Лабы / 3 / Bspl3

//‚лЇ®«­Ё« Ѓ аЄ®ў ЊЏ40
//Џа®Ја ¬¬  аЁбгҐв ЄаЁўлҐ Ї®  «Ј®аЁв¬г ‚-бЇ« ©­®ў (Є зҐб⢥­­® ᤥ« ­ )
#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<iostream.h>
#include<graphics.h>
int N;
float T[50];
float BSPLm(int m,int i, float t)
{

 if(m==0)
  {
   if ((t>=T[i])&&(t<=T[i+1]))
     return 1;
   else
     return 0;
  }

 else
  {
    return  ((t-T[i])/(T[i+m]-T[i])*BSPLm(m-1,i,t))+((T[i+m+1]-t)/(T[i+m+1]-T[i+1])*BSPLm(m-1,i+1,t));
  }
}

struct point{float x,y;} P[20];

void main(void)
{ clrscr();
 int gmode=VGAHI,gdriver=VGA;
 int j;
 float dx,dy;
 float tt;
 for(j=0;j<50;j++)
  T[j]=j;
 cout<<"‚ўҐ¤ЁвҐ Є®««ЁзҐбвў® ®Ї®а­ле в®зҐЄ: ";
 cin>>N;
 N+=2;
 randomize();
 initgraph(&gdriver,&gmode,"E:\\c3.1\\bgi");
 do
 {
 cleardevice();
 for(j=1;j<N-1;j++)
  {
   P[j].x=random(640);
   P[j].y=random(480);
  }
 P[0].x=2*(P[1].x)-P[2].x;
 P[N-1].x=2*(P[N-2].x)-P[N-3].x;
  P[0].y=2*(P[1].y)-P[2].y;
  P[N-1].y=2*(P[N-2].y)-P[N-3].y;
 setcolor(2);
 for(j=1;j<N-2;j++)
  {
   line(P[j].x,P[j].y,P[j+1].x,P[j+1].y);
  }
tt=3;
float sx;
float sy;

float BS;
while(tt<=T[N])
{
  sx=0;
  sy=0;
 for(j=0;j<N;j++)
 {
   BS=BSPLm(3,j,tt);
   sx=sx+(P[j].x)*BS;
   sy=sy+(P[j].y)*BS;
 }
putpixel(sx,sy,4);
tt=tt+0.0001;
}
}
while(getch()!=13);
closegraph();
}