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Circle

Introduction

Circle shape and methods, built-in methods of phaser.

  • Author: Richard Davey

Usage

Create shape

var circle = new Phaser.Geom.Circle(x, y, radius);

Clone shape

var circle1 = Phaser.Geom.Circle.Clone(circle0);

Draw on graphics

  • Fill shape 
    // graphics.fillStyle(color, alpha);   // color: 0xRRGGBB
graphics.fillCircleShape(circle);
  • Stroke shape 
    // graphics.lineStyle(lineWidth, color, alpha);   // color: 0xRRGGBB
graphics.strokeCircleShape(circle);

Note

Negative radius will be treated as positive radius. i.e. Math.abs(radius)

Set properties

  • All properties 
    circle.setTo(x, y, radius);
    or 
    Phaser.Geom.Circle.CopyFrom(source, dest);
  • Position 
    circle.setPosition(x, y);
    or 
    circle.x = 0;
circle.y = 0;
    or 
    circle.left = 0;       // circle.x
circle.top = 0;        // circle.y
// circle.right = 0;   // circle.x
// circle.bottom = 0;  // circle.y
    or 
    Phaser.Geom.Circle.Offset(circle, dx, dy); // circle.x += dx, circle.y += dy
    or 
    Phaser.Geom.Circle.OffsetPoint(circle, point); // circle.x += point.x, circle.y += point.y
  • Radius 
    circle.radius = radius;
    or 
    circle.diameter = diameter;  // diameter = 2 * radius

Get properties

  • Position 
    var x = circle.x;
var y = circle.y;
var top = circle.top;
var left = circle.left;
var right = circle.right;
var bottom = circle.bottom;
  • Radius 
    var radius = circle.radius;
// var diameter = circle.diameter;
  • Bound 
    var bound = Phaser.Geom.Circle.GetBounds(circle);
// var bound = Phaser.Geom.Circle.GetBounds(circle, bound);  // push bound
    • bound : A Rectangle shape object
  • Area 
    var area = Phaser.Geom.Circle.Area(circle);
  • Circumference 
    var circumference = Phaser.Geom.Circle.Circumference(circle);
  • Type: 
    var type = circle.type; // 0

Point(s) & shape

  • Get point at shape's edge 
    var point = circle.getPoint(t);  // t : 0 ~ 1 (angle/360)
// var point = circle.getPoint(t, point);  // modify point
    or 
    var point = Phaser.Geom.Circle.CircumferencePoint(circle, angle);  // angle in degrees
// var point = Phaser.Geom.Circle.CircumferencePoint(circle, angle, point);  // modify point
  • Get a random point inside shape 
    var point = circle.getRandomPoint();
// var point = circle.getRandomPoint(point);  // modify point
  • Get points around shape's edge 
    var points = circle.getPoints(quantity);
// var points = circle.getPoints(quantity, null, points);  // push points
    or calculate quantity from steps 
    var points = circle.getPoints(false, step);
// var points = circle.getPoints(false, step, points);  // push points
    • points : an array of point
  • Point is inside shape 
    var isInside = circle.contains(x, y);
    or 
    var isInside = Phaser.Geom.Circle.ContainsPoint(circle, point);
  • Rectangle is inside shape 
    var isInside = Phaser.Geom.Circle.ContainsRect(circle, rect);  // rect : 4 points

Empty

  • Set empty 
    circle.setEmpty();     // circle.radius = 0
  • Is empty 
    var isEmpty = circle.isEmpty();   // circle.radius <= 0

Equal

var isEqual = Phaser.Geom.Circle.Equals(circle0, circle1);

Position and radius are equal.

Intersection

Circle to circle

  • Is intersection 
    var result = Phaser.Geom.Intersects.CircleToCircle(circleA, circleB);
  • Get intersection points 
    var result = Phaser.Geom.Intersects.GetCircleToCircle(circleA, circleB);
// var out = Phaser.Geom.Intersects.GetCircleToCircle(circleA, circleB, out);

Circle to rectangle

  • Is intersection 
    var result = Phaser.Geom.Intersects.CircleToRectangle(circle, rect);
  • Get intersection points 
    var result = Phaser.Geom.Intersects.GetCircleToRectangle(circle, rect);
// var out = Phaser.Geom.Intersects.GetCircleToRectangle(circle, rect, out);

Circle to triangle

  • Is intersection 
    var result = Phaser.Geom.Intersects.TriangleToCircle(triangle, circle);
  • Get intersection points 
    var result = Phaser.Geom.Intersects.GetTriangleToCircle(triangle, circle);
// var out = Phaser.Geom.Intersects.GetTriangleToCircle(triangle, circle, out);

Circle to line

  • Is intersection 
    var result = Phaser.Geom.Intersects.LineToCircle(line, circle);
// var result = Phaser.Geom.Intersects.LineToCircle(line, circle, nearest);
    • nearest : Nearest point on line.
  • Get intersection points 
    var result = Phaser.Geom.Intersects.GetLineToCircle(line, circle);
// var out = Phaser.Geom.Intersects.GetLineToCircle(line, circle, out);