3_Board_Tools
The board tools located in bleepsix/js/brdtool often have a lot of logic
in them. This section is meant to briefly describe what the more complex tools
are doing.
bleepsix/js/brdtoo/toolTrace.js
toolTrace is in charge of laying down tracks. It keeps track of the current
list of track segments while the user clicks.
Things get complicated when collisions occur. The general policy is to keep the last known good state of the layed down tool trace and if a collision occurs, use that last known good state.
There is a feature called 'magnet pads' which 'grabs' the layed down track if they get close enough to a magnetized pad or track. Pads and tracks are magnetized if they are of the same net as the trace being layed down, as implied by the schematic.
This is implemented by having a wider area that is considered in the collision detection. Pads and tracks not of the same net will still allow connections but the cursor must be within a smaller region.
When collisions are detected, the trace 'ghosts' to allow for continued visual feedback but to give an indication that the trace placement is invalid. The last known good trace placement still appears on the board.
