point.h File Reference

#include "defines.h"

Include dependency graph for point.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	Point_T

Enumerations
enum	Turn_T { COLINEAR =1, LEFT_TURN =2, RIGHT_TURN =3 }

Functions
int	equal_Point (struct Point_T *p1, struct Point_T *p2)
int	higher_Point (struct Point_T *p1, struct Point_T *p2, int(*f)(struct Point_T *, struct Point_T *))
int	lower_X (struct Point_T *p1, struct Point_T *p2)
int	higher_X (struct Point_T *p1, struct Point_T *p2)
int	higher_Y (struct Point_T *p1, struct Point_T *p2)
int	lexicographic_Higher (struct Point_T *p1, struct Point_T *p2)
void	copy_Point (struct Point_T *p1, struct Point_T *p2)
TYPE	distance (struct Point_T *p, struct Point_T *q)
TYPE	signed_Area (struct Point_T *p1, struct Point_T *p2, struct Point_T *p3)
enum Turn_T	check_Turn (struct Point_T *p1, struct Point_T *p2, struct Point_T *p3)
int	in_Circle (struct Point_T *p1, struct Point_T *p2, struct Point_T *p3, struct Point_T *q)
bool	interior_Triangle (struct Point_T *p1, struct Point_T *p2, struct Point_T *p3, struct Point_T *q)
int	has_Extreme_Coordinates (struct Point_T *p)
void	print_Point (struct Point_T *point)

Enumeration Type Documentation

Turn_T

enum Turn_T

Enumerator
COLINEAR
LEFT_TURN
RIGHT_TURN

Definition at line 10 of file point.h.

{COLINEAR=1, LEFT_TURN=2, RIGHT_TURN=3};

Function Documentation

check_Turn()

enum Turn_T check_Turn	(	struct Point_T *	p1,
		struct Point_T *	p2,
		struct Point_T *	p3
	)

Definition at line 73 of file point.cpp.

{
    TYPE          area=0.0;       // Signed area.
    enum Turn_T     turn;           // Return value.

    // Compute signed area of the triangle formed by p1, p2 and p3.
    area = signed_Area( p1, p2, p3);

#ifdef DEBUG_CHECK_TURN
    printf("Area %f. P (%lf,%lf). Q (%lf,%lf). R (%lf,%lf)\n", area, p1->x, p1->y, p2->x, p2->y, p3->x, p3->y);
#endif

    // Higher than zero -> turn left.
    if (area > COLLINEAR_THRESHOLD)
    {
#ifdef DEBUG_CHECK_TURN
        printf("LEFT\n");
#endif
        turn = LEFT_TURN;
    }
    // Lower than zero -> turn right.
    else if (area < -COLLINEAR_THRESHOLD)
    {
#ifdef DEBUG_CHECK_TURN
        printf("RIGHT\n");
#endif
        turn = RIGHT_TURN;
    }
    // If area is close to zero then points are collinear.
    else
    {
#ifdef DEBUG_CHECK_TURN
        printf("COLLINEAR\n");
#endif
        turn = COLINEAR;
    }

    return(turn);
}

copy_Point()

void copy_Point	(	struct Point_T *	p1,
		struct Point_T *	p2
	)

Definition at line 241 of file point.cpp.

{
    // Copy p1 x and y values into p2.
    p2->x = p1->x;
    p2->y = p1->y;
}

distance()

TYPE distance	(	struct Point_T *	p,
		struct Point_T *	q
	)

Definition at line 28 of file point.cpp.

{
    TYPE dist=0.0;

    // Compute distance.
    dist = Euclidean( p, q);

    return(dist);
}

equal_Point()

int equal_Point	(	struct Point_T *	p1,
		struct Point_T *	p2
	)

Definition at line 39 of file point.cpp.

{
    int         equal=FALSE;        // Return value.
    POINT_T     diff=0.0;           // Coordinates difference value.

    // Check if points are too close.
    diff = p1->x - p2->x;
    if ((diff < DELTA_DIFF) && (diff > -DELTA_DIFF))
    {
        diff = p1->y - p2->y;
        if ((diff < DELTA_DIFF) && (diff > -DELTA_DIFF))
        {
            equal = TRUE;
        }
    }
    else
    {
        equal = FALSE;
    }

    return(equal);
}

has_Extreme_Coordinates()

int has_Extreme_Coordinates

(

struct Point_T *

p

)

Definition at line 172 of file point.cpp.

{
    int has_Extreme=FALSE;      // Return value.

    if ((p->x >= MAX_X_COORD) || (p->y >= MAX_Y_COORD) ||
        (p->x <= -MAX_X_COORD) || (p->y <= -MAX_Y_COORD))
    {
        has_Extreme = TRUE;
    }

    return(has_Extreme);
}

higher_Point()

int higher_Point	(	struct Point_T *	p1,
		struct Point_T *	p2,
		int(*)(struct Point_T *, struct Point_T *)	f
	)

Definition at line 62 of file point.cpp.

{
    return((*f)( p1, p2));
}

higher_X()

int higher_X	(	struct Point_T *	p1,
		struct Point_T *	p2
	)

Definition at line 191 of file point.cpp.

{
    // Return true if y coordinate is higher.
    return(p1->x > p2->x);
}

higher_Y()

int higher_Y	(	struct Point_T *	p1,
		struct Point_T *	p2
	)

Definition at line 197 of file point.cpp.

{
    // Return true if y coordinate is higher.
    return(p1->y > p2->y);
}

in_Circle()

int in_Circle	(	struct Point_T *	p1,
		struct Point_T *	p2,
		struct Point_T *	p3,
		struct Point_T *	q
	)

Definition at line 114 of file point.cpp.

{
    int         ret=0;          // Return value.
    POINT_T     value=0.0;      // Determinant value.
    POINT_T     temp[9];        // Intermediate values.

    // Compute Ax - Dx, Ay - Dy and (Ax-Dx)² + (Ay-Dy)²
    temp[0] = (p1->x - q->x);
    temp[1] = (p1->y - q->y);
    temp[2] = (POINT_T) (pow((p1->x - q->x), 2) + pow((p1->y - q->y), 2));

    // Compute Bx - Dx, By - Dy and (Bx-Dx)² + (By-Dy)²
    temp[3] = (p2->x - q->x);
    temp[4] = (p2->y - q->y);
    temp[5] = (POINT_T) (pow((p2->x - q->x), 2) + pow((p2->y - q->y), 2));

    // Compute Cx - Dx, Cy - Dy and (Cx-Dx)² + (Cy-Dy)²
    temp[6] = (p3->x - q->x);
    temp[7] = (p3->y - q->y);
    temp[8] = (POINT_T) (pow((p3->x - q->x), 2) + pow((p3->y - q->y), 2));

    // Compute determinant.
    value = (temp[0]*temp[4]*temp[8]) +
            (temp[1]*temp[5]*temp[6]) +
            (temp[2]*temp[3]*temp[7]) -
            (temp[2]*temp[4]*temp[6]) -
            (temp[5]*temp[7]*temp[0]) -
            (temp[8]*temp[1]*temp[3]);

    // If positive then point q belongs to p1-p2-p3 circumference.
    if (value > 0.0)
    {
        ret = 1;
    }

    return(ret);
}

interior_Triangle()

bool interior_Triangle	(	struct Point_T *	p1,
		struct Point_T *	p2,
		struct Point_T *	p3,
		struct Point_T *	q
	)

Definition at line 152 of file point.cpp.

{
    bool is_In_Triangle=false;   // Return value.

    // Check if new point is interior to triangle formed by p1, p2 and p3.
    if ((signed_Area( p1, p2, q) > 0) &&
        (signed_Area( p2, p3, q) > 0) &&
        (signed_Area( p3, p1, q) > 0))
    {
        is_In_Triangle = true;
    }
    else
    {
        is_In_Triangle = false;
    }

    return(is_In_Triangle);
}

lexicographic_Higher()

int lexicographic_Higher	(	struct Point_T *	p1,
		struct Point_T *	p2
	)

Definition at line 211 of file point.cpp.

{
    int     higher=FALSE;       // Return value.

    // Check if Y coordinate is higher.
    if (p1->y > p2->y)
    {
        higher = TRUE;
    }
    else
    {
        // If Y coordinate is equal then check X coordinate.
        if ((p1->y == p2->y) &&
            (p1->x > p2->x))
        {
            higher = TRUE;
        }
    }

    return(higher);
}

lower_X()

int lower_X	(	struct Point_T *	p1,
		struct Point_T *	p2
	)

Definition at line 185 of file point.cpp.

{
    // Return true if y coordinate is higher.
    return(p1->x < p2->x);
}

print_Point()

void print_Point

(

struct Point_T *

point

)

Definition at line 67 of file point.cpp.

{
    printf("Point (%f, %f)\n", point->x, point->y);
}

signed_Area()

TYPE signed_Area	(	struct Point_T *	p1,
		struct Point_T *	p2,
		struct Point_T *	p3
	)

Definition at line 267 of file point.cpp.

{
    double  area=0.0;           // Return value.

    area = (- (double) p2->x*p1->y + (double) p3->x*p1->y + (double) p1->x*p2->y -
            (double) p3->x*p2->y - (double) p1->x*p3->y + (double) p2->x*p3->y);

    return(area);
}