C语言常用二维解析几何函数集源代码

语言常用二维剖析几何函数集源代码2010-12-2922:29:28阅读50谈论0字号：大中小订阅这个代码是我今天放学后抽时间写的，采用了用于做动画也许游戏里较常用的数学函数（就是说不可以能很全面）包括简单的碰撞检测计算函数包括：向量加减法，向量点乘与叉乘，向量缩放，向量长度三角形面积，点到直线（和线段）的距离，判断直线平行，判断线段订交，求直线（和线段）的交点，点到直线的垂足，点关于直线的对称点，线段关于直线的反射线点绕给定点旋转判断点在三角形（和椭圆）内直线（和线段）与三角形碰撞，三角形与三角形碰撞两平行矩形碰撞，平行矩形与椭圆碰撞程序代码：#include<>//定义点结构typedefstructpoint{doublex;doubley;}point;//定义有向线段typedefstructsegment{points;pointe;}segment;//定义三角形typedefstructtriangle{pointp[3];}triangle;//定义精度误差constdoubleeps=1e-6;//两点距离doubledistance(constpoint*p1,constpoint*p2){doubledx=p1->x-p2->x,dy=p1->y-p2->y;returnsqrt(dx*dx+dy*dy);}//线段长doublelen(constsegment*seg){doubledx=seg->-seg->,dy=seg->-seg->;returnsqrt(dx*dx+dy*dy);}//线段长的平方doublelensqr(constsegment*seg){doubledx=seg->-seg->,dy=seg->-seg->;returndx*dx+dy*dy;}//向量加法pointadd(constpoint*p1,constpoint*p2){pointret;p1->x+p2->x;p1->y+p2->y;returnret;}//向量减法pointminus(constpoint*p1,constpoint*p2){pointret;p1->x-p2->x;p1->y-p2->y;returnret;}//向量缩放pointscale(constpoint*p,doubles){pointret;p->x*s;p->y*s;returnret;}//向量缩放（以o点为基准点）pointscale2(constpoint*p,constpoint*o,doubles){pointv;(p->x-o->x)*s;(p->y-o->y)*s;returnadd(&v,o);}//向量点乘doubledotmul(constpoint*p1,constpoint*p2){returnp1->x*p2->x+p1->y*p2->y;}//返回两点与原点组成的三角形面积的两倍（叉乘z值）doublemulti(constpoint*p1,constpoint*p2){returnp1->x*p2->y-p1->y*p2->x;}//返回三点组成的三角形面积的两倍（有次序，相当于叉乘）doublemulti3(pointp1,pointp2,pointp3){p2=minus(&p2,&p1);p3=minus(&p3,&p1);returnmulti(&p2,&p3);}//三角形面积doubletriangleArea(pointa,pointb,pointc){returnmulti3(a,b,c)/2;}//计算点到直线的距离，a,b定义那个直线，p为要计算的点doublepointToLine(pointa,pointb,pointp){a=minus(&a,&p);b=minus(&b,&p);returnfabs(multi(&a,&b))/distance(&a,&b);}//计算点到线段的距离，a,b定义那个线段，p为要计算的点doublepointToSeg(pointa,pointb,pointp){pointab,o={0};ab=minus(&b,&a);a=minus(&a,&p);b=minus(&b,&p);if(dotmul(&a,&ab)>-eps)returndistance(&o,&a);=;=;if(dotmul(&b,&ab)>-eps)returndistance(&o,&b);returnfabs(multi(&a,&b))/distance(&a,&b);}//判断两直线平行（重载1）intisParallelP(constpoint*as,constpoint*ae,constpoint*bs,constpoint*be){doubled1,d2;d1=multi3(*as,*bs,*ae);d2=multi3(*as,*ae,*be);returnfabs(d1+d2)<eps;}//判断两直线平行（重载2）intisParallelS(constsegment*a,constsegment*b){doubled1,d2;d1=multi3(a->s,b->s,a->e);d2=multi3(a->s,a->e,b->e);returnfabs(d1+d2)<eps;}//直线求交点（重载1）pointlinesIntersectP(constpoint*as,constpoint*ae,constpoint*bs,constpoint*be){pointret;doubled1,d2;d1=multi3(*as,*bs,*ae);d2=multi3(*as,*ae,*be);(bs->x*d2+be->x*d1)/(d1+d2);(bs->y*d2+be->y*d1)/(d1+d2);returnret;}//直线求交点（重载2）pointlinesIntersectS(constsegment*a,constsegment*b){pointret;doubled1,d2;d1=multi3(a->s,b->s,a->e);d2=multi3(a->s,a->e,b->e);(b->*d2+b->*d1)/(d1+d2);(b->*d2+b->*d1)/(d1+d2);returnret;}//点到直线的垂足pointpointToLineFoot(pointa,pointb,pointp){pointt;t=p;+=-;+=-;returnlinesIntersectP(&a,&b,&t,&p);}//点关于直线的对称点pointmirrorPoint(pointa,pointb,pointp){pointf;doubledis;dis=pointToSeg(a,b,p);if(dis<eps)returnp;f=pointToLineFoot(a,b,p);+=-;+=-;returnf;}//求对称线段也许反射线（返回点放回p,q）voidmirrorSeg(constpoint*a,constpoint*b,point*p,point*q){*p=mirrorPoint(*a,*b,*p);*q=mirrorPoint(*a,*b,*q);}//对p点以o点为中心逆时针旋转r弧度，计算结果返回p中（参数返回方式的重载）voidrotate(point*p,pointo,doubler){pointq;doublesr,cr;q=minus(p,&o);sr=sin(r);cr=cos(r);p->x=+(cr*-sr*;p->y=+(sr*+cr*;}//对p点以o点为中心逆时针旋转r弧度（直接返回点的重载）pointrotateR(pointp,pointo,doubler){pointq;doublesr,cr;q=minus(&p,&o);sr=sin(r);cr=cos(r);=+(cr*-sr*;=+(sr*+cr*;returnp;}//判断两线段订交（订交返回1，不订交返回0）intsegCrashSegP(constpoint*as,constpoint*ae,constpoint*bs,constpoint*be){doubles,t;s=multi3(*as,*bs,*be);t=multi3(*ae,*bs,*be);if(s*t>eps)return0;s=multi3(*bs,*as,*ae);t=multi3(*be,*as,*ae);if(s*t>eps)return0;return1;}//判断两线段订交（订交返回1，不订交返回0）intsegCrashSegS(constsegment*a,constsegment*b){doubles,t;s=multi3(a->s,b->s,b->e);t=multi3(a->e,b->s,b->e);if(s*t>eps)return0;s=multi3(b->s,a->s,a->e);t=multi3(b->e,a->s,a->e);if(s*t>eps)return0;return1;}//判断点在三角形内（返回1:内；返回0:边上；返回-1:外）intpointInTriangle(consttriangle*tri,constpoint*p){doubles,t;s=multi3(*p,tri->p[0],tri->p[1]);if(fabs(s)<eps)return0;t=multi3(*p,tri->p[1],tri->p[2]);if(fabs(t)<eps)return0;if((s<0)^(t<0))return-1;s=multi3(*p,tri->p[2],tri->p[0]);if(fabs(s)<eps)return0;if((s<0)^(t<0))return-1;return1;}//三角形与直线碰撞检测（碰撞返回1，不碰撞返回0）inttriangleCrashLine(consttriangle*tri,constsegment*seg){doubles,t;s=multi3(tri->p[0],seg->s,seg->e);t=multi3(tri->p[1],seg->s,seg->e);if((s<0)^(t<0))return1;s=multi3(tri->p[2],seg->s,seg->e);if((s<0)^(t<0))return1;return0;}//三角形与线段碰撞检测（碰撞返回1，不碰撞返回0）inttriangleCrashSeg(consttriangle*tri,constsegment*seg){if(pointInTriangle(tri,&seg->s)>0)return1;if(segCrashSegP(&tri->p[0],&tri->p[1],&seg->s,&seg->e))return1;if(segCrashSegP(&tri->p[0],&tri->p[2],&seg->s,&seg->e))return1;if(segCrashSegP(&tri->p[2],&tri->p[1],&seg->s,&seg->e))return1;return0;}//三角形与三角形碰撞检测（碰撞返回1，不碰撞返回0）inttriangleCrashTriangle(consttriangle*tri1,consttriangle*tri2){segmentseg;=tri2->p[0];=tri2->p[1];if(triangleCrashSeg(tri1,&seg))return1;=tri2->p[0];=tri2->p[2];if(triangleCrashSeg(tri1,&seg))return1;=tri2->p[2];=tri2->p[1];if(triangleCrashSeg(tri1,&seg))return1;return0;}//两平行于坐标轴的矩形碰撞检测（碰撞返回

1，不碰撞返回0）intrectCrashRect(constpoint*rect1lt,

constpoint*rect1rb,

const

point*

rect2lt,

constpoint*rect2rb){if(rect1lt->x>rect2rb->x||rect1lt->y>rect2rb->y)return0;if(rect2lt->x>rect1rb->x||rect2lt->y>rect1rb->y)return0;return1;}//判断点在椭圆内（返回1:内；返回0:边上；返回-1:外）intpointInEllipse(constpoint*elplt,constpoint*elprb,constpoint*pt){pointcenter,p;doublea,b,s;=(elplt->x+elprb->x)/2;a=-elplt->x;b=-elplt->y;a*=a;b*=b;p=minus(pt,¢er);s=*/a+*/b;if(fabs(s)<eps)return0;if(s>1)return-1;return1;

=(elplt->y+elprb->y)/2;}//判断平行矩形与椭圆碰撞（碰撞返回1，不碰撞返回0）intrectCrashEllipse(constpoint*rectlt,