func (q *commandQueue) Enqueue(command command) {
	// TODO: If dst is the screen, reorder the command to be the last.
	q.commands = append(q.commands, command)
}
func (q *commandQueue) Enqueue(command command) {
	// TODO: If dst is the screen, reorder the command to be the last.
	q.commands = append(q.commands, command)
}
// Enqueue enqueues a drawing command other than a draw-image command.
//
// For a draw-image command, use EnqueueDrawTrianglesCommand.