/// <summary>
/// 指定の法線の面の頂点データを作成します。
/// </summary>
/// <param name="source">対応する面の VertexSource。</param>
/// <param name="normal">面の法線。</param>
void InitializeSurface(SurfaceVertexSource source, Vector3 normal)
{
var quadrangle = new Quadrangle();
float s = Size * 0.5f;
var side1 = new Vector3(normal.Y, normal.Z, normal.X);
var side2 = Vector3.Cross(normal, side1);
quadrangle.Position0 = (normal - side1 - side2) * s;
quadrangle.Position1 = (normal - side1 + side2) * s;
quadrangle.Position2 = (normal + side1 + side2) * s;
quadrangle.Position3 = (normal + side1 - side2) * s;
quadrangle.Normal = normal;
quadrangle.Make(source);
}
/// <summary>
/// 面の頂点データを InterBlockMeshPart の頂点データへ設定します。
/// </summary>
/// <param name="meshPartVS">
/// InterBlockMeshPart の頂点データを保持する VertexSource。
/// </param>
/// <param name="surfaceVS">
/// 面の頂点データを提供する VertexSource。
/// </param>
/// <param name="transform">
/// 頂点の設定前に適用する変換行列。
/// </param>
static void AddSurfaceVertices(MeshPartVertexSource meshPartVS, SurfaceVertexSource surfaceVS, ref Matrix transform)
{
var startIndex = meshPartVS.Vertices.Count;
var vertexSource = surfaceVS;
foreach (var index in vertexSource.Indices)
{
meshPartVS.Indices.Add((ushort)(startIndex + index));
}
for (int i = 0; i < vertexSource.Vertices.Count; i++)
{
var cubeVertex = vertexSource.Vertices[i];
Vector3 transformedVertexPosition;
Vector3.Transform(ref cubeVertex.Position, ref transform, out transformedVertexPosition);
meshPartVS.Vertices.Add(new VertexPositionNormal(transformedVertexPosition, cubeVertex.Normal));
}
}
/// <summary>
/// インスタンスを生成します。
/// </summary>
/// <param name="size">辺のサイズ。</param>
public CubeSurfaceVertexSource(float size)
{
Size = size;
Surfaces = new SurfaceVertexSource[6];
Vector3[] normals =
{
new Vector3(1, 0, 0),
new Vector3(-1, 0, 0),
new Vector3(0, 1, 0),
new Vector3(0, -1, 0),
new Vector3(0, 0, 1),
new Vector3(0, 0, -1)
};
for (int i = 0; i < 6; i++)
{
Surfaces[i] = new SurfaceVertexSource();
InitializeSurface(Surfaces[i], normals[i]);
}
}
