How can I draw a spline curves with c in codeblocks? - c

Question

I am trying to draw a minimum enclosing circle and I need spline curves for points. but also I shouldn't use libraries. For preview, I used lines but they need curves. How can I fix it?
Which one is true arc, line or points?
#include <stdio.h>
#include <graphics.h>
#include <math.h>
#include <conio.h>
struct nokta
{
int x,y;
};
//-------------------------------------------------------------//
int main()
{
int gd = DETECT;
int gm;
initgraph(&gd, &gm, "C:\\TC\\BGI");
initwindow(800,800);
struct nokta noktalar[50];
FILE *noktaal=fopen("noktalar.txt","r");
int i=0;
int sayac=0;
if(noktaal==NULL)
{
printf("Dosya yok");
}
while(!feof(noktaal))
{
fscanf(noktaal,"%d %d",&noktalar[i].x,&noktalar[i].y);
sayac++;
i++;
};
for(int i=0; i<sayac-1; i++)
{
printf("%d %d \n",noktalar[i].x,noktalar[i].y);
}
fclose(noktaal);
//----------------------------------------------------------------//
if(sayac==1)//If there is no point
{
printf("Lutfen koordinat giriniz.");
}
if(sayac==2)// If there is one point
{
printf("Lutfen birden fazla koordinat giriniz.");
}
if(sayac==3)//If there is two point
{
int uzunluk1=abs(noktalar[1].x-noktalar[0].x);
int uzunluk2=abs(noktalar[1].y-noktalar[0].y);
double yaricap=sqrt(pow(uzunluk1,2)+pow(uzunluk2,2));
float merkezx=(noktalar[1].x+noktalar[0].x)/2.0;
float merkezy=(noktalar[1].y+noktalar[0].y)/2.0;
printf("Yaricap:%.2f\n",yaricap/2);
printf("Merkez noktasi:{%.2f,%.2f}",merkezx,merkezy);
line(getmaxx()/2,0,getmaxx()/2,getmaxy());//y düzlemi
line(0,getmaxy()/2,getmaxx(),getmaxy()/2);//x düzlemi
putpixel(((getmaxx()/2)+(noktalar[0].x*20)),(getmaxy()/2)-(noktalar[0].y*20),GREEN);
putpixel(((getmaxx()/2)+(noktalar[1].x*20)),(getmaxy()/2)-(noktalar[1].y*20),GREEN);
for(int i=20; i<=800; i=i+20)
{
line(i,getmaxy()/2.03,i,getmaxy()/1.97);
}
for(int i=20; i<=800; i=i+20)
{
line(getmaxx()/2.03,i,getmaxx()/1.97,i);
}
circle((getmaxx()/2)+(merkezx*20),(getmaxy()/2)-(merkezy*20),yaricap*7.9);
getch();
closegraph();
}
if(sayac>3)//If there is three or more points.
{
int karetoplam;
double enbuyuk=1.0,yaricap1;
float merkez1x,merkez1y;
int sayac1=0;
int ikinoktauzakligi=0;
for(int i=0; i<sayac-1; i++)
{
for(int j=0; j<sayac-1; j++)
{
float ykare=pow(abs(noktalar[i].y-noktalar[j].y),2);
float xkare=pow(abs(noktalar[i].x-noktalar[j].x),2);
karetoplam=ykare+xkare;
if(enbuyuk<=karetoplam)
{
enbuyuk=karetoplam;
}
if(enbuyuk==karetoplam)
{
merkez1x=(noktalar[i].x+noktalar[j].x)/2.0;
merkez1y=(noktalar[i].y+noktalar[j].y)/2.0;
++sayac1;
}
}
}
if(sayac1>=2)
{
double cap1=sqrt(enbuyuk);
yaricap1=cap1/2;
printf("Ilk yari capi:%.2f\n",yaricap1);
printf("Ilk merkez noktasi:{%.2f,%.2f}\n",merkez1x,merkez1y);
line(getmaxx()/2,0,getmaxx()/2,getmaxy());//y düzlemi
line(0,getmaxy()/2,getmaxx(),getmaxy()/2);//x düzlemi
for(int i=20; i<=800; i=i+20)
{
line(i,getmaxy()/2.03,i,getmaxy()/1.97);
}
for(int i=20; i<=800; i=i+20)
{
line(getmaxx()/2.03,i,getmaxx()/1.97,i);
}
for(int i=0; i<sayac-1; i++)
{
for(int j=0; j<sayac-1; j++)
{
putpixel((getmaxx()/2)+(noktalar[i].x*20),(getmaxy()/2)-(noktalar[i].y*20),GREEN);
}
}
float uzunluk2;
float arttir=0.0;
float enbuyuk2=0.0;
for(int i=0; i<100;i++)
{
for(int j=0; j<sayac-1; j++)
{
uzunluk2=sqrt((pow(noktalar[j].x,2)+pow(noktalar[j].y,2))-(pow(merkez1x,2)+pow(merkez1y,2)));
if(enbuyuk2<uzunluk2)
{
enbuyuk2=uzunluk2;
}
if(yaricap1<enbuyuk2)
{
yaricap1=yaricap1+0.1;
arttir=arttir+0.1;
}
}
}
printf("Son yari capi:%.2f\n",yaricap1);
printf("Son merkez noktasi:{%.2f,%.2f}",merkez1x+arttir,merkez1y+arttir);
int uzunluk3;
int enkucuk3=0;
for(i=0;i<sayac-1;i++)
{
line((getmaxx()/2)+(noktalar[i].x*20),((getmaxy()/2)+(noktalar[i].y*20)),((getmaxx()/2)+(noktalar[i+1].x*20)),((getmaxy()/2)+(noktalar[i+1].y*20)));
}
circle((getmaxx()/2)+((merkez1x+arttir)*20),(getmaxy()/2)-((merkez1y+arttir)*20),yaricap1*20);
getch();
closegraph();
}
}
}
//-------------------------------------------------------------------//
Minimum enclosing circle can be drawn with this but it doesn't show a curve. I need to show curves without libraries.