/// <summary>
/// Tests if the two intervals overlap
/// </summary>
/// <returns><c>true</c>, if intervals overlap, <c>false</c> otherwise.</returns>
/// <param name="rect1">Rect1.</param>
/// <param name="rect2">Rect2.</param>
/// <param name="axis">Axis.</param>
private static bool OverlapOnAxis(Rect rect1, Rect rect2, Vector2 axis)
{
SeparationAxisTheorem a = GetInterval(rect1, axis);
SeparationAxisTheorem b = GetInterval(rect2, axis);
return((b.min <= a.max) && (a.min <= b.max));
}
/// <summary>
/// Gets the interval projected along declared axis
/// </summary>
/// <returns>The interval.</returns>
/// <param name="rectangle">Rectangle.</param>
/// <param name="axis">Axis.</param>
private static SeparationAxisTheorem GetInterval(Rect rectangle, Vector2 axis)
{
SeparationAxisTheorem result = new SeparationAxisTheorem();
//The Maximum and minimum parts of a rectangle
Vector2 min, max;
min.x = rectangle.min.x;
min.y = rectangle.min.y;
max.x = rectangle.max.x;
max.y = rectangle.max.y;
//The Max and Min Vertices of a rectangle
Vector2[] vertsOfRect =
{
new Vector2(min.x, min.y),
new Vector2(min.x, max.y),
new Vector2(max.x, max.y),
new Vector2(max.x, min.y)
};
//Projects each vertex onto the axis, and store the smallest and largest values
result.min = result.max = Vector2.Dot(axis, vertsOfRect[0]);
for (int i = 1; i < 4; i++)
{
float projection = Vector2.Dot(axis, vertsOfRect[i]);
if (projection < result.min)
{
result.min = projection;
}
if (projection > result.max)
{
result.max = projection;
}
}
return(result);
}
