FloodFill.c

AIM:- WAP to fill a region using flood fill algorithm using 4 or 8 connected approaches.
CODE:-
#include<GL/glut.h>
#include<stdio.h>
#include<stdbool.h>
int x,y,z;
int numberOfPoints;
float ox = 200,oy = 200;//Origin Coordinates
int count = 0;

void init(void)
{
 glClearColor(1.0,1.0,1.0,0.0);
 glMatrixMode(GL_PROJECTION);
 gluOrtho2D(-200,200,-200,200.0);
}
void drawLine(float x1, float y1, float x2, float y2, float R, float G, float B){
  glColor3f(R,G,B);
  glBegin(GL_LINES);
    glVertex2f(x1,y1);
    glVertex2f(x2,y2);
  glEnd();
}
void getPixelColor(int x, int y, float *pixel){
  glReadPixels(x+oy, y+ox, 1.0, 1.0, GL_RGB, GL_FLOAT, pixel);
}
bool arrCmp(float *arr1, float *arr2, int size){
  for(int i=0;i<size;i++){
    if(arr1[i] != arr2[i])
      return false;
  }
  return true;
}
void plotPoint(int x,int y, float R, float G, float B)
{
 glColor3f(R,G,B);
 glBegin(GL_POINTS);
  glVertex2i(x,y);
 glEnd();
 glFlush();
}
void drawPolygon(int (*arr)[2], int n, float R, float G, float B){
  glColor3f(R,G,B);
  glBegin(GL_POLYGON);
    for(int i = 0; i < n; i++)
      glVertex2i(arr[i][0],arr[i][1]);
  glEnd();
}
void floodFill4(int x, int y, float *fill, float *old){
  float current[3];
  getPixelColor(x,y,current);
  if(arrCmp(old,current,3)){
    plotPoint(x,y,fill[0],fill[1],fill[2]);
    floodFill4(x+1,y,fill,old);
    floodFill4(x-1,y,fill,old);
    floodFill4(x,y+1,fill,old);
    floodFill4(x,y-1,fill,old);
  }
}
void mousePlotPoint(GLint button, GLint action, GLint xMouse, GLint yMouse)
{
  GLint wh=400;
  float x=xMouse-ox;
  float y=wh-yMouse-oy;
  static int arr[3][2];
  if(button == GLUT_LEFT_BUTTON && action == GLUT_UP)
  {
    if(count == -1){
      float fill[] = {x,y,z};
      float old[3];
      getPixelColor(x,y,old);
      floodFill4(x,y,fill,old);
    }
    else if(count == 2){
      printf("\nPoint: (%f, %f)",x, y);
      arr[2][0] = x;
      arr[2][1] = y;
      count++;
      drawPolygon(arr,count,1,0,0);
      count = -1;
    }
    else{
      printf("\nPoint: (%f, %f)",x, y);
      arr[count][0] = x;
      arr[count][1] = y;
      count++;
    }
    
  }
 glFlush();
}
void display(void)
{
  glClear(GL_COLOR_BUFFER_BIT);

  
}

int main(int argc, char** argv)
{ printf("Enter RGB values for new colour= ");
  //std::cin>>x>>y>>z;
  scanf("%d%d%d", &x, &y, &z);
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
  glutInitWindowPosition(0,0);
  glutInitWindowSize(400,400);
  glutCreateWindow("Flood Fill");

  init();
  glutDisplayFunc(display);
  glutMouseFunc(mousePlotPoint);

  glutMainLoop();
  return 0;
}