firefly

package
v0.4.1 Latest Latest
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 Go to latest Published: Aug 7, 2024 License: MIT Imports: 4 Imported by: 0

Documentation

Index

Constants

View Source 
const (
	// The screen width in pixels.
	Width = 240

	// The screen height in pixels.
	Height = 160
)
View Source 
const (
	// The lowest possible value for [Pad.X].
	PadMinX = -1000

	// The lowest possible value for [Pad.Y].
	PadMinY = -1000

	// The highest possible value for [Pad.X].
	PadMaxX = 1000

	// The highest possible value for [Pad.Y].
	PadMaxY = 1000
)

Variables

View Source 
var (
	// Callback to be called once when the app starts.
	//
	// Called after memory is initialized and host functions are registered
	// but before any other callback.
	Boot func()

	// Callback to be called on every update.
	//
	// Don't use it to draw on the screen, use [Render] instead.
	Update func()

	// Callback to be called before rendering the frame.
	//
	// Don't use it to update the state, use [Update] instead.
	Render func()

	// Callback to be called before rendering a horizontal line on the screen.
	//
	// Accepts the index of the line about to be rendered
	// and returns the index of the line for which it should be called next time.
	// Use it to update color palette to support more than 4 colors per frame.
	RenderLine func(int) int

	// Callback to be called when a cheat code is sent from firefly CLI.
	//
	// Accepts the command index and value and returns a response to show in CLI.
	Cheat func(int, int) int
)

Functions

func ClearScreen 

func ClearScreen(c Color)

Fill the whole frame with the given color.

func DrawArc 

func DrawArc(p Point, d int, start, sweep Angle, s Style)

Draw an arc.

func DrawCircle 

func DrawCircle(p Point, d int, s Style)

Draw a circle with the given diameter.

func DrawEllipse 

func DrawEllipse(p Point, b Size, s Style)

Draw an ellipse (oval).

func DrawImage 

func DrawImage(i Image, p Point)

Render an image using the given colors.

func DrawLine 

func DrawLine(a, b Point, s LineStyle)

Draw a straight line from point a to point b.

func DrawPoint 

func DrawPoint(p Point, c Color)

Set a single point (1 pixel is scaling is 1) on the frame.

func DrawRect 

func DrawRect(p Point, b Size, s Style)

Draw a rectangle filling the given bounding box.

func DrawRoundedRect 

func DrawRoundedRect(p Point, b, c Size, s Style)

Draw a rectangle with rounded corners.

func DrawSector 

func DrawSector(p Point, d int, start, sweep Angle, s Style)

Draw a sector.

func DrawSubImage 

func DrawSubImage(i SubImage, p Point)

Draw a subregion of an image.

Most often used to draw a sprite from a sprite atlas.

func DrawText 

func DrawText(t string, f Font, p Point, c Color)

Render text using the given font.

Unlike in the other drawing functions, here Point points not to the top-left corner but to the baseline start position.

func DrawTriangle 

func DrawTriangle(a, b, c Point, s Style)

Draw a triangle.

The order of points doesn't matter.

func DumpDataFile 

func DumpDataFile(path string, raw []byte)

Write a file into the app data dir.

func GetRandom 

func GetRandom() uint32

Get a random value.

func LogDebug 

func LogDebug(t string)

Log a debug message.

func LogError 

func LogError(t string)

Log an error message.

func Quit 

func Quit()

Exit the app after the current update is finished.

func RemoveDataFile 

func RemoveDataFile(path string)

Remove a file from the app data dir.

func Restart added in v0.3.0 

func Restart()

Restart the app.

func SetColor 

func SetColor(c Color, v RGB)

Set a color value in the palette.

func SetSeed 

func SetSeed(seed uint32)

Set the seed used to generate random values.

Types

type Angle 

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

An angle between two vectors.

Used by DrawArc and DrawSector. Constructed by [Dagrees] and Radians.

func Degrees 

func Degrees(a float32) Angle

Define an angle in radians where 360.0 is the full circle.

func Radians 

func Radians(a float32) Angle

Define an angle in radians where Tau (doubled Pi) is the full circle.

func (Angle) Degrees 

func (a Angle) Degrees() float32

Get the angle value in degrees.

func (Angle) Radians 

func (a Angle) Radians() float32

Get the angle value in radians.

type Buttons 

type Buttons struct {
	// If "a" button is pressed.
	A bool

	// If "b" button is pressed.
	B bool

	// If "x" button is pressed.
	X bool

	// If "y" button is pressed.
	Y bool

	// If "menu" button is pressed.
	//
	// For singleplayer games, the button press is always intercepted by the runtime.
	Menu bool
}

State of the buttons.

func ReadButtons 

func ReadButtons(p Peer) Buttons

Get the currently pressed buttons.

The peer can be Combined or one of the GetPeers.

func (Buttons) Held 

func (p Buttons) Held(old Buttons) Buttons

Given the old state, get buttons that were pressed and are still pressed now.

func (Buttons) JustPressed 

func (p Buttons) JustPressed(old Buttons) Buttons

Given the old state, get buttons that were not pressed but are pressed now.

func (Buttons) JustReleased 

func (p Buttons) JustReleased(old Buttons) Buttons

Given the old state, get buttons that were pressed but aren't pressed now.

type Color 

type Color uint8

A pointer to a color in the color palette. 

const (
	// No color (100% transparency).
	ColorNone Color = 0
	// Black color: #1A1C2C.
	ColorBlack Color = 1
	// Purple color: #5D275D.
	ColorPurple Color = 2
	// Red color: #B13E53.
	ColorRed Color = 3
	// Orange color: #EF7D57.
	ColorOrange Color = 4
	// Yellow color: #FFCD75.
	ColorYellow Color = 5
	// Light green color: #A7F070.
	ColorLightGreen Color = 6
	// Green color: #38B764.
	ColorGreen Color = 7
	// Dark green color: #257179.
	ColorDarkGreen Color = 8
	// Dark blue color: #29366F.
	ColorDarkBlue Color = 9
	// Blue color: #3B5DC9.
	ColorBlue Color = 10
	// Light blue color: #41A6F6.
	ColorLightBlue Color = 11
	// Cyan color: #73EFF7.
	ColorCyan Color = 12
	// White color: #F4F4F4.
	ColorWhite Color = 13
	// Light gray color: #94B0C2.
	ColorLightGray Color = 14
	// Gray color: #566C86.
	ColorGray Color = 15
	// Dark gray color: #333C57.
	ColorDarkGray Color = 16
)

type DPad 

type DPad struct {
	Left  bool
	Right bool
	Up    bool
	Down  bool
}

func (DPad) Held 

func (p DPad) Held(old DPad) DPad

Given the old state, get directions that were pressed and are still pressed now.

func (DPad) JustPressed 

func (p DPad) JustPressed(old DPad) DPad

Given the old state, get directions that were not pressed but are pressed now.

func (DPad) JustReleased 

func (p DPad) JustReleased(old DPad) DPad

Given the old state, get directions that were pressed but aren't pressed now.

type File 

type File struct {
	Raw []byte
}

A file loaded from the filesystem.

func LoadDataFile 

func LoadDataFile(path string) File

Read a file from the app data dir.

func LoadROMFile 

func LoadROMFile(path string) File

Read a file from the app ROM.

func (File) Font 

func (f File) Font() Font

Convert the File to a Font.

func (File) Image 

func (f File) Image() Image

Convert the File to an Image.

type Font 

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

A loaded font file.

Can be loaded using LoadROMFile.

type Image 

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

A loaded image file.

Can be loaded using LoadROMFile.

func (Image) Sub 

func (i Image) Sub(p Point, s Size) SubImage

Get a rectangle subregion of the image.

type LineStyle 

type LineStyle struct {
	Color Color
	Width int
}

The same as Style but without a fill color (only stroke color and width).

type Pad 

type Pad struct {
	X int
	Y int
}

A finger position on the touch pad.

Both X and Y are somewhere the range between -1000 and 1000 (both ends included). The 1000 X is on the right, the 1000 Y is on the top.

func ReadPad 

func ReadPad(p Peer) (Pad, bool)

Get the current touch pad state.

The peer can be Combined or one of the GetPeers.

func (Pad) Azimuth 

func (p Pad) Azimuth() Angle

The angle of the polar coordinate of the touch point.

func (Pad) DPad 

func (p Pad) DPad() DPad

Convert the Pad into DPad.

func (Pad) Point 

func (p Pad) Point() Point

Convert the Pad into a Point.

func (Pad) Radius 

func (p Pad) Radius() float32

The distance from the pad center to the touch point.

func (Pad) Size 

func (p Pad) Size() Size

Convert the Pad into a Size.

type Peer added in v0.3.0 

type Peer uint8

The peer ID. 

const Combined Peer = 0xFF

Peer value that can be passed to ReadPad and ReadButtons to get the combined input of all peers.

Useful for single-player games that want in multi-player to handle inputs from all devices as one input.

func GetMe added in v0.3.0 

func GetMe() Peer

Get the peer ID representing the local device.

type Peers added in v0.3.0 

type Peers uint32

The map of peers online.

func GetPeers added in v0.3.0 

func GetPeers() Peers

Get the list of peers that are currently online.

Includes the local device.

It can be used to detect if multiplayer is active: if there is more than 1 peer, you're playing with friends.

func (Peers) IsOnline added in v0.3.0 

func (peers Peers) IsOnline(peer Peer) bool

Check if the given peer is online.

func (Peers) Len added in v0.3.0 

func (peers Peers) Len() int

Get how many peers are online.

func (Peers) Slice added in v0.3.0 

func (peers Peers) Slice() []Peer

Get the slice of all peers that are online.

type Point 

type Point struct {
	X int
	Y int
}

A point on the screen.

Typically, the upper-left corner of a bounding box of a shape.

func (Point) Abs 

func (p Point) Abs() Point

Set X and Y to their absolute (non-negative) value.

func (Point) Add 

func (p Point) Add(r Point) Point

Add together two points.

func (Point) ComponentMax 

func (p Point) ComponentMax(r Point) Point

Set both X and Y to their maximum in the two given points.

func (Point) ComponentMin 

func (p Point) ComponentMin(r Point) Point

Set both X and Y to their minimum in the two given points.

func (Point) Pad 

func (p Point) Pad() Pad

Convert the Point to a Pad.

func (Point) Size 

func (p Point) Size() Size

Convert the Point to a Size.

func (Point) Sub 

func (p Point) Sub(r Point) Point

Subtract the given point from the current one.

type RGB 

type RGB struct {
	// Red component
	R uint8
	// Green component
	G uint8
	// Blue component
	B uint8
}

The RGB value of a color in the palette.

type Size 

type Size struct {
	// W is the width of the bounding box.
	W int
	// H is the height of the bounding box.
	H int
}

Size of a bounding box for a shape.

The width and height must be positive.

func (Size) Abs 

func (s Size) Abs() Size

Set W and H to their absolute (non-negative) value.

func (Size) Add 

func (s Size) Add(r Size) Size

Add two sizes.

func (Size) ComponentMax 

func (s Size) ComponentMax(r Size) Size

Set both W and H to their maximum in the two given sizes.

func (Size) ComponentMin 

func (s Size) ComponentMin(r Size) Size

Set both W and H to their minimum in the two given sizes.

func (Size) Pad 

func (s Size) Pad() Pad

Convert the Size to a Pad.

func (Size) Point 

func (s Size) Point() Point

Convert the Size to a Point.

func (Size) Sub 

func (s Size) Sub(r Size) Size

Subtract the given size from the current one.

type Style 

type Style struct {
	// The color to use to fill the shape.
	FillColor Color

	// The color to use for the shape stroke.
	StrokeColor Color

	// The width of the shape stroke.
	//
	// If zero, a solid shape without a stroke will be drawn.
	StrokeWidth int
}

Style of a shape.

func (Style) LineStyle 

func (s Style) LineStyle() LineStyle

Convert the Style to a LineStyle.

LineStyle is the same as Style except it doesn't have a fill color.

type SubImage 

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

A subregion of an image. Constructed using Image.Sub.

Source Files

View all Source files

Directories

Path Synopsis
Structs for working with shapes as values.
 Structs for working with shapes as values.

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