VertexBuffer.Lock Method

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How Do I...?

Create a Mesh Object

Locks a range of vertex data and obtains the vertex buffer memory.

Definition

Visual Basic Public Function Lock( _
    ByVal offsetToLock As Integer, _
    ByVal sizeToLock As Integer, _
    ByVal flags As LockFlags _
) As GraphicsStream

C# public GraphicsStream Lock(
    int offsetToLock,
    int sizeToLock,
    LockFlags flags
);

C++ public:
GraphicsStream^ Lock(
    int offsetToLock,
    int sizeToLock,
    LockFlags flags
);

JScript public function Lock(
    offsetToLock : int,
    sizeToLock : int,
    flags : LockFlags
) : GraphicsStream;

Visual Basic	Public Function Lock( _ ByVal offsetToLock As Integer, _ ByVal sizeToLock As Integer, _ ByVal flags As LockFlags _ ) As GraphicsStream
C#	public GraphicsStream Lock( int offsetToLock, int sizeToLock, LockFlags flags );
C++	public: GraphicsStream^ Lock( int offsetToLock, int sizeToLock, LockFlags flags );
JScript	public function Lock( offsetToLock : int, sizeToLock : int, flags : LockFlags ) : GraphicsStream;

Parameters

offsetToLock System.Int32
Offset into the vertex data to lock, in bytes. To lock the entire vertex buffer, specify 0 for both param_Int32_sizeToLock and param_Int32_offsetToLock.

sizeToLock System.Int32
Size of the vertex data to lock, in bytes. To lock the entire vertex buffer, specify 0 for both param_Int32_sizeToLock and param_Int32_offsetToLock.

flags Microsoft.DirectX.Direct3D.LockFlags
Zero or more LockFlags locking flags that describe the type of lock to perform. For this method, the valid flags are Discard, NoDirtyUpdate, NoSystemLock, ReadOnly, and NoOverWrite. For a description of the flags, see LockFlags.

Return Value

Microsoft.DirectX.GraphicsStream
A GraphicsStream object that represents the locked vertex buffer.

Remarks

When working with vertex buffers, multiple lock calls are allowed; however, the number of lock calls must match the number of unlock calls. Any outstanding lock count on any currently set vertex buffer causes the DrawPrimitives calls to fail.

When using a Lock method to retrieve an Array from a resource that was not created with a Type , always use the overload that accepts a Type . Use the ranks parameter to indicate the number of members in the returned Array .

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);
}

offsetToLock	System.Int32 Offset into the vertex data to lock, in bytes. To lock the entire vertex buffer, specify 0 for both param_Int32_sizeToLock and param_Int32_offsetToLock.
sizeToLock	System.Int32 Size of the vertex data to lock, in bytes. To lock the entire vertex buffer, specify 0 for both param_Int32_sizeToLock and param_Int32_offsetToLock.
flags	Microsoft.DirectX.Direct3D.LockFlags Zero or more LockFlags locking flags that describe the type of lock to perform. For this method, the valid flags are Discard, NoDirtyUpdate, NoSystemLock, ReadOnly, and NoOverWrite. For a description of the flags, see LockFlags.