]> Regions 3 CAIRO Library Regions Representing a pixel-aligned area cairo_region_t * cairo_region_create () cairo_region_t * cairo_region_create_rectangle () cairo_region_t * cairo_region_create_rectangles () cairo_region_t * cairo_region_copy () cairo_region_t * cairo_region_reference () void cairo_region_destroy () cairo_status_t cairo_region_status () void cairo_region_get_extents () int cairo_region_num_rectangles () void cairo_region_get_rectangle () cairo_bool_t cairo_region_is_empty () cairo_bool_t cairo_region_contains_point () cairo_region_overlap_t cairo_region_contains_rectangle () cairo_bool_t cairo_region_equal () void cairo_region_translate () cairo_status_t cairo_region_intersect () cairo_status_t cairo_region_intersect_rectangle () cairo_status_t cairo_region_subtract () cairo_status_t cairo_region_subtract_rectangle () cairo_status_t cairo_region_union () cairo_status_t cairo_region_union_rectangle () cairo_status_t cairo_region_xor () cairo_status_t cairo_region_xor_rectangle () typedefcairo_region_t enumcairo_region_overlap_t Regions are a simple graphical data type representing an area of integer-aligned rectangles. They are often used on raster surfaces to track areas of interest, such as change or clip areas. cairo_region_create cairo_region_t * cairo_region_create (void); Allocates a new empty region object. A newly allocated cairo_region_t. Free with cairo_region_destroy(). This function always returns a valid pointer; if memory cannot be allocated, then a special error object is returned where all operations on the object do nothing. You can check for this with cairo_region_status(). Since: 1.10 cairo_region_create_rectangle cairo_region_t * cairo_region_create_rectangle (const cairo_rectangle_int_t *rectangle); Allocates a new region object containing rectangle . rectangle a cairo_rectangle_int_t A newly allocated cairo_region_t. Free with cairo_region_destroy(). This function always returns a valid pointer; if memory cannot be allocated, then a special error object is returned where all operations on the object do nothing. You can check for this with cairo_region_status(). Since: 1.10 cairo_region_create_rectangles cairo_region_t * cairo_region_create_rectangles (const cairo_rectangle_int_t *rects, int count); Allocates a new region object containing the union of all given rects . rects an array of count rectangles count number of rectangles A newly allocated cairo_region_t. Free with cairo_region_destroy(). This function always returns a valid pointer; if memory cannot be allocated, then a special error object is returned where all operations on the object do nothing. You can check for this with cairo_region_status(). Since: 1.10 cairo_region_copy cairo_region_t * cairo_region_copy (const cairo_region_t *original); Allocates a new region object copying the area from original . original a cairo_region_t A newly allocated cairo_region_t. Free with cairo_region_destroy(). This function always returns a valid pointer; if memory cannot be allocated, then a special error object is returned where all operations on the object do nothing. You can check for this with cairo_region_status(). Since: 1.10 cairo_region_reference cairo_region_t * cairo_region_reference (cairo_region_t *region); Increases the reference count on region by one. This prevents region from being destroyed until a matching call to cairo_region_destroy() is made. region a cairo_region_t the referenced cairo_region_t. Since: 1.10 cairo_region_destroy void cairo_region_destroy (cairo_region_t *region); Destroys a cairo_region_t object created with cairo_region_create(), cairo_region_copy(), or or cairo_region_create_rectangle(). region a cairo_region_t Since: 1.10 cairo_region_status cairo_status_t cairo_region_status (const cairo_region_t *region); Checks whether an error has previous occurred for this region object. region a cairo_region_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_get_extents void cairo_region_get_extents (const cairo_region_t *region, cairo_rectangle_int_t *extents); Gets the bounding rectangle of region as a cairo_rectangle_int_t region a cairo_region_t extents rectangle into which to store the extents Since: 1.10 cairo_region_num_rectangles int cairo_region_num_rectangles (const cairo_region_t *region); Returns the number of rectangles contained in region . region a cairo_region_t The number of rectangles contained in region . Since: 1.10 cairo_region_get_rectangle void cairo_region_get_rectangle (const cairo_region_t *region, int nth, cairo_rectangle_int_t *rectangle); Stores the nth rectangle from the region in rectangle . region a cairo_region_t nth a number indicating which rectangle should be returned rectangle return location for a cairo_rectangle_int_t Since: 1.10 cairo_region_is_empty cairo_bool_t cairo_region_is_empty (const cairo_region_t *region); Checks whether region is empty. region a cairo_region_t TRUE if region is empty, FALSE if it isn't. Since: 1.10 cairo_region_contains_point cairo_bool_t cairo_region_contains_point (const cairo_region_t *region, int x, int y); Checks whether (x , y ) is contained in region . region a cairo_region_t x the x coordinate of a point y the y coordinate of a point TRUE if (x , y ) is contained in region , FALSE if it is not. Since: 1.10 cairo_region_contains_rectangle cairo_region_overlap_t cairo_region_contains_rectangle (const cairo_region_t *region, const cairo_rectangle_int_t *rectangle); Checks whether rectangle is inside, outside or partially contained in region region a cairo_region_t rectangle a cairo_rectangle_int_t CAIRO_REGION_OVERLAP_IN if rectangle is entirely inside region , CAIRO_REGION_OVERLAP_OUT if rectangle is entirely outside region , or CAIRO_REGION_OVERLAP_PART if rectangle is partially inside and partially outside region . Since: 1.10 cairo_region_equal cairo_bool_t cairo_region_equal (const cairo_region_t *a, const cairo_region_t *b); Compares whether region_a is equivalent to region_b. NULL as an argument is equal to itself, but not to any non-NULL region. a a cairo_region_t or NULL b a cairo_region_t or NULL TRUE if both regions contained the same coverage, FALSE if it is not or any region is in an error status. Since: 1.10 cairo_region_translate void cairo_region_translate (cairo_region_t *region, int dx, int dy); Translates region by (dx , dy ). region a cairo_region_t dx Amount to translate in the x direction dy Amount to translate in the y direction Since: 1.10 cairo_region_intersect cairo_status_t cairo_region_intersect (cairo_region_t *dst, const cairo_region_t *other); Computes the intersection of dst with other and places the result in dst dst a cairo_region_t other another cairo_region_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_intersect_rectangle cairo_status_t cairo_region_intersect_rectangle (cairo_region_t *dst, const cairo_rectangle_int_t *rectangle); Computes the intersection of dst with rectangle and places the result in dst dst a cairo_region_t rectangle a cairo_rectangle_int_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_subtract cairo_status_t cairo_region_subtract (cairo_region_t *dst, const cairo_region_t *other); Subtracts other from dst and places the result in dst dst a cairo_region_t other another cairo_region_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_subtract_rectangle cairo_status_t cairo_region_subtract_rectangle (cairo_region_t *dst, const cairo_rectangle_int_t *rectangle); Subtracts rectangle from dst and places the result in dst dst a cairo_region_t rectangle a cairo_rectangle_int_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_union cairo_status_t cairo_region_union (cairo_region_t *dst, const cairo_region_t *other); Computes the union of dst with other and places the result in dst dst a cairo_region_t other another cairo_region_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_union_rectangle cairo_status_t cairo_region_union_rectangle (cairo_region_t *dst, const cairo_rectangle_int_t *rectangle); Computes the union of dst with rectangle and places the result in dst . dst a cairo_region_t rectangle a cairo_rectangle_int_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_xor cairo_status_t cairo_region_xor (cairo_region_t *dst, const cairo_region_t *other); Computes the exclusive difference of dst with other and places the result in dst . That is, dst will be set to contain all areas that are either in dst or in other , but not in both. dst a cairo_region_t other another cairo_region_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_xor_rectangle cairo_status_t cairo_region_xor_rectangle (cairo_region_t *dst, const cairo_rectangle_int_t *rectangle); Computes the exclusive difference of dst with rectangle and places the result in dst . That is, dst will be set to contain all areas that are either in dst or in rectangle , but not in both. dst a cairo_region_t rectangle a cairo_rectangle_int_t CAIRO_STATUS_SUCCESS or CAIRO_STATUS_NO_MEMORY Since: 1.10 cairo_region_t typedef struct _cairo_region cairo_region_t; A cairo_region_t represents a set of integer-aligned rectangles. It allows set-theoretical operations like cairo_region_union() and cairo_region_intersect() to be performed on them. Memory management of cairo_region_t is done with cairo_region_reference() and cairo_region_destroy(). Since: 1.10 cairo_region_overlap_t Used as the return value for cairo_region_contains_rectangle(). CAIRO_REGION_OVERLAP_IN The contents are entirely inside the region. (Since 1.10) CAIRO_REGION_OVERLAP_OUT The contents are entirely outside the region. (Since 1.10) CAIRO_REGION_OVERLAP_PART The contents are partially inside and partially outside the region. (Since 1.10) Since: 1.10