(I'm not really sure of the proper way to title this question, so feel free to edit.)
I am mixing 4 shaders together: 1 diffuse and 3 toon diffuse, as seen in the image. By default, I want them all to have equal weight, hence the current mix factors. However, I want to use input factors on this group, such as facing or pointiness, to mix between Diffuse and Toon Diffuse. These input factors are all values of 0-1. If I plug them into the mix node between the diffuse and 3 toons, then the weighting will be skewed, as the average value is .5, not .75 I need either some math that would translate the incoming factor to have a new midpoint, or a different way to mix these shaders that will not be unbalanced at the average value of .5
If the group input value is .5, the mix factor should be .75. If the group input value is 1, it should be 1, and 0, should be 0. If it were .25, the mix fac should be .375, and .75 should be .875.
What math would give me this translation, or is there another way to setup the mix nodes that avoids needing to do this?