/// <summary>
/// Binds the specified buffer's vertex attributes to the currently cached program using the old API.
/// </summary>
private unsafe void BindVertexAttributesForBuffer_OldAPI(OpenGLVertexBuffer vbuffer, UInt32 binding, UInt32 frequency, UInt32?program, UInt32?offset)
{
OpenGLState.BindArrayBuffer(vbuffer.OpenGLName);
var position = offset ?? this.offset;
foreach (var element in vbuffer.VertexDeclaration)
{
var name = GetVertexAttributeNameFromUsage(element.Usage, element.Index);
var size = 0;
var stride = 0;
var normalize = false;
var type = GetVertexFormatGL(element.Format, out size, out stride, out normalize);
var category = OpenGLAttribCategory.Single;
var location = (UInt32)OpenGLState.CurrentProgram.GetAttribLocation(name, out category);
if (location >= 0)
{
if (program.HasValue)
{
if (gl.IsInstancedRenderingAvailable)
{
gl.VertexAttribDivisor(location, frequency);
gl.ThrowIfError();
}
else
{
if (frequency != 0)
{
throw new NotSupportedException(OpenGLStrings.InstancedRenderingNotSupported);
}
}
gl.EnableVertexAttribArray(location);
gl.ThrowIfError();
}
switch (category)
{
case OpenGLAttribCategory.Single:
{
gl.VertexAttribPointer(location, size, type, normalize, vbuffer.VertexDeclaration.VertexStride, (void *)(position));
gl.ThrowIfError();
}
break;
case OpenGLAttribCategory.Double:
{
if (!gl.IsDoublePrecisionVertexAttribAvailable)
{
throw new NotSupportedException(OpenGLStrings.DoublePrecisionVAttribsNotSupported);
}
gl.VertexAttribLPointer(location, size, type, vbuffer.VertexDeclaration.VertexStride, (void *)(position));
gl.ThrowIfError();
}
break;
case OpenGLAttribCategory.Integer:
{
if (!gl.IsIntegerVertexAttribAvailable)
{
throw new NotSupportedException(OpenGLStrings.IntegerVAttribsNotSupported);
}
gl.VertexAttribIPointer(location, size, type, vbuffer.VertexDeclaration.VertexStride, (void *)(position));
gl.ThrowIfError();
}
break;
}
}
position += (uint)stride;
}
}
/// <summary>
/// Binds the specified buffer's vertex attributes to the currently cached program using the new API.
/// </summary>
private unsafe void BindVertexAttributesForBuffer_NewAPI(OpenGLVertexBuffer vbuffer, UInt32 binding, UInt32 frequency, UInt32?program, UInt32?offset)
{
using (OpenGLState.ScopedBindVertexArrayObject(vao, glElementArrayBufferBinding ?? 0))
{
if (program.HasValue || offset.HasValue)
{
gl.VertexArrayVertexBuffer(vao, binding, vbuffer.OpenGLName, (IntPtr)(offset ?? 0), vbuffer.VertexDeclaration.VertexStride);
gl.ThrowIfError();
}
if (program.HasValue)
{
gl.VertexArrayBindingDivisor(vao, binding, frequency);
gl.ThrowIfError();
var position = 0u;
foreach (var element in vbuffer.VertexDeclaration)
{
var name = GetVertexAttributeNameFromUsage(element.Usage, element.Index);
var size = 0;
var stride = 0;
var normalize = false;
var type = GetVertexFormatGL(element.Format, out size, out stride, out normalize);
var category = OpenGLAttribCategory.Single;
var location = (UInt32)OpenGLState.CurrentProgram.GetAttribLocation(name, out category);
if (location >= 0)
{
gl.VertexArrayAttribBinding(vao, location, binding);
gl.ThrowIfError();
gl.EnableVertexArrayAttrib(vao, location);
gl.ThrowIfError();
unsafe
{
switch (category)
{
case OpenGLAttribCategory.Single:
{
gl.VertexArrayAttribFormat(vao, location, size, type, normalize, position);
gl.ThrowIfError();
}
break;
case OpenGLAttribCategory.Double:
{
if (!gl.IsDoublePrecisionVertexAttribAvailable)
{
throw new NotSupportedException(OpenGLStrings.DoublePrecisionVAttribsNotSupported);
}
gl.VertexArrayAttribLFormat(vao, location, size, type, position);
gl.ThrowIfError();
}
break;
case OpenGLAttribCategory.Integer:
{
if (!gl.IsIntegerVertexAttribAvailable)
{
throw new NotSupportedException(OpenGLStrings.IntegerVAttribsNotSupported);
}
gl.VertexArrayAttribIFormat(vao, location, size, type, position);
gl.ThrowIfError();
}
break;
}
}
}
position += (uint)stride;
}
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="VertexBufferBinding"/> structure.
/// </summary>
/// <param name="vbuffer">The vertex buffer which is bound to the geometry stream.</param>
/// <param name="instanceFrequency">The number of instances which are drawn for each
/// set of data in the vertex buffer.</param>
public VertexBufferBinding(OpenGLVertexBuffer vbuffer, Int32 instanceFrequency)
{
this.VertexBuffer = vbuffer;
this.InstanceFrequency = instanceFrequency;
}
