Hylograph.Canvas

data CanvasContext

Opaque handle to a Canvas rendering context

data CanvasElement

Opaque canvas element type for event binding

type CanvasConfig = { background :: String, centerOrigin :: Boolean, height :: Int, width :: Int }

Configuration for creating a Canvas

defaultConfig :: CanvasConfig

Default canvas configuration

createCanvas :: String -> CanvasConfig -> Effect CanvasContext

Create a Canvas in the specified container

clearCanvas :: CanvasContext -> Effect Unit

Clear the canvas

getCanvasElement :: CanvasContext -> Effect CanvasElement

Get the canvas DOM element (for attaching event listeners)

type Transform = { scale :: Number, translateX :: Number, translateY :: Number }

View transform for zoom/pan

defaultTransform :: Transform

Default transform (no zoom, no pan)

setTransform :: CanvasContext -> Transform -> Effect Unit

Set the view transform (for zoom/pan)

resetTransform :: CanvasContext -> Effect Unit

Reset transform to default

applyTransform :: Transform -> Transform -> Transform

Apply a transform to the current transform (multiply)

type CircleSpec = { fill :: String, opacity :: Number, radius :: Number, stroke :: String, strokeWidth :: Number, x :: Number, y :: Number }

Specification for drawing a circle

type LineSpec = { opacity :: Number, stroke :: String, strokeWidth :: Number, x1 :: Number, x2 :: Number, y1 :: Number, y2 :: Number }

Specification for drawing a line

drawCircle :: CanvasContext -> CircleSpec -> Effect Unit

Draw a single circle

drawLine :: CanvasContext -> LineSpec -> Effect Unit

Draw a single line

drawCircles :: CanvasContext -> Array CircleSpec -> Effect Unit

Draw multiple circles (more efficient than repeated drawCircle)

drawLines :: CanvasContext -> Array LineSpec -> Effect Unit

Draw multiple lines (more efficient than repeated drawLine)

beginScene :: CanvasContext -> Effect Unit

Begin a new scene (clears canvas)

endScene :: CanvasContext -> Effect Unit

End the current scene