Abusing C macros to render the Mandelbrot Set at compile-time (opens in new tab)

Case in point: that 4KB output file refers to the size of the uncompressed PNM file, and as such is an inaccurate hint as to the image dimensions.

It's 64x64.

gcc mandel.c -o mandel 95.84s user 3.99s system 71% cpu 2:18.88 total

thought it was just my notebook :) think it is the longest my machine spent on just 41 lines of code to compile

As someone who doesn't do much C++, could `constexpr` actually do this all on its own? My (limited) understanding of `constexpr` would lead me to think that using it alone you couldn't generate the contents of the array like this. IE. You could define a `constexpr` function to calculate a single entry in the array, but you'd still need to call that function for every entry. In this case, it looks to me like the bulk of the macros here are just to condense declaring the large array by using nested macros to repeat the computations and expand to a large number of array entries.

That said I absolutely don't disagree with you at all. It's really a bit silly C doesn't have it at this point. `gcc` will happily do all of this math for you at compile time even if you do as much of the math as you can in `static` functions. But to make it compile you have to declare `pixels` in `main` because you can't call the functions in the initializer for file-scoped variables - even though the compiler can already optimize them out.

The end to this madness is to move to C++, D, Rust, Swift, ...

The madness is all in the line that defines the pixels[] array (try 'tail' instead).

I suggest you buy more virtual memory.

Change the code from M4 to M3:-

>#define C1(x,y) M3(XF(x), YF(y), XF(x), YF(y)),

>// ^- change this to 5 or 6 to increase detail