bool test_pen ()
{
cout << "Testing turtle_pen_up and turtle_pen_down:" << endl;
turtle t;
/*
* This code one of the problems with using structures. Even though
* we want all the modification of the turtle structure to happen through
* our functions, the compiler will not prevent someone from changing
* the contents directly.
* This is helpful for my test program, but bad in general.
*/
t.x = 99;
t.y = 99;
t.angle = 99;
t.penDown = false;
t.writeToFile = true;
turtle_init(&t, 500,500, NULL);
turtle_pen_up(&t);
if (t.penDown)
{
display_result (__FILE__, __LINE__, testcount);
return false;
}
cout << "Test " << testcount << " passed." << endl;
testcount++;
turtle_pen_down(&t);
if (!t.penDown)
{
display_result (__FILE__, __LINE__, testcount);
return false;
}
cout << "Test " << testcount << " passed." << endl;
testcount++;
turtle_end(&t);
cout << endl;
return true;
}
void turtle_draw_turtle()
{
int i, j;
// We are going to make our own backup of the turtle, since turtle_backup()
// only gives us one level of undo.
turtle_t original_turtle = main_turtle;
turtle_pen_up();
// Draw the legs
for (i = -1; i < 2; i+=2) {
for (j = -1; j < 2; j+=2) {
turtle_backup();
turtle_forward(i * 7);
turtle_strafe_left(j * 7);
turtle_set_fill_color(
main_turtle.pen_color.red,
main_turtle.pen_color.green,
main_turtle.pen_color.blue
);
turtle_fill_circle_here(5);
turtle_set_fill_color(
original_turtle.fill_color.red,
original_turtle.fill_color.green,
original_turtle.fill_color.blue
);
turtle_fill_circle_here(3);
turtle_restore();
}
}
// Draw the head
turtle_backup();
turtle_forward(10);
turtle_set_fill_color(
main_turtle.pen_color.red,
main_turtle.pen_color.green,
main_turtle.pen_color.blue
);
turtle_fill_circle_here(5);
turtle_set_fill_color(
original_turtle.fill_color.red,
original_turtle.fill_color.green,
original_turtle.fill_color.blue
);
turtle_fill_circle_here(3);
turtle_restore();
// Draw the body
for (i = 9; i >= 0; i-=4) {
turtle_backup();
turtle_set_fill_color(
main_turtle.pen_color.red,
main_turtle.pen_color.green,
main_turtle.pen_color.blue
);
turtle_fill_circle_here(i+2);
turtle_set_fill_color(
original_turtle.fill_color.red,
original_turtle.fill_color.green,
original_turtle.fill_color.blue
);
turtle_fill_circle_here(i);
turtle_restore();
}
// Restore the original turtle position:
main_turtle = original_turtle;
}
