linealgo

linealgo.cpp

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

using namespace std;

double pointX1, pointY1, pointX2, pointY2;

float roundVal(float d)
{
    return floor(d + 0.5);
}
void LineDDA()
{
    double dx=(pointX2-pointX1);
    double dy=(pointY2-pointY1);
    double stepsNeeded;
    float xInc,yInc,x=pointX1,y=pointY1;

    if(abs(dx)>abs(dy))
    {
        stepsNeeded= (abs(dx));
    }
    else
    {
        stepsNeeded = (abs(dy));
    }
    xInc=dx/(float)stepsNeeded;
    yInc=dy/(float)stepsNeeded;


    glClear(GL_COLOR_BUFFER_BIT);
    glPointSize(1.0);
    glBegin(GL_POINTS);

    glVertex2d(x,y);
    int i;
    for(i=0; i<stepsNeeded; i++)
    {
        x+=xInc;
        y+=yInc;
        glVertex2d(roundVal(x), roundVal(y));
    }
    glEnd();

    glFlush();
}

void Bresenham()
{
    double dx=(pointX2-pointX1);
    double dy=(pointY2-pointY1);
    float X=pointX1,Y=pointY1,Xend=pointX2;
    double d;
    double de;
    double dne;
    d=2*dy-dx;
    de=2*dy;
    dne=2*(dy-dx);
    glClear(GL_COLOR_BUFFER_BIT);
    glBegin(GL_POINTS);

    while(X<Xend)
    {
        glVertex2d(X,Y);
        X++;
        if(de<=0)
        {
            d=d+de;
        }
        else
        {
            d=d+dne;
            Y++;
        }
    }

    glEnd();

    glFlush();
}
void myInit()
{
    glClearColor(1,1,1,0);
    glColor3f(0.0,0.0,0.0);
    gluOrtho2D(-320, 320, -240, 240);
}
void inputPoints()
{
    cout<<"Enter start points: "<<endl;
    cin>>pointX1;
    cin>>pointY1;
    cout<<"Enter end points:"<<endl;
    cin>>pointX2;
    cin>>pointY2;
}
int main(int argc, char **argv)
{


    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);

    glutInitWindowPosition(100,30);
    glutInitWindowSize(640,480);
    glutCreateWindow("Line Algorithms ");
    myInit();
    while(true)
    {
        cout<<"Choose option: "<<endl;
        cout<<"1.DDA Line"<<endl<<"2.Bresenham Algo"<<endl<<"3.Quit"<<endl;
        int c;
        cin>>c;

        if(c==1)
        {
            inputPoints();
            glutDisplayFunc(LineDDA);
            glutMainLoop();
        }
        else if(c==2)
        {
            inputPoints();
            glutDisplayFunc(Bresenham);
            glutMainLoop();
        }
        else if(c== 3)
        {
            cout<<"Exit";
            return 0;
        }
        else
        {
            continue;
        }



    }


}