On Monday, 1 January 2018 at 15:09:53 UTC, Lily wrote:
I started learning D a few days ago, coming from some very
basic C++ knowledge, and I'd like some help getting a program
to run faster.
So a few easy things you can do:
1) use `float` instead of `real`. real sucks, it is really slow
and weird. Making that one switch doubled the speed on my
computer.
2) preallocate the imageData. before the loop,
`imageData.reserve(width*height*3)`. Small savings on my computer
but an easy one.
3) make sure you use the compiler optimization options like `-O`
and `-inline` on dmd (or use the gdc and ldc compilers both of
which generally optimize better than dmd out of the box).
And if that isn't enough we can look into smaller things, but
these overall brought the time down to about 1/3 what it started
on my box.