optimize a finding method.
update
moved a setting param.
moved a setting param.
load a new JS file.
update
update
update parameters.
removed to calc tangent2.
removed one of constraints.
updated
update
added new files.
added a new file.
changed canvas bg color.
added a debug mode.
chagned canvas bg color.
modified a logic to detect origin is in a triangle.
removed comment out.
commented out a count up.