[fpc-pascal] FPC Graphics options?

[Michael Van Canneyt]

On Wed, 17 May 2017, noreply at z505.com wrote:

> On 2017-05-17 02:57, marcov at stack.nl wrote:
>> In our previous episode, noreply at z505.com said:
>>> 
>>> i.e. if you end up using opengl, or its successor, why does it even
>>> matter if FPC pure games without any libs are slow?
>> 
>> You still need to calculate all the vertices that you send to the 
>> graphics
>> card, even if the GPU renders then.
>> 
>
> True so a test to confirm that the calculating functions/procedure are 
> really the bottleneck, would need to be written, and compare it to the 
> equivalent c++ program with the same calculations
>
> It would just be silly to start optimizing the calculation functions 
> without any evidence that those are the issue..
>
> If it's fpc's internal functions such as sqrt() I wonder what those 
> internal functions actually are. Right now they are just magic, pointing 
> to a magic number, in my mind

They are mostly functions for which the compiler generates code directly
instead of calling actual pascal functions (although that still happens e.g.
for writeln).

You really need to check the generated code for the problem case.
If I understood the thread, Graeme published his ray-tracing code on a
forum, so it can probably be used as a base for examining the problem.

Michael.