DataStream GenerateMesh()
{
float offsetX = 1f / TesselationLevelsX;
float offsetY = 1f / TesselationLevelsY;
_numVertices = TesselationLevelsX * TesselationLevelsY * 6;
var stream = new DataStream(DXUtil.SizeOf <Vector2>() * _numVertices, false, true);
for (int i = 0; i < TesselationLevelsY; i++)
{
for (int j = TesselationLevelsX - 1; j >= 0; j--)
{
float x = offsetX * j;
float y = offsetY * i;
stream.Write(new Vector2(x, y));
stream.Write(new Vector2(x, y + offsetY));
stream.Write(new Vector2(x + offsetX, y));
stream.Write(new Vector2(x + offsetX, y));
stream.Write(new Vector2(x, y + offsetY));
stream.Write(new Vector2(x + offsetX, y + offsetY));
}
}
return(stream);
}
//----------------------------------------------------------------------
#region ** CustomEffect
/// <summary>
/// Creates any resources used repeatedly during subsequent rendering calls.
/// </summary>
public void Initialize(D2D.EffectContext effectContext, D2D.TransformGraph transformGraph)
{
if (_shaderBuffer == null)
{
Assembly asm = typeof(WarpEffect).Assembly;
using (Stream stream = asm.GetManifestResourceStream("BitmapSamples.Resources.WarpEffect.cso"))
{
int length = (int)stream.Length;
_shaderBuffer = new byte[length];
stream.Read(_shaderBuffer, 0, length);
}
}
effectContext.LoadVertexShader(GUID_WarpVertexShader, _shaderBuffer);
_vertexBuffer = effectContext.FindVertexBuffer(GUID_WarpVertexBuffer);
if (_vertexBuffer == null)
{
using (var meshStream = GenerateMesh())
{
var props = new D2D.VertexBufferProperties(1, D2D.VertexUsage.Static, meshStream);
var desc = new D2D.InputElement("MESH_POSITION", 0, DXGI.Format.R32G32_Float, 0, 0);
var custProps = new D2D.CustomVertexBufferProperties(_shaderBuffer, new D2D.InputElement[] { desc }, DXUtil.SizeOf <Vector2>());
_vertexBuffer = D2D.VertexBuffer.Create(effectContext, GUID_WarpVertexShader, props, custProps);
}
}
transformGraph.SetSingleTransformNode(this);
}