[Mesa-dev] [PATCH 2/2] mesa: simplify code setting boolean uniforms

[Brian Paul]

On 03/19/2015 09:26 AM, Matt Turner wrote:
> On Thu, Mar 19, 2015 at 7:53 AM, Brian Paul <brianp at vmware.com> wrote:
>> src[i] is a union.  Just check if src[i].u is non-zero to choose
>> between ctx->Const.UniformBooleanTrue and zero.
>> ---
>>   src/mesa/main/uniform_query.cpp | 6 +-----
>>   1 file changed, 1 insertion(+), 5 deletions(-)
>>
>> diff --git a/src/mesa/main/uniform_query.cpp b/src/mesa/main/uniform_query.cpp
>> index 2ab5528..9ce45ee 100644
>> --- a/src/mesa/main/uniform_query.cpp
>> +++ b/src/mesa/main/uniform_query.cpp
>> @@ -785,11 +785,7 @@ _mesa_uniform(struct gl_context *ctx, struct gl_shader_program *shProg,
>>         const unsigned elems = components * count;
>>
>>         for (unsigned i = 0; i < elems; i++) {
>> -        if (basicType == GLSL_TYPE_FLOAT) {
>> -            dst[i].i = src[i].f != 0.0f ? ctx->Const.UniformBooleanTrue : 0;
>
> I guess this also handles -0.0f as well, which isn't 0u. I'm not sure
> if that's desired behavior or not?

Good question.  But it seems a little far-fetched that a real app would 
rely on glUniform1f(loc, -0.0) to set a boolean to false.

I don't see any spec language about this case.

What do you think?

-Brian

>
>> -        } else {
>> -            dst[i].i = src[i].i != 0    ? ctx->Const.UniformBooleanTrue : 0;
>> -        }
>> +         dst[i].i = src[i].u ? ctx->Const.UniformBooleanTrue : 0;
>>         }
>>      }
>>
>> --
>> 1.9.1