using Azimuth;
using UnitTestSharp;

namespace Glass.UnitTests
{
    public class DrawStateTests : TestFixture
    {
        public class ModelToWorldTests : TestFixture
        {
            public void Unset_ReadsAsIdentity()
            {
                CheckEqual(AffineMatrix.Identity, default(DrawState).ModelToWorld);
            }

            public void Set_ReadsBackWhatItWasGiven()
            {
                var transform = AffineMatrix.BuildFromTranslation(new Vector(3, 4));

                CheckEqual(transform, new DrawState { ModelToWorld = transform }.ModelToWorld);
            }

            public void Unset_ComposesAsTheIdentityRatherThanCollapsingWhatItMultiplies()
            {
                var transform = AffineMatrix.BuildFromTranslation(new Vector(3, 4));

                DrawState drawState = default;
                drawState.ModelToWorld *= transform;

                CheckEqual(new Vector(8, 10), drawState.ModelToWorld.TransformPoint(new Vector(5, 6)));
            }
        }
    }
}