CGG Polygon

The boundary-fill algorithm stops filling when it encounters:

• Any pixel with the same color as the seed

• Pixels of the boundary color

• The maximum x-coordinate

• The maximum y-coordinate

In boundary-fill using 4-connected neighbors, which pixels are considered?

• Left, Right, Top, Bottom

• Diagonal only

• Left, Right, Top, Bottom, and Diagonals

• Random adjacent pixels

Which filling method can handle irregular boundaries more effectively?

• Boundary-fill

• Flood-fill

• Scan-line fill

• Polygon clipping

In flood-fill, filling continues until:

• The polygon is closed

• The boundary color is reached

• All pixels of a given interior color are replaced

• All edges are clipped

The main difference between boundary-fill and flood-fill is:

• Boundary-fill uses boundary color; flood-fill uses interior color

• Boundary-fill is only for convex polygons

• Flood-fill requires diagonals, boundary-fill does not

• Flood-fill is always faster

The Inside–Outside Test is used to:

• Identify active edges in scan-line fill

• Determine whether a point lies inside or outside a polygon

• Perform line clipping efficiently

• Transform window coordinates

In the Inside–Outside Test, if the scan line intersects polygon edges an odd number of times, the point is considered:

• Outside

• Inside

• On the boundary

• Undefined

In the Inside–Outside Test, an even number of intersections means the point is:

• Inside

• Outside

• On the vertex

• In a concave region only

The Winding Number Method works by:

• Counting how many times a scan line crosses the polygon

• Checking slope of polygon edges

• Calculating region codes for endpoints

• Sorting vertices of the polygon

In Winding Number Method, crossing the edge from right to left contributes:

• +1

• –1

• 0

• +2