Index | Files

package clip

import ""

Package clip provides operations for clipping paint operations. Drawing outside the current clip area is ignored.

The current clip is initially the infinite set. An Op sets the clip to the intersection of the current clip and the clip area it represents. If you need to reset the current clip to its value before applying an Op, use op.StackOp.

General clipping areas are constructed with Path. Simpler special cases such as rectangular clip areas also exist as convenient constructors.


Package Files

clip.go doc.go shapes.go

type Border Uses

type Border struct {
    // Rect is the bounds of the border.
    Rect  f32.Rectangle
    Width float32
    // The corner radii.
    SE, SW, NW, NE float32

Border represents the clip area of a rectangular border.

func (Border) Add Uses

func (rr Border) Add(ops *op.Ops)

Add the border clip.

type Op Uses

type Op struct {
    // contains filtered or unexported fields

Op sets the current clip to the intersection of the existing clip with this clip.

If you need to reset the clip to its previous values after applying a Op, use op.StackOp.

func (Op) Add Uses

func (p Op) Add(o *op.Ops)

type Path Uses

type Path struct {
    // contains filtered or unexported fields

Path constructs a Op clip path described by lines and Bézier curves, where drawing outside the Path is discarded. The inside-ness of a pixel is determines by the even-odd rule, similar to the SVG rule of the same name.

Path generates no garbage and can be used for dynamic paths; path data is stored directly in the Ops list supplied to Begin.

func (*Path) Arc Uses

func (p *Path) Arc(f1, f2 f32.Point, angle float32)

Arc adds an elliptical arc to the path. The implied ellipse is defined by its focus points f1 and f2. The arc starts in the current point and ends angle radians along the ellipse boundary. The sign of angle determines the direction; positive being counter-clockwise, negative clockwise.

func (*Path) Begin Uses

func (p *Path) Begin(ops *op.Ops)

Begin the path, storing the path data and final Op into ops.

func (*Path) Cube Uses

func (p *Path) Cube(ctrl0, ctrl1, to f32.Point)

Cube records a cubic Bézier from the pen through two control points ending in to.

func (*Path) End Uses

func (p *Path) End() Op

End the path and return a clip operation that represents it.

func (*Path) Line Uses

func (p *Path) Line(delta f32.Point)

Line moves the pen by the amount specified by delta, recording a line.

func (*Path) Move Uses

func (p *Path) Move(to f32.Point)

MoveTo moves the pen to the given position.

func (*Path) Pos Uses

func (p *Path) Pos() f32.Point

Pos returns the current pen position.

func (*Path) Quad Uses

func (p *Path) Quad(ctrl, to f32.Point)

Quad records a quadratic Bézier from the pen to end with the control point ctrl.

type RRect Uses

type RRect struct {
    Rect f32.Rectangle
    // The corner radii.
    SE, SW, NW, NE float32

RRect represents the clip area of a rectangle with rounded corners.

Specify a square with corner radii equal to half the square size to construct a circular clip area.

func (RRect) Add Uses

func (rr RRect) Add(ops *op.Ops)

Add the rectangle clip.

type Rect Uses

type Rect image.Rectangle

Rect represents the clip area of a pixel-aligned rectangle.

func (Rect) Add Uses

func (r Rect) Add(ops *op.Ops)

Add the clip operation.

Package clip imports 7 packages (graph) and is imported by 26 packages. Updated 2020-09-29. Refresh now. Tools for package owners.