Graphic Effects can have Infinity as argument

[apple502j]

Expected Behavior

Infinity should be handled as 0 or max value of the effect

Actual Behavior

Giving Infinity as argument causes unexpected graphic effect such as grayscale sprite (when color effect is used)

Steps to Reproduce

Run set color effect to (1/0).

Operating System and Browser

Any

[adroitwhiz]

Looks like 2.0 also handles this weirdly:

(This is in 2D/Pixelbender mode)

[apple502j]

Why reopen? forgot the PR is reverted

[fsih]

Design considerations @carljbowman
What currently happens in Scratch 3.0 at +infinity? Bolded effects feel like they might be unintended behavior

• Color effect becomes black (different on different computers)
• Fisheye has giant single-color circle appear on top of sprite
• Whirl effect cuts out giant circle from middle of sprite
• Pixelate turns into 1 pixel that's usually transparent
• Mosaic effect maxes out visually, but numerically, the number is not clamped (if you change graphics effect by a negative number, it doesn't become more normal)
• Brightness effect clamps to 100
• Ghost effect clamps to 100

What usually happens at -infinity?

• Color effect becomes black (different on different computers)
• Fisheye makes a circle of colors converge at a point. It looks similar to -100 but it's not clamped (if you change graphics effect by a positive number, it doesn't become more normal)
• Whirl makes the whole sprite 1 color, which is usually transparent
• Pixelate turns into 1 pixel that's usually transparent
• Mosaic effect maxes out visually, but numerically, the number is not clamped (if you change graphics effect by a positive number, it doesn't become more normal)
• Brightness effect clamps to -100
• Ghost effect clamps to -100

What happens in 2.0?
It's pretty similar to scratch 3, with the clamping and disappearing. Except that color and fisheye effects ignore being set to +/- infinity. (Unless you have pixelbender on like adroitwhiz's post, then color and fisheye do really strange things that we wouldn't want to copy)

Using the value 0 when infinity is entered feels weird, because e.g. if you add more and more whirl effect, you would expect infinity to be the most whirl effect, but it "jumps" back to looking like 0. Perhaps the whirl, pixelate, fisheye, and mosaic effects should clamp at some value, like brightness and ghost do?

However, color can't be clamped because it doesn't converge.

[husqwc]

Also, as the Wiki notes, large whirl values also act differently depending on the computer