Documentation ¶
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
- func CurrentFPS() float64
- func CursorPosition() (x, y int)
- func GamepadAxis(id int, axis int) float64
- func GamepadAxisNum(id int) int
- func GamepadButtonNum(id int) int
- func IsGamepadButtonPressed(id int, button GamepadButton) bool
- func IsKeyPressed(key Key) bool
- func IsMouseButtonPressed(mouseButton MouseButton) bool
- func IsRunningSlowly() bool
- func Run(f func(*Image) error, width, height int, scale float64, title string) error
- func RunWithoutMainLoop(f func(*Image) error, width, height int, scale float64, title string) <-chan error
- func ScreenScale() float64
- func SetCursorVisibility(visible bool)
- func SetScreenScale(scale float64)
- func SetScreenSize(width, height int)
- type ColorM
- func (c *ColorM) Add(other ColorM)
- func (c *ColorM) ChangeHSV(hueTheta float64, saturationScale float64, valueScale float64)
- func (c *ColorM) Concat(other ColorM)
- func (c *ColorM) Element(i, j int) float64
- func (c *ColorM) Reset()
- func (c *ColorM) RotateHue(theta float64)
- func (c *ColorM) Scale(r, g, b, a float64)
- func (c *ColorM) SetElement(i, j int, value float64)
- func (c *ColorM) Translate(r, g, b, a float64)
- type CompositeMode
- type DrawImageOptions
- type Filter
- type GamepadButton
- type GeoM
- type Image
- func (i *Image) At(x, y int) color.Color
- func (i *Image) Bounds() image.Rectangle
- func (i *Image) Clear() error
- func (i *Image) ColorModel() color.Model
- func (i *Image) Dispose() error
- func (i *Image) DrawImage(img *Image, options *DrawImageOptions) error
- func (i *Image) Fill(clr color.Color) error
- func (i *Image) ReplacePixels(p []uint8) error
- func (i *Image) Size() (width, height int)
- type ImagePart
- type ImageParts
- type Key
- type MouseButton
- type Touch
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) GamepadButton16 = GamepadButton(ui.GamepadButton16) GamepadButton17 = GamepadButton(ui.GamepadButton17) GamepadButton18 = GamepadButton(ui.GamepadButton18) GamepadButton19 = GamepadButton(ui.GamepadButton19) GamepadButton20 = GamepadButton(ui.GamepadButton20) GamepadButton21 = GamepadButton(ui.GamepadButton21) GamepadButton22 = GamepadButton(ui.GamepadButton22) GamepadButton23 = GamepadButton(ui.GamepadButton23) GamepadButton24 = GamepadButton(ui.GamepadButton24) GamepadButton25 = GamepadButton(ui.GamepadButton25) GamepadButton26 = GamepadButton(ui.GamepadButton26) GamepadButton27 = GamepadButton(ui.GamepadButton27) GamepadButton28 = GamepadButton(ui.GamepadButton28) GamepadButton29 = GamepadButton(ui.GamepadButton29) GamepadButton30 = GamepadButton(ui.GamepadButton30) GamepadButton31 = GamepadButton(ui.GamepadButton31) GamepadButtonMax = GamepadButton31 )
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 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) KeyApostrophe = Key(ui.KeyApostrophe) KeyBackslash = Key(ui.KeyBackslash) 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) KeyEqual = Key(ui.KeyEqual) 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) KeyGraveAccent = Key(ui.KeyGraveAccent) KeyHome = Key(ui.KeyHome) KeyInsert = Key(ui.KeyInsert) KeyLeft = Key(ui.KeyLeft) KeyLeftBracket = Key(ui.KeyLeftBracket) KeyMinus = Key(ui.KeyMinus) KeyPageDown = Key(ui.KeyPageDown) KeyPageUp = Key(ui.KeyPageUp) KeyPeriod = Key(ui.KeyPeriod) KeyRight = Key(ui.KeyRight) KeyRightBracket = Key(ui.KeyRightBracket) KeySemicolon = Key(ui.KeySemicolon) KeyShift = Key(ui.KeyShift) KeySlash = Key(ui.KeySlash) KeySpace = Key(ui.KeySpace) KeyTab = Key(ui.KeyTab) KeyUp = Key(ui.KeyUp) KeyMax = KeyUp )
Keys
const ( MouseButtonLeft = MouseButton(ui.MouseButtonLeft) MouseButtonRight = MouseButton(ui.MouseButtonRight) MouseButtonMiddle = MouseButton(ui.MouseButtonMiddle) )
MouseButtons
const ColorMDim = affine.ColorMDim
ColorMDim is a dimension of a ColorM.
const FPS = 60
FPS represents how many times game updating happens in a second.
const GeoMDim = affine.GeoMDim
GeoMDim is a dimension of a GeoM.
const MaxImageSize = graphics.MaxImageSize
Variables ¶
This section is empty.
Functions ¶
func CurrentFPS ¶ added in v1.2.0
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 ¶ added in v1.2.0
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 ¶ added in v1.2.0
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 ¶ added in v1.2.0
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 ¶ added in v1.2.0
func IsGamepadButtonPressed(id int, button GamepadButton) bool
IsGamepadButtonPressed returns the boolean indicating the buttons is pressed or not.
This function is concurrent-safe.
The key states vary depending on environments. There can be differences even between Chrome and Firefox. Don't assume that states of a keys are always same when same buttons are pressed.
NOTE: Gamepad API is available only on desktops, Chrome and Firefox. To use this API, browsers might require rebooting the browser.
func IsKeyPressed ¶
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 ¶ added in v1.3.0
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 ¶
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.
Run 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.
Run returns error when 1) OpenGL error happens, or 2) f returns error. In the case of 2), Run returns the same error.
The size unit is device-independent pixel.
func RunWithoutMainLoop ¶ added in v1.5.0
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 ¶ added in v1.3.0
func ScreenScale() float64
ScreenScale returns the current screen scale.
If Run is not called, this returns 0.
This function is concurrent-safe.
func SetCursorVisibility ¶ added in v1.5.0
func SetCursorVisibility(visible bool)
SetCursorVisibility changes the state of cursor visiblity.
This function is concurrent-safe.
func SetScreenScale ¶ added in v1.2.0
func SetScreenScale(scale float64)
SetScreenScale changes the scale of the screen.
This function is concurrent-safe.
func SetScreenSize ¶ added in v1.2.0
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.
Types ¶
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 ScaleColor ¶
ScaleColor is deprecated as of 1.2.0-alpha. Use Scale instead.
func TranslateColor ¶
TranslateColor is deprecated as of 1.2.0-alpha. Use Translate instead.
func (*ColorM) Add ¶
Add is deprecated as of 1.5.0-alpha. Note that this doesn't make sense as an operation for affine matrices.
func (*ColorM) ChangeHSV ¶ added in v1.3.0
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 ¶
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) Reset ¶ added in v1.5.0
func (c *ColorM) Reset()
Reset resets the ColorM as identity.
func (*ColorM) SetElement ¶
SetElement sets an element at (i, j).
type CompositeMode ¶ added in v1.3.0
type CompositeMode int
CompositeMode represents Porter-Duff composition mode.
type DrawImageOptions ¶
type DrawImageOptions struct { SourceRect *image.Rectangle GeoM GeoM ColorM ColorM CompositeMode CompositeMode // Deprecated (as of 1.5.0-alpha): Use Part instead. ImageParts ImageParts // Deprecated (as of 1.1.0-alpha): Use Part 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.
type GamepadButton ¶ added in v1.2.0
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 TranslateGeo ¶
TranslateGeo is deprecated as of 1.2.0-alpha. Use Translate instead.
func (*GeoM) Add ¶
Add is deprecated as of 1.5.0-alpha. Note that this doesn't make sense as an operation for affine matrices.
func (*GeoM) Concat ¶
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) SetElement ¶
SetElement sets an element at (i, j).
type Image ¶
type Image struct {
// contains filtered or unexported fields
}
Image represents an image. The pixel format is alpha-premultiplied. Image implements image.Image.
Functions of Image never returns error as of 1.5.0-alpha, and error values are always nil.
func NewImage ¶
NewImage returns an empty image.
If width or height is less than 1 or more than MaxImageSize, NewImage panics.
Error returned by NewImage is always nil as of 1.5.0-alpha.
func NewImageFromImage ¶
NewImageFromImage creates a new image with the given image (source).
If source's width or height is less than 1 or more than MaxImageSize, NewImageFromImage panics.
Error returned by NewImageFromImage is always nil as of 1.5.0-alpha.
func (*Image) At ¶
At returns the color of the image at (x, y).
This method loads pixels from GPU 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).
func (*Image) Clear ¶
Clear resets the pixels of the image into 0.
When the image is disposed, Clear does nothing.
Clear always returns nil as of 1.5.0-alpha.
func (*Image) ColorModel ¶
ColorModel returns the color model of the image.
func (*Image) Dispose ¶ added in v1.2.0
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.
When the image is disposed, Dipose does nothing.
Dipose always return nil as of 1.5.0-alpha.
func (*Image) DrawImage ¶
func (i *Image) DrawImage(img *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:
SourceRect: nil. When SourceRect is nil, the whole source image is used. GeoM: Identity matrix ColorM: Identity matrix (that changes no colors) CompositeMode: CompositeModeSourceOver (regular alpha blending)
For drawing, the pixels of the argument image at the time of this call is adopted. Even if the argument image is mutated after this call, the drawing result is never affected.
When the image is disposed, DrawImage does nothing.
When the given image is as same as i, DrawImage panics.
DrawImage always returns nil as of 1.5.0-alpha.
func (*Image) Fill ¶
Fill fills the image with a solid color.
When the image is disposed, Fill does nothing.
Fill always returns nil as of 1.5.0-alpha.
func (*Image) ReplacePixels ¶ added in v1.2.0
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).
ReplacePixels may be slow (as for implementation, this calls glTexSubImage2D).
When len(p) is not 4 * (width) * (height), ReplacePixels panics.
When the image is disposed, ReplacePixels does nothing.
ReplacePixels always returns nil as of 1.5.0-alpha.
type ImageParts ¶ added in v1.1.0
type ImageParts interface { Len() int Dst(i int) (x0, y0, x1, y1 int) Src(i int) (x0, y0, x1, y1 int) }
An ImageParts is deprecated (as of 1.5.0-alpha): Use SourceRect instead.