/// <summary>
/// Helper function creates a new geometry object,
/// and sets it to use our billboard effect.
/// </summary>
static GeometryContent CreateVegetationGeometry(string textureFilename,
float width, float height,
float windAmount,
ContentIdentity identity)
{
GeometryContent geometry = new GeometryContent();
// Add the vertex channels needed for our billboard geometry.
VertexChannelCollection channels = geometry.Vertices.Channels;
// Add a vertex channel holding normal vectors.
channels.Add <Vector3>(VertexChannelNames.Normal(), null);
// Add a vertex channel holding texture coordinates.
channels.Add <Vector2>(VertexChannelNames.TextureCoordinate(0), null);
// Add a second texture coordinate channel, holding a per-billboard
// random number. This is used to make each billboard come out a
// slightly different size, and to animate at different speeds.
channels.Add <float>(VertexChannelNames.TextureCoordinate(1), null);
// Create a material for rendering the billboards.
EffectMaterialContent material = new EffectMaterialContent();
// Point the material at our custom billboard effect.
string directory = Path.GetDirectoryName(identity.SourceFilename);
string effectFilename = Path.Combine(directory, "Billboard.fx");
material.Effect = new ExternalReference <EffectContent>(effectFilename);
// Set the texture to be used by these billboards.
textureFilename = Path.Combine(directory, textureFilename);
material.Textures.Add("Texture", new ExternalReference <TextureContent>(textureFilename));
// Set effect parameters describing the size and
// wind sensitivity of these billboards.
material.OpaqueData.Add("BillboardWidth", width);
material.OpaqueData.Add("BillboardHeight", height);
material.OpaqueData.Add("WindAmount", windAmount);
geometry.Material = material;
return(geometry);
}
} // Process
#endregion
#region Process Vertex Channel
/// <summary>
/// Processes geometry content vertex channels at the specified index.
/// </summary>
protected override void ProcessVertexChannel(GeometryContent geometry, int vertexChannelIndex, ContentProcessorContext context)
{
VertexChannelCollection channels = geometry.Vertices.Channels;
// If the model has only position and normals a UV channel is added.
// http://xnafinalengine.codeplex.com/wikipage?title=Compressed%20Vertex%20Data
if (channels.Count == 1 && channels.Contains(VertexChannelNames.Normal()))
{
channels.Add<Vector2>(VertexChannelNames.TextureCoordinate(0), null);
}
// If the model has position, normal and UV then the data is packed on 32 bytes aliagned vertex data.
if (channels.Count == 2 && channels.Contains(VertexChannelNames.Normal()) && channels.Contains(VertexChannelNames.TextureCoordinate(0)))
{
// No compressed Vertex Data
base.ProcessVertexChannel(geometry, vertexChannelIndex, context);
}
else // If not then the data is compressed.
{
string name = channels[vertexChannelIndex].Name;
if (name == VertexChannelNames.Normal())
{
channels.ConvertChannelContent<NormalizedShort4>(vertexChannelIndex);
}
else if (name == VertexChannelNames.TextureCoordinate(0))
{
// Clamp values.
/*for (int i = 0; i < channels[vertexChannelIndex].Count; i++)
{
Vector2 uv = (Vector2)channels[vertexChannelIndex][i];
if (uv.X < 0)
uv.X *= -1;
if (uv.Y < 0)
uv.Y *= -1;
Vector2 uvCampled = new Vector2(uv.X - (float)Math.Truncate(uv.X), uv.Y - (float)Math.Truncate(uv.Y));
channels[vertexChannelIndex][i] = uvCampled;
}
// If the resource has texture coordinates outside the range [-1, 1] the values will be clamped.
channels.ConvertChannelContent<NormalizedShort2>(vertexChannelIndex);*/
// Sometimes you can't just clamp values, because the distance between vertices surpass 1 uv unit.
// And given that I am not removing the binormals I won't normalize the UVs.
channels.ConvertChannelContent<HalfVector2>(vertexChannelIndex);
}
else if (name == VertexChannelNames.TextureCoordinate(1))
channels.Remove(VertexChannelNames.TextureCoordinate(1));
else if (name == VertexChannelNames.TextureCoordinate(2))
channels.Remove(VertexChannelNames.TextureCoordinate(2));
else if (name == VertexChannelNames.TextureCoordinate(3))
channels.Remove(VertexChannelNames.TextureCoordinate(3));
else if (name == VertexChannelNames.TextureCoordinate(4))
channels.Remove(VertexChannelNames.TextureCoordinate(4));
else if (name == VertexChannelNames.TextureCoordinate(5))
channels.Remove(VertexChannelNames.TextureCoordinate(5));
else if (name == VertexChannelNames.TextureCoordinate(6))
channels.Remove(VertexChannelNames.TextureCoordinate(6));
else if (name == VertexChannelNames.TextureCoordinate(7))
channels.Remove(VertexChannelNames.TextureCoordinate(7));
else if (name == VertexChannelNames.Color(0))
channels.Remove(VertexChannelNames.Color(0));
else if (name == VertexChannelNames.Tangent(0))
{
channels.ConvertChannelContent<NormalizedShort4>(vertexChannelIndex);
}
else if (name == VertexChannelNames.Binormal(0))
{
channels.ConvertChannelContent<NormalizedShort4>(vertexChannelIndex);
// If the binormal is removed then the position, the normal,
// the tangent and one texture coordinate can be fetched in one single block of 32 bytes.
// Still, it is more fast to just pass the value. At least on the test I made.
//channels.Remove(VertexChannelNames.Binormal(0));
}
else
{
base.ProcessVertexChannel(geometry, vertexChannelIndex, context);
}
}
} // ProcessVertexChannel
