dispose method
Free GL resources. Safe to call multiple times.
Implementation
@override
void dispose(RenderingContext gl) {
if (_prog != null) gl.deleteProgram(_prog!);
if (_vbo != null) gl.deleteBuffer(_vbo!);
if (_ebo != null) gl.deleteBuffer(_ebo!);
_prog = null;
_vbo = null;
_ebo = null;
_aPosition = null;
_uProjection = _uView = _uFocal = _uViewport =
_uSplatCount = _uOrderTexture = _uTexture = _uMaxSplatSize = null;
}