engo

package module
v0.0.0-...-e130e5a Latest Latest
Warning

This package is not in the latest version of its module.

 Go to latest Published: May 26, 2018 License: MIT Imports: 15 Imported by: 0

README

Engo

GoDoc License Build Status Build status Go Report Card Coverage Status

A cross-platform game engine written in Go following an interpretation of the Entity Component System paradigm. Engo is currently compilable for Mac OSX, Linux and Windows. With the release of Go 1.4, supporting Android and the inception of iOS compatibility, mobile has been be added as a release target. Web support (gopherjs) is also available.

v1.0 is now available! To celebrate, there will be a game jam coming soon to celebrate the release, start actually building things and hopefully find any issues. Updates for this will come soon.

Getting in touch / Contributing

We have a gitter chat for people to join who want to further discuss engo. We are happy to discuss bugs, feature requests and would love to hear about the projects you are building!

Getting Started

Theory: common vs engo

There are currently two major important packages within this repository: engo.io/engo and engo.io/engo/common.

The top level engo package contains the functionality of creating windows, starting the game, creating an OpenGL context and handling input. It is designed to be used with Systems designed as per engo.io/ecs specifications. The common package contains our ECS implementations of common game development Systems like a RenderSystem or CameraSystem.

Practice: Getting it to Run
  1. First, you have to install some dependencies:
  2. If you're running on Debian/Ubuntu: sudo apt-get install libasound2-dev libglu1-mesa-dev freeglut3-dev mesa-common-dev xorg-dev libgl1-mesa-dev git-all
  3. If you're running on Windows you'll need a gcc compiler that the go tool can use and have gcc.exe in your PATH environmental variable. We recommend Mingw since it has been tested. You'll also need git installed, we recommend getting it from The official Git site
  4. If you're on OSX, you will also need Git. You can find instructions here. You can also use homebrew to install git as well. Open an issue if you have any issues
  5. Then, you can go get it: go get -u engo.io/engo
  6. You may also want to get the dependencies of platform specific builds, so that build tools like godef can use them: go get -u -tags netgo ./... go get -u -tags android ./...
  7. Now, you have two choices:
  8. Visit our website, which hosts a full-blown tutorial series on how to create your own game, and on top of that, has some conceptual explanations;
  9. Check out some demos in our demos folder.
  10. Finally, if you run into problems, if you've encountered a bug, or want to request a feature, feel free to shoot us a DM or create an issue.

Breaking Changes Since v1.0

Engo is always undergoing a lot of optimizations and constantly gets new features. However, this sometimes means things break. In order to make transitioning easier for you, we have a list of those changes, with the most recent being at the top. If you run into any problems, please contact us at gitter.

  • No breaking changes yet!

Roadmap to v1.1

A list of issues for v1.1 can be found here. There's always room for improvement! Feel free to submit proposals, open issues, and let us know how we can improve!

History

Engo, originally known as Engi was written by ajhager as a general purpose Go game engine. With a desire to build it into an "ECS" game engine, it was forked to github.com/paked/engi. After passing through several iterations, it was decided that the project would be rebranded and rereleased as Engo on its own GitHub organization.

Credits

Thank you to everyone who has worked on, or with Engo. None of this would be possible without you, and your help has been truly amazing.

These are 3rd party projects that have made engo possible.

  • The original engi game engine which engo was based off of (BSD license)
  • Oto, a low-level cross-platform library to play sound. The AudioSystem uses this and is based on the audio package used in Ebiten.

Documentation

Index

Constants

View Source 
const (
	// DefaultVerticalAxis is the name of the default vertical axis, as used internally in `engo` when `StandardInputs`
	// is defined.
	DefaultVerticalAxis = "vertical"

	// DefaultHorizontalAxis is the name of the default horizontal axis, as used internally in `engo` when `StandardInputs`
	// is defined.
	DefaultHorizontalAxis = "horizontal"
	// DefaultMouseXAxis is the name of the default horizontal mouse axis
	DefaultMouseXAxis = "mouse x"
	// DefaultMouseYAxis is the name of the default vertical mouse axis
	DefaultMouseYAxis = "mouse y"
)
View Source 
const (
	// AxisMax is the maximum value a joystick or keypress axis will reach
	AxisMax float32 = 1
	// AxisNeutral is the value an axis returns if there has been to state change.
	AxisNeutral float32 = 0
	// AxisMin is the minimum value a joystick or keypress axis will reach
	AxisMin float32 = -1
)
View Source 
const (
	// KeyStateUp is a state for when the key is not currently being pressed
	KeyStateUp = iota
	// KeyStateDown is a state for when the key is currently being pressed
	KeyStateDown
	// KeyStateJustDown is a state for when a key was just pressed
	KeyStateJustDown
	// KeyStateJustUp is a state for when a key was just released
	KeyStateJustUp
)
View Source 
const (
	// Epsilon is some tiny value that determines how precisely equal we want our
	// floats to be.
	Epsilon float32 = 1e-3
	// MinNormal is the smallest normal value possible.
	MinNormal = float32(1.1754943508222875e-38) // 1 / 2**(127 - 1)
)

Variables

View Source 
var (
	// Time is the active FPS counter
	Time *Clock

	// Input handles all input: mouse, keyboard and touch
	Input *InputManager

	// Mailbox is used by all Systems to communicate
	Mailbox *MessageManager

	// CurrentBackEnd is the current back end used for window management
	CurrentBackEnd BackEnd
	// ResizeXOffset is how far the screen moves from (0,0) being the top-left corner
	// when the window is resized
	ResizeXOffset = float32(0)
	// ResizeYOffset is how far the screen moves from (0,0) being the top-left corner
	// when the window is resized
	ResizeYOffset = float32(0)
)
View Source 
var (
	// Move is an action representing mouse movement
	Move = Action(0)
	// Press is an action representing a mouse press/click
	Press = Action(1)
	// Release is an action representing a mouse a release
	Release = Action(2)
	// Neutral represents a neutral action
	Neutral = Action(99)
	// Shift represents the shift modifier.
	// It is triggered when the shift key is pressed simultaneously with another key
	Shift = Modifier(0x0001)
	// Control represents the control modifier
	// It is triggered when the ctrl key is pressed simultaneously with another key
	Control = Modifier(0x0002)
	// Alt represents the alt modifier
	// It is triggered when the alt key is pressed simultaneously with another key
	Alt = Modifier(0x0004)
	// Super represents the super modifier
	// (Windows key on Microsoft Windows, Command key on Apple OSX, and varies on Linux)
	// It is triggered when the super key is pressed simultaneously with another key
	Super = Modifier(0x0008)
)
View Source 
var Files = &Formats{formats: make(map[string]FileLoader)}

Files manages global resource handling of registered file formats for game assets.

View Source 
var (

	// Gl is the current OpenGL context
	Gl *gl.Context
)

Functions

func CanvasHeight 

func CanvasHeight() float32

CanvasHeight gets the height of the current OpenGL Framebuffer

func CanvasScale 

func CanvasScale() float32

CanvasScale gets the ratio of the canvas to the window sizes

func CanvasWidth 

func CanvasWidth() float32

CanvasWidth gets the width of the current OpenGL Framebuffer

func CreateWindow 

func CreateWindow(title string, width, height int, fullscreen bool, msaa int)

CreateWindow sets up the GLFW window and prepares the OpenGL surface for rendering

func CrossProduct 

func CrossProduct(this, that Point) float32

CrossProduct returns the 2 dimensional cross product of this and that, which represents the magnitude of the three dimensional cross product

func CursorPos 

func CursorPos() (x, y float32)

CursorPos returns the current cursor position

func DestroyWindow 

func DestroyWindow()

DestroyWindow handles the termination of windows

func DotProduct 

func DotProduct(this, that Point) float32

DotProduct returns the dot product between this and that

func Exit 

func Exit()

Exit is the safest way to close your game, as `engo` will correctly attempt to close all windows, handlers and contexts

func FloatEqual 

func FloatEqual(a, b float32) bool

FloatEqual is a safe utility function to compare floats. It's Taken from http://floating-point-gui.de/errors/comparison/

It is slightly altered to not call Abs when not needed.

func FloatEqualThreshold 

func FloatEqualThreshold(a, b, epsilon float32) bool

FloatEqualThreshold is a utility function to compare floats. It's Taken from http://floating-point-gui.de/errors/comparison/

It is slightly altered to not call Abs when not needed.

This differs from FloatEqual in that it lets you pass in your comparison threshold, so that you can adjust the comparison value to your specific needs

func GameHeight 

func GameHeight() float32

GameHeight returns the current game height

func GameWidth 

func GameWidth() float32

GameWidth returns the current game width

func Headless 

func Headless() bool

Headless indicates whether or not OpenGL-calls should be made

func IsAndroidChrome 

func IsAndroidChrome() bool

IsAndroidChrome tells if the browser is Chrome for android

func LineTraceFraction 

func LineTraceFraction(tracer, boundary Line) float32

LineTraceFraction returns the trace fraction of tracer through boundary 1 means no intersection 0 means tracer's origin lies on the boundary line

func RegisterScene 

func RegisterScene(s Scene)

RegisterScene registers the `Scene`, so it can later be used by `SetSceneByName`

func Run 

func Run(o RunOptions, defaultScene Scene)

Run is called to create a window, initialize everything, and start the main loop. Once this function returns, the game window has been closed already. You can supply a lot of options within `RunOptions`, and your starting `Scene` should be defined in `defaultScene`.

func RunIteration 

func RunIteration()

RunIteration runs one iteration per frame

func RunPreparation 

func RunPreparation(defaultScene Scene)

RunPreparation is called automatically when calling Open. It should only be called once.

func ScaleOnResize 

func ScaleOnResize() bool

ScaleOnResize indicates whether or not the screen should resize (i.e. make things look smaller/bigger) whenever the window resized. If `false`, then the size of the screen does not affect the size of the things drawn - it just makes less/more objects visible

func SetCursor 

func SetCursor(c Cursor)

SetCursor sets the pointer of the mouse to the defined standard cursor

func SetCursorVisibility 

func SetCursorVisibility(visible bool)

SetCursorVisibility sets the visibility of the cursor. If true the cursor is visible, if false the cursor is not.

func SetFPSLimit 

func SetFPSLimit(limit int) error

SetFPSLimit can be used to change the value in the given `RunOpts` after already having called `engo.Run`.

func SetGlobalScale 

func SetGlobalScale(p Point)

SetGlobalScale sets the GlobalScale to the given dimensions. If either dimension is less than or equal to zero, GlobalScale is set to (1, 1).

func SetOverrideCloseAction 

func SetOverrideCloseAction(value bool)

SetOverrideCloseAction can be used to change the value in the given `RunOpts` after already having called `engo.Run`.

func SetScaleOnResize 

func SetScaleOnResize(b bool)

SetScaleOnResize can be used to change the value in the given `RunOpts` after already having called `engo.Run`.

func SetScene 

func SetScene(s Scene, forceNewWorld bool)

SetScene sets the currentScene to the given Scene, and optionally forcing to create a new ecs.World that goes with it.

func SetSceneByName 

func SetSceneByName(name string, forceNewWorld bool) error

SetSceneByName does a lookup for the `Scene` where its `Type()` equals `name`, and then sets it as current `Scene`

func SetTitle 

func SetTitle(title string)

SetTitle sets the title of the window

func SetVSync 

func SetVSync(enabled bool)

SetVSync sets whether or not to use VSync

func WindowHeight 

func WindowHeight() float32

WindowHeight gets the current window height

func WindowSize 

func WindowSize() (w, h int)

WindowSize gets the current window size

func WindowWidth 

func WindowWidth() float32

WindowWidth gets the current window width

Types

type AABB 

type AABB struct {
	Min, Max Point
}

AABB describes two points of a rectangle: the upper-left corner and the lower-right corner. It should always hold that `Min.X <= Max.X` and `Min.Y <= Max.Y`.

type Action 

type Action int

Action corresponds to a control action such as move, press, release

type Axis 

type Axis struct {
	// Name represents the name of the axis (Horizontal, Vertical)
	Name string
	// Pairs represents the axis pairs of this acis
	Pairs []AxisPair
}

An Axis is an input which is a spectrum of values. An example of this is the horizontal movement in a game, or how far a joystick is pressed.

func (Axis) Value 

func (a Axis) Value() float32

Value returns the value of an Axis.

type AxisKeyPair 

type AxisKeyPair struct {
	Min Key
	Max Key
}

An AxisKeyPair is a set of Min/Max values used for detecting whether or not a key has been pressed.

func (AxisKeyPair) Value 

func (keys AxisKeyPair) Value() float32

Value returns the value of a keypress.

type AxisMouse 

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

AxisMouse is an axis for a single x or y component of the Mouse. The value returned from it is the delta movement, since the previous call and it is not constrained by the AxisMin and AxisMax values.

func NewAxisMouse 

func NewAxisMouse(d AxisMouseDirection) *AxisMouse

NewAxisMouse creates a new Mouse Axis in either direction AxisMouseVert or AxisMouseHori.

func (*AxisMouse) Value 

func (am *AxisMouse) Value() float32

Value returns the delta of a mouse movement.

type AxisMouseDirection 

type AxisMouseDirection uint

AxisMouseDirection is the direction (X or Y) which the mouse is being tracked for. 

const (
	// AxisMouseVert is vertical mouse axis
	AxisMouseVert AxisMouseDirection = 0
	// AxisMouseHori is vertical mouse axis
	AxisMouseHori AxisMouseDirection = 1
)

type AxisPair 

type AxisPair interface {
	Value() float32
}

An AxisPair is a set of Min/Max values which could possible be used by an Axis.

type BackEnd 

type BackEnd uint

BackEnd represents the back end used for the window management / GL Surface 

const (
	// BackEndGLFW uses glfw
	BackEndGLFW BackEnd = iota
	// BackEndWeb uses gopherjs
	BackEndWeb
	// BackEndMobile uses gomobile
	BackEndMobile
)

type Button 

type Button struct {
	Triggers []Key
	Name     string
}

A Button is an input which can be either JustPressed, JustReleased or Down. Common uses would be for, a jump key or an action key.

func (Button) Down 

func (b Button) Down() bool

Down checks whether the current input is being held down.

func (Button) JustPressed 

func (b Button) JustPressed() bool

JustPressed checks whether an input was pressed in the previous frame.

func (Button) JustReleased 

func (b Button) JustReleased() bool

JustReleased checks whether an input was released in the previous frame.

type Clock 

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

A Clock is a measurement built in `engo` to measure the actual frames per seconds (framerate).

func NewClock 

func NewClock() *Clock

NewClock creates a new timer which allows you to measure ticks per seconds. Be sure to call `Tick()` whenever you want a tick to occur - it does not automatically tick each frame.

func (*Clock) Delta 

func (c *Clock) Delta() float32

Delta is the amount of seconds between the last tick and the one before that

func (*Clock) FPS 

func (c *Clock) FPS() float32

FPS is the amount of frames per second, computed every time a tick occurs at least a second after the previous update

func (*Clock) Tick 

func (c *Clock) Tick()

Tick indicates a new tick/frame has occurred.

func (*Clock) Time 

func (c *Clock) Time() float32

Time is the number of seconds the clock has been running

type Container 

type Container interface {
	// Contains reports whether the container contains the given point.
	Contains(p Point) bool
}

A Container is a 2D closed shape which contains a set of points.

type Cursor 

type Cursor uint8

Cursor is a reference to standard cursors, to be used in conjunction with `SetCursor`. What they look like, is different for each platform. 

const (
	// CursorNone can be used to reset the cursor.
	CursorNone Cursor = iota
	// CursorArrow represents an arrow cursor
	CursorArrow
	// CursorCrosshair represents a crosshair cursor
	CursorCrosshair
	// CursorHand represents a hand cursor
	CursorHand
	// CursorIBeam represents an IBeam cursor
	CursorIBeam
	// CursorHResize represents a HResize cursor
	CursorHResize
	// CursorVResize represents a VResize cursor
	CursorVResize
)

type Exiter 

type Exiter interface {
	// Exit is called when the user or the system requests to close the game
	// This should be used to cleanup or prompt user if they're sure they want to close
	// To prevent the default action (close/exit) make sure to set OverrideCloseAction in
	// your RunOpts to `true`. You should then handle the exiting of the program by calling
	//    engo.Exit()
	Exit()
}

Exiter is an optional interface a Scene can implement, indicating it'll have custom behavior whenever the game get closed.

type FileLoader 

type FileLoader interface {
	// Load loads the given resource into memory.
	Load(url string, data io.Reader) error

	// Unload releases the given resource from memory.
	Unload(url string) error

	// Resource returns the given resource, and an error if it didn't succeed.
	Resource(url string) (Resource, error)
}

FileLoader implements support for loading and releasing file resources.

type Formats 

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

Formats manages resource handling of registered file formats.

func (*Formats) Load 

func (formats *Formats) Load(urls ...string) error

Load loads the given resource(s) into memory, stopping at the first error.

func (*Formats) LoadReaderData 

func (formats *Formats) LoadReaderData(url string, f io.Reader) error

LoadReaderData loads a resource when you already have the reader for it.

func (*Formats) Register 

func (formats *Formats) Register(ext string, loader FileLoader)

Register registers a resource loader for the given file format.

func (*Formats) Resource 

func (formats *Formats) Resource(url string) (Resource, error)

Resource returns the given resource, and an error if it didn't succeed.

func (*Formats) SetRoot 

func (formats *Formats) SetRoot(root string)

SetRoot can be used to change the default directory from `assets` to whatever you want.

Whenever `root` does not start with the directory `assets`, you will not be able to support mobile (Android/iOS) since they require you to put all resources within the `assets` directory. More information about that is available here: https://godoc.org/golang.org/x/mobile/asset

You can, however, use subfolders within the `assets` folder, and set those as `root`.

func (*Formats) Unload 

func (formats *Formats) Unload(url string) error

Unload releases the given resource from memory.

type Hider 

type Hider interface {
	// Hide is called when an other Scene becomes active
	Hide()
}

Hider is an optional interface a Scene can implement, indicating it'll have custom behavior whenever the Scene get hidden to make room fr other Scenes.

type InputManager 

type InputManager struct {
	// Mouse is InputManager's reference to the mouse. It is recommended to use the
	// Axis and Button system if at all possible.
	Mouse Mouse

	// Touches is the touches on the screen. There can be up to 5 recorded in Android,
	// and up to 4 on iOS. GLFW can also keep track of the touches. The latest touch is also
	// recorded in the Mouse so that touches readily work with the common.MouseSystem
	Touches map[int]Point
	// contains filtered or unexported fields
}

InputManager contains information about all forms of input.

func NewInputManager 

func NewInputManager() *InputManager

NewInputManager holds onto anything input related for engo

func (*InputManager) Axis 

func (im *InputManager) Axis(name string) Axis

Axis retrieves an Axis with a specified name.

func (*InputManager) Button 

func (im *InputManager) Button(name string) Button

Button retrieves a Button with a specified name.

func (*InputManager) RegisterAxis 

func (im *InputManager) RegisterAxis(name string, pairs ...AxisPair)

RegisterAxis registers a new axis which can be used to retrieve inputs which are spectrums.

func (*InputManager) RegisterButton 

func (im *InputManager) RegisterButton(name string, keys ...Key)

RegisterButton registers a new button input.

type Key 

type Key int

Key correspends to a keyboard key 

const (
	// KeyGrave represents the '`' keyboard key
	KeyGrave Key = Key(glfw.KeyGraveAccent)
	// KeyDash represents the '-' keyboard key
	KeyDash Key = Key(glfw.KeyMinus)
	// KeyApostrophe represents the `'` keyboard key
	KeyApostrophe Key = Key(glfw.KeyApostrophe)
	// KeySemicolon represents the ';' keyboard key
	KeySemicolon Key = Key(glfw.KeySemicolon)
	// KeyEquals reprsents the '=' keyboard key
	KeyEquals Key = Key(glfw.KeyEqual)
	// KeyComma represents the ',' keyboard key
	KeyComma Key = Key(glfw.KeyComma)
	// KeyPeriod represents the '.' keyboard key
	KeyPeriod Key = Key(glfw.KeyPeriod)
	// KeySlash represents the '/' keyboard key
	KeySlash Key = Key(glfw.KeySlash)
	// KeyBackslash represents the '\' keyboard key
	KeyBackslash Key = Key(glfw.KeyBackslash)
	// KeyBackspace represents the backspace keyboard key
	KeyBackspace Key = Key(glfw.KeyBackspace)
	// KeyTab represents the tab keyboard key
	KeyTab Key = Key(glfw.KeyTab)
	// KeyCapsLock represents the caps lock keyboard key
	KeyCapsLock Key = Key(glfw.KeyCapsLock)
	// KeySpace represents the space keyboard key
	KeySpace Key = Key(glfw.KeySpace)
	// KeyEnter represents the enter keyboard key
	KeyEnter Key = Key(glfw.KeyEnter)
	// KeyEscape represents the escape keyboard key
	KeyEscape Key = Key(glfw.KeyEscape)
	// KeyInsert represents the insert keyboard key
	KeyInsert Key = Key(glfw.KeyInsert)
	// KeyPrintScreen represents the print screen keyboard key often
	// represented by 'Prt Scrn', 'Prt Scn', or 'Print Screen'
	KeyPrintScreen Key = Key(glfw.KeyPrintScreen)
	// KeyDelete represents the delete keyboard key
	KeyDelete Key = Key(glfw.KeyDelete)
	// KeyPageUp represents the page up keyboard key
	KeyPageUp Key = Key(glfw.KeyPageUp)
	// KeyPageDown represents the page down keyboard key
	KeyPageDown Key = Key(glfw.KeyPageDown)
	// KeyHome represents the home keyboard key
	KeyHome Key = Key(glfw.KeyHome)
	// KeyEnd represents the end keyboard key
	KeyEnd Key = Key(glfw.KeyEnd)
	// KeyPause represents the pause keyboard key
	KeyPause Key = Key(glfw.KeyPause)
	// KeyScrollLock represents the scroll lock keyboard key
	KeyScrollLock Key = Key(glfw.KeyScrollLock)
	// KeyArrowLeft represents the arrow left keyboard key
	KeyArrowLeft Key = Key(glfw.KeyLeft)
	// KeyArrowRight represents the arrow right keyboard key
	KeyArrowRight Key = Key(glfw.KeyRight)
	// KeyArrowDown represents the down arrow keyboard key
	KeyArrowDown Key = Key(glfw.KeyDown)
	// KeyArrowUp represents the up arrow keyboard key
	KeyArrowUp Key = Key(glfw.KeyUp)
	// KeyLeftBracket represents the '[' keyboard key
	KeyLeftBracket Key = Key(glfw.KeyLeftBracket)
	// KeyLeftShift represents the left shift keyboard key
	KeyLeftShift Key = Key(glfw.KeyLeftShift)
	// KeyLeftControl represents the left control keyboard key
	KeyLeftControl Key = Key(glfw.KeyLeftControl)
	// KeyLeftSuper represents the left super keyboard key
	// (Windows key on Microsoft Windows, Command key on Apple OSX, and varies on Linux)
	KeyLeftSuper Key = Key(glfw.KeyLeftSuper)
	// KeyLeftAlt represents the left alt keyboard key
	KeyLeftAlt Key = Key(glfw.KeyLeftAlt)
	// KeyRightBracket represents the ']' keyboard key
	KeyRightBracket Key = Key(glfw.KeyRightBracket)
	// KeyRightShift represents the right shift keyboard key
	KeyRightShift Key = Key(glfw.KeyRightShift)
	// KeyRightControl represents the right control keyboard key
	KeyRightControl Key = Key(glfw.KeyRightControl)
	// KeyRightSuper represents the right super keyboard key
	// (Windows key on Microsoft Windows, Command key on Apple OSX, and varies on Linux)
	KeyRightSuper Key = Key(glfw.KeyRightSuper)
	// KeyRightAlt represents the left alt keyboard key
	KeyRightAlt Key = Key(glfw.KeyRightAlt)
	// KeyZero represents the '0' keyboard key
	KeyZero Key = Key(glfw.Key0)
	// KeyOne represents the '1' keyboard key
	KeyOne Key = Key(glfw.Key1)
	// KeyTwo represents the '2' keyboard key
	KeyTwo Key = Key(glfw.Key2)
	// KeyThree represents the '3' keyboard key
	KeyThree Key = Key(glfw.Key3)
	// KeyFour represents the '4' keyboard key
	KeyFour Key = Key(glfw.Key4)
	// KeyFive represents the '5' keyboard key
	KeyFive Key = Key(glfw.Key5)
	// KeySix represents the '6' keyboard key
	KeySix Key = Key(glfw.Key6)
	// KeySeven represents the '7' keyboard key
	KeySeven Key = Key(glfw.Key7)
	// KeyEight represents the '8' keyboard key
	KeyEight Key = Key(glfw.Key8)
	// KeyNine represents the  '9' keyboard key
	KeyNine Key = Key(glfw.Key9)
	// KeyF1 represents the 'F1' keyboard key
	KeyF1 Key = Key(glfw.KeyF1)
	// KeyF2 represents the 'F2' keyboard key
	KeyF2 Key = Key(glfw.KeyF2)
	// KeyF3 represents the 'F3' keyboard key
	KeyF3 Key = Key(glfw.KeyF3)
	// KeyF4 represents the 'F4' keyboard key
	KeyF4 Key = Key(glfw.KeyF4)
	// KeyF5 represents the 'F5' keyboard key
	KeyF5 Key = Key(glfw.KeyF5)
	// KeyF6 represents the 'F6' keyboard key
	KeyF6 Key = Key(glfw.KeyF6)
	// KeyF7 represents the 'F7' keyboard key
	KeyF7 Key = Key(glfw.KeyF7)
	// KeyF8 represents the 'F8' keyboard key
	KeyF8 Key = Key(glfw.KeyF8)
	// KeyF9 represents the 'F9' keyboard key
	KeyF9 Key = Key(glfw.KeyF9)
	// KeyF10 represents the 'F10' keyboard key
	KeyF10 Key = Key(glfw.KeyF10)
	// KeyF11 represents the 'F11' keyboard key
	KeyF11 Key = Key(glfw.KeyF11)
	// KeyF12 represents the 'F12' keyboard key
	KeyF12 Key = Key(glfw.KeyF12)
	// KeyA represents the 'A' keyboard key
	KeyA Key = Key(glfw.KeyA)
	// KeyB represents the 'B' keyboard key
	KeyB Key = Key(glfw.KeyB)
	// KeyC represents the 'C' keyboard key
	KeyC Key = Key(glfw.KeyC)
	// KeyD represents the 'D' keyboard key '
	KeyD Key = Key(glfw.KeyD)
	// KeyE represents the 'E' keyboard key
	KeyE Key = Key(glfw.KeyE)
	// KeyF represents the 'F' keyboard key
	KeyF Key = Key(glfw.KeyF)
	// KeyG represents the 'G' keyboard key
	KeyG Key = Key(glfw.KeyG)
	// KeyH represents the 'H' keyboard key
	KeyH Key = Key(glfw.KeyH)
	// KeyI represents the 'I' keyboard key
	KeyI Key = Key(glfw.KeyI)
	// KeyJ represents the 'J' keyboard key
	KeyJ Key = Key(glfw.KeyJ)
	// KeyK represents the 'K' keyboard key
	KeyK Key = Key(glfw.KeyK)
	// KeyL represents the 'L' keyboard key
	KeyL Key = Key(glfw.KeyL)
	// KeyM represents the 'M' keyboard key
	KeyM Key = Key(glfw.KeyM)
	// KeyN represents the 'N' keyboard key
	KeyN Key = Key(glfw.KeyN)
	// KeyO represents the 'O' keyboard key
	KeyO Key = Key(glfw.KeyO)
	// KeyP represents the 'P' keyboard key
	KeyP Key = Key(glfw.KeyP)
	// KeyQ represents the 'Q' keyboard key
	KeyQ Key = Key(glfw.KeyQ)
	// KeyR represents the 'R' keyboard key
	KeyR Key = Key(glfw.KeyR)
	// KeyS represents the 'S' keyboard key
	KeyS Key = Key(glfw.KeyS)
	// KeyT represents the 'T' keyboard key
	KeyT Key = Key(glfw.KeyT)
	// KeyU represents the 'U' keyboard key
	KeyU Key = Key(glfw.KeyU)
	// KeyV represents the 'V' keyboard key
	KeyV Key = Key(glfw.KeyV)
	// KeyW represents the 'W' keyboard key
	KeyW Key = Key(glfw.KeyW)
	// KeyX represents the 'X' keyboard key
	KeyX Key = Key(glfw.KeyX)
	// KeyY represents the 'Y' keyboard key
	KeyY Key = Key(glfw.KeyY)
	// KeyZ represents the 'Z' keyboard key
	KeyZ Key = Key(glfw.KeyZ)
	// KeyNumLock represents the NumLock keyboard key on the numpad
	KeyNumLock Key = Key(glfw.KeyNumLock)
	// KeyNumMultiply represents the NumMultiply keyboard key on the numpad
	KeyNumMultiply Key = Key(glfw.KeyKPMultiply)
	// KeyNumDivide represents the NumDivide keyboard key on the numpad
	KeyNumDivide Key = Key(glfw.KeyKPDivide)
	// KeyNumAdd represents the NumAdd keyboard key on the numpad
	KeyNumAdd Key = Key(glfw.KeyKPAdd)
	// KeyNumSubtract represents the NumSubtract keyboard key on the numpad
	KeyNumSubtract Key = Key(glfw.KeyKPSubtract)
	// KeyNumZero represents the NumZero keyboard key on the numpad
	KeyNumZero Key = Key(glfw.KeyKP0)
	// KeyNumOne represents the NumOne keyboard key on the numpad
	KeyNumOne Key = Key(glfw.KeyKP1)
	// KeyNumTwo represents the NumTwo keyboard key on the numpad
	KeyNumTwo Key = Key(glfw.KeyKP2)
	// KeyNumThree represents the NumThree keyboard key on the numpad
	KeyNumThree Key = Key(glfw.KeyKP3)
	// KeyNumFour represents the NumFour keyboard key on the numpad
	KeyNumFour Key = Key(glfw.KeyKP4)
	// KeyNumFive represents the NumFive keyboard key on the numpad
	KeyNumFive Key = Key(glfw.KeyKP5)
	// KeyNumSix represents the NumSix keyboard key on the numpad
	KeyNumSix Key = Key(glfw.KeyKP6)
	// KeyNumSeven represents the NumSeven keyboard key on the numpad
	KeyNumSeven Key = Key(glfw.KeyKP7)
	// KeyNumEight represents the NumEight keyboard key on the numpad
	KeyNumEight Key = Key(glfw.KeyKP8)
	// KeyNumNine represents the NumNine keyboard key on the numpad
	KeyNumNine Key = Key(glfw.KeyKP9)
	// KeyNumDecimal represents the NumDecimal keyboard key on the numpad
	KeyNumDecimal Key = Key(glfw.KeyKPDecimal)
	// KeyNumEnter represents the NumEnter keyboard key on the numpad
	KeyNumEnter Key = Key(glfw.KeyKPEnter)
)

type KeyManager 

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

KeyManager tracks which keys are pressed and released at the current point of time.

func NewKeyManager 

func NewKeyManager() *KeyManager

NewKeyManager creates a new KeyManager.

func (*KeyManager) Get 

func (km *KeyManager) Get(k Key) KeyState

Get retrieves a keys state.

func (*KeyManager) Set 

func (km *KeyManager) Set(k Key, state bool)

Set is used for updating whether or not a key is held down, or not held down.

type KeyState 

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

KeyState is used for detecting the state of a key press.

func (KeyState) Down 

func (key KeyState) Down() bool

Down returns wether a key is being pressed

func (KeyState) JustPressed 

func (key KeyState) JustPressed() bool

JustPressed returns whether a key was just pressed

func (KeyState) JustReleased 

func (key KeyState) JustReleased() bool

JustReleased returns whether a key was just released

func (*KeyState) State 

func (key *KeyState) State() int

State returns the raw state of a key.

func (KeyState) Up 

func (key KeyState) Up() bool

Up returns wheter a key is not being pressed

type Line 

type Line struct {
	P1 Point
	P2 Point
}

Line describes a line segment on a 2 dimensional euclidean space it can also be thought of as a 2 dimensional vector with an offset

func (*Line) Angle 

func (l *Line) Angle() float32

Angle returns the euclidean angle of l relative to X = 0 The return angle is in radians and goes counter-clockwise and returns [-pi, pi]

func (*Line) Normal 

func (l *Line) Normal() Point

Normal returns the left hand normal of the line segment l

func (*Line) PointDistance 

func (l *Line) PointDistance(point Point) float32

PointDistance Returns the euclidean distance from the point p to the line segment l

func (*Line) PointDistanceSquared 

func (l *Line) PointDistanceSquared(point Point) float32

PointDistanceSquared returns the squared euclidean distance from the point p to the line segment l

func (*Line) PointSide 

func (l *Line) PointSide(point Point) bool

PointSide returns which side of the line l the point p sits on true means the point is below/left of the line false means the point is above/right of the line or touching the line

type Message 

type Message interface {
	Type() string
}

A Message is used to send messages within the MessageManager

type MessageHandler 

type MessageHandler func(msg Message)

A MessageHandler is used to dispatch a message to the subscribed handler.

type MessageManager 

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

MessageManager manages messages and subscribed handlers

func (*MessageManager) Dispatch 

func (mm *MessageManager) Dispatch(message Message)

Dispatch sends a message to all subscribed handlers of the message's type

func (*MessageManager) Listen 

func (mm *MessageManager) Listen(messageType string, handler MessageHandler)

Listen subscribes to the specified message type and calls the specified handler when fired

type Modifier 

type Modifier int

Modifier represents a special key pressed along with another key

type Mouse 

type Mouse struct {
	X, Y             float32
	ScrollX, ScrollY float32
	Action           Action
	Button           MouseButton
	Modifer          Modifier
}

Mouse represents the mouse

type MouseButton 

type MouseButton int

MouseButton corresponds to a mouse button. 

const (
	// MouseButtonLeft represents the left mouse button
	MouseButtonLeft MouseButton = 0
	// MouseButtonRight represents the right mouse button
	MouseButtonRight MouseButton = 1
	// MouseButtonMiddle represent the middle mosue button
	MouseButtonMiddle MouseButton = 2
	// MouseButton4 represents the 4th mouse button
	MouseButton4 MouseButton = 3
	// MouseButton5 represents the 5th mouse button
	MouseButton5 MouseButton = 4
	// MouseButton6 represents the 6th mouse button
	MouseButton6 MouseButton = 5
	// MouseButton7 represents the 7th mouse button
	MouseButton7 MouseButton = 6
	// MouseButton4 represents the last mouse button
	MouseButtonLast MouseButton = 7
)

Mouse buttons

type MouseState 

type MouseState struct {
	// X and Y are the coordinates of the Mouse, relative to the `Canvas`.
	X, Y float32
	// ScrollX and ScrollY are the amount of scrolling the user has done with his mouse wheel in the respective directions.
	ScrollX, ScrollY float32
	// Action indicates what the gamer currently has done with his mouse.
	Action Action
	// Button indicates which button is being pressed by the gamer (if any).
	Button MouseButton
	// Modifier indicates which modifier (shift, alt, etc.) has been pressed during the Action.
	Modifier Modifier
}

MouseState represents the current state of the Mouse (or latest Touch-events).

type Point 

type Point struct {
	X, Y float32
}

Point describes a coordinate in a 2 dimensional euclidean space it can also be thought of as a 2 dimensional vector from the origin

func GetGlobalScale 

func GetGlobalScale() Point

GetGlobalScale returns the GlobalScale factor set in the RunOptions or via SetGlobalScale()

func LineIntersection 

func LineIntersection(one, two Line) (Point, bool)

LineIntersection returns the point where the line segments one and two intersect and true if there is intersection, nil and false when line segments one and two do not intersect

func (*Point) Add 

func (p *Point) Add(p2 Point)

Add sets the components of p to the pointwise summation of p + p2

func (*Point) AddScalar 

func (p *Point) AddScalar(s float32)

AddScalar adds s to each component of p

func (*Point) Equal 

func (p *Point) Equal(p2 Point) bool

Equal indicates whether two points have the same value, avoiding issues with float precision

func (*Point) Multiply 

func (p *Point) Multiply(p2 Point)

Multiply sets the components of p to the pointwise product of p * p2

func (*Point) MultiplyScalar 

func (p *Point) MultiplyScalar(s float32)

MultiplyScalar multiplies each component of p by s

func (*Point) Normalize 

func (p *Point) Normalize() (Point, float32)

Normalize returns the unit vector from p, and its magnitude. if you try to normalize the null vector, the return value will be null values

func (*Point) PointDistance 

func (p *Point) PointDistance(p2 Point) float32

PointDistance returns the euclidean distance between p and p2

func (*Point) PointDistanceSquared 

func (p *Point) PointDistanceSquared(p2 Point) float32

PointDistanceSquared returns the squared euclidean distance between p and p2

func (*Point) ProjectOnto 

func (p *Point) ProjectOnto(p2 Point) Point

ProjectOnto returns the vector produced by projecting p on to p2 returns an empty Point if they can't project onto one another

func (*Point) Set 

func (p *Point) Set(x, y float32)

Set sets the coordinates of p to x and y

func (*Point) Subtract 

func (p *Point) Subtract(p2 Point)

Subtract sets the components of p to the pointwise difference of p - p2

func (*Point) SubtractScalar 

func (p *Point) SubtractScalar(s float32)

SubtractScalar subtracts s from each component of p

func (Point) Within 

func (p Point) Within(c Container) bool

Within reports whether the point is contained within the given container.

type Resource 

type Resource interface {
	// URL returns the uniform resource locator of the given resource.
	URL() string
}

Resource represents a game resource, such as an image or a sound.

type RunOptions 

type RunOptions struct {
	// NoRun indicates the Open function should return immediately, without looping
	NoRun bool

	// Title is the Window title
	Title string

	// HeadlessMode indicates whether or not OpenGL calls should be made
	HeadlessMode bool

	// Fullscreen indicates the game should run in fullscreen mode if run on a desktop
	Fullscreen bool

	Width, Height int

	// GlobalScale scales all size/render components by the scale factor
	// Any point passed less than or equal to zero will result in the scale being set to
	// engo.Point{1, 1}.
	// All the systems in common should scale themselves accordingly (collision, camera, render, etc)
	// However, custom systems should be aware of this if this is set.
	GlobalScale Point

	// VSync indicates whether or not OpenGL should wait for the monitor to swp the buffers
	VSync bool

	// Resizable indicates whether or not the Window should be resizable.  Defaults to `true`.
	NotResizable bool

	// ScaleOnResize indicates whether or not engo should make things larger/smaller whenever the screen resizes
	ScaleOnResize bool

	// FPSLimit indicates the maximum number of frames per second
	FPSLimit int

	// OverrideCloseAction indicates that (when true) engo will never close whenever the gamer wants to close the
	// game - that will be your responsibility
	OverrideCloseAction bool

	// StandardInputs is an easy way to map common inputs to actions, such as "jump" being <SPACE>, and "action" being
	// <ENTER>.
	StandardInputs bool

	// MSAA indicates the amount of samples that should be taken. Leaving it blank will default to 1, and you may
	// use any positive value you wish. It may be possible that the operating system / environment doesn't support
	// the requested amount. In that case, GLFW will (hopefully) pick the highest supported sampling count. The higher
	// the value, the bigger the performance cost.
	//
	// Our `RenderSystem` automatically calls `gl.Enable(gl.MULTISAMPLE)` (which is required to make use of it), but
	// if you're going to use your own rendering `System` instead, you will have to call it yourself.
	//
	// Also note that this value is entirely ignored in WebGL - most browsers enable it by default when available, and
	// none of them (at time of writing) allow you to tune it.
	//
	// More info at https://www.opengl.org/wiki/Multisampling
	// "With multisampling, each pixel at the edge of a polygon is sampled multiple times."
	MSAA int

	// AssetsRoot is the path where all resources (images, audio files, fonts, etc.) can be found. Leaving this at
	// empty-string, will default this to `assets`.
	//
	// Whenever using any value that does not start with the directory `assets`, you will not be able to support
	// mobile (Android/iOS), because they **require** all assets to be within the `assets` directory. You may however
	// use any subfolder-structure within that `assets` directory.
	AssetsRoot string

	// MobileWidth and MobileHeight are the width and height given from the Android/iOS OpenGL Surface used for Gomobile bind
	MobileWidth, MobileHeight int

	// Update is the function called each frame during the runLoop to update all of the
	// systems. If left blank, it defaults to &ecs.World{}. Use this if you plan on utilizing
	// engo's window / GL management but don't want to use the ECS paradigm.
	Update Updater
}

RunOptions are the options used to Run engo

type Scene 

type Scene interface {
	// Preload is called before loading resources
	Preload()

	// Setup is called before the main loop
	Setup(Updater)

	// Type returns a unique string representation of the Scene, used to identify it
	Type() string
}

Scene represents a screen ingame. i.e.: main menu, settings, but also the game itself

func CurrentScene 

func CurrentScene() Scene

CurrentScene returns the SceneWorld that is currently active

type Shower 

type Shower interface {
	// Show is called whenever the other Scene becomes inactive, and this one becomes the active one
	Show()
}

Shower is an optional interface a Scene can implement, indicating it'll have custom behavior whenever the Scene gets shown again after being hidden (due to switching to other Scenes)

type Trace 

type Trace struct {
	Fraction    float32
	EndPosition Point
	Line
}

Trace describes all the values computed from a line trace

func LineTrace 

func LineTrace(tracer Line, boundaries []Line) Trace

LineTrace runs a series of line traces from tracer to each boundary line and returns the nearest trace values

type Updater 

type Updater interface {
	Update(float32)
}

Updater is an interface for what handles your game's Update during each frame. typically, this will be an *ecs.World, but you can implement your own Upodater and use engo without using engo's ecs

type WindowResizeMessage 

type WindowResizeMessage struct {
	OldWidth, OldHeight int
	NewWidth, NewHeight int
}

WindowResizeMessage is a message that's being dispatched whenever the game window is being resized by the gamer

func (WindowResizeMessage) Type 

func (WindowResizeMessage) Type() string

Type returns the type of the current object "WindowResizeMessage"

Source Files

View all Source files

Directories

Path Synopsis
Package common contains ECS implementations of commonly used game systems.
 Package common contains ECS implementations of commonly used game systems.
internal/decode/convert
package convert resamples and converts audio data
 package convert resamples and converts audio data
internal/decode/mp3
Package mp3 provides MP3 decoder.
 Package mp3 provides MP3 decoder.
internal/decode/vorbis
Package vorbis provides Ogg/Vorbis decoder.
 Package vorbis provides Ogg/Vorbis decoder.
internal/decode/wav
Package wav provides WAV (RIFF) decoder.
 Package wav provides WAV (RIFF) decoder.
Package math currently is a wrapper to github.com/engoengine/math.
 Package math currently is a wrapper to github.com/engoengine/math.
imath
span

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL
go.dev uses cookies from Google to deliver and enhance the quality of its services and to analyze traffic. Learn more.