Replaced float4 .w with more appropriate and functionally identical .a

[WilliamIsMe1]

float4.rgba is the same as float4.xyzw

Description

The use of the .w accessor (or whatever) for a variable named color, especially when it is clear that the alpha value is being checked, can confuse code readers. So I just replaced .w with .a, and in this case, it is functionally identical. All color float4s in metal shaders always use RGBA format.

Type of change

Consistency change

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation comments
• My changes generate no new warnings

[stackotter]

Thanks for that, no clue why I used w there given that it’s quite literally an alpha check hahah

[stackotter]

Damn, the Linux workflows are failing cause it’s been so long. I may have to quickly update those before merging this to avoid getting stuck with failing CI on main

[stackotter]

I've fixed the CI in #207. I'll merge that first and then you can update this branch (rebase or merge; whichever you prefer) and then the CI should work again. #207 also merges in a ton of other changes that have been sitting on the inventory branch for ages, but I don't believe that any of them should clash with your change.