mandelbrot

void displayfunc() {
        glClear(GL_COLOR_BUFFER_BIT);
        glColor3f(0.0, 1.0, 0.0);

        for (int x = 0; x < N; x++) {
                for (int y = 0; y < N; y++) {
                        glBegin(GL_POINTS);

                        double scaledX = (x - N / 2) * 4 / (N * 1.0);
                        double scaledY = (y - N / 2) * 4 / (N * 1.0); //dark voodoo magic

                        int count = 0;
                        int max = 256;

                        double a, b = 0.0;

                        while (count < max && ((a * a) + (b * b)) <= 4) {
                                int temp_a = (a * a) - (b * b) + scaledX;
                                b = 2 * a * b + scaledY;
                                a = temp_a;
                                count++;
                        }

                        if (count < max) {
                                glColor3f(1.0, 1.0, 0.0); //outside color
                        } else {
                                glColor3f(0.0, 0.0, 0.0); //inside color
                        }

                        glVertex2f(x, y); //draw a pixel of the color specified in glColor3f
                        glEnd();
                }
        }

        glutSwapBuffers(); //always at the end of displayfunc()
}