The Be Book - Classes And Methods

BPoint

Derived From:	–
Mix-in Classes:	–
Declared In:	`interface/Point.h`
Library:	`libbe.so`
Allocation:	Constructor or on the stack, typically the latter.

Class Overview

Data Members

float x

The coordinate value measured horizontally along the x-axis.

float y

The coordinate value measured vertically along the y-axis.

Constructor and Destructor

BPoint()

inline BPoint(float x,
              float y);

inline BPoint(const BPoint& point); inline BPoint();

Creates a new BPoint object that corresponds to the point (x, y), or BPoint that's copied from point. If no coordinate values are assigned, the BPoint's location is indeterminate.

See also: Set(), the assignment operator

Member Functions

ConstrainTo()

void ConstrainTo(BRect rect);

Ensures that the BPoint lies within rect. If it's already contained in the rectangle, the BPoint is unchanged; otherwise, it's moved to the rect's nearest edge.

PrintToStream()

void PrintToStream() const;

Prints the BPoint's coordinates to standard output in the form:

"BPoint(x, y)"

Set()

inline void Set(float x,
                float y);

Sets the BPoint's x and y coordinates.

Operators

= (assignment)

inline BPoint& operator =(const BPoint& from);

Copies from's coordinate data into the left-side object.

== (equality), != (inequality)

bool operator ==(BPoint) const;bool operator !=(BPoint) const;

== returns true if the two objects' point exactly coincide.

!= returns true if the two objects' points don't coincide.

+ (addition), += (addition and assignment)

BPoint operator +(const BPoint& ) const;BPoint operator +=(const BPoint& ) const;

+ creates and returns a new BPoint that adds the two operands together. The new object's x coordinate is the sum of the operands' x values; its y value is the sum of the operands' y values.

+= adds the operands together and stores the result in the left operand.

- (subtraction), -= (subtraction and assignment)

BPoint operator -(const BPoint& ) const;BPoint operator -=(const BPoint& ) const;

- creates and returns a new BPoint that subtracts the right operand from the left. The new object's x coordinate is the difference between the operands' x values; its y value is the difference between the operands' y values.

-= performs the subtraction and stores the result in the left operand.

Global Objects

B_ORIGIN

BPoint object that represents (0.0, 0.0).