IGIS provides a Swift object library running as a server on Linux for remote graphics via a browser client.
Very Preliminary API Documentation
In order to use the library, use the project IgisShellD as a starting point.
// Point Definition
public var x : Int
public var y : Int
public init()
public init(x:Int, y:Int)
public init(doublePoint:DoublePoint)
public func distanceSquared(target:Point) -> Int
public func distance(target:Point) -> Double
static public func Points(doublePoints:[DoublePoint]) -> [Point]
// DoublePoint Definition
public init()
public init(x:Double, y:Double)
public init(point:Point)
public func distanceSquared(target:DoublePoint)
public func distance(target:DoublePoint)
public func DoublePoints(points:[Point]) -> [DoublePoint]
// Size Definition
public var width : Int
public height : Int
public init()
public init(width:Int, height:Int)
public mutating func enlarge(change:Int)
public var center : Point // Calculated
// Provides a description of a rectangle relative to a target Point or Rect
public enum Containment {
// Special cases combining horizontal and vertical containment
case containedFully // Included in set when both containedHorizontally AND containedVertically (Points,Rects)
case overlapsFully // Included in set when both overlapsHorizontally AND overlapsVertically (Rects only)
case beyondFully // Included in set when both beyondHorizontally AND beyondVertically (Points,Rects)
case contact // Included in set when target is in contact with rectangle (Points, Rects)
// Horizontal cases
case beyondLeft // Indicates target's right side is beyond (to left of) object (Points,Rects)
case overlapsLeft // Indicates target's left is beyond left but target's right is (Rects only)
// within or beyond object (toward right)
case beyondHorizontally // Included in set when either beyondLeft OR beyondRight (Points,Rects)
case containedHorizontally // Target is contained within left and right of object (Points,Rects)
case overlapsHorizontally // Included in set when both overlapsLeft AND overlapsRight (Rects only)
case overlapsRight // Indicates target's right is beyond right but target's left is (Rects only)
// within or beyond object (toward left)
case beyondRight // Indicates target's left side is beyond (to right of) object (Points,Rects)
// Vertical cases
case beyondTop // Indicates target's bottom side is beyond (on top of) object (Points,Rects)
case overlapsTop // Indicates target's top is beyond top but target's bottom is (Rects only)
// within or beyond object (toward bottom)
case beyondVertically // Included in set when either beyondTop OR beyondBottom (Points,Rects)
case containedVertically // Target is contained within top and bottom of object (Points,Rects)
case overlapsVertically // Included in set when both overlapsTop AND overlapsBottom (Points,Rects)
case overlapsBottom // Indicates target's bottom is beyond bottom but target's top is (Rects only)
// within or beyond object (toward top)
case beyondBottom // Indicates target's top side is beyond (below) object (Points,Rects)
}
// Rect Definition
public var topLeft : Point
public var size : Size
public var center : Point // Calculated
public init()
public init(topLeft:Point, size:Size)
public init(bottomLeft:Point, size:Size)
public init(topRight:Point, size:Size)
public init(bottomRight:Point, size:Size)
public var left : Int // Calculated
public var top : Int // Calculated
public var right : Int // Calculated
public var bottom : Int // calculated
public func local(to origin:Rect) -> Rect
public func containment(target:Point) -> ContainmentSet
public func containment(target:Rect) -> ContainmentSet
public func unioned(other:Rect) -> Rect
public func inflated(change:Int) -> Rect
public mutating func inflate(change:Int)
public func inflated(change:Size) -> Rect
public mutating func inflate(change:Size)
// Matrix Definition
public typealias Vector = [Double]
public init(transform:Transform)
public init(values:[[Double]])
public func row(_ rowIndex:Int) -> Vector
public func column(_ columnIndex:Int) -> Vector
public func dotProduct(left:Vector, right:Vector) -> Double
public var description : String
public func multiply(byMatrix:Matrix) -> Matrix
public func apply(toDoublePoint:DoublePoint) -> DoublePoint
public func apply(toPoint:Point) -> Point
public func apply(toDoublePoints:[DoublePoint]) -> [DoublePoint]
public func apply(toPoints:[Point]) -> [Point]
static func multiply(matrices:[Matrix]) -> Matrix
// Color Definition
public init (red:UInt8, green:UInt8, blue:UInt8)
public init(_ name:Name)
public var red : UInt8 // Calculated
public var green : UInt8 // Calculated
public var blue : UInt8 // Calculated
Note: Color names are from w3 org.
Gradients must be setup before being rendered. Gradients are created by specifying a series of colors across a range of positions, from 0.0 to 1.0. There are two types of gradients, linear and radial. Both may be used for either StrokeStyle or FillStyle.
// ColorStop Definition
public init(position:Double, color:Color)
// Gradient Definition
public enum Mode {
case linear(start:Point, end:Point)
case radial(center1:Point, radius1:Double, center2:Point, radius2:Double)
}
public init(mode:Mode)
func addColorStop(_ colorStop:ColorStop)
// StrokeStyle Definition
public init(color:Color)
public init(gradient:Gradient)
// FillStyle Definition
public init(color:Color)
public init(gradient:Gradient)
public init(pattern:Pattern)
The painting of all objects occurs on a "canvas". The coordinate system of the canvas begins at (0,0) in the top-left corner. X increases toward right, and Y increases toward the bottom. Throughout this document, unless otherwise noted, all units are pixels.
IMPORTANT: Merely creating an object will not affect the display on the Canvas. In order for an object to be visible it must be painted on the canvas.
canvas.render(helloWorld)
Most objects can be created at anytime, however they may only be painted in an event which provides a Canvas as a parameter. The IgisShell project provides a useful shell to get started. In order to start Igis, a class implementing the PainterProtocol is required:
class Painter : PainterBase {
required init() {
}
override func setup(canvas:Canvas) {
}
override func calculate(canvasId:Int, canvasSize:Size?) {
// Calculate position and movement of objects here
// The canvasId may be used to distinguish between different clients
}
override func render(canvas:Canvas) {
// Render objects here
}
override func onClick(location:Point) {
}
}
In order to start Igis, the type of class is passed as an argument to Igis's run function:
print("Starting...")
do {
let igis = Igis()
try igis.run(painterType:Painter.self)
} catch (let error) {
print("Error: \(error)")
}
As a shortcut, if only a few methods are required to be overridden, the PainterBase class is available as a starting point.
// Text Definition
public init(location:Point, text:String, fillMode:FillMode = .fill)
// Optional:
font = "10pt Arial"
alignment = .left | .center | .right
baseline = .top | .hanging | .middle | .alphabetic | .ideographic | .bottom
// Create a text object to be painted at location (x:100, y:100) using the current font
// and current fill color.
// By default, the text will be filled.
let helloWorld = Text(location:Point(x:100, y:100), text:"Hello, World!")
// Create a text object with a specific font using the current fill color.
let helloWorld = Text(location:Point(x:100, y:100), text:"Hello, World!")
helloWorld.font = "50pt Arial bold"
// Stroke the text using the current stroke color rather than fill.
let helloWorld = Text(location:Point(x:100, y:100), text:"Hello, World!", fillMode:.stroke)
helloWorld.font = "50pt Arial bold"
TextMetric provides metrics regarding text and enables the determination of the bounding rect of arbitrary text, whether or not it is actually rendered.
// TextMetric definition
// Create a new TextMetric object from the specified text
public init(text:String)
// Optional:
font = "10pt Arial"
alignment = .left | .center | .right
baseline = .top | .hanging | .middle | .alphabetic | .ideographic | .bottom
// Create a new TextMetric object from the specified Text object
// This has the benefit of also setting the font, alignment, and baseline, if specified in the text object
public init(fromText:Text)
// TextMetric metrics are updated soon after they are rendered
// There's no point in rendering a TextMetric if it's already been rendered and hasn't changed
if textMetric.currentMetrics == nil {
canvas.render(textMetric)
}
// TextMetric metrics can most easily be used as follows:
if let metrics = textMetric.mostRecentMetrics {
let rect = metrics.actualBoundingBox(location:text.location)
let rect = metrics.fontBoundingBox(location:text.location)
}
// Rectangle Definition
public init(rect:Rect, fillMode:FillMode = .fill)
// Create a rectangle to be painted at location (x:100, y:100) of width 200 and height 100
// using the current fill color.
let box = Rectangle(rect:Rect(topLeft:Point(x:100, y:100), size:Size(width:200, height:100)))
// Create a rectangle to be stroked and filled using the current stroke color and current fill color.
let box = Rectangle(rect:Rect(topLeft:Point(x:100, y:100), size:Size(width:200, height:100)), fillMode:.fillAndStroke)
// Ellipse Definition
public init(center:Point, radiusX:Int, radiusY:Int,
rotation:Double=0.0, startAngle:Double=0.0, endAngle:Double=2.0*Double.pi,
antiClockwise:Bool=false, fillMode:FillMode = .stroke)
// Lines Definition
public init(from:Point, to:Point)
public func moveTo(_ point:Point) // Moves to the specified point without drawing
public func lineTo(_ point:Point) // Draws a line to the specified point
Transforms may be applied using the Transform object
// Translation
let transform = Transform(translate:DoublePoint(x:10, y:10))
// Rotation
let radians = 1.0 * Double.pi / 180.0
let transform = Transform(rotateRadians:radians)
// Scale
let transform = Transform(scale:DoublePoint(x:1.1, y:1.1))
// Shear
let transform = Transform(shear:DoublePoint(x:0.0, y:0.2))
// Return to identity transform
let transform = Transform() // or
let transform = Transform(mode: .toIdentity)
// Create a transform from a matrix
le transform = Transform(matrix:Matrix, mode:Mode)
// Mutliply transforms
public static func multiply(transforms:[Transform], mode:Mode = .fromCurrent) -> Matrix
Alpha may be applied using the Alpha object
let alpha = Alpha(alphaValue:0.3)
State may be saved and subsequently restored on a stack
let save = State(mode:.save)
...
let restore = State(mode:.restore)
Paths may be used to contruct arbitrary shapes
Paths support several operations:
let path = Path(fillMode:.fillAndStroke)
path.moveTo(Point(x:900, y:100))
path.lineTo(Point(x:1000, y:100))
path.quadraticCurveTo(controlPoint:Point(x:1000, y:200), endPoint:Point(x:900, y:200))
path.lineTo(Point(x:1000, y:200))
path.bezierCurveTo(controlPoint1:Point(x:1100, y:250), controlPoint2:Point(x:950, y:350), endPoint:Point(x:900, y:300))
path.arc(center:Point(x:950, y:350), radius:50, startAngle:Double.pi, endAngle:2*Double.pi, antiClockwise:true)
path.arcTo(controlPoint1:Point(x:1200, y:300), controlPoint2:Point(x:1200, y:400), radius:50)
path.lineTo(Point(x:850, y:500))
path.linesTo(points)
path.close()
let pathFromPoints = Path(points:[Point], fillMode:FillMode = .stroke)
Drawing may be clipped to a path by rendering a clipPath.
let clip = clipPath(path:Path(), windingRule:.evenOdd) // or
let clip = clipPath(path:Path(), windingRule:.nonZero)
In addition to the above objects, Igis supports traditional turtle graphics. For turtle graphics, the coordinate system is different. In this coordinate system, the center of the canvas is labeled as the origin (0,0), termed "home". When the turtle is in the home position, it is oriented up. Rotating to the right rotates the turtle clockwise from north the specified number of degreess, rotating left rotates the turtle counter-clockwise the specified number of degrees. The turtle can also move forwards or backwards a specified number of steps in the direction in which it is currently pointed.
Note: It's OK to mix objects and turtle graphics.
// Turtle Definition
public init(canvasSize:Size)
public func forward(steps:Int) // Move forward the specified number of steps
public func backward(steps:Int) // Move backward the specified number of steps
public func left(degrees:Double) // Turn left (counter-clockwise) the specified number of degrees
public func right(degrees:Double) // Turn right (clockwise) the specified number of degrees
public func penUp() // Lift the pen. Subsequent movement will not be visible.
public func penDown() // Drop the pen. Subsequent movement will be visible.
public func penColor(color:Color) // Set the color of the pen
public func penWidth(width:Int) // Set the width of the pen
public func push() // Push the current position, angle, and pen attributes onto the stack
public func pop() // Pop the previously pushed position, angle, and pen attributes
public func home() // Return to the home position
Audio may be rendered in a manner similar to images.
// Audio Definition
public init(sourceURL:URL, shouldLoop:Bool = false)
To play audio, render it in the same manner as images:
required init() {
...
background = Audio(sourceURL:backgroundURL, shouldLoop:true)
}
override func render(canvas:Canvas) {
...
if !isBackgroundPlaying && background.isReady {
canvas.render(background)
isBackgroundPlaying = true
}
}
Keyboard input is available from the painter methods:
func onKeyDown(key:String, code:String, ctrlKey:Bool, shiftKey:Bool, altKey:Bool, metaKey:Bool)
func onKeyUp(key:String, code:String, ctrlKey:Bool, shiftKey:Bool, altKey:Bool, metaKey:Bool)
Mouse input is availabe from the painter methods:
func onClick(location:Point)
func onMouseDown(location:Point)
func onMouseUp(location:Point)
func onWindowMouseUp(location:Point)
func onMouseMove(location:Point)
Cursor style may be set by rendering a CursorStyle object with the desired style.
Set the new style in render()
override func render(canvas:Canvas) {
...
let cursorStyle = CursorStyle(style:nextStyle)
canvas.render(cursorStyle)
...
}
Available styles:
public enum Style : String {
// Defaults
case initial
case auto
case defaultCursor
// None
case none
// Waiting
case progress
case wait
// Pointer types
case pointer
case crosshair
case help
case contextMenu
case alias
// Text and cells
case text
case textVertical
case cell
// Movement and dragging
case notAllowed
case noDrop
case allScroll
case move
case copy
case resizeNorth
case resizeNorthEast
case resizeEast
case resizeSouthEast
case resizeSouth
case resizeSouthWest
case resizeWest
case resizeNorthWest
case resizeRow
case resizeColumn
// Zooming
case zoomIn
case zoomOut
}
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