private static void _createCube( Mesh mesh )
{
SubMesh sub = mesh.CreateSubMesh();
const int NUM_VERTICES = 4 * 6; // 4 vertices per side * 6 sides
const int NUM_ENTRIES_PER_VERTEX = 8;
const int NUM_VERTEX_ENTRIES = NUM_VERTICES * NUM_ENTRIES_PER_VERTEX;
const int NUM_INDICES = 3 * 2 * 6; // 3 indices per face * 2 faces per side * 6 sides
const float CUBE_SIZE = 100.0f;
const float CUBE_HALF_SIZE = CUBE_SIZE / 2.0f;
// Create 4 vertices per side instead of 6 that are shared for the whole cube.
// The reason for this is with only 6 vertices the normals will look bad
// since each vertex can "point" in a different direction depending on the face it is included in.
float[] vertices = new float[ NUM_VERTEX_ENTRIES ] {
// front side
-CUBE_HALF_SIZE, -CUBE_HALF_SIZE, CUBE_HALF_SIZE, // pos
0,0,1, // normal
0,1, // texcoord
CUBE_HALF_SIZE, -CUBE_HALF_SIZE, CUBE_HALF_SIZE,
0,0,1,
1,1,
CUBE_HALF_SIZE, CUBE_HALF_SIZE, CUBE_HALF_SIZE,
0,0,1,
1,0,
-CUBE_HALF_SIZE, CUBE_HALF_SIZE, CUBE_HALF_SIZE ,
0,0,1,
0,0,
// back side
CUBE_HALF_SIZE, -CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
0,0,-1,
0,1,
-CUBE_HALF_SIZE, -CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
0,0,-1,
1,1,
-CUBE_HALF_SIZE, CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
0,0,-1,
1,0,
CUBE_HALF_SIZE, CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
0,0,-1,
0,0,
// left side
-CUBE_HALF_SIZE, -CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
-1,0,0,
0,1,
-CUBE_HALF_SIZE, -CUBE_HALF_SIZE, CUBE_HALF_SIZE,
-1,0,0,
1,1,
-CUBE_HALF_SIZE, CUBE_HALF_SIZE, CUBE_HALF_SIZE,
-1,0,0,
1,0,
-CUBE_HALF_SIZE, CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
-1,0,0,
0,0,
// right side
CUBE_HALF_SIZE, -CUBE_HALF_SIZE, CUBE_HALF_SIZE,
1,0,0,
0,1,
CUBE_HALF_SIZE, -CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
1,0,0,
1,1,
CUBE_HALF_SIZE, CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
1,0,0,
1,0,
CUBE_HALF_SIZE, CUBE_HALF_SIZE, CUBE_HALF_SIZE,
1,0,0,
0,0,
// up side
-CUBE_HALF_SIZE, CUBE_HALF_SIZE, CUBE_HALF_SIZE,
0,1,0,
0,1,
CUBE_HALF_SIZE, CUBE_HALF_SIZE, CUBE_HALF_SIZE,
0,1,0,
1,1,
CUBE_HALF_SIZE, CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
0,1,0,
1,0,
-CUBE_HALF_SIZE, CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
0,1,0,
0,0,
// down side
-CUBE_HALF_SIZE, -CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
0,-1,0,
0,1,
CUBE_HALF_SIZE, -CUBE_HALF_SIZE, -CUBE_HALF_SIZE,
0,-1,0,
1,1,
CUBE_HALF_SIZE, -CUBE_HALF_SIZE, CUBE_HALF_SIZE,
0,-1,0,
1,0,
-CUBE_HALF_SIZE, -CUBE_HALF_SIZE, CUBE_HALF_SIZE,
0,-1,0,
0,0
};
mesh.SharedVertexData = new VertexData();
mesh.SharedVertexData.vertexCount = NUM_VERTICES;
VertexDeclaration decl = mesh.SharedVertexData.vertexDeclaration;
VertexBufferBinding bind = mesh.SharedVertexData.vertexBufferBinding;
int offset = 0;
decl.AddElement( 0, offset, VertexElementType.Float3, VertexElementSemantic.Position );
offset += VertexElement.GetTypeSize( VertexElementType.Float3 );
decl.AddElement( 0, offset, VertexElementType.Float3, VertexElementSemantic.Normal );
offset += VertexElement.GetTypeSize( VertexElementType.Float3 );
decl.AddElement( 0, offset, VertexElementType.Float2, VertexElementSemantic.TexCoords, 0 );
offset += VertexElement.GetTypeSize( VertexElementType.Float2 );
HardwareVertexBuffer vbuf = HardwareBufferManager.Instance.CreateVertexBuffer( decl, NUM_VERTICES, BufferUsage.StaticWriteOnly );
bind.SetBinding( 0, vbuf );
vbuf.WriteData( 0, vbuf.Size, vertices, true );
sub.useSharedVertices = true;
HardwareIndexBuffer ibuf = HardwareBufferManager.Instance.CreateIndexBuffer( IndexType.Size16, NUM_INDICES, BufferUsage.StaticWriteOnly );
short[] faces = new short[ NUM_INDICES ] {
// front
0,1,2,
0,2,3,
// back
4,5,6,
4,6,7,
// left
8,9,10,
8,10,11,
// right
12,13,14,
12,14,15,
// up
16,17,18,
16,18,19,
// down
20,21,22,
20,22,23
};
sub.IndexData.indexBuffer = ibuf;
sub.IndexData.indexCount = NUM_INDICES;
sub.IndexData.indexStart = 0;
ibuf.WriteData( 0, ibuf.Size, faces, true );
mesh.BoundingBox = new AxisAlignedBox( new Vector3( -CUBE_HALF_SIZE, -CUBE_HALF_SIZE, -CUBE_HALF_SIZE ),
new Vector3( CUBE_HALF_SIZE, CUBE_HALF_SIZE, CUBE_HALF_SIZE ) );
mesh.BoundingSphereRadius = CUBE_HALF_SIZE;
}
