This should be really simple, but, so far, I can't find an app that does this. MSpaint offers the "Bezier" tool, which requires TWO CONTROL points, but, I need one that only needs ONE control point. I wrote a small app in C that does this, but, I don't know how to embed it in any of the drawing programs I have used.
The idea is that you draw a straight line by specifying the starting point and the ending point (this feature is common everywhere, using the mouse, Shift key, etc). What I need is to be able to "bend" that straight line into a circular arc, depending on how much bend I specify (either with the mouse wheel, arrow keys, or whatever). That is easy to program. The only other control I need is to "skew" that arc between the two end points, depending on how much "skew" I specify (using arrow keys, mouse wheel, or whatever - this is also programmable, but, a bit more involved- it makes the arc look elliptical).
I need to be able to a) draw the straight line, fully stroked, and then, using my arrow keys, (up/down for "bend", right/left for "skew"), and mouse movement to reposition the end point, interactively so that I can tweek this bent/skewed line until it is just right.
If there is an application that already has this feature, I'd buy it in a heartbeat. If not, if there is an app that has an easy way for me to embed the code (I have already written it for single pixel black lines), I'd like to explore that.
I'm surprised this feature wasn't part of photoshop nor illustrator.