fiery river
Hey guys, I'm playing with DirectInput, and I'm stuck because of a macro.
#define MAKEDIPROP(prop) (*(const GUID *)(prop))
#define DIPROP_BUFFERSIZE MAKEDIPROP(1)
I'm trying something like that:
const key = @as(*win32.zig.Guid, @ptrFromInt(@as(usize, 1)));
but got:
error: pointer type '*win32.zig.Guid' requires aligned address
wraith root
the natural alignment of Guid is larger than 1, so the address cannot itself be 1. you've gotta do something like
@as(*align(1) win32.zig.Guid, @ptrFromInt(1));
Thanks for the answer, unfortunately, I have to use the pointer, and I an not cast it back to align(4).
wraith root
of course you cant, the address isn't a multiple of 4
what API requires it be aligned to 4?
fiery river
IDirectInputDevice8W.SetProperty
right now, my workaround is to cast the pointer function.
pub inline fn DirectInputDevice8_SetProperty(device: *IDirectInputDevice8W, param0: usize, param1: ?*DIPROPHEADER) win32.foundation.HRESULT {
const SetPropertyType = *const fn (self: *const IDirectInputDevice8W, param0: usize, param1: ?*DIPROPHEADER) win32.foundation.HRESULT;
const func: SetPropertyType = @ptrCast(device.vtable.SetProperty);
return func(device, param0, param1);
}
vtable.SetProperty not have the right proto in the first place?
fiery river
I'm not sure, it's the way Win32 / Direct X works I guess.
They have a generic api, and do hacks to make it work.
wraith root
i mean, direct X isn't written in Zig, where does the SetProperty come from?
