|
 |
Le 30/05/2016 18:30, Bald Eagle a écrit :
> "Cousin Ricky" <rickysttATyahooDOTcom> wrote:
>> "Bald Eagle" <cre### [at] netscape net> wrote:
>>> Could someone please post a small, simple macro that results in a scalar, a
>>> vector, and an array getting passed "out" to the global SDL world?
>>
>> You can pass them back through the macro arguments by declaring the formal
>> parameters with the final results. For example:
>>
>> #macro MyMacro (S, V, A)
>> #declare S = 1;
>> #declare V = <2, 3, 4>;
>> #declare A = array[5]
>> #for (I, 0, 4)
>> #declare A[I] = pow (I, 2);
>> #end
>> #end
>>
>> The argument identifiers would need to be declared with dummy values before
>> passing them to the macro.
>>
>> Be careful with this technique. It is frowned upon in structured programming,
>> but without heterogeneous data structure capability, POV-Ray SDL leaves you
>> little choice.
>
> I see what you're doing - I'd call that "redeclaring" the values of existing
> variables.
> Could you perhaps illuminate me as to how say, array A, on a line all its own,
> gets passed out of a macro?
> I have both sucessfuly and unsuccessfully done it that way, but I can't clearly
> see what happens to make it work or not work.
>
> So, for instance:
> #macro MyMacro (Input)
> #declare Output = pow (Input, 2);
> Output
> #end
>
> #declare Variable = MyMacro (2);
>
> Can I have several lines such as
> Output1
> Output2
> Output3 ?
>
> Can I have SDL inside the macro that creates a sphere and then returns Input^2 ?
Do not see macro as a function calls, but as text substitution.
It might help.
Post a reply to this message
|
|
