public double Compute(Rectangle rectangle)
{
// Adapt rectangle to become two triangles
Library.TriangleStrip triangles = new Library.TriangleStrip(
new Library.Vertex(rectangle.BottomLeft.x, rectangle.TopRight.y), // v1
rectangle.BottomLeft.ToVertex(), // v2
rectangle.TopRight.ToVertex(), // v3
new Library.Vertex(rectangle.TopRight.x, rectangle.BottomLeft.y) // v4
);
return(_adaptee.GetArea(triangles));
}
/// <summary>
/// Computes the area of the <see cref="TriangleStrip"/> specified by <paramref name="ts"/>.
/// </summary>
/// <param name="ts"><see cref="TriangleStrip"/> object containing vertices.</param>
/// <returns>Area of total shape specified by <paramref name="ts"/>.</returns>
public double GetArea(TriangleStrip ts)
{
Vertex[] vertices = ts.Vertices.ToArray();
if (vertices.Length < 3)
{
throw new ShapeProcessorException("Too few vertices");
}
double area = 0;
for (int i = 0; i < vertices.Length - 2; i++)
{
double a = (vertices[i + 1] - vertices[i]).Length;
double b = (vertices[i + 2] - vertices[i]).Length;
double c = (vertices[i + 2] - vertices[i + 1]).Length;
area += GetTriangleArea(a, b, c);
}
return(area);
}
