Split into category packages; module github.com/ZacharyZhang-NY/MujicaUI

core/geometry.go

@@ -0,0 +1,28 @@
+package core
+
+import (
+	"math"
+
+	"github.com/egoist/mygo/ui"
+
+	"github.com/ZacharyZhang-NY/MujicaUI/internal"
+)
+
+// ProgressArc is the arc from turn a to turn b, clockwise from twelve o'clock.
+func ProgressArc(pt *ui.Painter, cx, cy, r float32, a, b float32) *ui.Path {
+	var p ui.Path
+	n := max(2, int(math.Ceil(float64((b-a)*64))))
+	for i := 0; i <= n; i++ {
+		t := float64(a + (b-a)*float32(i)/float32(n))
+		x := cx + r*float32(math.Sin(2*math.Pi*t))
+		y := cy - r*float32(math.Cos(2*math.Pi*t))
+		if i == 0 {
+			p.MoveTo(internal.Snap(pt, x), internal.Snap(pt, y))
+		} else {
+			p.LineTo(internal.Snap(pt, x), internal.Snap(pt, y))
+		}
+	}
+	return &p
+}
+
+func Abs32(v float32) float32 { return float32(math.Abs(float64(v))) }