Rectangle: Graphene Reference Manual

## Rectangle Rectangle — Rectangular shape type |

## Functions

#define | GRAPHENE_RECT_INIT()
graphene_rect_t * | graphene_rect_alloc ()
void | graphene_rect_free ()
graphene_rect_t * | graphene_rect_init ()
graphene_rect_t * | graphene_rect_init_from_rect ()
bool | graphene_rect_equal ()
graphene_rect_t * | graphene_rect_normalize ()
void | graphene_rect_get_center ()
void | graphene_rect_get_top_left ()
void | graphene_rect_get_top_right ()
void | graphene_rect_get_bottom_right ()
void | graphene_rect_get_bottom_left ()
float | graphene_rect_get_x ()
float | graphene_rect_get_y ()
float | graphene_rect_get_width ()
float | graphene_rect_get_height ()
void | graphene_rect_union ()
bool | graphene_rect_intersection ()
bool | graphene_rect_contains_point ()
bool | graphene_rect_contains_rect ()
graphene_rect_t * | graphene_rect_offset ()
graphene_rect_t * | graphene_rect_inset ()
graphene_rect_t * | graphene_rect_round_to_pixel ()
void | graphene_rect_interpolate ()

## Types and Values

| graphene_rect_t

## Description

graphene_rect_t is a type representing a rectangle through an origin graphene_point_t point and a graphene_size_t size.

Operations on a graphene_rect_t will normalize the rectangle, to ensure that the origin is always the top-left corner of the rectangle and that the size is always positive.

## Functions

### GRAPHENE_RECT_INIT()

    #define             GRAPHENE_RECT_INIT(x,y,w,h)

Initializes a graphene_rect_t when declaring it.

#### Parameters

x | the X coordinate of the origin |
y | the Y coordinate of the origin |
w | the width |
h | the height |

Since: 1.0

### graphene_rect_alloc ()

    graphene_rect_t *
    graphene_rect_alloc (void);

Allocates a new graphene_rect_t.

The contents of the returned rectangle are undefined.

#### Returns

the newly allocated rectangle.

[transfer full]

Since: 1.0

### graphene_rect_free ()

    void
    graphene_rect_free (graphene_rect_t *r);

Frees the resources allocated by `graphene_rect_alloc()`.

#### Parameters

r | a graphene_rect_t |

Since: 1.0

### graphene_rect_init ()

    graphene_rect_t *
    graphene_rect_init (graphene_rect_t *r,
                        float x,
                        float y,
                        float width,
                        float height);

Initializes the given graphene_rect_t with the given values.

This function will implicitly normalize the graphene_rect_t before returning.

#### Parameters

r | a graphene_rect_t |
x | the X coordinate of the `graphene_rect_t.origin` |
y | the Y coordinate of the `graphene_rect_t.origin` |
width | the width of the `graphene_rect_t.size` |
height | the height of the `graphene_rect_t.size` |

#### Returns

the initialized rectangle.

[transfer none]

Since: 1.0

### graphene_rect_init_from_rect ()

    graphene_rect_t *
    graphene_rect_init_from_rect (graphene_rect_t *r,
                                  const graphene_rect_t *src);

Initializes `r` using the given `src` rectangle.

This function will implicitly normalize the graphene_rect_t before returning.

#### Parameters

r | a graphene_rect_t |
src | a graphene_rect_t |

#### Returns

the initialized rectangle.

[transfer none]

Since: 1.0

### graphene_rect_equal ()

    bool
    graphene_rect_equal (const graphene_rect_t *a,
                         const graphene_rect_t *b);

Checks whether the two given rectangle are equal.

#### Parameters

a | a graphene_rect_t |
b | a graphene_rect_t |

#### Returns

`true` if the rectangles are equal

Since: 1.0

### graphene_rect_normalize ()

    graphene_rect_t *
    graphene_rect_normalize (graphene_rect_t *r);

Normalizes the passed rectangle.

This function ensures that the size of the rectangle is made of positive values, and that the origin is the top-left corner of the rectangle.

#### Parameters

r | a graphene_rect_t |

#### Returns

the normalized rectangle.

[transfer none]

Since: 1.0

### graphene_rect_get_center ()

    void
    graphene_rect_get_center (const graphene_rect_t *r,
                              graphene_point_t *p);

Retrieves the coordinates of the center of the given rectangle.

#### Parameters

r | a graphene_rect_t |
p | return location for a graphene_point_t. | [out caller-allocates]

Since: 1.0

### graphene_rect_get_top_left ()

    void
    graphene_rect_get_top_left (const graphene_rect_t *r,
                                graphene_point_t *p);

Retrieves the coordinates of the top-left corner of the given rectangle.

#### Parameters

r | a graphene_rect_t |
p | return location for a graphene_point_t. | [out caller-allocates]

Since: 1.0

### graphene_rect_get_top_right ()

    void
    graphene_rect_get_top_right (const graphene_rect_t *r,
                                 graphene_point_t *p);

Retrieves the coordinates of the top-right corner of the given rectangle.

#### Parameters

r | a graphene_rect_t |
p | return location for a graphene_point_t. | [out caller-allocates]

Since: 1.0

### graphene_rect_get_bottom_right ()

    void
    graphene_rect_get_bottom_right (const graphene_rect_t *r,
                                    graphene_point_t *p);

Retrieves the coordinates of the bottom-right corner of the given rectangle.

#### Parameters

r | a graphene_rect_t |
p | return location for a graphene_point_t. | [out caller-allocates]

Since: 1.0

### graphene_rect_get_bottom_left ()

    void
    graphene_rect_get_bottom_left (const graphene_rect_t *r,
                                   graphene_point_t *p);

Retrieves the coordinates of the bottom-left corner of the given rectangle.

#### Parameters

r | a graphene_rect_t |
p | return location for a graphene_point_t. | [out caller-allocates]

Since: 1.0

### graphene_rect_get_x ()

    float
    graphene_rect_get_x (const graphene_rect_t *r);

Retrieves the normalized X coordinate of the origin of the given rectangle.

#### Parameters

r | a graphene_rect_t |

#### Returns

the normalized X coordinate of the rectangle

Since: 1.0

### graphene_rect_get_y ()

    float
    graphene_rect_get_y (const graphene_rect_t *r);

Retrieves the normalized Y coordinate of the origin of the given rectangle.

#### Parameters

r | a graphene_rect_t |

#### Returns

the normalized Y coordinate of the rectangle

Since: 1.0

### graphene_rect_get_width ()

    float
    graphene_rect_get_width (const graphene_rect_t *r);

Retrieves the normalized width of the given rectangle.

#### Parameters

r | a graphene_rect_t |

#### Returns

the normalized width of the rectangle

Since: 1.0

### graphene_rect_get_height ()

    float
    graphene_rect_get_height (const graphene_rect_t *r);

Retrieves the normalized height of the given rectangle.

#### Parameters

r | a graphene_rect_t |

#### Returns

the normalized height of the rectangle

Since: 1.0

### graphene_rect_union ()

    void
    graphene_rect_union (const graphene_rect_t *a,
                         const graphene_rect_t *b,
                         graphene_rect_t *res);

Computes the union of the two given rectangles.

#### Parameters

a | a graphene_rect_t |
b | a graphene_rect_t |
res | return location for a graphene_rect_t. | [out caller-allocates]

Since: 1.0

### graphene_rect_intersection ()

    bool
    graphene_rect_intersection (const graphene_rect_t *a,
                                const graphene_rect_t *b,
                                graphene_rect_t *res);

Computes the intersection of the two given rectangles.

If the two rectangles do not intersect, `res` will contain a degenerate rectangle with origin in (0, 0) and a size of 0.

#### Parameters

a | a graphene_rect_t |
b | a graphene_rect_t |
res | return location for a graphene_rect_t. | [out caller-allocates][optional]

#### Returns

`true` if the two rectangles intersect

Since: 1.0

### graphene_rect_contains_point ()

    bool
    graphene_rect_contains_point (const graphene_rect_t *r,
                                  const graphene_point_t *p);

Checks whether a graphene_rect_t contains the given coordinates.

#### Parameters

r | a graphene_rect_t |
p | a graphene_point_t |

#### Returns

`true` if the rectangle contains the point

Since: 1.0

### graphene_rect_contains_rect ()

    bool
    graphene_rect_contains_rect (const graphene_rect_t *a,
                                 const graphene_rect_t *b);

Checks whether a graphene_rect_t fully contains the given rectangle.

#### Parameters

a | a graphene_rect_t |
b | a graphene_rect_t |

#### Returns

`true` if the rectangle `a` fully contains `b`

Since: 1.0

### graphene_rect_offset ()

    graphene_rect_t *
    graphene_rect_offset (graphene_rect_t *r,
                          float d_x,
                          float d_y);

Offsets the origin by `d_x` and `d_y` .

The size of the rectangle is unchanged.

#### Parameters

r | a graphene_rect_t |
d_x | the horizontal offset |
d_y | the vertical offset |

#### Returns

the offset rectangle.

[transfer none]

Since: 1.0

### graphene_rect_inset ()

    graphene_rect_t *
    graphene_rect_inset (graphene_rect_t *r,
                         float d_x,
                         float d_y);

Changes the given rectangle to be smaller, or larger depending on the given inset parameters.

To create an inset rectangle, use positive `d_x` or `d_y` values; to create a larger, encompassing rectangle, use negative `d_x` or `d_y` values.

The origin of the rectangle is offset by `d_x` and `d_y` , while the size is adjusted by (2 * `d_x` , 2 * `d_y` ). If `d_x` and `d_y` are positive values, the size of the rectangle is decreased; if `d_x` and `d_y` are negative values, the size of the rectangle is increased.

If the size of the resulting inset rectangle has a negative width or height then the size will be set to zero.

#### Parameters

r | a graphene_rect_t |
d_x | the horizontal inset |
d_y | the vertical inset |

#### Returns

the inset rectangle.

[transfer none]

Since: 1.0

### graphene_rect_round_to_pixel ()

    graphene_rect_t *
    graphene_rect_round_to_pixel (graphene_rect_t *r);

Rounds the origin and the size of the given rectangle to their nearest integer values; the rounding is guaranteed to be large enough to contain the original rectangle.

#### Parameters

r | a graphene_rect_t |

#### Returns

the pixel-aligned rectangle.

[transfer none]

Since: 1.0

### graphene_rect_interpolate ()

    void
    graphene_rect_interpolate (const graphene_rect_t *a,
                               const graphene_rect_t *b,
                               double factor,
                               graphene_rect_t *res);

Linearly interpolates the origin and size of the two given rectangles.

#### Parameters

a | a graphene_rect_t |
b | a graphene_rect_t |
factor | the linear interpolation factor |
res | return location for the interpolated rectangle. | [out caller-allocates]

Since: 1.0

## Types and Values

### graphene_rect_t

    typedef struct {
      graphene_point_t origin;
      graphene_size_t size;
    } graphene_rect_t;

The location and size of a rectangle region.

The width and height of a graphene_rect_t can be negative; for instance, a graphene_rect_t with an origin of [ 0, 0 ] and a size of [ 10, 10 ] is equivalent to a graphene_rect_t with an origin of [ 10, 10 ] and a size of [ -10, -10 ].

Application code can normalize rectangles using `graphene_rect_normalize()`; this function will ensure that the width and height of a rectangle are positive values. All functions taking a graphene_rect_t as an argument will internally operate on a normalized copy; all functions returning a graphene_rect_t will always return a normalized rectangle.

#### Members

graphene_point_t `origin`; | the coordinates of the origin of the rectangle |
graphene_size_t `size`; | the size of the rectangle |

Since: 1.0