/// <summary>
/// 将VBO上传到GPU后，就得到VBO的指针。CPU内存中的VBO数据就可以释放掉了。
/// VBO's pointer got from Buffer's GetBufferPtr() method. It's totally OK to free memory of unmanaged array stored in this buffer object now.
/// </summary>
/// <param name="bufferId">用glGenBuffers()得到的VBO的Id。<para>Id got from glGenBuffers();</para></param>
/// <param name="length">此VBO含有多个个元素？<para>How many elements?</para></param>
/// <param name="byteLength">此VBO中的数据在内存中占用多少个字节？<para>How many bytes in this buffer?</para></param>
internal BufferPtr(uint bufferId, int length, int byteLength)
{
if (glBindBuffer == null)
{
glBindBuffer = OpenGL.GetDelegateFor <OpenGL.glBindBuffer>();
glDeleteBuffers = OpenGL.GetDelegateFor <OpenGL.glDeleteBuffers>();
glMapBuffer = OpenGL.GetDelegateFor <OpenGL.glMapBuffer>();
glMapBufferRange = OpenGL.GetDelegateFor <OpenGL.glMapBufferRange>();
glUnmapBuffer = OpenGL.GetDelegateFor <OpenGL.glUnmapBuffer>();
}
this.BufferId = bufferId;
this.Length = length;
this.ByteLength = byteLength;
}
/// <summary>
/// Stop reading/writing buffer.
/// </summary>
/// <param name="unbind"></param>
public virtual bool UnmapBuffer(bool unbind = true)
{
if (glUnmapBuffer == null)
{
glUnmapBuffer = OpenGL.GetDelegateFor <OpenGL.glUnmapBuffer>();
}
bool result = glUnmapBuffer((uint)this.Target);
if (unbind)
{
if (glBindBuffer == null)
{
glBindBuffer = OpenGL.GetDelegateFor <OpenGL.glBindBuffer>();
}
glBindBuffer((uint)this.Target, 0);
}
return(result);
}
/// <summary>
/// Stop reading/writing buffer.
/// </summary>
/// <param name="unbind"></param>
public virtual bool UnmapBuffer(bool unbind = true)
{
if (glUnmapBuffer == null) { glUnmapBuffer = OpenGL.GetDelegateFor<OpenGL.glUnmapBuffer>(); }
bool result = glUnmapBuffer((uint)this.Target);
if (unbind)
{
if (glBindBuffer == null) { glBindBuffer = OpenGL.GetDelegateFor<OpenGL.glBindBuffer>(); }
glBindBuffer((uint)this.Target, 0);
}
return result;
}