1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>
#include<stdio.h>
 
 
 
int n;
double P[3][10];
double P2[3][10];
 
double S[3][3];
 
float m; int b;
 
 
 
void INPUT()
{
int ch;
cout<<"\n For Polygon where No of edges (>=3) = ";
cin>>n;
 
cout<<"\n Enter the coordinates of "<<n<<" sided Polygon: \n";
 
for(int i=0; i<n; i++)
{
cout<<" "<<i+1<<" Point (x,y) : ";
cin>>P[0][i]>>P[1][i];
P[2][i]=1;
}
 
cout<<"\n Enter the equation of line ( Y = m X + b) : ";
char ch1;
 
cin>>ch1;
cin>>ch1;
cin>>m;
cin>>ch1;
cin>>ch1;
cin>>b;
 
//cout<<"\n Slope = "<<m<<"\n Y Intercept = "<<b;
}
 
 
 
 
void ReflectPoint()
{
 
// S[3][3] : Reflect Transform MATRIX
// P[3][n] : 3 x n MATRIX
// P2[3][n] : Final MATRIX
 
//Reflect Transform Matrix:
//1st - making the identity Matrix
for(int i=0; i<3; i++)
{
for(int j=0; j<3; j++)
{
        if(i==j)     //DIAGONAL
        S[i][j] = 1;
        else
        S[i][j] = 0;
}
}
//2nd - making changes
S[0][0] = (1-m*m) / (m*m+1) ;
S[0][1] = (2*m) / (m*m+1) ;
S[0][2] = (-2*m*b) / (m*m+1) ;
S[1][0] = (2*m) / (m*m+1) ;
S[1][1] = (m*m-1) / (m*m+1) ;
S[1][2] =  (2*b) / (m*m+1);
 
 
// Matrix Multiplication
// S(3x3)  x  P(3xN)
 
for(i=0; i<3; i++)
{
for(int j=0; j<n; j++)
{
        P2[i][j]=0;
for(int k=0; k<3; k++)
{
P2[i][j]+=S[i][k]*P[k][j];
}
}
}
 
}
 
void Display_Matrix(double p[3][10])
{
 
for(int i=0; i<3; i++)
{
cout<<"\n |";
for(int j=0; j<n; j++)
cout<<"  "<<p[i][j];
cout<<"  |";
}
 
}
 
void DRAW(double p[3][10])
{
 
for(int i=0; i<n-1; i++)
{
line(getmaxx()*0.5+p[0][i], getmaxy()*0.5+p[1][i], 
               getmaxx()*0.5+p[0][i+1], getmaxy()*0.5+p[1][i+1]);
}
line(getmaxx()*0.5+p[0][n-1], getmaxy()*0.5+p[1][n-1], 
                    getmaxx()*0.5+p[0][0], getmaxy()*0.5+p[1][0]);
 
}
 
 
void main()
{
INPUT();
Display_Matrix(P);
cout<<endl;
 
ReflectPoint();
 
for(int i=0; i<3; i++)
{
cout<<"\n |";
for(int j=0; j<3; j++)
cout<<" "<<S[i][j];
cout<<" |";
}
cout<<endl;
 
Display_Matrix(P2);
 
cout<<"\n\n Press Enter to see Graphically? ";
getch();
 
int gdriver=DETECT,gmode;
initgraph(&gdriver,&gmode,"C:/TC/BGI");
 
 
setcolor(DARKGRAY);
//X AXIS
line(getmaxx()*0.5, 0, getmaxx()*0.5, getmaxy());
//Y AXIS
line(0, getmaxy()*0.5, getmaxx(), getmaxy()*0.5);
 
 
setcolor(CYAN);
DRAW(P);
setcolor(GREEN);
DRAW(P2);
 
getch();
closegraph();
 
}