Is the basic approach used to fill the polygon?

Is the basic approach used to fill the polygon?

Polygon Filling:- There are two basic approaches used to fill the polygon. One way to fill polygon is to start from given “seed”, point known to be inside the polygon and highlight outward from this point i.e. neigh-bouring pixels until we encounter the boundary pixels.

How do you fill a polygon explain any one algorithm?

Polygon Filling Algorithm

1. Step 1 − Find out the Ymin and Ymax from the given polygon.
2. Step 2 − ScanLine intersects with each edge of the polygon from Ymin to Ymax.
3. Step 3 − Sort the intersection point in the increasing order of X coordinate i.e. p0,p1, p1,p2, and p2,p3.

How is the test point checked in polygon algorithm?

Each iteration of the loop, the test point is checked against one of the polygon’s edges. The first line of the if-test succeeds if the point’s y-coord is within the edge’s scope. The second line checks whether the test point is to the left of the line (I think – I haven’t got any scrap paper to hand to check).

How to check if a given point lies inside or outside a polygon?

1) Draw a horizontal line to the right of each point and extend it to infinity 1) Count the number of times the line intersects with polygon edges. 2) A point is inside the polygon if either count of intersections is odd or point lies on an edge of polygon. If none of the conditions is true, then point lies outside.

When does the if test succeed in polygon?

The first line of the if-test succeeds if the point’s y-coord is within the edge’s scope. The second line checks whether the test point is to the left of the line (I think – I haven’t got any scrap paper to hand to check).

Which is inside the polygon a or B?

In above image, Point ‘A’ is outside the Polygon, Point ‘B’ is on the polygon boundary while Point ‘C’ is inside the Polygon. Let’s understand.