- private static final boolean isArcRectCollides(int arcX,int arcY,int arcR,int rectX,int rectY,int rectW,int rectH){
- int arcOx = arcX + arcR;//圆心X坐标
- int arcOy = arcY + arcR;//圆心Y坐标
- if(((rectX-arcOx) * (rectX-arcOx) + (rectY-arcOy) * (rectY-arcOy)) <= arcR * arcR)
- return true;
- if(((rectX+rectW-arcOx) * (rectX+rectW-arcOx) + (rectY-arcOy) * (rectY-arcOy)) <= arcR * arcR)
- return true;
- if(((rectX-arcOx) * (rectX-arcOx) + (rectY+rectH-arcOy) * (rectY+rectH-arcOy)) <= arcR * arcR)
- return true;
- if(((rectX+rectW-arcOx) * (rectX+rectW-arcOx) + (rectY+rectH-arcOy) * (rectY+rectH-arcOy)) <= arcR * arcR)
- return true;
- //分别判断矩形4个顶点与圆心的距离是否<=圆半径；如果<=，说明碰撞成功
- int minDisX = 0;
- if(arcOy >= rectY && arcOy <= rectY + rectH){
- if(arcOx < rectX)
- minDisX = rectX - arcOx;
- else if(arcOx > rectX + rectW)
- minDisX = arcOx - rectX - rectW;
- else
- return true;
- if(minDisX <= arcR)
- return true;
- }//判断当圆心的Y坐标进入矩形内时X的位置，如果X在(rectX-arcR)到(rectX+rectW+arcR)这个范围内，则碰撞成功
- int minDisY = 0;
- if(arcOx >= rectX && arcOx <= rectX + rectW){
- if(arcOy < rectY)
- minDisY = rectY - arcOy;
- else if(arcOy > rectY + rectH)
- minDisY = arcOy - rectY - rectH;
- else
- return true;
- if(minDisY <= arcR)
- return true;
- }//判断当圆心的X坐标进入矩形内时Y的位置，如果X在(rectY-arcR)到(rectY+rectH+arcR)这个范围内，则碰撞成功
- return false;
- }
/*
* arcX,arcY表示圆的绘制坐标，就是左上角坐标 ，arcR为圆半径；rectX，rectY，rectW，rectH分别表示矩形的绘制坐标与宽高
*/
private static final boolean isArcRectCollides(int arcX,int arcY,int arcR,int rectX,int rectY,int rectW,int rectH){
int arcOx = arcX + arcR;//圆心X坐标
int arcOy = arcY + arcR;//圆心Y坐标
if(((rectX-arcOx) * (rectX-arcOx) + (rectY-arcOy) * (rectY-arcOy)) <= arcR * arcR)
return true;
if(((rectX+rectW-arcOx) * (rectX+rectW-arcOx) + (rectY-arcOy) * (rectY-arcOy)) <= arcR * arcR)
return true;
if(((rectX-arcOx) * (rectX-arcOx) + (rectY+rectH-arcOy) * (rectY+rectH-arcOy)) <= arcR * arcR)
return true;
if(((rectX+rectW-arcOx) * (rectX+rectW-arcOx) + (rectY+rectH-arcOy) * (rectY+rectH-arcOy)) <= arcR * arcR)
return true;
//分别判断矩形4个顶点与圆心的距离是否<=圆半径；如果<=，说明碰撞成功
int minDisX = 0;
if(arcOy >= rectY && arcOy <= rectY + rectH){
if(arcOx < rectX)
minDisX = rectX - arcOx;
else if(arcOx > rectX + rectW)
minDisX = arcOx - rectX - rectW;
else
return true;
if(minDisX <= arcR)
return true;
}//判断当圆心的Y坐标进入矩形内时X的位置，如果X在(rectX-arcR)到(rectX+rectW+arcR)这个范围内，则碰撞成功
int minDisY = 0;
if(arcOx >= rectX && arcOx <= rectX + rectW){
if(arcOy < rectY)
minDisY = rectY - arcOy;
else if(arcOy > rectY + rectH)
minDisY = arcOy - rectY - rectH;
else
return true;
if(minDisY <= arcR)
return true;
}//判断当圆心的X坐标进入矩形内时Y的位置，如果X在(rectY-arcR)到(rectY+rectH+arcR)这个范围内，则碰撞成功
return false;
}
//假定矩形由d1,d2,d3,d4顶点按顺时针方向组成,ywz为圆心位置，yzj为圆直径。
int Y_ZFX_WZ(D3DXVECTOR2 &ywz,float &yzj,D3DXVECTOR2 &d1,D3DXVECTOR2 &d2,D3DXVECTOR2 &d3,D3DXVECTOR2 &d4)
{
float k,k1,k2;
k=4*pow((d2.x-d1.x)*(d2.x-ywz.x)+(d2.y-d1.y)*(d2.y-ywz.y),2)-4*(pow(d2.x-d1.x,2)+pow(d2.y-d1.y,2))*(pow(d1.x-ywz.x,2)+pow(d1.y-ywz.y,2)-pow(yzj,2));
//如果有在d2-d1确定的直线上有交点
if (k>=0)
{
k1=(-2*(d2.x-d1.x)*(d2.x-ywz.x)-2*(d2.y-d1.y)*(d2.y-ywz.y)+sqrt(k))/(2*(pow(d2.x-d1.x,2)+pow(d2.y-d1.y,2)));
k2=(-2*(d2.x-d1.x)*(d2.x-ywz.x)-2*(d2.y-d1.y)*(d2.y-ywz.y)-sqrt(k))/(2*(pow(d2.x-d1.x,2)+pow(d2.y-d1.y,2)));
if ((k1>0)&&(k1<1)) return 2;
if ((k2>0)&&(k2<1)) return 2;
}
k=4*pow((d3.x-d2.x)*(d3.x-ywz.x)+(d3.y-d2.y)*(d3.y-ywz.y),2)-4*(pow(d3.x-d2.x,2)+pow(d3.y-d2.y,2))*(pow(d2.x-ywz.x,2)+pow(d2.y-ywz.y,2)-pow(yzj,2));
//如果有在d3-d2确定的直线上有交点
if (k>=0)
{
k1=(-2*(d3.x-d2.x)*(d3.x-ywz.x)-2*(d3.y-d2.y)*(d3.y-ywz.y)+sqrt(k))/(2*(pow(d3.x-d2.x,2)+pow(d3.y-d2.y,2)));
k2=(-2*(d3.x-d2.x)*(d3.x-ywz.x)-2*(d3.y-d2.y)*(d3.y-ywz.y)-sqrt(k))/(2*(pow(d3.x-d2.x,2)+pow(d3.y-d2.y,2)));
if ((k1>0)&&(k1<1)) return 2;
if ((k2>0)&&(k2<1)) return 2;
}
k=4*pow((d4.x-d3.x)*(d4.x-ywz.x)+(d4.y-d3.y)*(d4.y-ywz.y),2)-4*(pow(d4.x-d3.x,2)+pow(d4.y-d3.y,2))*(pow(d3.x-ywz.x,2)+pow(d3.y-ywz.y,2)-pow(yzj,2));
//如果有在d4-d3确定的直线上有交点
if (k>=0)
{
k1=(-2*(d4.x-d3.x)*(d4.x-ywz.x)-2*(d4.y-d3.y)*(d4.y-ywz.y)+sqrt(k))/(2*(pow(d4.x-d3.x,2)+pow(d4.y-d3.y,2)));
k2=(-2*(d4.x-d3.x)*(d4.x-ywz.x)-2*(d4.y-d3.y)*(d4.y-ywz.y)-sqrt(k))/(2*(pow(d4.x-d3.x,2)+pow(d3.y-d3.y,2)));
if ((k1>0)&&(k1<1)) return 2;
if ((k2>0)&&(k2<1)) return 2;
}
k=4*pow((d1.x-d4.x)*(d1.x-ywz.x)+(d1.y-d4.y)*(d1.y-ywz.y),2)-4*(pow(d1.x-d4.x,2)+pow(d1.y-d4.y,2))*(pow(d4.x-ywz.x,2)+pow(d4.y-ywz.y,2)-pow(yzj,2));
//如果有在d1-d4确定的直线上有交点
if (k>=0)
{
k1=(-2*(d1.x-d4.x)*(d1.x-ywz.x)-2*(d1.y-d4.y)*(d1.y-ywz.y)+sqrt(k))/(2*(pow(d1.x-d4.x,2)+pow(d1.y-d4.y,2)));
k2=(-2*(d1.x-d4.x)*(d1.x-ywz.x)-2*(d1.y-d4.y)*(d1.y-ywz.y)-sqrt(k))/(2*(pow(d1.x-d4.x,2)+pow(d1.y-d4.y,2)));
if ((k1>0)&&(k1<1)) return 2;
if ((k2>0)&&(k2<1)) return 2;
}
D3DXVECTOR2 ls;
float z,l1,l2,l3,l4;//l1,l2,l3,l4为记录圆心点与四边的距离，在边法向量正侧为正，反之为负
ls=d2-d1;
z=ls.x;ls.x=ls.y;ls.y=-z;
D3DXVec2Normalize(&ls,&ls);//第一个边的法向量
l1= ls.x*(ywz.x-d1.x)+ls.y*(ywz.y-d1.y); //圆心与d2-d1边的距离
l2= ls.y*(ywz.x-d2.x)-ls.x*(ywz.y-d2.y); //圆心与d3-d2边的距离
l3= -ls.x*(ywz.x-d3.x)-ls.y*(ywz.y-d3.y); // 圆心与d4-d3边的距离
l4= -ls.y*(ywz.x-d4.x)+ls.x*(ywz.y-d4.y); //圆心与d1-d4边的距离
if ((l1>=yzj)&&(l2>=yzj)&&(l3>=yzj)&&(l4>=yzj))
return 3; //圆在长方形内部，也就是长方形包含圆
//3、如果矩形四个顶点都在圆内，则返回4
if ((pow(d1.x-ywz.x,2)+pow(d1.y-ywz.y,2)<=yzj*yzj)&&(pow(d2.x-ywz.x,2)+pow(d2.y-ywz.y,2)<=yzj*yzj)&&(pow(d3.x-ywz.x,2)+pow(d3.y-ywz.y,2)<=yzj*yzj)&&(pow(d4.x-ywz.x,2)+pow(d4.y-ywz.y,2)<=yzj*yzj))
return 4;
//4、必定剩余第一种情况，圆与正方形不相交，也不包含
return 1;
}
![第二章 PDF 马达启动－2.1.1[图]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)