72 lines
1.4 KiB
Go
72 lines
1.4 KiB
Go
package machine
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import "tetris/game/state"
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type Machine struct {
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current state.Handler
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pending string
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registry map[string]state.Handler
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}
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// New creates an empty machine.
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func New() *Machine {
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return &Machine{registry: make(map[string]state.Handler)}
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}
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// Register binds a name to a factory that returns a fresh state.Handler.
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func (m *Machine) Register(name string, handler state.Handler) {
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m.registry[name] = handler
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}
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// Start switches to the named initial state immediately (calls Enter()).
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func (m *Machine) Start(name string) {
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m.switchNow(name)
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}
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// Switch queues a transition to be applied after the current Update finishes.
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func (m *Machine) Switch(name string) {
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if name == "" || name == m.pending {
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return
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}
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m.pending = name
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}
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// Update ticks the current state, then applies any queued transition.
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func (m *Machine) Update(delta float32) bool {
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if m.current == nil {
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return false
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}
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m.current.Update(m, delta)
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if m.pending != "" {
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if m.pending == "quit" {
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return false
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}
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next := m.pending
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m.pending = ""
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m.switchNow(next)
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}
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return true
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}
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// Render proxies to current state.
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func (m *Machine) Render() {
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if m.current != nil {
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m.current.Render()
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}
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}
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func (m *Machine) switchNow(name string) {
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handler, ok := m.registry[name]
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if !ok {
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// Unknown state: dont switch.
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return
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}
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if m.current != nil {
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m.current.Exit()
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}
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m.current = handler
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m.current.Enter()
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}
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