sixteen

Documentation

Overview

Package sixteen simulates a 16-segment display drawn on a canvas.

Given a canvas, determines the placement and size of the individual segments and exposes API that can turn individual segments on and off or display ASCII characters.

The following outlines segments in the display and their names.

     A1      A2
   ------- -------
  | \     |     / |
  |  \    |    /  |
F |   H   J   K   | B
  |    \  |  /    |
  |     \ | /     |
   -G1---- ----G2-
  |     / | \     |
  |    /  |  \    |
E |   N   M   L   | C
  |  /    |    \  |
  | /     |     \ |
   ------- -------
     D1      D2

Index

• func Sanitize(s string) string
• func SupportsChars(s string) (bool, []rune)
• type Attributes
  • func NewAttributes(bcAr image.Rectangle) *Attributes
• type Display
  • func New(opts ...Option) *Display
  • func (d *Display) Clear(opts ...Option)
  • func (d *Display) ClearSegment(s Segment) error
  • func (d *Display) Draw(cvs *canvas.Canvas, opts ...Option) error
  • func (d *Display) SetCharacter(c rune) error
  • func (d *Display) SetSegment(s Segment) error
  • func (d *Display) ToggleSegment(s Segment) error
• type Option
  • func CellOpts(cOpts ...cell.Option) Option
• type Segment
  • func AllSegments() []Segment
  • func (s Segment) String() string

Functions

func Sanitize

func Sanitize(s string) string

Sanitize returns a copy of the string, replacing all unsupported characters with a space character.

func SupportsChars

func SupportsChars(s string) (bool, []rune)

SupportsChars asserts whether the display supports all runes in the provided string. The display only supports a subset of ASCII characters. Returns any unsupported runes found in the string in an unspecified order.

Types

type Attributes

type Attributes struct {

	// VertBotY is the Y coordinate where the area of the segment vertically
	// at the bottom starts, i.e. Y coordinate of D1 and D2.
	VertBotY int
	// contains filtered or unexported fields
}

Attributes contains attributes needed to draw the segment display. Refer to doc/segment_placement.svg for a visual aid and explanation of the usage of the square roots.

func NewAttributes

func NewAttributes(bcAr image.Rectangle) *Attributes

NewAttributes calculates attributes needed to place the segments for the provided pixel area.

type Display

type Display struct {
	// contains filtered or unexported fields
}

Display represents the segment display. This object is not thread-safe.

func New

func New(opts ...Option) *Display

New creates a new segment display. Initially all the segments are off.

func (*Display) Clear

func (d *Display) Clear(opts ...Option)

Clear clears the entire display, turning all segments off.

func (*Display) ClearSegment

func (d *Display) ClearSegment(s Segment) error

ClearSegment sets the specified segment off. This method is idempotent.

func (*Display) Draw

func (d *Display) Draw(cvs *canvas.Canvas, opts ...Option) error

Draw draws the current state of the segment display onto the canvas. The canvas must be at least MinCols x MinRows cells, or an error will be returned. Any options provided to draw overwrite the values provided to New.

func (*Display) SetCharacter

func (d *Display) SetCharacter(c rune) error

SetCharacter sets all the segments that are needed to display the provided character. The display only supports a subset of ASCII characters, use SupportsChars() or Sanitize() to ensure the provided character is supported. Doesn't clear the display of segments set previously.

func (*Display) SetSegment

func (d *Display) SetSegment(s Segment) error

SetSegment sets the specified segment on. This method is idempotent.

func (*Display) ToggleSegment

func (d *Display) ToggleSegment(s Segment) error

ToggleSegment toggles the state of the specified segment, i.e it either sets or clears it depending on its current state.

type Option

type Option interface {
	// contains filtered or unexported methods
}

Option is used to provide options.

func CellOpts

func CellOpts(cOpts ...cell.Option) Option

CellOpts sets the cell options on the cells that contain the segment display.

type Segment

type Segment int

Segment represents a single segment in the display.

const (

	// A1 is a segment, see the diagram above.
	A1 Segment
	// A2 is a segment, see the diagram above.
	A2
	// B is a segment, see the diagram above.
	B
	// C is a segment, see the diagram above.
	C
	// D1 is a segment, see the diagram above.
	D1
	// D2 is a segment, see the diagram above.
	D2
	// E is a segment, see the diagram above.
	E
	// F is a segment, see the diagram above.
	F
	// G1 is a segment, see the diagram above.
	G1
	// G2 is a segment, see the diagram above.
	G2
	// H is a segment, see the diagram above.
	H
	// J is a segment, see the diagram above.
	J
	// K is a segment, see the diagram above.
	K
	// L is a segment, see the diagram above.
	L
	// M is a segment, see the diagram above.
	M
	// N is a segment, see the diagram above.
	N
)

func AllSegments

func AllSegments() []Segment

AllSegments returns all 16 segments in an undefined order.

func (Segment) String

func (s Segment) String() string

String implements fmt.Stringer()