WIP #212 Light card support

lib/plugins/circular_slider/utils.dart

@@ -0,0 +1,75 @@
+import 'dart:math';
+import 'dart:ui';
+
+double percentageToRadians(double percentage) => ((2 * pi * percentage) / 100);
+
+double radiansToPercentage(double radians) {
+  var normalized = radians < 0 ? -radians : 2 * pi - radians;
+  var percentage = ((100 * normalized) / (2 * pi));
+  // TODO we have an inconsistency of pi/2 in terms of percentage and radians
+  return (percentage + 25) % 100;
+}
+
+double coordinatesToRadians(Offset center, Offset coords) {
+  var a = coords.dx - center.dx;
+  var b = center.dy - coords.dy;
+  return atan2(b, a);
+}
+
+Offset radiansToCoordinates(Offset center, double radians, double radius) {
+  var dx = center.dx + radius * cos(radians);
+  var dy = center.dy + radius * sin(radians);
+  return Offset(dx, dy);
+}
+
+double valueToPercentage(int time, int intervals) => (time / intervals) * 100;
+
+int percentageToValue(double percentage, int intervals) =>
+    ((percentage * intervals) / 100).round();
+
+bool isPointInsideCircle(Offset point, Offset center, double rradius) {
+  var radius = rradius * 1.2;
+  return point.dx < (center.dx + radius) &&
+      point.dx > (center.dx - radius) &&
+      point.dy < (center.dy + radius) &&
+      point.dy > (center.dy - radius);
+}
+
+bool isPointAlongCircle(Offset point, Offset center, double radius) {
+  // distance is root(sqr(x2 - x1) + sqr(y2 - y1))
+  // i.e., (7,8) and (3,2) -> 7.21
+  var d1 = pow(point.dx - center.dx, 2);
+  var d2 = pow(point.dy - center.dy, 2);
+  var distance = sqrt(d1 + d2);
+  return (distance - radius).abs() < 10;
+}
+
+double getSweepAngle(double init, double end) {
+  if (end > init) {
+    return end - init;
+  }
+  return (100 - init + end).abs();
+}
+
+List<Offset> getSectionsCoordinatesInCircle(
+    Offset center, double radius, int sections) {
+  var intervalAngle = (pi * 2) / sections;
+  return List<int>.generate(sections, (int index) => index).map((i) {
+    var radians = (pi / 2) + (intervalAngle * i);
+    return radiansToCoordinates(center, radians, radius);
+  }).toList();
+}
+
+bool isAngleInsideRadiansSelection(double angle, double start, double sweep) {
+  var normalized = angle > pi / 2 ? 5 * pi / 2 - angle : pi / 2 - angle;
+  var end = (start + sweep) % (2 * pi);
+  return end > start
+      ? normalized > start && normalized < end
+      : normalized > start || normalized < end;
+}
+
+// this is not 100% accurate but it works
+// we just want to see if a value changed drastically its value
+bool radiansWasModuloed(double current, double previous) {
+  return (previous - current).abs() > (3 * pi / 2);
+}