public void TestLookAtFromWorldCenter() {
Camera testCamera = new Camera(Matrix.Identity, Matrix.Identity);
testCamera.LookAt(Vector3.UnitX); // Look to the right
Vector3 leftPoint = -Vector3.UnitX;
Vector3 transformed = Vector3.Transform(leftPoint, testCamera.View);
// The point should be behind the camera
Assert.Greater(transformed.Z, 0.0f);
}
public void TestLookAtFromArbitraryPosition() {
Camera testCamera = new Camera(Matrix.Identity, Matrix.Identity);
testCamera.MoveTo(new Vector3(100.0f, 200.0f, 300.0f));
testCamera.LookAt(Vector3.Zero); // Look to the right
Vector3 leftPoint = new Vector3(99.0f, 200.0f, 300.0f);
Vector3 behindPoint = new Vector3(100.0f, 200.0f, 299.0f);
Vector3 transformedLeft = Vector3.Transform(leftPoint, testCamera.View);
Vector3 transformedBehind = Vector3.Transform(behindPoint, testCamera.View);
// The left point should be in front of the camera
Assert.Less(transformedLeft.Z, 0.0f);
// The behind point should be right of the camera
Assert.Greater(transformedBehind.X, 0.0f);
}