using Hi.Geom;
using Hi.Disp;

namespace Sample.Disp
{
    /// <summary>
    /// Demonstrates a simple solar system animation using <see cref="IDisplayee"/> interface.
    /// Shows how to create a hierarchical transform structure with sun, earth and moon using
    /// <see cref="mat4d_t"/> matrices and model matrix stack transformations.
    /// </summary>
    /// <remarks>
    /// ### Source Code
    /// [!code-csharp[SampleCode](~/../Hi.Sample/Disp/DemoSatellite.cs)]
    /// </remarks>
    public class DemoSatellite : IDisplayee
	{
		Drawing sun;
		Drawing earth;
		Drawing moon;
		double angle_earth;
		double angle_moon;
		DemoSatellite()
		{
			sun = box3d_t.CenterUnitBox.ScaledFromCenter(4).ToDraw_Face();
			earth = box3d_t.CenterUnitBox.ScaledFromCenter(2).ToDraw_Face();
			moon = box3d_t.CenterUnitBox.ToDraw_Face();
		}
        /// <inheritdoc/>
        public void Display(Bind bind)
		{
			sun.Display(bind);
			bind.ModelMatStack.Push();
			bind.ModelMatStack.Mul(new mat4d_t(new AxisAngle4d(new vec3d_t(0, 0, 1), angle_earth += 0.03)));
			bind.ModelMatStack.Mul(new mat4d_t(new vec3d_t(12, 0, 0)));
			earth.Display(bind);
			bind.ModelMatStack.Push();
			bind.ModelMatStack.Mul(new mat4d_t(new AxisAngle4d(new vec3d_t(0, 0, 1), angle_moon += 0.02)));
			bind.ModelMatStack.Mul(new mat4d_t(new vec3d_t(4, 0, 0)));
			moon.Display(bind);
			bind.ModelMatStack.Pop();
			bind.ModelMatStack.Pop();
		}
		/// <inheritdoc/>
		public void ExpandToBox3d(ref box3d_t dst)
		{
			dst = dst.Expanded(new vec3d_t(-14, -14, -2));
			dst = dst.Expanded(new vec3d_t(14, 14, 2));
		}

		static void Main()
		{
            DemoUtil.Present("DemoSatellite", new DemoSatellite());
		}
	}
}