add pattern effects.

effects/pattern.go

@@ -0,0 +1,24 @@
+package effects
+
+import (
+	"fmt"
+	"git.aiterp.net/lucifer3/server/device"
+	"time"
+)
+
+type Pattern struct {
+	States  []device.State `json:"states,omitempty"`
+	ShiftMS int64          `json:"shiftMs,omitempty"`
+}
+
+func (p Pattern) State(index, round, _ int) device.State {
+	return p.States[(index+round)%len(p.States)]
+}
+
+func (p Pattern) Frequency() time.Duration {
+	return time.Duration(p.ShiftMS) * time.Millisecond
+}
+
+func (p Pattern) EffectDescription() string {
+	return fmt.Sprintf("Pattern(len:%d, animation:%dms)", len(p.States), p.ShiftMS)
+}