/*COMPLIED BY SANDESH*/
		    /*program for translating a polygonal figure*/
 #include<stdio.h>
 #include<conio.h>
 #include<graphics.h>
 #include<math.h>
 struct figure
 { int X;
   int Y;
 };
 void main()
 {
  struct figure arr[10];
  int i,j;
  float sx,sy;
  float *ptrsx,*ptrsy;
  int gd=DETECT,gm=DETECT;
  int tx,ty;
  float tetha,*o;
  unsigned int *ptrx,*ptry,*ptrtx,*ptrty;
  detectgraph(&gm,&gd);
  initgraph(&gm,&gd,"c:\\tc\\bgi");
  cleardevice();
  printf("\n\t\t°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²");
  printf("\n\t\t²      POLYGONAL  TRANSLATION   PROGRAM       ±");
  printf("\n\t\t°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²±°²");

  printf("\nENTER THE NUMBER OF SIZE OF THE POLYGON(IT MUST BE GREATER THAN '2')\n\t->>");
  scanf("\t%d",&j);
  if((j>2)&&(j<10))
  {
  printf("\nINPUT THE (X,Y) PARAMETERS OF POLYGON");
  for(i=0;i<j;i++)        /*inputs from user*/
  {
  printf("\n\aX: ");
  scanf("%d",&arr[i].X);
  printf("Y: ");
  scanf("%d",&arr[i].Y);
  }
  }
  else{clrscr();printf("\n\n\n\n\tFORCED TERMINATION");delay(1000); exit();}
  printf("\nENTER THE POINT ABOUT WHICH YOU WANT TO ROTATE THE POLYGON");
  printf("\nTX:");
  scanf("%d",&tx);
  printf("\nTY:");
  scanf("%d",&ty);
  putpixel(tx,ty,CYAN);
  printf("\nINPUT ANGLE THETA BY WHICH YOU WANT TO ROTATE THE POLYGON ABOUT (TX,TY):");
  scanf("%f",&tetha);
  printf("\nINPUT THE SCALING IN X,Y DIRECTION");
  printf("\nSCALE-X:");
  scanf("%f",&sx);
  printf("\nSCALE-Y:");
  scanf("%f",&sy);
  for(i=0;i<(j-1);i++)
  draw(arr[i].X,arr[i].Y,arr[i+1].X,arr[i+1].Y);
  line(arr[0].X,arr[0].Y,arr[j-1].X,arr[j-1].Y);
  printf("\nPRESS ANY KEY TO MAKE TRANSFORMATION");
  getch();
  for(i=0;i<j;i++)
  {
  ptrx=&arr[i].X;  /*to initialise apointer to each variable*/
  ptry=&arr[i].Y;
  ptrtx=&tx;
  ptrty=&ty;
  ptrsx=&sx;
  ptrsy=&sy;
  o=&tetha;
  rotate_matrix(ptrx,ptry,ptrtx,ptrty,o);
  scale_matrix(ptrx,ptry,ptrtx,ptrty,ptrsx,ptrsy);
  }
  setcolor(RED);
  for(i=0;i<(j-1);i++)
  draw(arr[i].X,arr[i].Y,arr[i+1].X,arr[i+1].Y);
  line(arr[0].X,arr[0].Y,arr[j-1].X,arr[j-1].Y);
  getch();
  closegraph();
 }                      /*END OF MAIN FUNCTION*/

	   /*program to rotate an arbitrary point*/
  rotate_matrix(unsigned int *X,unsigned int *Y,unsigned int *tx,unsigned int *ty,float *o)
 {
  float temp1,temp2;
  double rad;
  float result[3][3]={1,1,1,1,1,1,1,1,1}; /*result matrix after rotation*/
  float sum;
  float rot[3][3]={1,0,0,0,1,0,0,0,1};  /*rotation matrix*/
  float point[3][3]={1,0,0,0,1,0,1,0,1};  /*point to be processed*/
  float t1[3][3]={1,0,0,0,1,0,0,0,1}; /*translate matrix*/
  float t2[3][3]={1,0,0,0,1,0,0,0,1}; /*inverse translate*/
  float mul1[3][3]={1,0,0,0,1,0,0,0,1};
  float mul2[3][3]={1,0,0,0,1,0,0,0,1};
  point[0][0]=*X;     /*initialise the point matrix*/
  point[1][0]=*Y;
  rad=M_PI/180*(*o);
  rot[0][0]=cos(rad);/*initialise the rotation matrix*/
  rot[0][1]=-sin(rad);
  rot[1][0]=sin(rad);
  rot[1][1]=cos(rad);
  temp1=*tx;
  temp2=*ty;
  t1[0][2]=-temp1;     /*initialise the translation matrixs*/
  t1[1][2]=-temp2;
  t2[0][2]=*tx;
  t2[1][2]=*ty;
  mulflot_mat(t2,rot,mul1);
  mulflot_mat(mul1,t1,mul2);
  mulflot_mat(mul2,point,result);
  *X=result[0][0];
  *Y=result[1][0];
  return(0);
 }

  scale_matrix(unsigned int *X,unsigned int *Y,unsigned int *tx,unsigned int *ty,float *sx,float *sy)
 {
  float temp1,temp2;
  float result[3][3]={1,1,1,1,1,1,1,1,1}; /*result matrix after rotation*/
  float sum;
  float scale[3][3]={1,0,0,0,1,0,0,0,1};  /*rotation matrix*/
  float point[3][3]={1,0,0,0,1,0,1,0,1};  /*point to be processed*/
  float t1[3][3]={1,0,0,0,1,0,0,0,1}; /*translate matrix*/
  float t2[3][3]={1,0,0,0,1,0,0,0,1}; /*inverse translate*/
  float mul1[3][3]={1,0,0,0,1,0,0,0,1};
  float mul2[3][3]={1,0,0,0,1,0,0,0,1};
  point[0][0]=*X;     /*initialise the point matrix*/
  point[1][0]=*Y;
  scale[0][0]=*sx;/*initialise the scaling matrix*/
  scale[1][1]=*sy;
  temp1=*tx;
  temp2=*ty;
  t1[0][2]=-temp1;     /*initialise the translation matrixs*/
  t1[1][2]=-temp2;
  t2[0][2]=*tx;
  t2[1][2]=*ty;
  mulflot_mat(t2,scale,mul1);
  mulflot_mat(mul1,t1,mul2);
  mulflot_mat(mul2,point,result);
  *X=result[0][0];
  *Y=result[1][0];
  return(0);
 }



	  /*procedure to multiply floting point matrix[3][3]*/
 mulflot_mat(float *mat1,float *mat2,float *result)
 {
  int i,j,k;
  float sum,b,c;

 for(i=0;i<3;i++)     /*multiplication for loop*/
 {
  for(j=0;j<3;j++)
   {
     sum=0;
     for(k=0;k<3;k++)
     {
     b= *(mat1+(i*3)+k);
     c= *(mat2+(k*3)+j);
     sum = sum + (b * c) ;
     }
    *result=sum;
    result++;
   }
 }/*end of for loop for multiplication*/
 return(0);
}
		       /*to draw the figure*/
 draw(int X1,int Y1,int X2,int Y2)
 {
  line(X1,Y1,X2,Y2);
 return(0);
 }