Program to transform object ( Tringle or rectangle or Polygon) from window to view port. - MASTER GUIDE

 Program to transform object ( Tringle or rectangle or Polygon)from window to view port.

#include <stdio.h>

#include<graphics.h>

void main()

{

int gd=DETECT,gm,n,i;

int xwmax , ywmax , xwmin , ywmin; // boundary values for window

int xvmax , yvmax , xvmin , yvmin ; // boundary values for viewport

float sx, sy;

//obj - object inside the window , view - object inside viewport

int objx[10],objy[10],viewx[10],viewy[10];

initgraph(&gd,&gm,"C:\\TURBOC3\\BGI");

printf("Enter the window coordinates(xwmin,ywmin,xwmax,ywmax):");

scanf("%d%d%d%d",&xwmin,&ywmin,&xwmax,&ywmax);

printf("Enter viewport coordinates (xvmin,yvmin,xvmax,yvmax):");

scanf("%d%d%d%d",&xvmin,&yvmin,&xvmax,&yvmax);

printf("Enter number of vertices:");

scanf("%d",&n);

for(i=0;i<n;i++)

{

printf("Enter x and y coordinates of vertices:");

scanf("%d%d",&objx[i],&objy[i]);

}

cleardevice();

//draw window and plot an object inside the window

setcolor(RED);

outtextxy(xwmin,ywmin-10, "Window");

rectangle(xwmin,ywmin,xwmax,ywmax);

for(i=0;i<n-1;i++)

  line(objx[i],objy[i],objx[i+1],objy[i+1]);

line(objx[i],objy[i],objx[0],objy[0]);

getch();

// calculating scaling factor sx and sy

sx = (float)(xvmax - xvmin) / (xwmax - xwmin);

sy = (float)(yvmax - yvmin) / (ywmax - ywmin);

// calculating the points of an object on viewport

for(i=0;i<n;i++)

{

viewx[i]= xvmin + (float)((objx[i] - xwmin) * sx);

viewy[i]=yvmin + (float)((objy[i] - ywmin) * sy);

}

//draw viewport and plot an object inside viewport

setcolor(BLUE);

outtextxy(xvmin,yvmin-10, "Viewport");

rectangle(xvmin,yvmin,xvmax,yvmax);

for(i=0;i<n-1;i++)

line(viewx[i],viewy[i],viewx[i+1],viewy[i+1]);

line(viewx[i],viewy[i],viewx[0],viewy[0]);

getch();

closegraph();

}

OUTPUT: