Cairo (gb.cairo)

This class is used for drawing on an Image object or any CairoSurface with the Cairo library.

Before starting drawing anything, you must call the Begin method by passing it the Image where you want to draw.

Then you can call any of the drawing methods to define paths, stroke them, fill them, and so on...

When your drawing is finished, you must call the End method.

Constants

AntiAliasDefault	Use the default antialiasing for the subsystem and target device.
AntiAliasGray	Perform single-color antialiasing (using shades of gray for black text on a white background, for example).
AntiAliasNone	Use a bilevel alpha mask.
AntiAliasSubPixel	Perform antialiasing by taking advantage of the order of subpixel elements on devices such as LCD panels.
ExtendNone	Pixels outside of the source pattern are fully transparent.
ExtendPad	Pixels outside of the pattern copy the closest pixel from the source.
ExtendReflect	The pattern is tiled by reflecting at the edges.
ExtendRepeat	The pattern is tiled by repeating.
FillRuleEvenOdd	Constant used to select how paths are filled.
FillRuleWinding	Constant used to select how paths are filled.
FilterBest	The highest-quality available, performance may not be suitable for interactive use.
FilterBilinear	Linear interpolation in two dimensions.
FilterFast	A high-performance filter, with quality similar to FilterNearest.
FilterGaussian	This filter value is currently unimplemented, and should not be used in current code.
FilterGood	A reasonable-performance filter, with quality similar to FilterBilinear.
FilterNearest	Nearest-neighbor filtering.
FontSlantItalic	Italic font style.
FontSlantNormal	Upright font style.
FontSlantOblique	Oblique font style.
FontWeightBold	Bold font weight.
FontWeightNormal	Normal font weight.
LineCapButt	Specifies to render the endpoints of the path when stroking by starting(stopping) the line exactly at the start(end) point.
LineCapRound	Specifies to render the endpoints of the path when stroking by using a round ending, the center of the circle being the end point.
LineCapSquare	Specifies to render the endpoints of the path when stroking by using squared ending, the center of the square being the end point.
LineJoinBevel	Specifies to render the junction of two lines by using a cut-off join, the join being cut off at half the line width from the joint point.
LineJoinMiter	Specifies to render the junction of two lines by using a sharp (angled) corner.
LineJoinRound	Specifies to render the junction of two lines by using a rounded join, the center of the circle being the joint point.
OperatorATop	Compositing operator that draws the source on top of destination content and only there.
OperatorAdd	Compositing operator that accumulates the source and destination layers.
OperatorClear	Compositing operator that clears the destination layer (bounded).
OperatorDest	Compositing operator that ignores the source.
OperatorDestATop	Compositing operator that leaves the destination on top of source content and only there (unbounded).
OperatorDestIn	Compositing operator that leaves the destination only where there was source content (unbounded).
OperatorDestOut	Compositing operator that leaves the destination only where there was no source content.
OperatorDestOver	Compositing operator that draws the destination on top of the source.
OperatorIn	Compositing operator that draws the source where there was destination content (unbounded).
OperatorOut	Compositing operator that draws the source where there was no destination content (unbounded).
OperatorOver	Compositing operator that draws the source layer on top of the destination layer (bounded).
OperatorSaturate	Compositing operator that behaves like OperatorOver, but assuming source and dest are disjoint geometries.
OperatorSource	Compositing operator that replaces the destination layer (bounded).
OperatorXor	Compositing operator that shows source and destination where there is only one of them.
StatusClipNotRepresentable	This constant is used by the Status property to represent the following error:
StatusFileNotFound	This constant is used by the Status property to represent the following error:
StatusFontTypeMismatch	This constant is used by the Status property to represent the following error:
StatusInvalidClusters	This constant is used by the Status property to represent the following error:
StatusInvalidContent	This constant is used by the Status property to represent the following error:
StatusInvalidDash	This constant is used by the Status property to represent the following error:
StatusInvalidDscComment	This constant is used by the Status property to represent the following error:
StatusInvalidFormat	This constant is used by the Status property to represent the following error:
StatusInvalidIndex	This constant is used by the Status property to represent the following error:
StatusInvalidMatrix	This constant is used by the Status property to represent the following error:
StatusInvalidPathData	This constant is used by the Status property to represent the following error:
StatusInvalidPopGroup	This constant is used by the Status property to represent the following error:
StatusInvalidRestore	This constant is used by the Status property to represent the following error:
StatusInvalidSlant	This constant is used by the Status property to represent the following error:
StatusInvalidStatus	This constant is used by the Status property to represent the following error:
StatusInvalidStride	This constant is used by the Status property to represent the following error:
StatusInvalidString	This constant is used by the Status property to represent the following error:
StatusInvalidVisual	This constant is used by the Status property to represent the following error:
StatusInvalidWeight	This constant is used by the Status property to represent the following error:
StatusNegativeCount	This constant is used by the Status property to represent the following error:
StatusNoCurrentPoint	This constant is used by the Status property to represent the following error:
StatusNoMemory	This constant is used by the Status property to represent the following error:
StatusNullPointer	This constant is used by the Status property to represent the following error:
StatusPatternTypeMismatch	This constant is used by the Status property to represent the following error:
StatusReadError	This constant is used by the Status property to represent the following error:
StatusSuccess	This constant is used by the Status property when no error has occured.
StatusSurfaceFinished	This constant is used by the Status property to represent the following error:
StatusSurfaceTypeMismatch	This constant is used by the Status property to represent the following error:
StatusTempFileError	This constant is used by the Status property to represent the following error:
StatusUserFontError	This constant is used by the Status property to represent the following error:
StatusUserFontImmutable	This constant is used by the Status property to represent the following error:
StatusWriteError	This constant is used by the Status property to represent the following error:

Static properties

AntiAlias	Returns or sets the antialiasing mode of the rasterizer used for drawing shapes.
ClipExtents	Computes a bounding box in user coordinates covering the area inside the current clip.
Dash	Returns or sets the dash pattern to be used by Cairo.Stroke.
DashOffset	Returns or sets the offset used for drawing dashes.
Device	Returns the device you are drawing on with the Cairo class.
FillExtents	Computes a bounding box in user coordinates covering the area that would be affected, (the "inked" area), by a Fill operation given the current path and fill parameters. If the current path is empty, returns an empty rectangle ((0,0), (0,0)). surface dimensions and clipping are not taken into account.
FillRule	Returns or sets the current fill rule within the current drawing.
Font	Return the font used for drawing text.
LineCap	Returns or sets the current line cap style within the cairo context.
LineJoin	Returns or sets the current line join style within the current cairo context.
LineWidth	Returns or sets the current line width. The line width value specifies the diameter of a pen that is circular in user space, though device-space pen may be an ellipse in general due to scaling/shear/rotation of the current transformation matrix (CTM).
Matrix	Returns or sets the current transformation matrix.
MiterLimit	Returns or sets the current miter limit.
Operator	Returns or sets the compositing operator to be used for all drawing operations. See each one of the constants below for details on the semantics of each available compositing operator.
PathExtents	Computes a bounding box in user-space coordinates covering the points on the current path. If the current path is empty, returns an empty rectangle. Stroke parameters, fill rule, surface dimensions and clipping are not taken into account.
Source	Returns or sets the source pattern used for drawing.
Status	Checks whether an error has previously occurred, by returning the state of the current drawing.
StrokeExtents	Computes a bounding box in user coordinates covering the area that would be affected, (the "inked" area), by a Cairo.Stroke operation given the current path and stroke parameters. If the current path is empty, returns an empty rectangle. Surface dimensions and clipping are not taken into account.
Tolerance	Returns or sets the tolerance used when converting paths into trapezoids.

Static methods

Arc	Adds a circular arc of the given Radius to the current path. The arc is centered at (XC, YC), begins at Angle1 and proceeds in the direction of increasing angles to end at Angle2. If Angle2 is less than Angle1 it will be progressively increased by 2 * π until it is greater than Angle1.
ArcNegative
Begin	Starts drawing on the specified device.
Clip	Establishes a new clip region by intersecting the current clip region with the current path as it would be filled by Cairo.Fill and according to the current fill rule (see Cairo.FillRule).
ClosePath	Adds a line segment to the path from the current point to the beginning of the current sub-path, (the most recent point passed to Cairo.MoveTo), and closes this sub-path. After this call the current point will be at the joined endpoint of the sub-path.
ColorPattern	Creates a new Cairo pattern corresponding to an opaque or translucent color.
CopyPage	Emits the current page for backends that support multiple pages, but doesn't clear it, so, the contents of the current page will be retained for the next page too.
CurveTo	Adds a cubic Bézier spline to the path from the current point to position (X3, Y3) in user-space coordinates, using (X1, Y1) and (X2, Y2) as the control points. After this call the current point will be (X3, Y3).
DrawText	A drawing operator that generates the shape from a string of UTF-8 characters, rendered according to the current font.
End	Ends a drawing.
Fill	A drawing operator that fills the current path according to the current fill rule, (each sub-path is implicitly closed before being filled).
ImagePattern	Creates a new Cairo pattern from an image.
InFill	Tests whether the given point is inside the area that would be affected by a Cairo.Fill operation given the current path and filling parameters. surface dimensions and clipping are not taken into account.
InStroke	Tests whether the given point is inside the area that would be affected by a Cairo.Stroke operation given the current path and stroking parameters. surface dimensions and clipping are not taken into account.
LineTo	Adds a line to the path from the current point to position (X, Y) in user-space coordinates. After this call the current point will be (X, Y).
LinearGradient	Creates a new linear gradient Cairo pattern along the line defined by (X0, Y0) and (X1, Y1), and using color stops defined by the Colors argument.
Mask	A drawing operator that paints the current source using the alpha channel of pattern as a mask. (Opaque areas of pattern are painted with the source, transparent areas are not painted.)
MoveTo	Begin a new sub-path. After this call the current point will be (X, Y).
NewPath	Clears the current path. After this call there will be no path and no current point.
NewSubPath	Begin a new sub-path.
Paint	A drawing operator that paints the current source everywhere within the current clip region.
RadialGradient	Creates a new radial gradient Cairo pattern between the two circles defined by (CX0, CY0, Radius0) and (CX1, CY1, Radius1), and using color stops defined by the Colors argument.
Rectangle	Adds a closed sub-path rectangle of the given size to the current path at position (X, Y) in user-space coordinates.
RelCurveTo	Relative-coordinate version of Cairo.CurveTo.
RelLineTo	Relative-coordinate version of Cairo.LineTo().
RelMoveTo	Begin a new sub-path. After this call the current point will offset by (DX, DY).
ResetClip	Reset the current clip region to its original, unrestricted state. That is, set the clip region to an infinitely large shape containing the target surface. Equivalently, if infinity is too hard to grasp, one can imagine the clip region being reset to the exact bounds of the target surface.
Restore	Restores the drawing state to the state saved by a preceding call to Save and removes that state from the stack of saved states.
Rotate	Modifies the current transformation matrix (CTM) by rotating the user-space axes by angle radians. The rotation of the axes takes places after any existing transformation of user space. The rotation direction for positive angles is from the positive X axis toward the positive Y axis.
Save	Makes a copy of the current drawing state and saves it on an internal stack of saved states.
Scale	Modifies the current transformation matrix (CTM) by scaling the X and Y user-space axes by sx and sy respectively. The scaling of the axes takes place after any existing transformation of user space.
ShowPage	Emits and clears the current page for backends that support multiple pages.
SolidPattern	Creates a new Cairo pattern corresponding to an opaque or translucent color.
Stroke	A drawing operator that strokes the current path according to the current line width, line join, line cap, and dash settings.
Text	Adds closed paths for text to the current path. The generated path if filled, achieves an effect similar to that of Cairo.DrawText.
TextExtents	Gets the extents for a string of text.
Translate	Modifies the current transformation matrix (CTM) by translating the user-space origin by (TX, TY).