Rectangle

Rectangle — Rectangular shape type

Functions

Types and Values

Includes

#include <graphene.h>

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

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

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

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

Returns

the normalized rectangle.

[transfer none]

Since: 1.0


graphene_rect_normalize_r ()

void
graphene_rect_normalize_r (const graphene_rect_t *r,
                           graphene_rect_t *res);

Normalizes the passed rectangle.

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

Parameters

r

a graphene_rect_t

 

res

the return location for the normalized rectangle.

[out caller-allocates]

Since: 1.4


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

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

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

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

Returns

the normalized height of the rectangle

Since: 1.0


graphene_rect_get_area ()

float
graphene_rect_get_area (const graphene_rect_t *r);

Compute the area of given normalized rectangle.

Parameters

Returns

the area of the normalized rectangle

Since: 1.10


graphene_rect_get_vertices ()

void
graphene_rect_get_vertices (const graphene_rect_t *r,
                            graphene_vec2_t vertices[]);

Computes the four vertices of a graphene_rect_t.

Parameters

r

a graphene_rect_t

 

vertices

return location for an array of 4 graphene_vec2_t.

[out][array fixed-size=4]

Since: 1.4


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.

The union in the image above is the blue outline.

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.

The intersection in the image above is the blue outline.

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

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

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_offset_r ()

void
graphene_rect_offset_r (const graphene_rect_t *r,
                        float d_x,
                        float d_y,
                        graphene_rect_t *res);

Offsets the origin of the given rectangle by d_x and d_y .

The size of the rectangle is left unchanged.

Parameters

r

a graphene_rect_t

 

d_x

the horizontal offset

 

d_y

the vertical offset

 

res

return location for the offset rectangle.

[out caller-allocates]

Since: 1.4


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_inset_r ()

void
graphene_rect_inset_r (const graphene_rect_t *r,
                       float d_x,
                       float d_y,
                       graphene_rect_t *res);

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

 

res

return location for the inset rectangle.

[out caller-allocates]

Since: 1.4


graphene_rect_round_to_pixel ()

graphene_rect_t *
graphene_rect_round_to_pixel (graphene_rect_t *r);

graphene_rect_round_to_pixel has been deprecated since version 1.4 and should not be used in newly-written code.

Use graphene_rect_round() instead

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

Returns

the pixel-aligned rectangle.

[transfer none]

Since: 1.0


graphene_rect_round ()

void
graphene_rect_round (const graphene_rect_t *r,
                     graphene_rect_t *res);

graphene_rect_round has been deprecated since version 1.10 and should not be used in newly-written code.

Use graphene_rect_round_extents() instead

Rounds the origin and size of the given rectangle to their nearest integer values; the rounding is guaranteed to be large enough to have an area bigger or equal to the original rectangle, but might not fully contain its extents. Use graphene_rect_round_extents() in case you need to round to a rectangle that covers fully the original one.

This function is the equivalent of calling floor on the coordinates of the origin, and ceil on the size.

Parameters

r

a graphene_rect_t

 

res

return location for the rounded rectangle.

[out caller-allocates]

Since: 1.4


graphene_rect_round_extents ()

void
graphene_rect_round_extents (const graphene_rect_t *r,
                             graphene_rect_t *res);

Rounds the origin of the given rectangle to its nearest integer value and and recompute the size so that the rectangle is large enough to contain all the conrners of the original rectangle.

This function is the equivalent of calling floor on the coordinates of the origin, and recomputing the size calling ceil on the bottom-right coordinates.

If you want to be sure that the rounded rectangle completely covers the area that was covered by the original rectangle — i.e. you want to cover the area including all its corners — this function will make sure that the size is recomputed taking into account the ceiling of the coordinates of the bottom-right corner. If the difference between the original coordinates and the coordinates of the rounded rectangle is greater than the difference between the original size and and the rounded size, then the move of the origin would not be compensated by a move in the anti-origin, leaving the corners of the original rectangle outside the rounded one.

Parameters

r

a graphene_rect_t

 

res

return location for the rectangle with rounded extents.

[out caller-allocates]

Since: 1.10


graphene_rect_expand ()

void
graphene_rect_expand (const graphene_rect_t *r,
                      const graphene_point_t *p,
                      graphene_rect_t *res);

Expands a graphene_rect_t to contain the given graphene_point_t.

Parameters

r

a graphene_rect_t

 

p

a graphene_point_t

 

res

return location for the expanded rectangle.

[out caller-allocates]

Since: 1.4


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


graphene_rect_zero ()

const graphene_rect_t *
graphene_rect_zero (void);

Returns a degenerate rectangle with origin fixed at (0, 0) and a size of 0, 0.

Returns

a fixed rectangle.

[transfer none]

Since: 1.4


graphene_rect_scale ()

void
graphene_rect_scale (const graphene_rect_t *r,
                     float s_h,
                     float s_v,
                     graphene_rect_t *res);

Scales the size and origin of a rectangle horizontaly by s_h , and vertically by s_v . The result res is normalized.

Parameters

r

a graphene_rect_t

 

s_h

horizontal scale factor

 

s_v

vertical scale factor

 

res

return location for the scaled rectangle.

[out caller-allocates]

Since: 1.10

Types and Values

GRAPHENE_RECT_INIT_ZERO

#define GRAPHENE_RECT_INIT_ZERO         GRAPHENE_RECT_INIT (0.f, 0.f, 0.f, 0.f)

Initializes a graphene_rect_t to a degenerate rectangle with an origin in (0, 0) and a size of 0.

Since: 1.10


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