Question

Test link: http://bit.ly/Runmah

pick one item from left side for testing.

it’s rotating when he find two intersect points on the line.

i want to move red rectangle within the polygon. It shouldn’t go outside of polygon.

My code is: http://pastebin.com/pRMpk81f

Edit 1: http://pastebin.com/C3j4WSC1

Answer 1

If you know how to find the intersection of points on the line then you should be able to find distance between wall and furniture (line and edge of rectangle), you can check this value and for example stop draging and snap,

EDIT1:
when dragged item is selected (mouse is down) than you constantly check distance (e.g. on mouse move), then you can decide that if distance is within some threshold you will stop movement (basicaly you will set calculated position- snap – instead of applying mouse position) otherwise you will follow mouse.

EDIT2:
also you can test if the point is inside the shape by calculating intersection points – even number the point is outside, odd number – the point is inside

best regards