public void ColorWhenRayHits()
{
var w = World.Default();
var r = new Ray(new Point(0, 0, -5), new Vector(0, 0, 1));
var c = PhongShading.ColorAt(w, r);
c.Should().Be(new Color(0.38066f, 0.47583f, 0.2855f));
}
public void ColorWhenRayMissesIsBlack()
{
var w = World.Default();
var r = new Ray(new Point(0, 0, -5), new Vector(0, 1, 0));
var c = PhongShading.ColorAt(w, r);
c.Should().Be(new Color(0, 0, 0));
}
public void ColorWithIntersectionBehind()
{
var w = World.Default();
w.Objects[0].Material.Ambient = 1f;
w.Objects[1].Material.Ambient = 1f;
var r = new Ray(new Point(0, 0, 0.75f), new Vector(0, 0, -1));
var c = PhongShading.ColorAt(w, r);
c.Should().Be(w.Objects[1].Material.Texture.LocalColorAt(Point.Zero));
}
public void HandleParallelReflectiveSurfaces()
{
var w = new World();
w.SetLights(new PointLight(new Point(0, 0, 0), Colors.White));
var lower = new Plane {
Material = { Reflective = 1f }
};
lower.SetTransform(Transform.Translate(0, -1, 0));
var upper = new Plane {
Material = { Reflective = 1f }
};
upper.SetTransform(Transform.Translate(0, 1, 0));
w.SetObjects(lower, upper);
var r = new Ray(new Point(0, 0, 0), new Vector(0, 1, 0));
// Test to ensure an infinite loop is not hit.
PhongShading.ColorAt(w, r).Should().NotBe(new Color(1, 0, 0));
}