Use recursionDepth+1 instead of ++recursionDepth

[samreid]

During code review #103, we observed this code:

faradays-electromagnetic-lab/js/common/model/Electron.ts

Lines 199 to 201 in c503836

	// Did we overshoot the curve? If so, call this method recursively.
	if ( coilSegmentPosition < 0.0 ) {
	this.switchCurves( coilSegmentPosition, ++recursionDepth );

This code incorrectly increments the recursionDepth variable. Someone debugging the code and looking at that value after the recursive call completed would see an incorrect value for recursionDepth.

This can be remedied by changing it to recursionDepth+1 in both cases.

[pixelzoom]

Good point. I replaced ++recursionDepth with recursionDepth + 1 in the above commit.

FYI, recursionDepth was not present in the Java implementation. It was added as a safeguard, and its only purpose is to prevent infinite recursion via this assertion:

assert && assert( recursionDepth < this.coilSegments.length, `infinite loop? recursionDepth=${recursionDepth}` );

Closing.