[Mesa-dev] [PATCH 02/29] mesa: Set normalized=true for float array formats.

[Jason Ekstrand]

On Thu, Nov 20, 2014 at 11:33 PM, Iago Toral <itoral at igalia.com> wrote:

> On Thu, 2014-11-20 at 10:40 -0800, Jason Ekstrand wrote:
> >
> >
> > On Wed, Nov 19, 2014 at 11:24 PM, Iago Toral <itoral at igalia.com>
> > wrote:
> >         Hi Jason,
> >
> >         we discussed this some weeks ago actually, the detailed
> >         explanation is
> >         here:
> >         https://bugs.freedesktop.org/show_bug.cgi?id=84566#c5
> >
> >         the short answer is that this is necessary because there is a
> >         normalized
> >         parameter to _mesa_swizzle_and_convert, and when we deal with
> >         float
> >         types we want to set this to true.
> >
> >
> > I went back and looked at that and I thought the result of the
> > discussion was to fix the assert in mesa_format_convert and compute
> > the normalized parameter correctly.  After that, I thought this
> > shouldn't be strictly needed.  It may still be a good idea for
> > consistency, but I want to make sure we're doing the right thing in
> > mesa_format_convert
>
> With this patch, in mesa_format_convert we simply take the "normalized"
> value for mesa_swizzle_and_convert from the normalized field of the
> array format, since we make sure that all float array formats will have
> this set to 1.
>
> Without this patch we would have to do something like this (pseudocode)
> in mesa_format_convert:
>
> normalized = array_format.normalized || array_format.type == FLOAT ||
>              array_format.type == HALF_FLOAT;
>
> We can do it either way, I just think that the latter is a bit
> inconsistent because:
>
> a) why would we want to generate array formats with a normalized setting
> of 0 if we then want to set normalized to true when they are involved?.
>
> b) Other parts of Mesa check if a format is normalized by doing
> normalized = !_mesa_is_enum_format_integer(srcFormat), which will make
> float types normalized.
>
> Iago
>

That's fine.  I just wanted to make sure that this wasn't hiding some
fundamental breakage of the mesa_format_convert function.
--Jason


>
> >         Iago
> >
> >         On Wed, 2014-11-19 at 11:31 -0800, Jason Ekstrand wrote:
> >         > I'm not sure what I think about this.  Does it make a
> >         functional
> >         > change other than consistancy?
> >         >
> >         > --Jason
> >         >
> >         >
> >         > On Tue, Nov 18, 2014 at 1:23 AM, Iago Toral Quiroga
> >         > <itoral at igalia.com> wrote:
> >         >         In order to check if a format is normalized Mesa
> >         does
> >         >         something like this:
> >         >         normalized = !
> >         _mesa_is_enum_format_integer(srcFormat);
> >         >
> >         >         So all float types will set normalized to true.
> >         Since our
> >         >         mesa_array_format
> >         >         includes a normalized flag for each type we want to
> >         make it
> >         >         consistent with
> >         >         this.
> >         >         ---
> >         >          src/mesa/main/format_info.py | 3 ++-
> >         >          src/mesa/main/format_utils.c | 2 +-
> >         >          2 files changed, 3 insertions(+), 2 deletions(-)
> >         >
> >         >         diff --git a/src/mesa/main/format_info.py
> >         >         b/src/mesa/main/format_info.py
> >         >         index 315767d..d4bc276 100644
> >         >         --- a/src/mesa/main/format_info.py
> >         >         +++ b/src/mesa/main/format_info.py
> >         >         @@ -220,9 +220,10 @@ for fmat in formats:
> >         >             print '      {{ {0} }},'.format(',
> >         '.join(map(str,
> >         >         fmat.swizzle)))
> >         >             if fmat.is_array() and fmat.colorspace in
> >         ('rgb', 'srgb'):
> >         >                chan = fmat.array_element()
> >         >         +      norm = chan.norm or chan.type == parser.FLOAT
> >         >                print '      {{{{ {0} }}}},'.format(',
> >         '.join([
> >         >                   get_array_format_datatype(chan),
> >         >         -         str(int(chan.norm)),
> >         >         +         str(int(norm)),
> >         >                   str(len(fmat.channels)),
> >         >                   str(fmat.swizzle[0]),
> >         >                   str(fmat.swizzle[1]),
> >         >         diff --git a/src/mesa/main/format_utils.c
> >         >         b/src/mesa/main/format_utils.c
> >         >         index c3815cb..1d65f2b 100644
> >         >         --- a/src/mesa/main/format_utils.c
> >         >         +++ b/src/mesa/main/format_utils.c
> >         >         @@ -30,7 +30,7 @@
> >         >
> >         >          mesa_array_format RGBA8888_FLOAT = {{
> >         >             MESA_ARRAY_FORMAT_TYPE_FLOAT,
> >         >         -   0,
> >         >         +   1,
> >         >             4,
> >         >             0, 1, 2, 3,
> >         >             0, 1
> >         >         --
> >         >         1.9.1
> >         >
> >         >         _______________________________________________
> >         >         mesa-dev mailing list
> >         >         mesa-dev at lists.freedesktop.org
> >         >
> >          http://lists.freedesktop.org/mailman/listinfo/mesa-dev
> >         >
> >         >
> >
> >
> >
> >
> >
>
>
>
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