README
¶
bento
Bento is a high-level game engine based on ebiten that simplifies creating 2D games.
Bento is meant to be used together with ebiten; you can always fallback to ebiten for finer-grained control over graphics.
You may want to read the API documentation and general reference first.
Disclaimer
Bento is experimental, and it is under developement. Its API is subject to breaking changes.
Documentation
¶
Index ¶
- Constants
- func Bound(point, size image.Point) image.Rectangle
- func DPIScale(res int) int
- func Keypress(keys []ebiten.Key) bool
- func NewImageBound(bound image.Rectangle) *ebiten.Image
- func Pad(bound image.Rectangle, pad image.Point) image.Rectangle
- func Radian(degree float64) float64
- func SecondToTick(seconds float64) int
- func TickToSecond(ticks int) float64
- func Unpad(bound image.Rectangle, pad image.Point) image.Rectangle
- type Align
- type Animation
- type Clock
- type Component
- type Debug
- type Delta
- type DeltaAlgorithm
- type Entity
- type Font
- func (f *Font) Draw(str string, clr color.Color, img *ebiten.Image, point image.Point)
- func (f *Font) Load(src []byte, opts *opentype.FaceOptions) error
- func (f *Font) Write(str string, clr color.Color, img *ebiten.Image, point image.Point, align Align) image.Rectangle
- func (f *Font) WriteCenter(str string, clr color.Color, img *ebiten.Image) image.Rectangle
- type InitError
- type RenderState
- type Scene
- type Scroll
- type Sprite
- type Stage
- type Stream
- type Tileset
- type Transition
- type Vec
- func (vec *Vec) Arc(center image.Point, radius int, from, to float32)
- func (vec *Vec) Circle(center image.Point, radius int)
- func (vec *Vec) Draw(clr color.Color, img *ebiten.Image, o *ebiten.DrawTrianglesOptions)
- func (vec *Vec) DrawShader(clr color.Color, img *ebiten.Image, shader *ebiten.Shader, ...)
- func (vec *Vec) Line(to image.Point)
- func (vec *Vec) Move(to image.Point)
- func (vec *Vec) Rect(bounds image.Rectangle)
Constants ¶
const ( // Right moves an image to the right of a point. Right Align = 1 << iota // HCenter moves an image to the horizontal center of a point. HCenter // Left moves an image to the left of a point. Left // Top moves an image above a point. Top // VCenter moves an image to the vertical center of a point. VCenter // Bottom moves an image below a point. Bottom // Default is the default alignment of an image (to the right and below). Default = BottomRight TopLeft = Top | Left TopCenter = Top | HCenter TopRight = Top | Right CenterLeft = VCenter | Left Center = VCenter | HCenter CenterRight = VCenter | Right BottomLeft = Bottom | Left BottomCenter = Bottom | Center BottomRight = Bottom | Right )
Variables ¶
This section is empty.
Functions ¶
func DPIScale ¶
DPIScale scales the given resolution by the device's scale factor. This allows high-DPI rendering.
func Keypress ¶
func Keypress(keys []ebiten.Key) bool
Keypress checks if the key is pressed in the current frame.
func NewImageBound ¶
NewImageBound creates an image from a bound.
Types ¶
type Align ¶
type Align int
Align specifies the alignment to render an image at a point (x, y). Align must have at most one horizontal (AlignRight, AlignHCenter, AlignLeft) and vertical (AlignTop, AlignVCenter, AlignBottom) flag.
type Animation ¶
type Animation interface {
Component
// Draw renders the animation to the image.
Draw(img *ebiten.Image)
// Done checks if the animation has finished.
Done() bool
}
Animation is a effect rendered on a scene/sprite.
type Clock ¶
type Clock struct {
// contains filtered or unexported fields
}
Clock acts as a basic scheduler for operations. One tick is equivalent to a single frame, where 1 second is 60 frames.
func NewClockOnce ¶
NewClockOnce creates a new clock that triggers once after n seconds.
func (*Clock) Done ¶
Done checks if the clock's timer has triggered on the current tick. If the timer was set with ScheduleOnce, this will only return true one time.
func (*Clock) Schedule ¶
Schedule sets the clock's timer to trigger every n seconds. This will panic if n is too small to calculate ticks for.
func (*Clock) ScheduleOnce ¶
ScheduleOnce sets the clock's timer to trigger once, after n seconds. This will panic if n is too small to calculate ticks for.
type Component ¶ added in v0.2.0
type Component interface {
Update() error
}
Component is a state that updates every tick. Update must be called before using the component's state, i.e
type myComponent struct {
sub Component
}
func (mc *myComponent) Update() error {
if err := mc.sub.Update(); err != nil {
return err
}
// use mc.sub here
}
or else accessing the component's state may result in undefined behaviour/panics.
type Debug ¶
type Debug struct {
Font *Font
}
Debug is a struct of options for debug mode. A font is required to render certain elements.
type Delta ¶
type Delta struct {
// contains filtered or unexported fields
}
Delta is a delta that changes over time.
func NewDelta ¶
func NewDelta( dalgo DeltaAlgorithm, delta image.Point, period float64, ) *Delta
NewDelta creates an delta with the total delta, and the period over which to increase the current delta.
func (*Delta) Delta ¶
Delta returns the current delta. This will panic if delta has not been updated yet.
type DeltaAlgorithm ¶
type DeltaAlgorithm int
DeltaAlgorithm specifies the algorithm to use when generating deltas.
const ( // Linear specifies a delta is constant. Linear DeltaAlgorithm = iota // Exponential specifies a delta in exponential (e^x) space. Exponential )
type Entity ¶
type Entity struct {
Sprite
*Transition
Op *ebiten.DrawImageOptions
}
Entity is a sprite with rendering state. While a sprite renders to an image, an entity handles drawing the rendered image to the screen. Op is the options used to draw the entity to the screen.
func NewEntities ¶
NewEntities constructs a slice of entities from several sprites.
type Font ¶
Font is a wrapper around a fontface, used to render text to images.
func (*Font) Draw ¶
Draw renders the text on an image at the point as-is (i.e without any alignment). NOTE: point is the bottom-left point of the text.
func (*Font) Load ¶
func (f *Font) Load(src []byte, opts *opentype.FaceOptions) error
Load loads an OpenType fontface from a source.
type InitError ¶ added in v0.2.0
type InitError struct {
// contains filtered or unexported fields
}
InitError indicates that the component has not been updated yet with .Update.
type RenderState ¶
type RenderState int
RenderState represents the rendering state of an entity on the stage.
The render lifecycle has several states: Hidden (default): The entity is not rendering to the screen. Entering: An enter transition is being rendered on the entity. Visible: The entity is rendering normally. Exiting: An exit transition is being rendered on the entity.
After an entity has exited the stage, the render state will change back to Hidden.
const ( Hidden RenderState = iota Entering Visible Exiting )
func (RenderState) String ¶
func (i RenderState) String() string
type Scene ¶
type Scene interface {
// Update updates the state of the scene, if any.
Update(stage *Stage) error
// Draw renders the scene on screen.
Draw(screen *ebiten.Image)
// Enter returns the enter transition of the scene, if any.
Enter() Animation
// Exit returns the enter transition of the scene, if any.
Exit() Animation
// Entities returns a slice of entities to render on the scene.
Entities() []*Entity
}
Scene is a special kind of entity that draws directly to a screen instead of rendering to a image.
type Scroll ¶
type Scroll struct {
Font *Font
// contains filtered or unexported fields
}
Scroll allows several pieces of text to be scrolled across an image.
func (*Scroll) Draw ¶
Draw renders the scroll on a new image. point is the bottom-left point of the scroll.
func (*Scroll) Skip ¶
func (s *Scroll) Skip()
Skip causes the next render to render the whole text instead of waiting for scrolling.
type Sprite ¶
type Sprite interface {
Component
// Render renders the sprite to an image, given the screen's size.
Render(entity *Entity, size image.Point) *ebiten.Image
}
Sprite is an image with state.
type Stage ¶
type Stage struct {
// contains filtered or unexported fields
}
Stage is a scene manager which implements the ebiten.Game interface. The current scene must never be nil. If debug is not nil, debug mode is enabled.
func NewStage ¶
NewStage creates a stage with an inital scene. NOTE: The initial scene's enter animation is rendered!
func (*Stage) Draw ¶
func (s *Stage) Draw(screen *ebiten.Image)
Draw renders the current scene to the screen.
type Stream ¶
type Stream struct {
// contains filtered or unexported fields
}
Stream is a stream of text over a channel.
type Tileset ¶
type Tileset struct {
// contains filtered or unexported fields
}
Tileset is a image with tiles that can be tiled into a single sprite.
func NewTileset ¶
NewTileset creates a new tileset with a image and tile size. If cache is true, calls to the Tile method will lazily cache tile images for faster loading.
func (*Tileset) Render ¶
Render renders the tileset to an image, given a tilemap. The tilemap must have at least one row, and all rows must have equal length.
type Transition ¶
type Transition struct {
// contains filtered or unexported fields
}
func (*Transition) Draw ¶
func (t *Transition) Draw(image *ebiten.Image)
Draw draws the transition onto the image.
func (*Transition) Hide ¶
func (t *Transition) Hide(exit Animation)
Hide sets the render state to Hidden after rendering an exit transition. If exit is nil, the state is immediately changed.
func (*Transition) RenderState ¶
func (t *Transition) RenderState() RenderState
RenderState returns the rendering state of the transition.
func (*Transition) Show ¶
func (t *Transition) Show(enter Animation)
Show sets the render state to Visible after rendering an enter animation. If enter is nil, the state is immediately changed.
func (*Transition) Update ¶
func (t *Transition) Update() error
Update updates the transition's state.
type Vec ¶
Vec is a wrapper around ebiten's vector path for drawing operations.
func (*Vec) Arc ¶
Arc draws a circular arc with a center and radius. from and to are angles in radians.
func (*Vec) DrawShader ¶
func (vec *Vec) DrawShader( clr color.Color, img *ebiten.Image, shader *ebiten.Shader, o *ebiten.DrawTrianglesShaderOptions, )
DrawShader renders this vector path with a shader to an image.
Source Files
Directories