IndexBuffer.Lock(Int32,Type,LockFlags,Int32[]) Method (Microsoft.DirectX.Direct3D)

How Do I...?

• Create a Mesh Object

Locks a range of index data and obtains a pointer to the index buffer memory.

Definition

Visual Basic	Public Function Lock( _     ByVal offsetToLock As Integer, _     ByVal typeIndex As Type, _     ByVal flags As LockFlags, _     ByVal ranks() As Integer _ ) As Array
C#	public Array Lock(     int offsetToLock,     Type typeIndex,     LockFlags flags,     int[] ranks );
C++	public: Array^ Lock(     int offsetToLock,     Type^ typeIndex,     LockFlags flags,     array<int>^ ranks );
JScript	public function Lock(     offsetToLock : int,     typeIndex : Type,     flags : LockFlags,     ranks : int[] ) : Array;

Parameters

offsetToLock	System.Int32 Offset into the index data to lock, in bytes. To lock the entire index buffer, specify 0 for the param_Int32_sizeToLock and param_Int32_offsetToLock parameters.
typeIndex	System.Type A Type object that indicates the type of array data to return. This can be a value type or any type that contains only value types.
flags	Microsoft.DirectX.Direct3D.LockFlags Zero or more LockFlags that describe the type of lock to perform. For this method, the valid flags are Discard, NoDirtyUpdate, NoSystemLock, NoOverwrite, and ReadOnly.
ranks	System.Int32[] Array of 1 to 3 Int32 values that indicate the dimensions of the returning Array.

Return Value

System.Array
An Array that represents the locked index buffer.

Remarks

When working with index buffers, multiple lock calls are allowed. However, the number of lock calls must match the number of unlock calls. None of the DrawPrimitives calls will succeed with any outstanding lock count on any currently set index buffer.

The Lock.Discard and NoOverWrite flags are valid only on buffers created with Dynamic.

Exceptions

InvalidCallException

The method call is invalid. For example, a method's parameter might contain an invalid value.

How Do I...?

Create a Mesh Object

This example shows how to create a Mesh object.

In the following C# code example, device is assumed to be the rendering Device.

              [C#]
              
int numberVerts = 8;
short[] indices = {
    0,1,2, // Front Face 
    1,3,2, // Front Face 
    4,5,6, // Back Face 
    6,5,7, // Back Face 
    0,5,4, // Top Face 
    0,2,5, // Top Face 
    1,6,7, // Bottom Face 
    1,7,3, // Bottom Face 
    0,6,1, // Left Face 
    4,6,0, // Left Face 
    2,3,7, // Right Face 
    5,2,7 // Right Face 
};

Mesh mesh = new Mesh(numberVerts * 3, numberVerts, MeshFlags.Managed,
                     CustomVertex.PositionColored.Format, device);

using(VertexBuffer vb = mesh.VertexBuffer)
{
    GraphicsStream data = vb.Lock(0, 0, LockFlags.None);

    data.Write(new CustomVertex.PositionColored(-1.0f, 1.0f, 1.0f, 0x00ff00ff));
    data.Write(new CustomVertex.PositionColored(-1.0f, -1.0f, 1.0f, 0x00ff00ff));
    data.Write(new CustomVertex.PositionColored(1.0f, 1.0f, 1.0f, 0x00ff00ff));
    data.Write(new CustomVertex.PositionColored(1.0f, -1.0f, 1.0f, 0x00ff00ff));
    data.Write(new CustomVertex.PositionColored(-1.0f, 1.0f, -1.0f, 0x00ff00ff));
    data.Write(new CustomVertex.PositionColored(1.0f, 1.0f, -1.0f, 0x00ff00ff));
    data.Write(new CustomVertex.PositionColored(-1.0f, -1.0f, -1.0f, 0x00ff00ff));
    data.Write(new CustomVertex.PositionColored(1.0f, -1.0f, -1.0f, 0x00ff00ff));

    vb.Unlock();
}

using (IndexBuffer ib = mesh.IndexBuffer)
{
    ib.SetData(indices, 0, LockFlags.None);
}

See Also

• Unlock