[Mesa-dev] [PATCH 2/2] mesa: fix unpack_ARGB1555_REV()

[Michel Dänzer]

On Mit, 2011-11-30 at 20:36 -0700, Brian Paul wrote: 
> We weren't doing the necessary byte swap.

I just stumbled over this as well.


> ---
>  src/mesa/main/format_unpack.c |    9 +++++----
>  1 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/src/mesa/main/format_unpack.c b/src/mesa/main/format_unpack.c
> index 4b4ee6b..fc0db34 100644
> --- a/src/mesa/main/format_unpack.c
> +++ b/src/mesa/main/format_unpack.c
> @@ -275,10 +275,11 @@ unpack_ARGB1555_REV(const void *src, GLfloat dst[][4], GLuint n)
>     const GLushort *s = ((const GLushort *) src);
>     GLuint i;
>     for (i = 0; i < n; i++) {
> -      dst[i][RCOMP] = UBYTE_TO_FLOAT( ((s[i] >>  7) & 0xf8) | ((s[i] >> 12) & 0x7) );
> -      dst[i][GCOMP] = UBYTE_TO_FLOAT( ((s[i] >>  2) & 0xf8) | ((s[i] >>  7) & 0x7) );
> -      dst[i][BCOMP] = UBYTE_TO_FLOAT( ((s[i] <<  3) & 0xf8) | ((s[i] >>  2) & 0x7) );
> -      dst[i][ACOMP] = UBYTE_TO_FLOAT( ((s[i] >> 15) & 0x01) * 255 );
> +      GLushort tmp = (s[i] << 8) | (s[i] >> 8); /* byteswap */

A BSWAP16() macro might be nice for this, but I wouldn't let that hold
up this fix.

> +      dst[i][RCOMP] = UBYTE_TO_FLOAT( ((tmp >>  7) & 0xf8) | ((tmp >> 12) & 0x7) );
> +      dst[i][GCOMP] = UBYTE_TO_FLOAT( ((tmp >>  2) & 0xf8) | ((tmp >>  7) & 0x7) );
> +      dst[i][BCOMP] = UBYTE_TO_FLOAT( ((tmp <<  3) & 0xf8) | ((tmp >>  2) & 0x7) );

Don't these lines need to be changed to be the same as in
unpack_ARGB1555()?


-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer