private void UpdateObjectCBs()
{
foreach (RenderItem e in _allRitems)
{
// Only update the cbuffer data if the constants have changed.
// This needs to be tracked per frame resource.
if (e.NumFramesDirty > 0)
{
var objConstants = new ObjectConstants {
World = Matrix.Transpose(e.World)
};
CurrFrameResource.ObjectCB.CopyData(e.ObjCBIndex, ref objConstants);
// Next FrameResource need to be updated too.
e.NumFramesDirty--;
}
}
}
protected override void Update(GameTimer gt)
{
// Convert Spherical to Cartesian coordinates.
float x = _radius * MathHelper.Sinf(_phi) * MathHelper.Cosf(_theta);
float z = _radius * MathHelper.Sinf(_phi) * MathHelper.Sinf(_theta);
float y = _radius * MathHelper.Cosf(_phi);
// Build the view matrix.
_view = Matrix.LookAtLH(new Vector3(x, y, z), Vector3.Zero, Vector3.Up);
// Simply use identity for world matrix for this demo.
Matrix world = Matrix.Identity;
var cb = new ObjectConstants
{
WorldViewProj = Matrix.Transpose(world * _view * _proj)
};
// Update the constant buffer with the latest worldViewProj matrix.
_objectCB.CopyData(0, ref cb);
}