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);