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# Patterns

Patterns are the paint with which cairo draws. The primary use of patterns is as the source for all cairo drawing operations, although they can also be used as masks, that is, as the brush too.

A cairo Pattern is created by using one of the PatternType constructors listed below, or implicitly through Context.set_source_<type>() methods.

## class Pattern()

Pattern is the abstract base class from which all the other pattern classes derive. It cannot be instantiated directly.

class `cairo.``Pattern`
  `get_extend`()

    Returns: | the current extend strategy used for drawing the Pattern.
    Return type: | int

    Gets the current extend mode for the Pattern. See EXTEND attributes for details on the semantics of each extend strategy.

  `get_matrix`()

    Returns: | a new `Matrix` which stores a copy of the Pattern’s transformation matrix

  `set_extend`(extend)

    Parameters: | extend – an EXTEND describing how the area outside of the Pattern will be drawn

    Sets the mode to be used for drawing outside the area of a Pattern.

    The default extend mode is `cairo.EXTEND_NONE` for `SurfacePattern` and `cairo.EXTEND_PAD` for `Gradient` Patterns.

  `set_matrix`(matrix)

    Parameters: | matrix – a `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:

        matrix = cairo.Matrix(xx=0.5,yy=0.5)
        pattern.set_matrix(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 `Context.set_source`.

## class SolidPattern(`Pattern`)

class `cairo.``SolidPattern`(red, green, blue, alpha=1.0)

  Parameters: | red (float) – red component of the color green (float) – green component of the color blue (float) – blue component of the color alpha (float) – alpha component of the color
  Returns: | a new SolidPattern
  Raises : | MemoryError in case of no memory

  Creates a new SolidPattern 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.

  `get_rgba`()

    Returns: | (red, green, blue, alpha) a tuple of float

    Gets the solid color for a SolidPattern.

    New in version 1.4.

## class SurfacePattern(`Pattern`)

class `cairo.``SurfacePattern`(surface)

  Parameters: | surface – a cairo `Surface`
  Returns: | a newly created SurfacePattern for the given surface.
  Raises : | MemoryError in case of no memory.

  `get_filter`()

    Returns: | the current FILTER used for resizing the SurfacePattern.

  `get_surface`()

    Returns: | the `Surface` of the SurfacePattern.

    New in version 1.4.

  `set_filter`(filter)

    Parameters: | filter – a FILTER describing the filter to use for resizing the Pattern

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

        context.set_source_surface(image, x, y)
        surfacepattern.set_filter(context.get_source(), cairo.FILTER_NEAREST)

## class Gradient(`Pattern`)

Gradient is an abstract base class from which other Pattern classes derive. It cannot be instantiated directly.

class `cairo.``Gradient`
  `add_color_stop_rgb`(offset, red, green, blue)

    Parameters: | offset (float) – an offset in the range [0.0 .. 1.0] red (float) – red component of color green (float) – green component of color blue (float) – blue component of color

    Adds an opaque color stop to a Gradient pattern. The offset specifies the location along the gradient’s control vector. For example, a LinearGradient’s control vector is from (x0,y0) to (x1,y1) while a RadialGradient’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 `Context.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.

  `add_color_stop_rgba`(offset, red, green, blue, alpha)

    Parameters: | offset (float) – an offset in the range [0.0 .. 1.0] red (float) – red component of color green (float) – green component of color blue (float) – blue component of color alpha (float) – alpha component of color

    Adds an opaque color stop to a Gradient pattern. The offset specifies the location along the gradient’s control vector. For example, a LinearGradient’s control vector is from (x0,y0) to (x1,y1) while a RadialGradient’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 `Context.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.

## class LinearGradient(`Gradient`)

class `cairo.``LinearGradient`(x0, y0, x1, y1)

  Parameters: | x0 (float) – x coordinate of the start point y0 (float) – y coordinate of the start point x1 (float) – x coordinate of the end point y1 (float) – y coordinate of the end point
  Returns: | a new LinearGradient
  Raises : | MemoryError in case of no memory

  Create a new LinearGradient along the line defined by (x0, y0) and (x1, y1). Before using the Gradient pattern, a number of color stops should be defined using `Gradient.add_color_stop_rgb()` or `Gradient.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 `Pattern.set_matrix()`

  `get_linear_points`()

    Returns: | (x0, y0, x1, y1) - a tuple of float x0: return value for the x coordinate of the first point y0: return value for the y coordinate of the first point x1: return value for the x coordinate of the second point y1: return value for the y coordinate of the second point

    Gets the gradient endpoints for a LinearGradient.

    New in version 1.4.

## class RadialGradient(`Gradient`)

class `cairo.``RadialGradient`(cx0, cy0, radius0, cx1, cy1, radius1)

  Parameters: | cx0 (float) – x coordinate for the center of the start circle cy0 (float) – y coordinate for the center of the start circle radius0 (float) – radius of the start circle cx1 (float) – x coordinate for the center of the end circle cy1 (float) – y coordinate for the center of the end circle radius1 (float) – radius of the end circle
  Returns: | the newly created RadialGradient
  Raises : | MemoryError in case of no memory

  Creates a new RadialGradient pattern 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 `Gradient.add_color_stop_rgb()` or `Gradient.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 `Pattern.set_matrix()`.

  `get_radial_circles`()

    Returns: | (x0, y0, r0, x1, y1, r1) - a tuple of float x0: return value for the x coordinate of the center of the first circle y0: return value for the y coordinate of the center of the first circle r0: return value for the radius of the first circle x1: return value for the x coordinate of the center of the second circle y1: return value for the y coordinate of the center of the second circle r1: return value for the radius of the second circle

    Gets the Gradient endpoint circles for a RadialGradient, each specified as a center coordinate and a radius.

    New in version 1.4.

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