Попадание точки в заштрихованную область - C (СИ) (152086)

#include <math.h>       // hypot, atan2
#include <stdio.h>      // puts, scanf
 
typedef struct point {
    double x;
    double y;
} Point;
 
void
Point_Init(Point* const this, const double x, const double y)
{
    this->x = x;
    this->y = y;
}
 
double
Point_Distance(const Point* const this, const Point* const p)
{
    return hypot(this->x - p->x, this->y - p->y);
}
 
double
Point_Angle(const Point* const this)
{
    if( this->x == 0.0 ) {
        return this->y < 0.0? -90.0 : 90.0;
    }
    return atan2(this->y, this->x) * 180.0 * M_1_PI;
}
 
typedef struct circle {
    Point center;
    double radius;
} Circle;
 
void
Circle_Init(Circle* const this, const Point* const center, const double radius)
{
    this->center = *center;
    this->radius = radius;
}
 
int
Circle_Contains(const Circle* const this, const Point* const p)
{
    return Point_Distance(&(this->center), p) <= this->radius;
}
 
typedef struct figure {
    Circle circle;
    double angle;
} Figure;
 
void
Figure_Init(Figure* const this, const double radius, const double angle)
{
    Point p;
    Point_Init(&p, 0.0, 0.0);
    Circle_Init(&(this->circle), &p, radius);
    this->angle = angle;
}
 
int
Figure_Contains(const Figure* const this, const Point* const p)
{
    if( !Circle_Contains(&(this->circle), p) ) { return 0; }
    double a = Point_Angle(p);
    return (a <= 90.0 && a >= this->angle)
        || (a <= -90.0 && a >= this->angle - 180.0);
}
 
int
main(void)
{
    const double angle = 45.0;
 
    while ( 1 ) {
        double x, y, radius;
        do {
            puts("Input x, y, radius:");
        } while( scanf("%lf %lf %lf", &x, &y, &radius) != 3 );
 
        if( radius <= 0.0 ) { break; }
 
        Figure figure;
        Figure_Init(&figure, radius, angle);
 
        Point point;
        Point_Init(&point, x, y);
 
        puts( Figure_Contains(&figure, &point)? "In" : "Out" );
    }
    return 0;
}