. Can't this be done
in a similar way with real functions? If not, I'd rather have the
copy-pasted code than these difficult macros.

Andrew