bohut koshter foshol.

bazier.cpp

#include <stdio.h>
#include <GL/gl.h>
#include <GL/glut.h>
#include <math.h>
#include <iostream>



long long C(int n, int r) {
    if(r > n / 2) r = n - r; // because C(n, r) == C(n, n - r)
    long long ans = 1;
    int i;

    for(i = 1; i <= r; i++) {
        ans *= n - r + i;
        ans /= i;
    }

    return ans;
}

void drawBezier(int numsX[], int numsY[]){
glColor3f (0.0, 1.0, 0.0);


    float n=4-1;
    float inc=0.001;


	for(float t=0.0;t<=1;t+=inc)
    {
        float x=0.0;
        float y=0.0;

        float p=0.0;
        for(int i=0;i<=n;i++){
            p=C(n,i)*pow(1-t,n-i)*pow(t,i);
            x+=p*numsX[i];
            y+=p*numsY[i];
        }
        glBegin(GL_POINTS);
        glVertex2f(x,y);
        glEnd();
    }



    glColor3f (1.0, 0.0, 0.0);
    glBegin(GL_POINTS);
    glVertex2i(numsX[0],numsY[0]);
    glVertex2i(numsX[1],numsY[1]);
    glVertex2i(numsX[2],numsY[2]);
    glVertex2i(numsX[3],numsY[3]);
    glEnd();

}


void showdraw(void)
{
    glClear (GL_COLOR_BUFFER_BIT);

    glPointSize(4.0);

    //int n = 4;
    int numsX[4] = {100,200,200,100};
    int numsY[4] = {100,250,350,400};

    drawBezier(numsX,numsY);


    int nums1X[4] = {400,300,300,400};
    int nums1Y[4] = {100,250,350,400};

    drawBezier(nums1X,nums1Y);


    int nums2X[4] = {100,50,50,100};
    int nums2Y[4] = {400,440,460,500};

    drawBezier(nums2X,nums2Y);



    int nums3X[4] = {400,450,450,400};
    int nums3Y[4] = {400,440,460,500};

    drawBezier(nums3X,nums3Y);


    int nums4X[4] = {400,350,350,200};
    int nums4Y[4] = {500,600,600,500};

    drawBezier(nums4X,nums4Y);


    int nums5X[4] = {200,175,150,100};
    int nums5Y[4] = {500,600,600,500};

    drawBezier(nums5X,nums5Y);



    glFlush ();
}

void myInit(void)
{
    glClearColor(1.0, 1.0, 1.0, 0.0);
    glColor3f(0.0f, 0.0f, 0.0f);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluOrtho2D(0, 800, 0, 800);
}

main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize (800, 800);
    glutInitWindowPosition (0, 0);
    glutCreateWindow ("show");

    glutDisplayFunc(showdraw);
    myInit();
    glutMainLoop();
}