dispose method
Releases GPU resources and resets internal state.
Implementation
@override
void dispose(RenderingContext gl) {
if (_tex != null) {
try {
gl.deleteTexture(_tex!);
} catch (_) {}
_tex = null;
}
if (_program != null) {
try {
gl.deleteProgram(_program!);
} catch (_) {}
_program = null;
}
_uBg = _uViewport = _uFocal = _uInvViewRot = _uBgRot = null;
}