MatrixProtocol

public protocol MatrixProtocol

A PangoMatrix specifies a transformation between user-space and device coordinates.

The transformation is given by

x_device = x_user * matrix->xx + y_user * matrix->xy + matrix->x0;
y_device = x_user * matrix->yx + y_user * matrix->yy + matrix->y0;

The MatrixProtocol protocol exposes the methods and properties of an underlying PangoMatrix instance. The default implementation of these can be found in the protocol extension below. For a concrete class that implements these methods and properties, see Matrix. Alternatively, use MatrixRef as a lighweight, unowned reference if you already have an instance you just want to use.

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  • ptr

    Untyped pointer to the underlying PangoMatrix instance.

    Declaration

    Swift

    var ptr: UnsafeMutableRawPointer! { get }
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  • matrix_ptr Default implementation

    Typed pointer to the underlying PangoMatrix instance.

    Default Implementation

    Return the stored, untyped pointer as a typed pointer to the PangoMatrix instance.

    Declaration

    Swift

    var matrix_ptr: UnsafeMutablePointer<PangoMatrix>! { get }
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  • Required Initialiser for types conforming to MatrixProtocol

    Declaration

    Swift

    init(raw: UnsafeMutableRawPointer)
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Matrix Record: MatrixProtocol extension (methods and fields)

  • concat(newMatrix:) Extension method

    Changes the transformation represented by matrix to be the transformation given by first applying transformation given by new_matrix then applying the original transformation.

    Declaration

    Swift

    @inlinable
func concat<MatrixT>(newMatrix: MatrixT) where MatrixT : MatrixProtocol
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  • copy() Extension method

    Copies a PangoMatrix.

    Declaration

    Swift

    @inlinable
func copy() -> Pango.MatrixRef!
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  • free() Extension method

    Free a PangoMatrix.

    Declaration

    Swift

    @inlinable
func free()
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  • getFontScaleFactor() Extension method

    Returns the scale factor of a matrix on the height of the font.

    That is, the scale factor in the direction perpendicular to the vector that the X coordinate is mapped to. If the scale in the X coordinate is needed as well, use [methodPango.Matrix.get_font_scale_factors].

    Declaration

    Swift

    @inlinable
func getFontScaleFactor() -> CDouble
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  • Calculates the scale factor of a matrix on the width and height of the font.

    That is, xscale is the scale factor in the direction of the X coordinate, and yscale is the scale factor in the direction perpendicular to the vector that the X coordinate is mapped to.

    Note that output numbers will always be non-negative.

    Declaration

    Swift

    @inlinable
func getFontScaleFactors(xscale: UnsafeMutablePointer<CDouble>! = nil, yscale: UnsafeMutablePointer<CDouble>! = nil)
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  • getSlantRatio() Extension method

    Gets the slant ratio of a matrix.

    For a simple shear matrix in the form:

    1 λ
0 1

    this is simply λ.

    Declaration

    Swift

    @inlinable
func getSlantRatio() -> CDouble
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  • rotate(degrees:) Extension method

    Changes the transformation represented by matrix to be the transformation given by first rotating by degrees degrees counter-clockwise then applying the original transformation.

    Declaration

    Swift

    @inlinable
func rotate(degrees: CDouble)
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  • scale(scaleX:scaleY:) Extension method

    Changes the transformation represented by matrix to be the transformation given by first scaling by sx in the X direction and sy in the Y direction then applying the original transformation.

    Declaration

    Swift

    @inlinable
func scale(scaleX: CDouble, scaleY: CDouble)
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  • transformDistance(dx:dy:) Extension method

    Transforms the distance vector (dx,dy) by matrix.

    This is similar to [methodPango.Matrix.transform_point], except that the translation components of the transformation are ignored. The calculation of the returned vector is as follows:

    dx2 = dx1 * xx + dy1 * xy;
dy2 = dx1 * yx + dy1 * yy;

    Affine transformations are position invariant, so the same vector always transforms to the same vector. If (x1,y1) transforms to (x2,y2) then (x1+dx1,y1+dy1) will transform to (x1+dx2,y1+dy2) for all values of x1 and x2.

    Declaration

    Swift

    @inlinable
func transformDistance(dx: UnsafeMutablePointer<CDouble>!, dy: UnsafeMutablePointer<CDouble>!)
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  • First transforms the rect using matrix, then calculates the bounding box of the transformed rectangle.

    This function is useful for example when you want to draw a rotated PangoLayout to an image buffer, and want to know how large the image should be and how much you should shift the layout when rendering.

    For better accuracy, you should use [methodPango.Matrix.transform_rectangle] on original rectangle in Pango units and convert to pixels afterward using [funcextents_to_pixels]‘s first argument.

    Declaration

    Swift

    @inlinable
func transformPixelRectangle<RectangleT>(rect: RectangleT) where RectangleT : RectangleProtocol
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  • transformPoint(x:y:) Extension method

    Transforms the point (x, y) by matrix.

    Declaration

    Swift

    @inlinable
func transformPoint(x: UnsafeMutablePointer<CDouble>!, y: UnsafeMutablePointer<CDouble>!)
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  • transformRectangle(rect:) Extension method

    First transforms rect using matrix, then calculates the bounding box of the transformed rectangle.

    This function is useful for example when you want to draw a rotated PangoLayout to an image buffer, and want to know how large the image should be and how much you should shift the layout when rendering.

    If you have a rectangle in device units (pixels), use [methodPango.Matrix.transform_pixel_rectangle].

    If you have the rectangle in Pango units and want to convert to transformed pixel bounding box, it is more accurate to transform it first (using this function) and pass the result to pango_extents_to_pixels(), first argument, for an inclusive rounded rectangle. However, there are valid reasons that you may want to convert to pixels first and then transform, for example when the transformed coordinates may overflow in Pango units (large matrix translation for example).

    Declaration

    Swift

    @inlinable
func transformRectangle<RectangleT>(rect: RectangleT) where RectangleT : RectangleProtocol
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  • translate(tx:ty:) Extension method

    Changes the transformation represented by matrix to be the transformation given by first translating by (tx, ty) then applying the original transformation.

    Declaration

    Swift

    @inlinable
func translate(tx: CDouble, ty: CDouble)
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  • gravityGetForMatrix() Extension method

    Finds the gravity that best matches the rotation component in a PangoMatrix.

    Declaration

    Swift

    @inlinable
func gravityGetForMatrix() -> PangoGravity
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  • fontScaleFactor Extension method

    Returns the scale factor of a matrix on the height of the font.

    That is, the scale factor in the direction perpendicular to the vector that the X coordinate is mapped to. If the scale in the X coordinate is needed as well, use [methodPango.Matrix.get_font_scale_factors].

    Declaration

    Swift

    @inlinable
var fontScaleFactor: CDouble { get }
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  • slantRatio Extension method

    Gets the slant ratio of a matrix.

    For a simple shear matrix in the form:

    1 λ
0 1

    this is simply λ.

    Declaration

    Swift

    @inlinable
var slantRatio: CDouble { get }
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  • xx Extension method

    1st component of the transformation matrix

    Declaration

    Swift

    @inlinable
var xx: CDouble { get set }
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  • xy Extension method

    2nd component of the transformation matrix

    Declaration

    Swift

    @inlinable
var xy: CDouble { get set }
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  • yx Extension method

    3rd component of the transformation matrix

    Declaration

    Swift

    @inlinable
var yx: CDouble { get set }
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  • yy Extension method

    4th component of the transformation matrix

    Declaration

    Swift

    @inlinable
var yy: CDouble { get set }
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  • x0 Extension method

    x translation

    Declaration

    Swift

    @inlinable
var x0: CDouble { get set }
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  • y0 Extension method

    y translation

    Declaration

    Swift

    @inlinable
var y0: CDouble { get set }
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