// PROGRAM simple_map

#include "TrueBASIC.h"
int main();
void initial(double *x0, double *y0);

int main()
{
    double x, xnew, y;
    int i;

    GWopen(0);

    initial(&x, &y);
    for(i = 1; i <= 100000; ++i)
    {
        xnew = 1 - y + fabs(x);
        y = x;
        x = xnew;
        GWsetpxl((float)(x), (float)(y), BLUE);
    }

    GWquit();
    return 0;
}

void initial(double *x0, double *y0)
{
    float mx, my, xmax, xmin, ymax, ymin;
    char Stmp1_[_LBUFF_];

    printf("initial value of x = ");
    fgets(Stmp1_, _LBUFF_, stdin);
    sscanf(Stmp1_, "%lg", x0);
    printf("initial value of y = ");
    fgets(Stmp1_, _LBUFF_, stdin);
    sscanf(Stmp1_, "%lg", y0);
    xmin = -3;
    xmax = 8;
    ymin = -3;
    ymax = 8;
    mx = 0.01f*(xmax - xmin);               // マージン
    my = 0.01f*(ymax - ymin);
    GWindow(xmin - mx, ymin - my, xmax + mx, ymax + my);
    GWrect(xmin, ymin, xmax, ymax);         // 境界線を描く
}