release() {
    const gl = cc._renderContext;
    if (this.frameBuffer != null) {
      gl.deleteFramebuffer(this.frameBuffer);
    }
    if (this.renderBuffer != null) {
      gl.deleteRenderbuffer(this.renderBuffer);
    }
    if (this._quadBuffer != null) {
      gl.deleteBuffer(this._quadBuffer);
    }
    if (this.texture != null) {
      this.texture.releaseTexture();
    }
  }
Releases a render pass by cleaning up buffers and textures.