Inspector: Color picker: Add button to toggle between Alpha value 0-255 and percentage 0-100% (or ratio 0.0-1.0)

[hsandt]

Problem

I want to set my sprite opacity to 50% or 75% via Modulate/Self-Modulate, but the color inspector field shows values in 0-255 range so I must compute myself the wanted value or tune by eye.

Suggestion

Setting alpha transparency / opacity by percentage or ratio would make it easier to estimate progression between full transparency and fully opaque. It would also allow copy-pasting values taken from external software that formats alpha in a different way (but more rare, since such software would generally just give the RGBA).

Possible implementation

A button or dropdown to toggle between the current Alpha value (0-255), percentage (0-100%) and possibly ratio (0.0-1.0).

Alternatively, an editor settings as in Aseprite would be great, if user wants to use the same representation everywhere.

Limitation: ratio and percentage are not exact values, so user should be aware of that, and maybe see the 0-255 alpha value in read-only gray or something. That said, it's not different from editing an angle in degrees even if it's stored in radians.

Question to answer before turning this into a proposal

• What alternative formats do we choose? Percentage, Ratio, both?
• Should this be an editor setting (applies to all values), a local option (button near the alpha field in color picker), or a hybrid (editor setting is the default, but you can always override this locally for a specific color in the color picker)
• Button style: toggle or dropdown? (toggle only works for 2 modes, dropdown is better for 3)
• Do we need to indicate to the user that the alternative format is not exact, but rather just an approximate representation?