2D Transformations

Include:



 stdio.h 

 math.h 

 conio.h 

 graphics.h





float input[20][3];

      float resM[20][3];

      float scaleM[3][3];

      float R[3][3],T[3][3];

      int edges;



//  Plotting Center Of Screen

    void plot(float mat[20][3])

{

    int i;

    setcolor(10);

    line(0,240,639,240);

    line(320,0,320,479);

    outtextxy(295,243,"0,0");



    setcolor(WHITE);

  for(i=0;i  line(320+mat[i][0],240-mat[i][1],320+mat[i+1][0],240-mat[i+1][1]);

    line(320+mat[0][0],240-mat[0][1],320+mat[i][0],240-mat[i][1]);

}

// Accepting Co-ordinates for Polygon

void accept()

{

    int i,j;

    printf("\n Enter no of edges in fig:");

    scanf("%d",&edges);

    printf("\n Enter co-ordinates of matrix:");



    for(i=0;i    {

	for(j=0;j<2;j++)

	{

	    printf("\n A[%d][%d]:",i,j);

	    scanf("%f",&input[i][j]);

	}

    }

    for(i=0;i	input[i][2]=1;



    plot(input);

    getch();

}



void mult(float a[20][3],float b[3][3],float c[20][3])

{

  int i;

  for(i=0;i  {

  c[i][0]=(a[i][0]*b[0][0])+(a[i][1]*b[1][0])+(a[i][2]*b[2][0]);

  c[i][1]=(a[i][0]*b[0][1])+(a[i][1]*b[1][1])+(a[i][2]*b[2][1]);

  c[i][2]=(a[i][0]*b[0][2])+(a[i][1]*b[1][2])+(a[i][2]*b[2][2]);

  }

}

//  Function for Scaling Operation

void scale()

{

    int i;

    float sx,sy;

    printf("\n Enter ScaleX: ");

    scanf("%f",&sx);

    printf("\n Enter ScaleY:");

    scanf("%f",&sy);



    scaleM[0][1]=scaleM[1][0]=0;

    scaleM[0][2]=scaleM[2][0]=scaleM[2][1]=0;

    scaleM[2][2]=1;



    scaleM[0][0]=sx;

    scaleM[1][1]=sy;

    plot(input);

    mult(input,scaleM,resM);

    plot(resM);

    getch();

}





//  Function For Translation Operation

    void translate()

 {

     int tx,ty,i;

     printf("\n Enter Tx and Ty: ");

     scanf("%d%d",&tx,&ty);

     T[0][0]=T[1][1]=T[2][2]=1;

     T[0][1]=T[0][2]=T[1][0]=T[1][2]=0;

     T[2][0]=tx;

     T[2][1]=ty;



    plot(input);

    mult(input,T,resM);

    plot(resM);

    getch();

}





//  Function For Rotatation Operation

   void rotate()

{

    float R[3][3],a,b,thita;

    int thita1,xm,ym,clock=1;

    xm=input[0][0];

    ym=input[0][1];



    printf("\n Enter Rotation Angle : ");

    scanf("%d",&thita1);

    printf("\n Clockwise or Anticlockwise(0 or 1) : ");

    scanf("%d",&clock);



   thita=((3.14*thita1)/180);



    if(clock==1)

  {

    a=-xm*cos(thita)+ym*sin(thita)+xm;

    b=-xm*sin(thita)-ym*cos(thita)+ym;

    R[0][0]=R[1][1]=cos(thita);

    R[0][1]=sin(thita);

    R[1][0]=-sin(thita);

    R[2][0]=a;

    R[2][1]=b;

    R[0][2]=R[1][2]=0;

    R[2][2]=1;

  }

   else

  {

  a=-xm*cos(thita)-ym*sin(thita)+xm;

  b=xm*sin(thita)-ym*cos(thita)+ym;

  R[0][0]=R[1][1]=cos(thita);

  R[0][1]=-sin(thita);

  R[1][0]=sin(thita);

  R[2][0]=a;

  R[2][1]=b;

  R[0][2]=R[1][2]=0;

  R[2][2]=1;



  }

  mult(input,R,resM);

  plot(resM);

  getch();

}





 //   Main Function

   void main()

{

  int gd=DETECT,gm,ch;

  initgraph(&gd,&gm,"BGI");

  cleardevice();

  while(1)

  {

   cleardevice();

   printf("\n 1.Accept\n 2.Scaling\n 3.Translate\n 4.Rotation\n 5.Exit");

   printf("\n\n Enter Your Choice: ");

   scanf("%d",&ch);



   switch(ch)

   {

   case 1:

	  accept();

	  break;

   case 2:

	  cleardevice();

	  scale();

	  break;

   case 3:

	   cleardevice();

	   translate();

	   break;



   case 4:

	   cleardevice();

	   rotate();

	   break;



   case 5:exit(1);

   }

 }

}