#include <stdio.h>
#include <GL/glut.h>
#include <math.h>
#include <stdlib.h>
#include <time.h>
void Filling( float x, float y, float CurentColor[3], float NewColor[3] )
{
float CurentPixel[3] ;
glReadPixels(x, y , 1, 1, GL_RGB, GL_FLOAT, &CurentPixel);
if ( CurentPixel[0] == CurentColor[0] && CurentPixel[1] == CurentColor[1] && CurentPixel[2] == CurentColor[2] )
{
glBegin(GL_POINTS);
glColor3f( NewColor[0], NewColor[1], NewColor[2] );
glVertex2f(x,y);
glEnd();
Filling( x + 1, y, CurentColor, NewColor ) ;
Filling( x - 1, y, CurentColor, NewColor ) ;
Filling( x, y - 1, CurentColor, NewColor ) ;
Filling( x, y + 1, CurentColor, NewColor ) ;
}
return ;
}
void DrawCircle(float cx, float cy, float r, int num_segments)
{
int i;
float theta = 2 * 3.1415926 / num_segments;
float c = cosf(theta);
float s = sinf(theta);
float t;
float x = r;
float y = 0;
glBegin(GL_LINE_LOOP);
for( i = 0; i < num_segments; i++)
{
glVertex2f(x + cx, y + cy);
t = x;
x = c * x - s * y;
y = s * t + c * y;
}
glEnd();
}
void Display(void)
{
glMatrixMode( GL_PROJECTION );
glLoadIdentity(); // Reset The Current Matrix to E
glOrtho( 0, 400, 400, 0, 0, 1 );
glMatrixMode(GL_MODELVIEW);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
glLoadIdentity(); // Reset The View
DrawCircle( 200, 200, 50, 360 ) ; //Draw circle
float CurentColor[3] = { 0.0, 0.0, 0.0 } ;
float NewColor[3] = { 0.0, 0.0, 1.0 } ;
Filling( 200, 200, CurentColor, NewColor ) ;
DrawCircle( 100, 100, 50, 360 ) ; //check
glFlush();
}
int main(int argc, char **argv)
{
srand( time( NULL ) ) ;
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(400,400);
glutCreateWindow("Intro");
glutDisplayFunc(Display);
glutMainLoop();
return 0;
}