I have a project with a graphic object called GraphicsLine. What it does is simply draw line on every mousedown and stop on every mouseup, nothing complicated. It stores coordinates for the start and the end of the line (x,y). Now what I want to know is whenever a shape is created. For example, you create 4 lines that forms a square, I want to be able to run an algorithm that can tell me that there is a square in the drawing.
Note that the shape can be anything that is "closed". Not only square, rectangle or triangle.
The goal of this is to calculate the area of the created shapes.
Is there something that already exists for doing this? I've been struggling to find something that could fit my needs.
EDIT 1:
I added some additionnal information :
Lines are either "cliped" to another line start or end point or they are not. There is no close closure, it is on the same point or not closed at all. 1 line can be used in multiple shapes.
EDIT 2 :
So basically, I want something that can give me an array of "GraphicsLine" that forms a shape. So if we have 6 lines in the drawing but 4 of them forms a square, I want something that returns those 4 lines so I can create another object from it.
Thanks in advance.
I know it is 2 years + later, but I found a way with a recursive function to know when the shapes are "closed". You start from any points of the last drawed line, then you check if the other point is connected to another line. You do this until you reach the starting point. I save all the lines into another class called Polygon. This way, they keep all the lines with the start and finish that forms the polygon. Then to calculate the area, I do as Eduardo Cobuci said in his answer.
Hope this helps.