DragFloatRange2 and DragIntRange2 fail to check bounds

[sammalt]

There is a bug in both of these, which makes it to not respect the bounds set by v_min and v_max parameters.

Repro

1. open imgui demo -> widgets -> Range Widgets
2. drag Min: 10.0 % to 0 %
3. drag Max: 90.0 % to 0 %
4. drag Min: 0% left -> boom.

Now Min widget no longer respects the v_min and v_max parameters, you can drag it negative percents (below v_min), over the current max value and over v_max. You can do it also the other way around: drag the min value all the way to v_max, and then the current max no longer respects the bounds.

You can observe the same behavior in DragIntRange2 - but not in the ImGui demo, of course ;)

Edit: version 1.52

[ocornut]

Ouch, this is quite an issue.

It's a little delicate to fix because DragFloat() signature basically says that when v_min==v_max there's no bound. So we'd need to fix that, and probably switch to using -FLT_MAX..FLT_MAX as default values, but it makes DragFloat() less welcoming when you want to fill in the extra parameters (also I wonder if all languages have access to a reliable version of FLT_MAX).

The other solution would be to make that change only in an internal version DragFloatEx() which is wrapped by DragFloat() with a translation of v_min==v_max to -FLT_MAX,FLT_MAX, and then the DragFloatRange2() can use this function directly.

I think I prefer the second solution as it won't break user code, and we can always morph the second solution into the first one later if we want to.

Added reference to #76

[ocornut]

Hello @sammalt,
When exploring old issues I realized that this was now easily fixable with the changes made by 0537ac0.
So this is now fixed.
Thank you.