Allow midpoints of color maps to be adjusted with adjacent points being moved
Here is a proposal from Ken Moreland. Great idea, and it is needed as we add a new default color map. In essence, allow adjustment of control points in the color map editor to proportionally scale all other control points. Keep the original behavior as an option. Make the new behavior the default.
From Ken:
To follow up on Francesca’s description of moving the midpoint of the colormap, I suggested a slightly more general feature. The idea would be that you would be able to adjust a control point such that the remaining control points would be proportionally scaled with respect to that point. The main use case would be to change the center point as Francesca suggests, but it would work with any control point.
To make the idea clearer, here is an example. Let’s say you have a colormap with 7 evenly spaced control points. Now let’s say you grab the middle control point (the 4th one) and move it to the left. The rest of the control points stay exactly where they are, and the movement of the middle point is constrained to be between the 3rd and 5th point. To really adjust the color map to move the “middle point” from the center of the range, you must independently adjust all the control points, which is problematic even with only 7. What we would like is an alternate move mode where when I move the 4th control point to the left, the 2nd and 3rd control points move closer together and left so that points 1, 2, 3, and 4 remain evenly spaced. Likewise, the 5th and 6th control points move further apart and left so that points 4, 5, 6, and 7 remain evenly spaced.