resize method
Implementation
void resize(int width, int height) {
if (_width != width || _height != height) {
_width = width;
_height = height;
if (_renderContext == null || _renderbuffer == null) return;
if (_renderContext!.contextIdentifier != contextIdentifier) return;
_renderContext!.activateRenderStencilBuffer(this);
_renderingContext!.renderbufferStorage(
gl.WebGL.RENDERBUFFER, gl.WebGL.DEPTH_STENCIL, _width, _height);
}
}