ColormapScale function cannot handle inverted min / max ranges

[WeirdRubberDuck]

See example in demo, where I set min > max:

The ticks and labels do not show up in the ColromapScale. Would be great if they did, or if there was another way to invert the color map

[epezent]

Thanks for flagging this -- we can work in support for inverted scales. I think it would make more sense to enable inversion with e.g. ImPlotColormapScaleFlags_Invert than misconstruing the min/max values (this flag could also allow for more options/customization in the future). Thoughts?

[epezent]

Hi, let me know if https://github.com/epezent/implot/commit/0f4d4dccc333c4e5aeebeb27866857cc45627dfe helps you achieve the functionality you need. See below:

[WeirdRubberDuck]

I agree, an invert flag is perfect.

However, in that flip, I would expect 0 db to be mapped to yellow and 100 dB to be mapped to purple when the ImPlotColormapScaleFlags_Invert is set to true

[epezent]

Oh! I completely missed your point. I see now you want to invert the mapping from from the data range to color range. I thought you just wanted to turn the widget upside down 😂

In that case, I think your original proposal of flipping min/max scale is the right one. I'll take a look and figure out why that's not working. Sorry for the mixup!

[epezent]

Ok, give https://github.com/epezent/implot/commit/6c00109636a78cd317de2b2a02744deec523b181 a go! To summarize the new behavior, scale_min > scale_max will reverse the mapping from the scale range to the color range (i.e. only affects axis direction) and ImPlotColormapScale_Invert will invert both the colormap bar and axis. See below:

scale_min < scale_max	scale_min > scale_max
ImPlotColormapScaleFlags_None
ImPlotColormapScaleFlags_Invert

[WeirdRubberDuck]

Cool! Have some other things to prioritize but will try that out asap 😄 Thanks !