lighting

Documentation

Index

• Variables
• func GenerateCircle(radius float64) *ebiten.Image
• type Light
• type LightLayer
  • func NewLightLayer(w, h int, ambientAlpha float64) *LightLayer
  • func (ll *LightLayer) AddLight(l *Light)
  • func (ll *LightLayer) AmbientAlpha() float64
  • func (ll *LightLayer) ClearLights()
  • func (ll *LightLayer) Dispose()
  • func (ll *LightLayer) Lights() []*Light
  • func (ll *LightLayer) Node() *node.Node
  • func (ll *LightLayer) Redraw()
  • func (ll *LightLayer) RemoveLight(l *Light)
  • func (ll *LightLayer) RenderTextureImage() *ebiten.Image
  • func (ll *LightLayer) SetAmbientAlpha(a float64)
  • func (ll *LightLayer) SetCircleRadius(radius float64)
  • func (ll *LightLayer) SetPages(pages []*ebiten.Image)

Variables

var (
	// NewRenderTextureFn creates a RenderTexture and returns it as any.
	NewRenderTextureFn func(w, h int) any

	// RenderTextureImageFn returns the *ebiten.Image from a RenderTexture (any).
	RenderTextureImageFn func(rt any) *ebiten.Image

	// RenderTextureNewSpriteFn creates a sprite node from a RenderTexture.
	RenderTextureNewSpriteFn func(rt any, name string) *node.Node

	// RenderTextureDisposeFn disposes a RenderTexture.
	RenderTextureDisposeFn func(rt any)

	// MagentaPlaceholderPage is the sentinel page index.
	MagentaPlaceholderPage uint16 = 0xFFFF

	// EnsureMagentaImageFn returns the 1x1 magenta placeholder image.
	EnsureMagentaImageFn func() *ebiten.Image

	// Clamp01Fn clamps a value to [0, 1].
	Clamp01Fn func(v float64) float64
)

Function pointers wired by root to break dependency on render/ and atlas/.

Functions

func GenerateCircle

func GenerateCircle(radius float64) *ebiten.Image

GenerateCircle creates a feathered white circle image with the given radius.

Types

type Light

type Light struct {
	X, Y      float64
	Radius    float64
	Rotation  float64
	Intensity float64
	Enabled   bool
	Color     types.Color
	// TextureRegion, if non-zero, uses this sprite sheet region instead of
	// the default feathered circle.
	TextureRegion types.TextureRegion
	// Target, if set, makes the light follow this node's pivot point each Redraw.
	Target  *node.Node
	OffsetX float64
	OffsetY float64
}

Light represents a light source in a LightLayer.

type LightLayer

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

LightLayer provides a convenient 2D lighting effect using erase blending.

func NewLightLayer

func NewLightLayer(w, h int, ambientAlpha float64) *LightLayer

NewLightLayer creates a light layer covering (w x h) pixels.

func (*LightLayer) AddLight

func (ll *LightLayer) AddLight(l *Light)

AddLight adds a light to the layer.

func (*LightLayer) AmbientAlpha

func (ll *LightLayer) AmbientAlpha() float64

AmbientAlpha returns the current ambient darkness level.

func (*LightLayer) ClearLights

func (ll *LightLayer) ClearLights()

ClearLights removes all lights from the layer.

func (*LightLayer) Dispose

func (ll *LightLayer) Dispose()

Dispose releases all resources owned by the light layer.

func (*LightLayer) Lights

func (ll *LightLayer) Lights() []*Light

Lights returns the current light list. The returned slice MUST NOT be mutated.

func (*LightLayer) Node

func (ll *LightLayer) Node() *node.Node

Node returns the sprite node that displays the light layer.

func (*LightLayer) Redraw

func (ll *LightLayer) Redraw()

Redraw fills the texture with ambient darkness then erases light shapes.

func (*LightLayer) RemoveLight

func (ll *LightLayer) RemoveLight(l *Light)

RemoveLight removes a light from the layer.

func (*LightLayer) RenderTextureImage

func (ll *LightLayer) RenderTextureImage() *ebiten.Image

RenderTextureImage returns the underlying *ebiten.Image of the render texture.

func (*LightLayer) SetAmbientAlpha

func (ll *LightLayer) SetAmbientAlpha(a float64)

SetAmbientAlpha sets the base darkness level.

func (*LightLayer) SetCircleRadius

func (ll *LightLayer) SetCircleRadius(radius float64)

SetCircleRadius pre-generates a feathered circle texture at the given radius.

func (*LightLayer) SetPages

func (ll *LightLayer) SetPages(pages []*ebiten.Image)

SetPages stores the atlas page images used to resolve Light.TextureRegion.