public void Update(ITimer timer)
{
float t = timer == null ? 0.0f : (float)timer.TotalSeconds;
this.worldMatrix1 = XMMatrix.RotationY(t);
XMMatrix spin = XMMatrix.RotationZ(-t);
XMMatrix orbit = XMMatrix.RotationY(-t * 2.0f);
XMMatrix translate = XMMatrix.Translation(-4.0f, 0.0f, 0.0f);
XMMatrix scale = XMMatrix.Scaling(0.3f, 0.3f, 0.3f);
this.worldMatrix2 = scale * spin * translate * orbit;
}
static void Transform(XMMatrix target, Viewport viewport, float angle, float scale, float w, float h)
{
using var r = new XMMatrix();
using var b = new XMMatrix();
using var s = new XMMatrix();
using var t = new XMMatrix();
r.RotationZ((float)(angle / 180 * Math.PI));
s.Scaling(scale, scale, 1.0f);
t.Translation(viewport.Width / 2 - w * scale / 2, viewport.Height / 2 - h * scale / 2, 0.0f);
b.Translation(-viewport.Width / 2, -viewport.Height / 2, 0.0f);
b.Multiply(r);
r.Set(b);
b.Identity();
b.Translation(viewport.Width / 2, viewport.Height / 2, 0.0f);
r.Multiply(b);
s.Multiply(t);
s.Multiply(r);
target.Set(s);
}