cairo_pattern_t

typedef struct _cairo_pattern cairo_pattern_t;

A cairo_pattern_t represents a source when drawing onto a surface. There are different subtypes of cairo_pattern_t, for different types of sources; for example, cairo_pattern_create_rgb() creates a pattern for a solid opaque color.

Other than various cairo_pattern_create_type() functions, some of the pattern types can be implicitly created using various cairo_set_source_type() functions; for example cairo_set_source_rgb().

The type of a pattern can be queried with cairo_pattern_get_type().

Memory management of cairo_pattern_t is done with cairo_pattern_reference() and cairo_pattern_destroy().

cairo_pattern_add_color_stop_rgb ()

void                cairo_pattern_add_color_stop_rgb    (cairo_pattern_t *pattern,
                                                         double offset,
                                                         double red,
                                                         double green,
                                                         double blue);

Adds an opaque color stop to a gradient pattern. The offset specifies the location along the gradient's control vector. For example, a linear gradient's control vector is from (x0,y0) to (x1,y1) while a radial gradient's control vector is from any point on the start circle to the corresponding point on the end circle.

The color is specified in the same way as in cairo_set_source_rgb().

If two (or more) stops are specified with identical offset values, they will be sorted according to the order in which the stops are added, (stops added earlier will compare less than stops added later). This can be useful for reliably making sharp color transitions instead of the typical blend.

Note: If the pattern is not a gradient pattern, (eg. a linear or radial pattern), then the pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH.

cairo_pattern_add_color_stop_rgba ()

void                cairo_pattern_add_color_stop_rgba   (cairo_pattern_t *pattern,
                                                         double offset,
                                                         double red,
                                                         double green,
                                                         double blue,
                                                         double alpha);

Adds a translucent color stop to a gradient pattern. The offset specifies the location along the gradient's control vector. For example, a linear gradient's control vector is from (x0,y0) to (x1,y1) while a radial gradient's control vector is from any point on the start circle to the corresponding point on the end circle.

The color is specified in the same way as in cairo_set_source_rgba().

If two (or more) stops are specified with identical offset values, they will be sorted according to the order in which the stops are added, (stops added earlier will compare less than stops added later). This can be useful for reliably making sharp color transitions instead of the typical blend.

Note: If the pattern is not a gradient pattern, (eg. a linear or radial pattern), then the pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH.

cairo_pattern_get_color_stop_count ()

cairo_status_t      cairo_pattern_get_color_stop_count  (cairo_pattern_t *pattern,
                                                         int *count);

Gets the number of color stops specified in the given gradient pattern.

Since 1.4

cairo_pattern_get_color_stop_rgba ()

cairo_status_t      cairo_pattern_get_color_stop_rgba   (cairo_pattern_t *pattern,
                                                         int index,
                                                         double *offset,
                                                         double *red,
                                                         double *green,
                                                         double *blue,
                                                         double *alpha);

Gets the color and offset information at the given index for a gradient pattern. Values of index are 0 to 1 less than the number returned by cairo_pattern_get_color_stop_count().

Since 1.4

cairo_pattern_create_rgb ()

cairo_pattern_t *   cairo_pattern_create_rgb            (double red,
                                                         double green,
                                                         double blue);

Creates a new cairo_pattern_t corresponding to an opaque color. The color components are floating point numbers in the range 0 to 1. If the values passed in are outside that range, they will be clamped.

cairo_pattern_create_rgba ()

cairo_pattern_t *   cairo_pattern_create_rgba           (double red,
                                                         double green,
                                                         double blue,
                                                         double alpha);

Creates a new cairo_pattern_t corresponding to a translucent color. The color components are floating point numbers in the range 0 to 1. If the values passed in are outside that range, they will be clamped.

cairo_pattern_get_rgba ()

cairo_status_t      cairo_pattern_get_rgba              (cairo_pattern_t *pattern,
                                                         double *red,
                                                         double *green,
                                                         double *blue,
                                                         double *alpha);

Gets the solid color for a solid color pattern.

Since 1.4

cairo_pattern_create_for_surface ()

cairo_pattern_t *   cairo_pattern_create_for_surface    (cairo_surface_t *surface);

Create a new cairo_pattern_t for the given surface.

cairo_pattern_get_surface ()

cairo_status_t      cairo_pattern_get_surface           (cairo_pattern_t *pattern,
                                                         cairo_surface_t **surface);

Gets the surface of a surface pattern. The reference returned in surface is owned by the pattern; the caller should call cairo_surface_reference() if the surface is to be retained.

Since 1.4

cairo_pattern_create_linear ()

cairo_pattern_t *   cairo_pattern_create_linear         (double x0,
                                                         double y0,
                                                         double x1,
                                                         double y1);

Create a new linear gradient cairo_pattern_t along the line defined by (x0, y0) and (x1, y1). Before using the gradient pattern, a number of color stops should be defined using cairo_pattern_add_color_stop_rgb() or cairo_pattern_add_color_stop_rgba().

Note: The coordinates here are in pattern space. For a new pattern, pattern space is identical to user space, but the relationship between the spaces can be changed with cairo_pattern_set_matrix().

cairo_pattern_get_linear_points ()

cairo_status_t      cairo_pattern_get_linear_points     (cairo_pattern_t *pattern,
                                                         double *x0,
                                                         double *y0,
                                                         double *x1,
                                                         double *y1);

Gets the gradient endpoints for a linear gradient.

Since 1.4

cairo_pattern_create_radial ()

cairo_pattern_t *   cairo_pattern_create_radial         (double cx0,
                                                         double cy0,
                                                         double radius0,
                                                         double cx1,
                                                         double cy1,
                                                         double radius1);

Creates a new radial gradient cairo_pattern_t between the two circles defined by (cx0, cy0, radius0) and (cx1, cy1, radius1). Before using the gradient pattern, a number of color stops should be defined using cairo_pattern_add_color_stop_rgb() or cairo_pattern_add_color_stop_rgba().

Note: The coordinates here are in pattern space. For a new pattern, pattern space is identical to user space, but the relationship between the spaces can be changed with cairo_pattern_set_matrix().

cairo_pattern_get_radial_circles ()

cairo_status_t      cairo_pattern_get_radial_circles    (cairo_pattern_t *pattern,
                                                         double *x0,
                                                         double *y0,
                                                         double *r0,
                                                         double *x1,
                                                         double *y1,
                                                         double *r1);

Gets the gradient endpoint circles for a radial gradient, each specified as a center coordinate and a radius.

Since 1.4

cairo_pattern_create_mesh ()

cairo_pattern_t *   cairo_pattern_create_mesh           (void);

Create a new mesh pattern.

Mesh patterns are tensor-product patch meshes (type 7 shadings in PDF). Mesh patterns may also be used to create other types of shadings that are special cases of tensor-product patch meshes such as Coons patch meshes (type 6 shading in PDF) and Gouraud-shaded triangle meshes (type 4 and 5 shadings in PDF).

Mesh patterns consist of one or more tensor-product patches, which should be defined before using the mesh pattern. Using a mesh pattern with a partially defined patch as source or mask will put the context in an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

A tensor-product patch is defined by 4 Bézier curves (side 0, 1, 2, 3) and by 4 additional control points (P0, P1, P2, P3) that provide further control over the patch and complete the definition of the tensor-product patch. The corner C0 is the first point of the patch.

Degenerate sides are permitted so straight lines may be used. A zero length line on one side may be used to create 3 sided patches.

      C1     Side 1       C2
       +---------------+
       |               |
       |  P1       P2  |
       |               |
Side 0 |               | Side 2
       |               |
       |               |
       |  P0       P3  |
       |               |
       +---------------+
     C0     Side 3        C3

Each patch is constructed by first calling cairo_pattern_mesh_begin_patch(), then cairo_pattern_mesh_move_to() to specify the first point in the patch (C0). Then the sides are specified with calls to cairo_pattern_mesh_curve_to() and cairo_pattern_mesh_line_to().

The four additional control points (P0, P1, P2, P3) in a patch can be specified with cairo_pattern_mesh_set_control_point().

At each corner of the patch (C0, C1, C2, C3) a color may be specified with cairo_pattern_mesh_set_corner_color_rgb() or cairo_pattern_mesh_set_corner_color_rgba(). Any corner whose color is not explicitly specified defaults to transparent black.

A Coons patch is a special case of the tensor-product patch where the control points are implicitly defined by the sides of the patch. The default value for any control point not specified is the implicit value for a Coons patch, i.e. if no control points are specified the patch is a Coons patch.

A triangle is a special case of the tensor-product patch where the control points are implicitly defined by the sides of the patch, all the sides are lines and one of them has length 0, i.e. if the patch is specified using just 3 lines, it is a triangle. If the corners connected by the 0-length side have the same color, the patch is a Gouraud-shaded triangle.

Patches may be oriented differently to the above diagram. For example the first point could be at the top left. The diagram only shows the relationship between the sides, corners and control points. Regardless of where the first point is located, when specifying colors, corner 0 will always be the first point, corner 1 the point between side 0 and side 1 etc.

Calling cairo_pattern_mesh_end_patch() completes the current patch. If less than 4 sides have been defined, the first missing side is defined as a line from the current point to the first point of the patch (C0) and the other sides are degenerate lines from C0 to C0. The corners between the added sides will all be coincident with C0 of the patch and their color will be set to be the same as the color of C0.

Additional patches may be added with additional calls to cairo_pattern_mesh_begin_patch()/cairo_pattern_mesh_end_patch().

cairo_pattern_t *mesh = cairo_pattern_mesh_create_mesh ();

/* Add a Coons patch */
cairo_pattern_mesh_begin_patch (mesh);
cairo_pattern_mesh_move_to (pattern, 0, 0);
cairo_pattern_mesh_curve_to (pattern, 30, -30,  60,  30, 100, 0);
cairo_pattern_mesh_curve_to (pattern, 60,  30, 130,  60, 100, 100);
cairo_pattern_mesh_curve_to (pattern, 60,  70,  30, 130,   0, 100);
cairo_pattern_mesh_curve_to (pattern, 30,  70, -30,  30,   0, 0);
cairo_pattern_mesh_set_corner_color_rgb (pattern, 0, 1, 0, 0);
cairo_pattern_mesh_set_corner_color_rgb (pattern, 1, 0, 1, 0);
cairo_pattern_mesh_set_corner_color_rgb (pattern, 2, 0, 0, 1);
cairo_pattern_mesh_set_corner_color_rgb (pattern, 3, 1, 1, 0);
cairo_pattern_mesh_end_patch (mesh);

/* Add a Gouraud-shaded triangle */
cairo_pattern_mesh_begin_patch (mesh)
cairo_pattern_mesh_move_to (pattern, 100, 100);
cairo_pattern_mesh_line_to (pattern, 130, 130);
cairo_pattern_mesh_line_to (pattern, 130,  70);
cairo_pattern_mesh_set_corner_color_rgb (pattern, 0, 1, 0, 0);
cairo_pattern_mesh_set_corner_color_rgb (pattern, 1, 0, 1, 0);
cairo_pattern_mesh_set_corner_color_rgb (pattern, 2, 0, 0, 1);
cairo_pattern_mesh_end_patch (mesh)

When two patches overlap, the last one that has been added is drawn over the first one.

When a patch folds over itself, points are sorted depending on their parameter coordinates inside the patch. The v coordinate ranges from 0 to 1 when moving from side 3 to side 1; the u coordinate ranges from 0 to 1 when going from side 0 to side 2. Points with higher v coordinate hide points with lower v coordinate. When two points have the same v coordinate, the one with higher u coordinate is above. This means that points nearer to side 1 are above points nearer to side 3; when this is not sufficient to decide which point is above (for example when both points belong to side 1 or side 3) points nearer to side 2 are above points nearer to side 0.

For a complete definition of tensor-product patches, see the PDF specification (ISO32000), which describes the parametrization in detail.

Note: The coordinates are always in pattern space. For a new pattern, pattern space is identical to user space, but the relationship between the spaces can be changed with cairo_pattern_set_matrix().

Since 1.12

cairo_pattern_mesh_begin_patch ()

void                cairo_pattern_mesh_begin_patch      (cairo_pattern_t *pattern);

Begin a patch in a mesh pattern.

After calling this function, the patch shape should be defined with cairo_pattern_mesh_move_to(), cairo_pattern_mesh_line_to() and cairo_pattern_mesh_curve_to().

After defining the patch, cairo_pattern_mesh_end_patch() must be called before using pattern as a source or mask.

Note: If pattern is not a mesh pattern then pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH. If pattern already has a current patch, it will be put into an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

Since 1.12

cairo_pattern_mesh_end_patch ()

void                cairo_pattern_mesh_end_patch        (cairo_pattern_t *pattern);

Indicates the end of the current patch in a mesh pattern.

If the current patch has less than 4 sides, it is closed with a straight line from the current point to the first point of the patch as if cairo_pattern_mesh_line_to() was used.

Note: If pattern is not a mesh pattern then pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH. If pattern has no current patch or the current patch has no current point, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

Since 1.12

cairo_pattern_mesh_move_to ()

void                cairo_pattern_mesh_move_to          (cairo_pattern_t *pattern,
                                                         double x,
                                                         double y);

Define the first point of the current patch in a mesh pattern.

After this call the current point will be (x, y).

Note: If pattern is not a mesh pattern then pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH. If pattern has no current patch or the current patch already has at leas one side, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

Since 1.12

cairo_pattern_mesh_line_to ()

void                cairo_pattern_mesh_line_to          (cairo_pattern_t *pattern,
                                                         double x,
                                                         double y);

Adds a line to the current patch from the current point to position (x, y) in pattern-space coordinates.

If there is no current point before the call to cairo_pattern_mesh_line_to() this function will behave as cairo_pattern_mesh_move_to(pattern, x, y).

After this call the current point will be (x, y).

Note: If pattern is not a mesh pattern then pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH. If pattern has no current patch or the current patch already has 4 sides, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

Since 1.12

cairo_pattern_mesh_curve_to ()

void                cairo_pattern_mesh_curve_to         (cairo_pattern_t *pattern,
                                                         double x1,
                                                         double y1,
                                                         double x2,
                                                         double y2,
                                                         double x3,
                                                         double y3);

Adds a cubic Bézier spline to the current patch from the current point to position (x3, y3) in pattern-space coordinates, using (x1, y1) and (x2, y2) as the control points.

If the current patch has no current point before the call to cairo_pattern_mesh_curve_to(), this function will behave as if preceded by a call to cairo_pattern_mesh_move_to(pattern, x1, y1).

After this call the current point will be (x3, y3).

Note: If pattern is not a mesh pattern then pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH. If pattern has no current patch or the current patch already has 4 sides, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

Since 1.12

cairo_pattern_mesh_set_control_point ()

void                cairo_pattern_mesh_set_control_point
                                                        (cairo_pattern_t *pattern,
                                                         unsigned int point_num,
                                                         double x,
                                                         double y);

Set an internal control point of the current patch.

Valid values for point_num are from 0 to 3 and identify the control points as explained in cairo_pattern_create_mesh().

Note: If pattern is not a mesh pattern then pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH. If point_num is not valid, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_INDEX. If pattern has no current patch, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

Since 1.12

cairo_pattern_mesh_set_corner_color_rgb ()

void                cairo_pattern_mesh_set_corner_color_rgb
                                                        (cairo_pattern_t *pattern,
                                                         unsigned int corner_num,
                                                         double red,
                                                         double green,
                                                         double blue);

Sets the color of a corner of the current patch in a mesh pattern.

The color is specified in the same way as in cairo_set_source_rgb().

Valid values for corner_num are from 0 to 3 and identify the corners as explained in cairo_pattern_create_mesh().

Note: If pattern is not a mesh pattern then pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH. If corner_num is not valid, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_INDEX. If pattern has no current patch, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

Since 1.12

cairo_pattern_mesh_set_corner_color_rgba ()

void                cairo_pattern_mesh_set_corner_color_rgba
                                                        (cairo_pattern_t *pattern,
                                                         unsigned int corner_num,
                                                         double red,
                                                         double green,
                                                         double blue,
                                                         double alpha);

Sets the color of a corner of the current patch in a mesh pattern.

The color is specified in the same way as in cairo_set_source_rgba().

Valid values for corner_num are from 0 to 3 and identify the corners as explained in cairo_pattern_create_mesh().

Note: If pattern is not a mesh pattern then pattern will be put into an error status with a status of CAIRO_STATUS_PATTERN_TYPE_MISMATCH. If corner_num is not valid, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_INDEX. If pattern has no current patch, pattern will be put into an error status with a status of CAIRO_STATUS_INVALID_MESH_CONSTRUCTION.

Since 1.12

cairo_pattern_mesh_get_patch_count ()

cairo_status_t      cairo_pattern_mesh_get_patch_count  (cairo_pattern_t *pattern,
                                                         unsigned int *count);

Gets the number of patches specified in the given mesh pattern.

The number only includes patches which have been finished by calling cairo_pattern_mesh_end_patch(). For example it will be 0 during the definition of the first patch.

Since 1.12

cairo_pattern_mesh_get_path ()

cairo_path_t *      cairo_pattern_mesh_get_path         (cairo_pattern_t *pattern,
                                                         unsigned int patch_num);

Gets path defining the patch patch_num for a mesh pattern.

patch_num can range 0 to 1 less than the number returned by cairo_pattern_mesh_get_patch_count().

Since 1.12

cairo_pattern_mesh_get_control_point ()

cairo_status_t      cairo_pattern_mesh_get_control_point
                                                        (cairo_pattern_t *pattern,
                                                         unsigned int patch_num,
                                                         unsigned int point_num,
                                                         double *x,
                                                         double *y);

Gets the control point point_num of patch patch_num for a mesh pattern.

patch_num can range 0 to 1 less than the number returned by cairo_pattern_mesh_get_patch_count().

Valid values for point_num are from 0 to 3 and identify the control points as explained in cairo_pattern_create_mesh().

Since 1.12

cairo_pattern_mesh_get_corner_color_rgba ()

cairo_status_t      cairo_pattern_mesh_get_corner_color_rgba
                                                        (cairo_pattern_t *pattern,
                                                         unsigned int patch_num,
                                                         unsigned int corner_num,
                                                         double *red,
                                                         double *green,
                                                         double *blue,
                                                         double *alpha);

Gets the color information in corner corner_num of patch patch_num for a mesh pattern.

patch_num can range 0 to 1 less than the number returned by cairo_pattern_mesh_get_patch_count().

Valid values for corner_num are from 0 to 3 and identify the corners as explained in cairo_pattern_create_mesh().

Since 1.12

cairo_pattern_reference ()

cairo_pattern_t *   cairo_pattern_reference             (cairo_pattern_t *pattern);

Increases the reference count on pattern by one. This prevents pattern from being destroyed until a matching call to cairo_pattern_destroy() is made.

The number of references to a cairo_pattern_t can be get using cairo_pattern_get_reference_count().

cairo_pattern_destroy ()

void                cairo_pattern_destroy               (cairo_pattern_t *pattern);

Decreases the reference count on pattern by one. If the result is zero, then pattern and all associated resources are freed. See cairo_pattern_reference().

cairo_pattern_status ()

cairo_status_t      cairo_pattern_status                (cairo_pattern_t *pattern);

Checks whether an error has previously occurred for this pattern.

enum cairo_extend_t

typedef enum _cairo_extend {
    CAIRO_EXTEND_NONE,
    CAIRO_EXTEND_REPEAT,
    CAIRO_EXTEND_REFLECT,
    CAIRO_EXTEND_PAD
} cairo_extend_t;

cairo_extend_t is used to describe how pattern color/alpha will be determined for areas "outside" the pattern's natural area, (for example, outside the surface bounds or outside the gradient geometry).

Mesh patterns are not affected by the extend mode.

The default extend mode is CAIRO_EXTEND_NONE for surface patterns and CAIRO_EXTEND_PAD for gradient patterns.

New entries may be added in future versions.

cairo_pattern_set_extend ()

void                cairo_pattern_set_extend            (cairo_pattern_t *pattern,
                                                         cairo_extend_t extend);

Sets the mode to be used for drawing outside the area of a pattern. See cairo_extend_t for details on the semantics of each extend strategy.

The default extend mode is CAIRO_EXTEND_NONE for surface patterns and CAIRO_EXTEND_PAD for gradient patterns.

cairo_pattern_get_extend ()

cairo_extend_t      cairo_pattern_get_extend            (cairo_pattern_t *pattern);

Gets the current extend mode for a pattern. See cairo_extend_t for details on the semantics of each extend strategy.

enum cairo_filter_t

typedef enum _cairo_filter {
    CAIRO_FILTER_FAST,
    CAIRO_FILTER_GOOD,
    CAIRO_FILTER_BEST,
    CAIRO_FILTER_NEAREST,
    CAIRO_FILTER_BILINEAR,
    CAIRO_FILTER_GAUSSIAN
} cairo_filter_t;

cairo_filter_t is used to indicate what filtering should be applied when reading pixel values from patterns. See cairo_pattern_set_filter() for indicating the desired filter to be used with a particular pattern.

cairo_pattern_set_filter ()

void                cairo_pattern_set_filter            (cairo_pattern_t *pattern,
                                                         cairo_filter_t filter);

Sets the filter to be used for resizing when using this pattern. See cairo_filter_t for details on each filter.

* Note that you might want to control filtering even when you do not have an explicit cairo_pattern_t object, (for example when using cairo_set_source_surface()). In these cases, it is convenient to use cairo_get_source() to get access to the pattern that cairo creates implicitly. For example:

cairo_set_source_surface (cr, image, x, y);
cairo_pattern_set_filter (cairo_get_source (cr), CAIRO_FILTER_NEAREST);

cairo_pattern_get_filter ()

cairo_filter_t      cairo_pattern_get_filter            (cairo_pattern_t *pattern);

Gets the current filter for a pattern. See cairo_filter_t for details on each filter.

cairo_pattern_set_matrix ()

void                cairo_pattern_set_matrix            (cairo_pattern_t *pattern,
                                                         const cairo_matrix_t *matrix);

Sets the pattern's transformation matrix to matrix. This matrix is a transformation from user space to pattern space.

When a pattern is first created it always has the identity matrix for its transformation matrix, which means that pattern space is initially identical to user space.

Important: Please note that the direction of this transformation matrix is from user space to pattern space. This means that if you imagine the flow from a pattern to user space (and on to device space), then coordinates in that flow will be transformed by the inverse of the pattern matrix.

For example, if you want to make a pattern appear twice as large as it does by default the correct code to use is:

cairo_matrix_init_scale (&matrix, 0.5, 0.5);
cairo_pattern_set_matrix (pattern, &matrix);

Meanwhile, using values of 2.0 rather than 0.5 in the code above would cause the pattern to appear at half of its default size.

Also, please note the discussion of the user-space locking semantics of cairo_set_source().

cairo_pattern_get_matrix ()

void                cairo_pattern_get_matrix            (cairo_pattern_t *pattern,
                                                         cairo_matrix_t *matrix);

Stores the pattern's transformation matrix into matrix.

enum cairo_pattern_type_t

typedef enum _cairo_pattern_type {
    CAIRO_PATTERN_TYPE_SOLID,
    CAIRO_PATTERN_TYPE_SURFACE,
    CAIRO_PATTERN_TYPE_LINEAR,
    CAIRO_PATTERN_TYPE_RADIAL,
    CAIRO_PATTERN_TYPE_MESH
} cairo_pattern_type_t;

cairo_pattern_type_t is used to describe the type of a given pattern.

The type of a pattern is determined by the function used to create it. The cairo_pattern_create_rgb() and cairo_pattern_create_rgba() functions create SOLID patterns. The remaining cairo_pattern_create functions map to pattern types in obvious ways.

The pattern type can be queried with cairo_pattern_get_type()

Most cairo_pattern_t functions can be called with a pattern of any type, (though trying to change the extend or filter for a solid pattern will have no effect). A notable exception is cairo_pattern_add_color_stop_rgb() and cairo_pattern_add_color_stop_rgba() which must only be called with gradient patterns (either LINEAR or RADIAL). Otherwise the pattern will be shutdown and put into an error state.

New entries may be added in future versions.

Since 1.2

cairo_pattern_get_type ()

cairo_pattern_type_t  cairo_pattern_get_type            (cairo_pattern_t *pattern);

This function returns the type a pattern. See cairo_pattern_type_t for available types.

Since 1.2

cairo_pattern_get_reference_count ()

unsigned int        cairo_pattern_get_reference_count   (cairo_pattern_t *pattern);

Returns the current reference count of pattern.

Since 1.4

cairo_pattern_set_user_data ()

cairo_status_t      cairo_pattern_set_user_data         (cairo_pattern_t *pattern,
                                                         const cairo_user_data_key_t *key,
                                                         void *user_data,
                                                         cairo_destroy_func_t destroy);

Attach user data to pattern. To remove user data from a surface, call this function with the key that was used to set it and NULL for data.

Since 1.4

cairo_pattern_get_user_data ()

void *              cairo_pattern_get_user_data         (cairo_pattern_t *pattern,
                                                         const cairo_user_data_key_t *key);

Return user data previously attached to pattern using the specified key. If no user data has been attached with the given key this function returns NULL.

Since 1.4