iDate.w milliseconds out of sync

[Vipitis]

Implemented way back in pygfx/wgpu-py#428 and had an issue ever since.

milliseconds aren't in sync with seconds. The example clock we have includes milliseconds but it's difficult to spot the problem.

Run for example wgpu-shadertoy https://www.shadertoy.com/view/XXGXzK or wgpu-shadertoy https://www.shadertoy.com/view/ll3yWj and you will easily spot it.

the code in question: (milliseconds are from the perf_counter() used by iTime and iTimeDelta and not the time_struct for iDate)

shadertoy/wgpu_shadertoy/shadertoy.py

Lines 616 to 624 in eb14d38

	time_struct = time.localtime()
	self._uniform_data["date"] = (
	float(time_struct.tm_year),
	float(time_struct.tm_mon - 1),
	float(time_struct.tm_mday),
	time_struct.tm_hour * 3600
	+ time_struct.tm_min * 60
	+ time_struct.tm_sec
	+ now % 1,

I think there are several better solutions, will try a few and hopefully open a PR next week.

[Vipitis]

would be great to also be able to mock iDate for taking snapshots that are reproducible. So that might be something to consider when addressing this!