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VertexBuffer.Lock(Int32,Int32,LockFlags) Method (Microsoft.DirectX.Direct3D)

  • Article

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;

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 ArrayLeave Site from a resource that was not created with a TypeLeave Site, always use the overload that accepts a TypeLeave Site. Use the ranks parameter to indicate the number of members in the returned ArrayLeave Site.

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