/// <summary>
/// Constructor, sets up transform parameters.
/// See <href>https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/glBeginTransformFeedback.xhtml</href>
/// </summary>
/// <param name="primitivetype">Primitive type for transform feedback (Points/Lines/Triangles) </param>
/// <param name="transformfeedback">The GLTransformfeedback instance, previously created. Created externally as it does not have to be created per render</param>
/// <param name="buffers">An array of buffers to receive the transform feedback into, starting at index 0. Must be created and allocated with DynamicCopy. See <href>https://www.khronos.org/opengl/wiki/Transform_Feedback</href> for details on how to use multiple buffers</param>
/// <param name="offset">Offset into buffer if size != -1</param>
/// <param name="size">Buffer area allocated. If size == -1, all of buffer</param>
public GLOperationTransformFeedback(TransformFeedbackPrimitiveType primitivetype, GLTransformFeedback transformfeedback,
GLBuffer[] buffers, int[] offset = null, int[] size = null)
{
this.PrimitiveType = primitivetype;
this.TransformFeedback = transformfeedback;
this.Id = TransformFeedback.Id; // mirror the ID, we are the same
this.VaryingBuffers = buffers;
this.Offsets = offset;
this.Sizes = size;
}
public void BeginTransformFeedback(PrimitiveTopology topology)
{
GL.BeginTransformFeedback(_tfTopology = topology.ConvertToTfType());
_tfEnabled = true;
}
// use to start/end up the bound transform (either default or this one)
/// <summary> Start feedback on the primitive type </summary>
public static void Begin(TransformFeedbackPrimitiveType t)
{
GL.BeginTransformFeedback(t);
}
/// <summary>
/// Start transform feedback operation.
/// </summary>
/// <param name="primitiveMode">Specify the output type of the primitives that will be recorded into the buffer objects that are bound for transform feedback.</param>
public void Begin(TransformFeedbackPrimitiveType primitiveMode)
{
AssertActive();
GL.BeginTransformFeedback(primitiveMode);
}
