[Mesa-dev] [PATCH] glsl: Use M_PI_* macros.

[Matt Turner]

On Mon, Apr 7, 2014 at 10:28 AM, Aaron Watry <awatry at gmail.com> wrote:
> On Mon, Apr 7, 2014 at 12:19 PM, Matt Turner <mattst88 at gmail.com> wrote:
>> Notice our multiple values for M_PI_2, which rounded ...32 up to
>> ...4 and ...5.
>> ---
>> The float casts are ugly. I tried to define M_PI_2f using the
>> preprocessor -- something like
>>    #define M_PI_2f M_PI_2##f
>> but no luck.
>>
>>  src/glsl/builtin_functions.cpp | 14 +++++++-------
>>  1 file changed, 7 insertions(+), 7 deletions(-)
>>
>> diff --git a/src/glsl/builtin_functions.cpp b/src/glsl/builtin_functions.cpp
>> index 26ea923..62bf154 100644
>> --- a/src/glsl/builtin_functions.cpp
>> +++ b/src/glsl/builtin_functions.cpp
>> @@ -2538,11 +2538,11 @@ ir_expression *
>>  builtin_builder::asin_expr(ir_variable *x)
>>  {
>>     return mul(sign(x),
>> -              sub(imm(1.5707964f),
>> +              sub(imm((float)M_PI_2),
>>                    mul(sqrt(sub(imm(1.0f), abs(x))),
>> -                      add(imm(1.5707964f),
>> +                      add(imm((float)M_PI_2),
>>                            mul(abs(x),
>> -                              add(imm(-0.21460183f),
>> +                              add(imm((float)(1.0 - M_PI_4)),
>
> 1 - M_PI_4 comes out to 0.21460 (positive), not -0.21460.  You
> probably want to switch the operand order in the subtraction here
> (unless this change was intentional).
>
> --Aaron

Indeed, thanks for noticing.