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github.com/hajimehoshi/ebiten

Package ebiten

v1.4.0
Latest Go to latest

The highest tagged major version is v2.

Published: Feb 25, 2019 | License: Apache-2.0 | Module: github.com/hajimehoshi/ebiten

Overview

Package ebiten provides graphics and input API to develop a 2D game.

You can start the game by calling the function Run.

func update(screen *ebiten.Image) error {
    // Define your game.
}

func main() {
    ebiten.Run(update, 320, 240, 2, "Your game's title")
}

Index

Constants

const (
	GamepadButton0  = GamepadButton(ui.GamepadButton0)
	GamepadButton1  = GamepadButton(ui.GamepadButton1)
	GamepadButton2  = GamepadButton(ui.GamepadButton2)
	GamepadButton3  = GamepadButton(ui.GamepadButton3)
	GamepadButton4  = GamepadButton(ui.GamepadButton4)
	GamepadButton5  = GamepadButton(ui.GamepadButton5)
	GamepadButton6  = GamepadButton(ui.GamepadButton6)
	GamepadButton7  = GamepadButton(ui.GamepadButton7)
	GamepadButton8  = GamepadButton(ui.GamepadButton8)
	GamepadButton9  = GamepadButton(ui.GamepadButton9)
	GamepadButton10 = GamepadButton(ui.GamepadButton10)
	GamepadButton11 = GamepadButton(ui.GamepadButton11)
	GamepadButton12 = GamepadButton(ui.GamepadButton12)
	GamepadButton13 = GamepadButton(ui.GamepadButton13)
	GamepadButton14 = GamepadButton(ui.GamepadButton14)
	GamepadButton15 = GamepadButton(ui.GamepadButton15)
)

GamepadButtons

const (
	// Regular alpha blending
	// c_out = c_src + c_dst × (1 - α_src)
	CompositeModeSourceOver CompositeMode = CompositeMode(opengl.CompositeModeSourceOver)

	// c_out = 0
	CompositeModeClear = CompositeMode(opengl.CompositeModeClear)

	// c_out = c_src
	CompositeModeCopy = CompositeMode(opengl.CompositeModeCopy)

	// c_out = c_dst
	CompositeModeDestination = CompositeMode(opengl.CompositeModeDestination)

	// c_out = c_src × (1 - α_dst) + c_dst
	CompositeModeDestinationOver = CompositeMode(opengl.CompositeModeDestinationOver)

	// c_out = c_src × α_dst
	CompositeModeSourceIn = CompositeMode(opengl.CompositeModeSourceIn)

	// c_out = c_dst × α_src
	CompositeModeDestinationIn = CompositeMode(opengl.CompositeModeDestinationIn)

	// c_out = c_src × (1 - α_dst)
	CompositeModeSourceOut = CompositeMode(opengl.CompositeModeSourceOut)

	// c_out = c_dst × (1 - α_src)
	CompositeModeDestinationOut = CompositeMode(opengl.CompositeModeDestinationOut)

	// c_out = c_src × α_dst + c_dst × (1 - α_src)
	CompositeModeSourceAtop = CompositeMode(opengl.CompositeModeSourceAtop)

	// c_out = c_src × (1 - α_dst) + c_dst × α_src
	CompositeModeDestinationAtop = CompositeMode(opengl.CompositeModeDestinationAtop)

	// c_out = c_src × (1 - α_dst) + c_dst × (1 - α_src)
	CompositeModeXor = CompositeMode(opengl.CompositeModeXor)

	// Sum of source and destination (a.k.a. 'plus' or 'additive')
	// c_out = c_src + c_dst
	CompositeModeLighter = CompositeMode(opengl.CompositeModeLighter)
)

This name convention follows CSS compositing: https://drafts.fxtf.org/compositing-2/.

In the above comments, c_src, c_dst and c_out represent alpha-premultiplied RGB values of source, destination and output respectively. α_src and α_dst represent alpha values of source and destination respectively.

const (
	Key0         = Key(ui.Key0)
	Key1         = Key(ui.Key1)
	Key2         = Key(ui.Key2)
	Key3         = Key(ui.Key3)
	Key4         = Key(ui.Key4)
	Key5         = Key(ui.Key5)
	Key6         = Key(ui.Key6)
	Key7         = Key(ui.Key7)
	Key8         = Key(ui.Key8)
	Key9         = Key(ui.Key9)
	KeyA         = Key(ui.KeyA)
	KeyB         = Key(ui.KeyB)
	KeyC         = Key(ui.KeyC)
	KeyD         = Key(ui.KeyD)
	KeyE         = Key(ui.KeyE)
	KeyF         = Key(ui.KeyF)
	KeyG         = Key(ui.KeyG)
	KeyH         = Key(ui.KeyH)
	KeyI         = Key(ui.KeyI)
	KeyJ         = Key(ui.KeyJ)
	KeyK         = Key(ui.KeyK)
	KeyL         = Key(ui.KeyL)
	KeyM         = Key(ui.KeyM)
	KeyN         = Key(ui.KeyN)
	KeyO         = Key(ui.KeyO)
	KeyP         = Key(ui.KeyP)
	KeyQ         = Key(ui.KeyQ)
	KeyR         = Key(ui.KeyR)
	KeyS         = Key(ui.KeyS)
	KeyT         = Key(ui.KeyT)
	KeyU         = Key(ui.KeyU)
	KeyV         = Key(ui.KeyV)
	KeyW         = Key(ui.KeyW)
	KeyX         = Key(ui.KeyX)
	KeyY         = Key(ui.KeyY)
	KeyZ         = Key(ui.KeyZ)
	KeyAlt       = Key(ui.KeyAlt)
	KeyBackspace = Key(ui.KeyBackspace)
	KeyCapsLock  = Key(ui.KeyCapsLock)
	KeyComma     = Key(ui.KeyComma)
	KeyControl   = Key(ui.KeyControl)
	KeyDelete    = Key(ui.KeyDelete)
	KeyDown      = Key(ui.KeyDown)
	KeyEnd       = Key(ui.KeyEnd)
	KeyEnter     = Key(ui.KeyEnter)
	KeyEscape    = Key(ui.KeyEscape)
	KeyF1        = Key(ui.KeyF1)
	KeyF2        = Key(ui.KeyF2)
	KeyF3        = Key(ui.KeyF3)
	KeyF4        = Key(ui.KeyF4)
	KeyF5        = Key(ui.KeyF5)
	KeyF6        = Key(ui.KeyF6)
	KeyF7        = Key(ui.KeyF7)
	KeyF8        = Key(ui.KeyF8)
	KeyF9        = Key(ui.KeyF9)
	KeyF10       = Key(ui.KeyF10)
	KeyF11       = Key(ui.KeyF11)
	KeyF12       = Key(ui.KeyF12)
	KeyHome      = Key(ui.KeyHome)
	KeyInsert    = Key(ui.KeyInsert)
	KeyLeft      = Key(ui.KeyLeft)
	KeyPageDown  = Key(ui.KeyPageDown)
	KeyPageUp    = Key(ui.KeyPageUp)
	KeyPeriod    = Key(ui.KeyPeriod)
	KeyRight     = Key(ui.KeyRight)
	KeyShift     = Key(ui.KeyShift)
	KeySpace     = Key(ui.KeySpace)
	KeyTab       = Key(ui.KeyTab)
	KeyUp        = Key(ui.KeyUp)
)

Keys

const (
	MouseButtonLeft   = MouseButton(ui.MouseButtonLeft)
	MouseButtonRight  = MouseButton(ui.MouseButtonRight)
	MouseButtonMiddle = MouseButton(ui.MouseButtonMiddle)
)

MouseButtons

const ColorMDim = 5

ColorMDim is a dimension of a ColorM.

const FPS = 60

FPS represents how many times game updating happens in a second.

const GeoMDim = 3

GeoMDim is a dimension of a GeoM.

func CurrentFPS

func CurrentFPS() float64

CurrentFPS returns the current number of frames per second of rendering.

This function is concurrent-safe.

This value represents how many times rendering happens in 1/60 second and NOT how many times logical game updating (a passed function to Run) happens. Note that logical game updating is assured to happen 60 times in a second as long as the screen is active.

func CursorPosition

func CursorPosition() (x, y int)

CursorPosition returns a position of a mouse cursor.

This function is concurrent-safe.

func GamepadAxis

func GamepadAxis(id int, axis int) float64

GamepadAxis returns the float value [-1.0 - 1.0] of the axis.

This function is concurrent-safe.

NOTE: Gamepad API is available only on desktops, Chrome and Firefox. To use this API, browsers might require rebooting the browser.

func GamepadAxisNum

func GamepadAxisNum(id int) int

GamepadAxisNum returns the number of axes of the gamepad.

This function is concurrent-safe.

NOTE: Gamepad API is available only on desktops, Chrome and Firefox. To use this API, browsers might require rebooting the browser.

func GamepadButtonNum

func GamepadButtonNum(id int) int

GamepadButtonNum returns the number of the buttons of the gamepad.

This function is concurrent-safe.

NOTE: Gamepad API is available only on desktops, Chrome and Firefox. To use this API, browsers might require rebooting the browser.

func IsGamepadButtonPressed

func IsGamepadButtonPressed(id int, button GamepadButton) bool

IsGamepadButtonPressed returns the boolean indicating the buttons is pressed or not.

This function is concurrent-safe.

NOTE: Gamepad API is available only on desktops, Chrome and Firefox. To use this API, browsers might require rebooting the browser.

func IsKeyPressed

func IsKeyPressed(key Key) bool

IsKeyPressed returns a boolean indicating whether key is pressed.

This function is concurrent-safe.

func IsMouseButtonPressed

func IsMouseButtonPressed(mouseButton MouseButton) bool

IsMouseButtonPressed returns a boolean indicating whether mouseButton is pressed.

This function is concurrent-safe.

Note that touch events not longer affect this function's result as of 1.4.0-alpha. Use Touches instead.

func IsRunningSlowly

func IsRunningSlowly() bool

IsRunningSlowly returns true if the game is running too slowly to keep 60 FPS of rendering. The game screen is not updated when IsRunningSlowly is true. It is recommended to skip heavy processing, especially drawing, when IsRunningSlowly is true.

This function is concurrent-safe.

func Run

func Run(f func(*Image) error, width, height int, scale float64, title string) error

Run runs the game. f is a function which is called at every frame. The argument (*Image) is the render target that represents the screen.

This function must be called from the main thread. Note that ebiten bounds the main goroutine to the main OS thread by runtime.LockOSThread.

The given function f is guaranteed to be called 60 times a second even if a rendering frame is skipped. f is not called when the screen is not shown.

The size unit is device-independent pixel.

func RunWithoutMainLoop

func RunWithoutMainLoop(f func(*Image) error, width, height int, scale float64, title string) <-chan error

RunWithoutMainLoop runs the game, but don't call the loop on the main (UI) thread. Different from Run, this function returns immediately.

Typically, Ebiten users don't have to call this directly. Instead, functions in github.com/hajimehoshi/ebiten/mobile module call this.

The size unit is device-independent pixel.

func ScreenScale

func ScreenScale() float64

ScreenScale returns the current screen scale.

If Run is not called, this returns NaN.

This function is concurrent-safe.

func SetScreenScale

func SetScreenScale(scale float64)

SetScreenScale changes the scale of the screen.

This function is concurrent-safe.

func SetScreenSize

func SetScreenSize(width, height int)

SetScreenSize changes the (logical) size of the screen. This doesn't affect the current scale of the screen.

Unit is device-independent pixel.

This function is concurrent-safe.

type ColorM

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

A ColorM represents a matrix to transform coloring when rendering an image.

A ColorM is applied to the source alpha color while an Image's pixels' format is alpha premultiplied. Before applying a matrix, a color is un-multiplied, and after applying the matrix, the color is multiplied again.

The initial value is identity.

func Monochrome

func Monochrome() ColorM

Monochrome returns a color matrix to make an image monochrome.

func RotateHue

func RotateHue(theta float64) ColorM

RotateHue is deprecated as of 1.2.0-alpha. Use RotateHue member function instead.

func ScaleColor

func ScaleColor(r, g, b, a float64) ColorM

ScaleColor is deprecated as of 1.2.0-alpha. Use Scale instead.

func TranslateColor

func TranslateColor(r, g, b, a float64) ColorM

TranslateColor is deprecated as of 1.2.0-alpha. Use Translate instead.

func (*ColorM) Add

func (c *ColorM) Add(other ColorM)

Add adds a color matrix with the other color matrix.

func (*ColorM) ChangeHSV

func (c *ColorM) ChangeHSV(hueTheta float64, saturationScale float64, valueScale float64)

ChangeHSV changes HSV (Hue-Saturation-Value) values. hueTheta is a radian value to ratate hue. saturationScale is a value to scale saturation. valueScale is a value to scale value (a.k.a. brightness).

This conversion uses RGB to/from YCrCb conversion.

func (*ColorM) Concat

func (c *ColorM) Concat(other ColorM)

Concat multiplies a color matrix with the other color matrix. This is same as muptiplying the matrix other and the matrix c in this order.

func (*ColorM) Element

func (c *ColorM) Element(i, j int) float64

Element returns a value of a matrix at (i, j).

func (*ColorM) RotateHue

func (c *ColorM) RotateHue(theta float64)

RotateHue rotates the hue.

func (*ColorM) Scale

func (c *ColorM) Scale(r, g, b, a float64)

Scale scales the matrix by (r, g, b, a).

func (*ColorM) SetElement

func (c *ColorM) SetElement(i, j int, element float64)

SetElement sets an element at (i, j).

func (*ColorM) Translate

func (c *ColorM) Translate(r, g, b, a float64)

Translate translates the matrix by (r, g, b, a).

type CompositeMode

type CompositeMode int

CompositeMode represents Porter-Duff composition mode.

type DrawImageOptions

type DrawImageOptions struct {
	ImageParts    ImageParts
	GeoM          GeoM
	ColorM        ColorM
	CompositeMode CompositeMode

	// Deprecated (as of 1.1.0-alpha): Use ImageParts instead.
	Parts []ImagePart
}

A DrawImageOptions represents options to render an image on an image.

type Filter

type Filter int

Filter represents the type of filter to be used when an image is maginified or minified.

const (
	// FilterNearest represents nearest (crisp-edged) filter
	FilterNearest Filter = iota

	// FilterLinear represents linear filter
	FilterLinear
)

type GamepadButton

type GamepadButton int

A GamepadButton represents a gamepad button.

type GeoM

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

A GeoM represents a matrix to transform geometry when rendering an image.

The initial value is identity.

func RotateGeo

func RotateGeo(theta float64) GeoM

RotateGeo is deprecated as of 1.2.0-alpha. Use Rotate instead.

func ScaleGeo

func ScaleGeo(x, y float64) GeoM

ScaleGeo is deprecated as of 1.2.0-alpha. Use Scale instead.

func TranslateGeo

func TranslateGeo(tx, ty float64) GeoM

TranslateGeo is deprecated as of 1.2.0-alpha. Use Translate instead.

func (*GeoM) Add

func (g *GeoM) Add(other GeoM)

Add adds a geometry matrix with the other geometry matrix.

func (*GeoM) Concat

func (g *GeoM) Concat(other GeoM)

Concat multiplies a geometry matrix with the other geometry matrix. This is same as muptiplying the matrix other and the matrix g in this order.

func (*GeoM) Element

func (g *GeoM) Element(i, j int) float64

Element returns a value of a matrix at (i, j).

func (*GeoM) Rotate

func (g *GeoM) Rotate(theta float64)

Rotate rotates the matrix by theta.

func (*GeoM) Scale

func (g *GeoM) Scale(x, y float64)

Scale scales the matrix by (x, y).

func (*GeoM) SetElement

func (g *GeoM) SetElement(i, j int, element float64)

SetElement sets an element at (i, j).

func (*GeoM) Translate

func (g *GeoM) Translate(tx, ty float64)

Translate translates the matrix by (x, y).

type Image

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

Image represents an image. The pixel format is alpha-premultiplied. Image implements image.Image.

func NewImage

func NewImage(width, height int, filter Filter) (*Image, error)

NewImage returns an empty image.

NewImage generates a new texture and a new framebuffer.

This function is concurrent-safe.

func NewImageFromImage

func NewImageFromImage(source image.Image, filter Filter) (*Image, error)

NewImageFromImage creates a new image with the given image (source).

NewImageFromImage generates a new texture and a new framebuffer.

This function is concurrent-safe.

func (*Image) At

func (i *Image) At(x, y int) color.Color

At returns the color of the image at (x, y).

This method loads pixels from VRAM to system memory if necessary.

This method can't be called before the main loop (ebiten.Run) starts (as of version 1.4.0-alpha).

This function is concurrent-safe.

func (*Image) Bounds

func (i *Image) Bounds() image.Rectangle

Bounds returns the bounds of the image.

This function is concurrent-safe.

func (*Image) Clear

func (i *Image) Clear() error

Clear resets the pixels of the image into 0.

This function is concurrent-safe.

func (*Image) ColorModel

func (i *Image) ColorModel() color.Model

ColorModel returns the color model of the image.

This function is concurrent-safe.

func (*Image) Dispose

func (i *Image) Dispose() error

Dispose disposes the image data. After disposing, the image becomes invalid. This is useful to save memory.

The behavior of any functions for a disposed image is undefined.

This function is concurrent-safe.

func (*Image) DrawImage

func (i *Image) DrawImage(image *Image, options *DrawImageOptions) error

DrawImage draws the given image on the receiver image.

This method accepts the options. The parts of the given image at the parts of the destination. After determining parts to draw, this applies the geometry matrix and the color matrix.

Here are the default values:

ImageParts:    (0, 0) - (source width, source height) to (0, 0) - (source width, source height)
               (i.e. the whole source image)
GeoM:          Identity matrix
ColorM:        Identity matrix (that changes no colors)
CompositeMode: CompositeModeSourceOver (regular alpha blending)

Note that this function returns immediately and actual drawing is done lazily.

This function is concurrent-safe.

func (*Image) Fill

func (i *Image) Fill(clr color.Color) error

Fill fills the image with a solid color.

This function is concurrent-safe.

func (*Image) ReplacePixels

func (i *Image) ReplacePixels(p []uint8) error

ReplacePixels replaces the pixels of the image with p.

The given p must represent RGBA pre-multiplied alpha values. len(p) must equal to 4 * (image width) * (image height).

This function may be slow (as for implementation, this calls glTexSubImage2D).

This function is concurrent-safe.

func (*Image) Size

func (i *Image) Size() (width, height int)

Size returns the size of the image.

This function is concurrent-safe.

type ImagePart

type ImagePart struct {
	Dst image.Rectangle
	Src image.Rectangle
}

An ImagePart is deprecated (as of 1.1.0-alpha): Use ImageParts instead.

type ImageParts

type ImageParts interface {
	Len() int
	Dst(i int) (x0, y0, x1, y1 int)
	Src(i int) (x0, y0, x1, y1 int)
}

An ImageParts represents the parts of the destination image and the parts of the source image.

type Key

type Key int

A Key represents a keyboard key.

type MouseButton

type MouseButton int

A MouseButton represents a mouse button.

type Touch

type Touch interface {
	ID() int
	Position() (x, y int)
}

Touch represents a pointer state.

func Touches

func Touches() []Touch

Touches returns the current touch states.

Package Files

Documentation was rendered with GOOS=linux and GOARCH=amd64.

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