Add feedback components 106-130; inert scope, focus return, two-step deploy

feedback/feedback.go

@@ -0,0 +1,66 @@
+// Package feedback tells the player what is going on.
+package feedback
+
+import (
+	"strconv"
+	"time"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+// pingpong runs n back and forth over 0…span.
+func pingpong(n, span int) int {
+	if span <= 0 {
+		return 0
+	}
+	n %= 2 * span
+	if n > span {
+		return 2*span - n
+	}
+	return n
+}
+
+// level is Good, then Warn past warn, Bad past bad.
+func level(v, warn, bad float64) pixel.Slot {
+	switch {
+	case bad != 0 && v > bad:
+		return pixel.Bad
+	case warn != 0 && v > warn:
+		return pixel.Warn
+	}
+	return pixel.Good
+}
+
+// fmtNum prints a number without trailing zeros.
+func fmtNum(v float64) string { return strconv.FormatFloat(v, 'g', 4, 64) }
+
+type cueKey struct{}
+
+// cued is a cue's last value and when it changed.
+type cued struct {
+	n  int
+	at time.Time
+}
+
+// cue is when n last changed; zero until it does.
+func cue(e *ui.Element, k pixel.Kit, n int) time.Time {
+	s := ui.Local(e, cueKey{}, func() cued { return cued{n: n} })
+	if s.n != n {
+		s.n, s.at = n, k.Now()
+	}
+	return s.at
+}
+
+// since counts steps at fps from t, up to done.
+func since(c *ui.Context, k pixel.Kit, t time.Time, fps, done int) int {
+	if t.IsZero() {
+		return done
+	}
+	n := int(k.Now().Sub(t) * time.Duration(fps) / time.Second)
+	if n < done {
+		k.Tick(c, fps)
+	}
+	return min(n, done)
+}