IndexBuffer Class |
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Manipulates an index buffer resource.
Visual Basic NotInheritable Public Class IndexBuffer
Inherits Resource
Implements IDisposableC# public sealed class IndexBuffer : Resource, IDisposable C++ public ref class IndexBuffer sealed : Resource, IDisposable JScript public final class IndexBuffer extends Resource implements IDisposable
This object inherits additional functionality from the Resource object.
Read and Write VertexBuffer and IndexBuffer Data With GraphicsStreams
This example demonstrates how to use GraphicsStream objects to fill and retrieve data from a VertexBuffer and IndexBuffer objects.
[C#]
In the following C# code example, a VertexBuffer object is created using a flexible vertex format (FVF) type defined by the PositionNormalTexVertex structure. The vertex buffer data is then locked using its offset and size in bytes. A GraphicsStream object is returned which is derived from Stream
and can be used in a similar fashon. In the code example, the Write method is used to copy data into the stream from an array of vertex data.
The second part of the method shows use of GraphicsStream using unsafe data access. The InternalDataPointerGraphicsStream.InternalData property returns a void pointer to the vertex buffer data. In this code example, the data is cast to an array of PositionNormalTexVertex structures which makes data manipulation more readable.
using System; using Microsoft.DirectX; using Microsoft.DirectX.Direct3D; public struct PositionNormalTexVertex { public Vector3 Position; public Vector3 Normal; public float Tu0, Tv0; public static readonly VertexFormats FVF = VertexFormats.Position | VertexFormats.Texture1; } public class Example { public unsafe void GraphicsStreamReadWrite() { //Create a vertex buffer in the managed pool VertexBuffer vb = new VertexBuffer(typeof(PositionNormalTexVertex), 100, device, Usage.None, PositionNormalTexVertex.FVF, Pool.Managed); //First, fill an array of PositionNormalTexVertex elements with data. PositionNormalTexVertex[] vertices = new PositionNormalTexVertex[50]; for(int i=0; i<50; i++) { //fill the vertices with some data... vertices[i].Position = new Vector3(3f,4f,5f); } //The size of the verticies are 32-bytes each (float3 (12) + float3 (12) + float(4) + float(4)) //To lock 50 verticies, the size of the lock would be 1600 (32 * 50) GraphicsStream vbData = vb.Lock(0,1600, LockFlags.None); //copy the vertex data into the vertex buffer vbData.Write(vertices); //Unlock the VB vb.Unlock(); //This time, lock the entire VertexBuffer vbData = vb.Lock(0, 3200, LockFlags.None); //Cast the InternalDataPointer (a void pointer) to an array of verticies PositionNormalTexVertex* vbArray = (PositionNormalTexVertex*) vbData.InternalDataPointer; for(int i=0; i<100; i++) { //perform some operations on the data vbArray[i].Tu0 = i; vbArray[i].Tv0 = vbArray[i].Tu0 * 2; Console.WriteLine(vbArray[i].Tv0.ToString()); } //Unlock the buffer vb.Unlock(); vb.Dispose(); } }Read and Write VertexBuffer Data With Arrays
This example demonstrates how to use arrays to fill and retrieve data from a VertexBuffer and IndexBuffer objects.
[C#]
In the following C# code example, a VertexBuffer object is created using a FVF type defined by the PositionNormalTexVertex structure. The first part of the code sample shows the use of Lock to lock an arbitrary number of vertices and fill them with data. The second part shows how to lock an entire VertexBuffer for reading and retrieving data from the array. A similar procedure can be used to write to and read from nearly all Microsoft Direct3D resource types.
Using Arrays
using System; using Microsoft.DirectX; using Microsoft.DirectX.Direct3D; public struct PositionNormalTexVertex { public Vector3 Position; public Vector3 Normal; public float Tu0, Tv0; public static readonly VertexFormats FVF = VertexFormats.Position | VertexFormats.Texture1; } public class Example { public void ArrayBasedReadWrite() { //Create a vertex buffer in the managed pool VertexBuffer vb = new VertexBuffer(typeof(PositionNormalTexVertex), 100, device, Usage.None, PositionNormalTex1Vertex.FVF, Pool.Managed); //Fill an array of the appropriate type with the VB data using Lock() PositionNormalTexVertex[] vbData = (PositionNormalTexVertex[]) vb.Lock(0, typeof(PositionNormalTexVertex), LockFlags.None, 50); for(int i=0; i<50; i++) { //set your vertices to something... vbData[i].Position = new Vector3(2f,2f,2f); vbData[i].Normal = new Vector3(1f,0f,0f); vbData[i].Tu0 = i; vbData[i].Tv0 = i; } //Unlock the vb before you can use it elsewhere vb.Unlock(); //This lock overload simply locks the entire VB -- setting ReadOnly can improve perf when reading a vertexbuffer vbData = (PositionNormalTexVertex[]) vb.Lock(0, LockFlags.ReadOnly); for(int i=0; i<100; i++) { //read some vertex data Console.WriteLine("Vertex " + i + "Tu: " + vbData[i].Tu0 + " , Tv: " + vbData[i].Tv0); } //Unlock the buffer vb.Unlock(); vb.Dispose(); } }
Namespace Microsoft.DirectX.Direct3D Assembly Microsoft.DirectX.Direct3D (microsoft.directx.direct3d.dll) Strong Name Microsoft.DirectX.Direct3D, Version=1.0.900.0, Culture=neutral, PublicKeyToken=d3231b57b74a1492
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