/// <summary>
/// </summary>
/// <param name="offset"> </param>
/// <param name="length"> </param>
/// <param name="locking"> </param>
/// <returns> </returns>
protected override BufferBase LockImpl(int offset, int length, BufferLocking locking)
{
All access = 0;
if (isLocked)
{
throw new AxiomException("Invalid attempt to lock an index buffer that has already been locked");
}
BufferBase retPtr = null;
if (length < MapBufferThreshold)
{
retPtr = ((GLESHardwareBufferManager)HardwareBufferManager.Instance).AllocateScratch(length);
if (retPtr != null)
{
this._lockedToScratch = true;
this._scratchOffset = offset;
this._scratchSize = length;
this._scratchPtr = retPtr;
this._scratchUploadOnUnlock = (locking != BufferLocking.ReadOnly);
if (locking != BufferLocking.Discard)
{
this.ReadData(offset, length, retPtr);
}
}
}
else
{
throw new AxiomException("Invalid Buffer lockSize");
}
if (retPtr == null)
{
OpenGL.BindBuffer(All.ElementArrayBuffer, this._bufferId);
GLESConfig.GlCheckError(this);
// Use glMapBuffer
if (locking == BufferLocking.Discard)
{
OpenGL.BufferData(All.ElementArrayBuffer, new IntPtr(sizeInBytes), IntPtr.Zero, GLESHardwareBufferManager.GetGLUsage(usage));
GLESConfig.GlCheckError(this);
}
if ((usage & BufferUsage.WriteOnly) != 0)
{
access = All.WriteOnlyOes;
}
IntPtr pBuffer = OpenGLOES.MapBuffer(All.ElementArrayBuffer, access);
GLESConfig.GlCheckError(this);
if (pBuffer == IntPtr.Zero)
{
throw new AxiomException("Index Buffer: Out of memory");
}
unsafe
{
// return offset
retPtr = BufferBase.Wrap(pBuffer, sizeInBytes);
}
this._lockedToScratch = false;
}
isLocked = true;
return(retPtr);
}
