A C++ program to show Point Clipping


# include <iostream.h>
# include <graphics.h>
# include <conio.h>
# include <math.h>
class WindowCoordinates{
public:
int x_min, y_min,x_max,y_max;
WindowCoordinates(const int x1,const int y1,const int x2,const int y2)
{
x_min=x1;
y_min=y1;
x_max=x2;
y_max=y2;
}};
const int clip_point(const WindowCoordinates,const int,const int);
void Rectangle(const int,const int,const int,const int);
void Line(const int,const int,const int,const int);
int main( )
{
int driver=VGA;
int mode=VGAHI;
initgraph(&driver,&mode,”..\\Bgi”);
WindowCoordinates WC(180,140,470,340);
setcolor(15);
Rectangle(WC.x_min,WC.y_min,WC.x_max,WC.y_max);
int points[12][2]={ {160,160} , {155,300} , {200,200} , {320,240} ,
{225,175} , {400,150} , {275,325} , {450,320} ,
{300,120} , {500,225} , {350,350} , {500,360} };
for(int count_1=0;count_1<12;count_1++)
putpixel(points[count_1][0],points[count_1][1],7);
char Key=NULL;
do{
Key=getch( );}
while(Key!=’C’ && Key!=’c’);
settextstyle(0,0,1);
setcolor(3);
outtextxy(165,450,” Press ‘C’ to see the Clipped Points. “);
setcolor(3);
outtextxy(165,450,”—— ——-“);
setcolor(12);
outtextxy(213,450,” Press any Key to exit. “);
for(int count_2=0;count_2<12;count_2++){
if(clip_point(WC,points[count_2][0],points[count_2][1]))
putpixel(points[count_2][0],points[count_2][1],RED);}
getch( );
return 0;
}
//clip_point( )
const int clip_point(const WindowCoordinates wc,const int x,const int y){
if((x>=wc.x_min && x<=wc.x_max) && (y>=wc.y_min && y<=wc.y_max))
return 1;
return 0;}
void Rectangle(const int x_1,const int y_1,const int x_2,const int y_2){
Line(x_1,y_1,x_2,y_1);
Line(x_2,y_1,x_2,y_2);
Line(x_2,y_2,x_1,y_2);
Line(x_1,y_2,x_1,y_1);}
void Line(const int x_1,const int y_1,const int x_2,const int y_2){
int color=getcolor( );
int x1=x_1;
int y1=y_1;
int x2=x_2;
int y2=y_2;
if(x_1>x_2){
x1=x_2;
y1=y_2;
x2=x_1;
y2=y_1;}
int dx=abs(x2-x1);
int dy=abs(y2-y1);
int inc_dec=((y2>=y1)?1:-1);
if(dx>dy) {
int two_dy=(2*dy);
int two_dy_dx=(2*(dy-dx));
int p=((2*dy)-dx);
int x=x1;
int y=y1;
putpixel(x,y,color);
while(x<x2){
x++;
if(p<0)
p+=two_dy;
else{
y+=inc_dec;
p+=two_dy_dx;}
putpixel(x,y,color);
}}
elsen {
int two_dx=(2*dx);
int two_dx_dy=(2*(dx-dy));
int p=((2*dx)-dy);
int x=x1;
int y=y1;
putpixel(x,y,color);
while(y!=y2){
y+=inc_dec;
if(p<0)
p+=two_dx;
else {
x++;
p+=two_dx_dy;}
putpixel(x,y,color);
}} }