寒假学习（五）模拟图形绘制

case class Point(var x:Double,var y:Double) extends Drawable{
 def shift(deltaX:Double,deltaY:Double){x+=deltaX;y+=deltaY}
}
trait Drawable{
def draw(){println(this.toString)}
}
// 请完成 Shape 类、Line 类和 Circle 类的定义。
object MyDraw{
 def main(args: Array[String]) {
 val p=new Point(10,30) 
p.draw;
val line1 = new Line(Point(0,0),Point(20,20))
line1.draw
line1.moveTo(Point(5,5)) //移动到一个新的点
line1.draw
line1.zoom(2) //放大两倍
line1.draw
val cir= new Circle(Point(10,10),5)
cir.draw
cir.moveTo(Point(30,20))
cir.draw
cir.zoom(0.5)
cir.draw
 } 
}

case class Point(var x:Double,var y:Double) extends Drawable{
def shift(deltaX:Double,deltaY:Double){x+=deltaX;y+=deltaY}
}
trait Drawable{
def draw(){println(this.toString)}
}
abstract class Shape(var location:Point){//location是Shape的一个可变字段
def moveTo(newLocation:Point){ //默认实现，只是修改位置
location = newLocation
}
 def zoom(scale:Double)
}
class Line(beginPoint:Point,var endPoint:Point) extends 
Shape(beginPoint) with Drawable{
override def draw(){
println(s"Line:(${location.x},${location.y})--(${endPoint.x},${en
dPoint.y})")} //按指定格式重载click
override def moveTo(newLocation:Point){
endPoint.shift(newLocation.x - location.x,newLocation.y -
location.y) //直线移动时，先移动另外一个端点
location = newLocation //移动位置
}
override def zoom(scale:Double){
val midPoint = Point((endPoint.x + location.x)/2,(endPoint.y + 
location.y)/2) //求出中点，并按中点进行缩放
location.x = midPoint.x + scale * (location.x - midPoint.x)
location.y = midPoint.y + scale * (location.y -midPoint.y)
endPoint.x = midPoint.x + scale * (endPoint.x - midPoint.x)
endPoint.y = midPoint.y + scale * (endPoint.y -midPoint.y)
}}
class Circle(center:Point,var radius:Double) extends Shape(center) 
with Drawable{
override def draw(){//按指定格式重载click
println(s"Circle 
center:(${location.x},${location.y}),R=$radius")}
override def zoom(scale:Double){
radius = radius*scale //对圆的缩放只用修改半径
} }
object MyDraw{
 def main(args: Array[String]) {
 val p=new Point(10,30)
p.draw;
val line1 = new Line(Point(0,0),Point(20,20))
line1.draw
line1.moveTo(Point(5,5))
line1.draw
line1.zoom(2)
line1.draw
val cir= new Circle(Point(10,10),5)
cir.draw
cir.moveTo(Point(30,20))
cir.draw
cir.zoom(0.5)
cir.draw
 }
}