internal int GetLayout(VertexDescription description, Shader shader)
{
if (!OpenGLCapabilities.VertexAttribBinding)
{
throw new PlatformNotSupportedException("VertexAttribBinding (separat vertex attributes) are not supported by the driver");
}
int layout;
if (inputLayoutPool.TryGetValue(description, out layout))
{
return(layout);
}
layout = GL.GenVertexArray();
if (OpenGLCapabilities.DirectStateAccess == DirectStateAccess.None)
{
BindManager.VertexArray = layout;
int offset = 0;
VertexElement[] elements = description.GetElements();
for (int i = 0; i < description.ElementCount; i++)
{
if (offset > OpenGLCapabilities.MaxVertexAttribBindingOffset)
{
throw new PlatformNotSupportedException("offset is higher than maximum supportet offset.");
}
GL.EnableVertexAttribArray(i);
GL.VertexAttribBinding(i, 0);
GL.VertexAttribFormat(i, GetComponentsOf(elements[i].Type), VertexAttribType.Float, false, offset);
offset += GetSizeOf(elements[i].Type);
}
}
else if (OpenGLCapabilities.DirectStateAccess == DirectStateAccess.Extension)
{
int offset = 0;
VertexElement[] elements = description.GetElements();
for (int i = 0; i < description.ElementCount; i++)
{
if (offset > OpenGLCapabilities.MaxVertexAttribBindingOffset)
{
throw new PlatformNotSupportedException("offset is higher than maximum supportet offset.");
}
Ext.EnableVertexArrayAttrib(layout, i);
Ext.VertexArrayVertexAttribBinding(layout, i, elements[i].UsageIndex);
Ext.VertexArrayVertexAttribFormat(layout, i, GetComponentsOf(elements[i].Type), (OpenTK.Graphics.OpenGL.ExtDirectStateAccess)VertexAttribType.Float, false, offset);
offset += GetSizeOf(elements[i].Type);
}
}
inputLayoutPool.Add(description, layout);
return(layout);
}