Android 2D graphics (circle, straight line, point) tool class (continuous update)

Android 2D graphics (circle, straight line, point) tool class (continuous update)

public class Circle {private PointF centerPoint;private float radius;public PointF getCenterPoint() {return centerPoint;}public void setCenterPoint(PointF centerPoint) {this.centerPoint = centerPoint;}public float getRadius() {return radius;}public void setRadius(float radius) {this.radius = radius;}}

Public class CircleUtils {/*** calculate the coordinates and radius of the center of the Circle based on the three points on the Circle * @ param pA * @ param pB * @ param pC * @ return */public static Circle getCircle (PointF pA, pointF pB, PointF pC) {float mat1, mat2, mat3; mat1 = (pB. x * pB. x + pB. y * pB. y)-(pA. x * pA. x + pA. y * pA. y) * (2 * (pC. y-pA.y)-(pC. x * pC. x + pC. y * pC. y)-(pA. x * pA. x + pA. y * pA. y) * (2 * (pB. y-pA.y); mat2 = (2 * (pB. x-pA.x) * (pC. x * pC. x + pC. y * pC. y)-(pA. x * pA. x + pA. y * pA. y)-(2 * (pC. x-pA.x) * (pB. x * pB. x + pB. y * pB. y)-(pA. x * pA. x + pA. y * pA. y); mat3 = 4 * (pB. x-pA.x) * (pC. y-pA.y)-(pC. x-pA.x) * (pB. y-pA.y); Circle circle = new Circle (); PointF centerPoint = new PointF (); float radius; centerPoint. x = mat1/mat3; centerPoint. y = mat2/mat3; radius = (float) Math. sqrt (pA. x-centerPoint.x. x-centerPoint.x) +. y-centerPoint.y. y-centerPoint.y); circle. setCenterPoint (centerPoint); circle. setRadius (radius); return circle ;} /*** obtain the coordinates of another point on both ends of an arc * @ param circle * @ param startP the point on one end of the arc * @ param angle of the arc * @ return */public PointF getEndPointOfArc (Circle circle, pointF startP, float angle) {PointF centerP = circle. getCenterPoint (); PointF endPointF = new PointF (); endPointF. x = (float) (centerP. x + (startP. x-centerP.x) * Math. cos (angle * Math. PI/180)-(startP. y-centerP.y) * Math. sin (angle * Math. PI/180); endPointF. y = (float) (centerP. y + (startP. x-centerP.x) * Math. sin (angle * Math. PI/180) + (startP. y-centerP.y) * Math. cos (angle * Math. PI/180); return endPointF ;}}