[Mesa-dev] [PATCH] mesa: fix UNCLAMPED_FLOAT_TO_UBYTE() macro for MSVC

[Brian Paul]

On 09/10/2014 12:02 PM, Ian Romanick wrote:
> On 09/10/2014 07:21 AM, Brian Paul wrote:
>> MSVC replaces the "F" in "255.0F" with the macro argument which leads
>> to an error.  s/F/FLT/ to avoid that.
>>
>> It turns out we weren't using this macro at all on MSVC until the
>> recent "mesa: Drop USE_IEEE define." change.
>> ---
>>   src/mesa/main/macros.h |    9 +++++----
>>   1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/src/mesa/main/macros.h b/src/mesa/main/macros.h
>> index 7b6148d..b3e214f 100644
>> --- a/src/mesa/main/macros.h
>> +++ b/src/mesa/main/macros.h
>> @@ -144,23 +144,24 @@ extern GLfloat _mesa_ubyte_to_float_color_tab[256];
>>   /* This function/macro is sensitive to precision.  Test very carefully
>>    * if you change it!
>>    */
>> -#define UNCLAMPED_FLOAT_TO_UBYTE(UB, F)					\
>> +#define UNCLAMPED_FLOAT_TO_UBYTE(UB, FLT)				\
>>           do {								\
>>              fi_type __tmp;						\
>> -           __tmp.f = (F);						\
>> +           __tmp.f = (FLT);						\
>>              if (__tmp.i < 0)						\
>>                 UB = (GLubyte) 0;						\
>>              else if (__tmp.i >= IEEE_ONE)				\
>>                 UB = (GLubyte) 255;					\
>>              else {							\
>>                 __tmp.f = __tmp.f * (255.0F/256.0F) + 32768.0F;		\
>> +              __tmp.f = __tmp.f * (float) ((255.0/256.0) + 32768.0);     \
>
> Something looks fishy here.  Do you need the addition?  Or should the
> previous line be removed?

Oops, that's a left-over from another change I tried.  Thanks for 
catching that.

>
>>                 UB = (GLubyte) __tmp.i;					\
>>              }								\
>>           } while (0)
>> -#define CLAMPED_FLOAT_TO_UBYTE(UB, F)					\
>> +#define CLAMPED_FLOAT_TO_UBYTE(UB, FLT)					\
>>           do {								\
>>              fi_type __tmp;						\
>> -           __tmp.f = (F) * (255.0F/256.0F) + 32768.0F;			\
>> +           __tmp.f = (FLT) * (255.0F/256.0F) + 32768.0F;		\
>>              UB = (GLubyte) __tmp.i;					\
>>           } while (0)
>>   #else
>>
>