Here are some considerations about the convolve matrix ui current implementation:
(1) I think that the rows and cols parameters dont need a scroll bar since they are integer values selectable within a very small range. The scroll bar is only wasting space there since its even easiear to select the desired value directly typing it or by using the up or dow arrows.
(2) I have drawn a spline and have imported a bitmap. I have applied the same filter to both (convolve matrix) when I change the divisor or the bias parameters, the effect on the spline updates automaticaly while I scroll the bar, but on the image I MUST double click on the filter name to have the effect aplied. It is a weird behaviour I think. Do you know why is it happenning?
(3) the bias and divisor scroll bars bypass the default value behaviour (which could be desired in some ocasions, mainly because the default value seems to be usually a good choice aesteticaly) Maybe a good soulition woul be to initialize it with the default value, not zero. Also it limits the range of possible values.
(4) how do we set the targetX and targetY? Maybe we could have a little black dot indicating it on the matrix
And one desired feature for the filters ui in general: (5) it would be nice if we coul drag and drop a filter from the left list into the filter diagram area at the right in order to use it as if it was a filter primitive. In the UI it would show the filter name (it's an abstraction to the user) but behind the scenes it would probably be a copy of the filter structure connected to the rest of the real primitives implementing a "higher level" filter. You understand what I mean?
best wishes, Juca