/// <summary>
/// Creates a sub-type of <see cref="GLBuffer"/> object directly in server side(GPU) without initializing its value.
/// </summary>
/// <param name="target"></param>
/// <param name="elementType"></param>
/// <param name="length"></param>
/// <param name="usage"></param>
/// <returns></returns>
public static GLBuffer Create(IndependentBufferTarget target, Type elementType, int length, BufferUsage usage)
{
if (!elementType.IsValueType)
{
throw new ArgumentException(string.Format("{0} must be a value type!", elementType));
}
uint bufferTarget = (uint)target;
int byteLength = Marshal.SizeOf(elementType) * length;
uint[] buffers = new uint[1];
glGenBuffers(1, buffers);
glBindBuffer(bufferTarget, buffers[0]);
glBufferData(bufferTarget, byteLength, IntPtr.Zero, (uint)usage);
glBindBuffer(bufferTarget, 0);
GLBuffer buffer;
switch (target)
{
case IndependentBufferTarget.AtomicCounterBuffer:
buffer = new AtomicCounterBuffer(buffers[0], length, byteLength);
break;
case IndependentBufferTarget.PixelPackBuffer:
buffer = new PixelPackBuffer(buffers[0], length, byteLength);
break;
case IndependentBufferTarget.PixelUnpackBuffer:
buffer = new PixelUnpackBuffer(buffers[0], length, byteLength);
break;
case IndependentBufferTarget.ShaderStorageBuffer:
buffer = new ShaderStorageBuffer(buffers[0], length, byteLength);
break;
case IndependentBufferTarget.TextureBuffer:
buffer = new TextureBuffer(buffers[0], length, byteLength);
break;
case IndependentBufferTarget.UniformBuffer:
buffer = new UniformBuffer(buffers[0], length, byteLength);
break;
case IndependentBufferTarget.TransformFeedbackBuffer:
buffer = new TransformFeedbackBuffer(buffers[0], length, byteLength);
break;
default:
throw new Exception("Unexpected IndependentBufferTarget!");
}
return(buffer);
}
///// <summary>
///// Generates an atomic counter buffer.
///// </summary>
///// <param name="array"></param>
///// <param name="usage"></param>
///// <returns></returns>
//public static AtomicCounterBuffer GenAtomicCounterBuffer(this UnmanagedArrayBase array, BufferUsage usage)
//{
// return GenIndependentBuffer(array, IndependentBufferTarget.AtomicCounterBuffer, usage) as AtomicCounterBuffer;
//}
///// <summary>
///// Generates a pixel pack buffer.
///// </summary>
///// <param name="array"></param>
///// <param name="usage"></param>
///// <returns></returns>
//public static PixelPackBuffer GenPixelPackBuffer(this UnmanagedArrayBase array, BufferUsage usage)
//{
// return GenIndependentBuffer(array, IndependentBufferTarget.PixelPackBuffer, usage) as PixelPackBuffer;
//}
///// <summary>
///// Generates a pixel unpack buffer.
///// </summary>
///// <param name="array"></param>
///// <param name="usage"></param>
///// <returns></returns>
//public static PixelUnpackBuffer GenPixelUnpackBuffer(this UnmanagedArrayBase array, BufferUsage usage)
//{
// return GenIndependentBuffer(array, IndependentBufferTarget.PixelUnpackBuffer, usage) as PixelUnpackBuffer;
//}
///// <summary>
///// Generates a shader storage buffer.
///// </summary>
///// <param name="array"></param>
///// <param name="usage"></param>
///// <returns></returns>
//public static ShaderStorageBuffer GenShaderStorageBuffer(this UnmanagedArrayBase array, BufferUsage usage)
//{
// return GenIndependentBuffer(array, IndependentBufferTarget.ShaderStorageBuffer, usage) as ShaderStorageBuffer;
//}
///// <summary>
///// Generates a texture buffer.
///// </summary>
///// <param name="array"></param>
///// <param name="usage"></param>
///// <returns></returns>
//public static TextureBuffer GenTextureBuffer(this UnmanagedArrayBase array, BufferUsage usage)
//{
// return GenIndependentBuffer(array, IndependentBufferTarget.TextureBuffer, usage) as TextureBuffer;
//}
///// <summary>
///// Generates an uniform buffer.
///// </summary>
///// <param name="array"></param>
///// <param name="usage"></param>
///// <returns></returns>
//public static UniformBuffer GenUniformBuffer(this UnmanagedArrayBase array, BufferUsage usage)
//{
// return GenIndependentBuffer(array, IndependentBufferTarget.UniformBuffer, usage) as UniformBuffer;
//}
/// <summary>
/// Generates an independent buffer.
/// </summary>
/// <param name="array"></param>
/// <param name="bufferTarget"></param>
/// <param name="usage"></param>
/// <returns></returns>
private static GLBuffer GenIndependentBuffer(this UnmanagedArrayBase array, IndependentBufferTarget bufferTarget, BufferUsage usage)
{
uint[] ids = new uint[1];
{
glGenBuffers(1, ids);
var target = (uint)bufferTarget;
glBindBuffer(target, ids[0]);
glBufferData(target, array.ByteLength, array.Header, (uint)usage);
glBindBuffer(target, 0);
}
GLBuffer buffer = null;
switch (bufferTarget)
{
case IndependentBufferTarget.AtomicCounterBuffer:
buffer = new AtomicCounterBuffer(ids[0], array.Length, array.ByteLength);
break;
case IndependentBufferTarget.PixelPackBuffer:
buffer = new PixelPackBuffer(ids[0], array.Length, array.ByteLength);
break;
case IndependentBufferTarget.PixelUnpackBuffer:
buffer = new PixelUnpackBuffer(ids[0], array.Length, array.ByteLength);
break;
case IndependentBufferTarget.ShaderStorageBuffer:
buffer = new ShaderStorageBuffer(ids[0], array.Length, array.ByteLength);
break;
case IndependentBufferTarget.TextureBuffer:
buffer = new TextureBuffer(ids[0], array.Length, array.ByteLength);
break;
case IndependentBufferTarget.UniformBuffer:
buffer = new UniformBuffer(ids[0], array.Length, array.ByteLength);
break;
case IndependentBufferTarget.TransformFeedbackBuffer:
buffer = new TransformFeedbackBuffer(ids[0], array.Length, array.ByteLength);
break;
default:
throw new NotDealWithNewEnumItemException(typeof(IndependentBufferTarget));
}
return(buffer);
}
