PixelKit

a Live Graphics Framework for iOS and macOS
powered by Metal - inspired by TouchDesigner

Content: Camera - Image - Video - Screen Capture- Color - Circle - Rectangle - Polygon - Gradient - Noise - Text
Effects: Levels - Blur - Edge - Threshold - Quantize - Transform - Kaleidoscope - Twirl - Feedback - Channel Mix - Chroma Key - Corner Pin - HueSat - Crop - Flip Flop - Range - Sharpen - Slope - Cross - Blend - Lookup - Displace - Remap - Reorder - Blends

Examples: Camera Effects - Green Screen - Hello Pixels App - Code Examples
Info: Coordinate Space - Blend Operators - Effect Convenience Funcs - File IO - High Bit Mode - Apps

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Install

pod 'PixelKit'

import PixelKit

Note that PixelKit dose not have simulator support. Metal for iOS can only run on a physical device.

To gain camera access, on macOS, check Camera in the App Sandbox in your Xcode project settings under Capabilities.

Docs

Jazzy Docs

Tutorials

Getting started with PixelKit in Swift
Getting started with Metal in PixelKit
Green Screen in Swift & PixelKit
Particles in VertexKit & PixelKit

Examples

Hello Pixels App (iOS & macOS)
Code Examples of all PIXs

Example: Camera Effects

import PixelKit

let camera = CameraPIX()

let levels = LevelsPIX()
levels.inPix = camera
levels.brightness = 1.5
levels.gamma = 0.5

let hueSat = HueSatPIX()
hueSat.inPix = levels
hueSat.sat = 0.5

let blur = BlurPIX()
blur.inPix = hueSat
blur.radius = 0.25

let res: PIX.Res = .custom(w: 1500, h: 1000)
let circle = CirclePIX(res: res)
circle.radius = 0.45
circle.bgColor = .clear

let finalPix: PIX = blur & (camera * circle)
finalPix.view.frame = view.bounds
view.addSubview(finalPix.view)

This can also be done with Effect Convenience Funcs:

let pix = CameraPIX()._brightness(1.5)._gamma(0.5)._saturation(0.5)._blur(0.25)

Remeber to add NSCameraUsageDescription to your info.plist

Example: Green Screen

import PixelKit

let cityImage = ImagePIX()
cityImage.image = UIImage(named: "city")

let supermanVideo = VideoPIX()
supermanVideo.load(fileNamed: "superman", withExtension: "mov")

let supermanKeyed = ChromaKeyPIX()
supermanKeyed.inPix = supermanVideo
supermanKeyed.keyColor = .green

let blendPix = BlendPIX()
blendPix.blendingMode = .over
blendPix.inPixA = cityImage
blendPix.inPixB = supermanKeyed

let finalPix: PIX = blendPix
finalPix.view.frame = view.bounds
view.addSubview(finalPix.view)

This can also be done with Blend Operators and Effect Convenience Funcs:

let pix = ImagePIX("city") & VideoPIX("superman.mov")._chromaKey(.green)

This is a representation of the Pixel Nodes Green Screen project.

Coordinate Space

PixelKit coordinate space is normailzed to the vertical axis (1.0 in height) with the origin (0.0, 0.0) in the center.
Note that compared to native UIKit views the vertical axis is flipped and origin is moved, this is more convinent when working with graphics is PixelKit. A full rotation is defined by 1.0

Center: CGPoint(x: 0, y: 0)
Bottom Left: CGPoint(x: -0.5 * aspectRatio, y: -0.5)
Top Right: CGPoint(x: 0.5 * aspectRatio, y: 0.5)

Tip: PIX.Res has an .aspect property:
let aspectRatio: LiveFloat = PIX.Res._1080p.aspect

Blend Operators

A quick and convenient way to blend PIXs
These are the supported PIX.BlendingMode operators:

&	!&	+	-	*	**	!**	%	<>	><	--	~
.over	.under	.add	.subtract	.multiply	.power	.gamma	.difference	.minimum	.maximum	.subtractWithAlpha	.average

let blendPix = (CameraPIX() !** NoisePIX(res: .fullHD(.portrait))) * CirclePIX(res: .fullHD(.portrait))

Note when using Live values, one line if else statments are written with <?> & <=>:

let a: LiveFloat = 1.0
let b: LiveFloat = 2.0
let isOdd: LiveBool = .seconds % 2.0 < 1.0
let ab: LiveFloat = isOdd <?> a <=> b

The default global blend operator fill mode is .aspectFit, change it like this:
PIX.blendOperators.globalPlacement = .aspectFill

Live Values

Live values can be a constant (let) and still have changin values. Live values are ease to animate with the .live or .seconds static properites.

The Live Values:

• CGFloat --> LiveFloat
• Int --> LiveInt
• Bool --> LiveBool
• CGPoint --> LivePoint
• CGSize --> LiveSize
• CGRect --> LiveRect

Static properites:

• LiveFloat.live
• LiveFloat.seconds
• LiveFloat.secondsSince1970
• LiveFloat.touch / LiveFloat.mouseLeft
• LiveFloat.touchX / LiveFloat.mouseX
• LiveFloat.touchY / LiveFloat.mouseY
• LivePoint.touchXY / LiveFloat.mouseXY

Functions:

• liveFloat.delay(seconds: 1.0)
• liveFloat.filter(seconds: 1.0)
• liveFloat.filter(frames: 60)

Static functions:

• LiveFloat.noise(range: -1.0...1.0, for: 1.0)
• LiveFloat.wave(range: -1.0...1.0, for: 1.0)

Effect Convenience Funcs

• pix._reRes(to: ._1080p * 0.5) -> ResPIX
• pix._reRes(by: 0.5) -> ResPIX
• pix._brightness(0.5) -> LevelsPIX
• pix._darkness(0.5) -> LevelsPIX
• pix._contrast(0.5) -> LevelsPIX
• pix._gamma(0.5) -> LevelsPIX
• pix._invert() -> LevelsPIX
• pix._opacity(0.5) -> LevelsPIX
• pix._blur(0.5) -> BlurPIX
• pix._edge() -> EdgePIX
• pix._threshold(at: 0.5) -> ThresholdPIX
• pix._quantize(by: 0.5) -> QuantizePIX
• pix._position(at: CGPoint(x: 0.5, y: 0.5)) -> TransformPIX
• pix._rotatate(to: .pi) -> TransformPIX
• pix._scale(by: 0.5) -> TransformPIX
• pix._kaleidoscope() -> KaleidoscopePIX
• pix._twirl(0.5) -> TwirlPIX
• pix._swap(.red, .blue) -> ChannelMixPIX
• pix._key(.green) -> ChromaKeyPIX
• pix._hue(0.5) -> HueSatPIX
• pix._saturation(0.5) -> HueSatPIX
• pix._crop(CGRect(x: 0.5, y 0.5, width: 0.5, height: 0.5)) -> CropPIX
• pix._flipX() -> FlipFlopPIX
• pix._flipY() -> FlipFlopPIX
• pix._flopLeft() -> FlipFlopPIX
• pix._flopRight() -> FlipFlopPIX
• pix._range(inLow: 0.0, inHigh: 0.5, outLow: 0.5, outHigh: 1.0) -> RangePIX
• pix._range(inLow: .clear, inHigh: .gray, outLow: .gray, outHigh: .white) -> RangePIX
• pix._sharpen() -> SharpenPIX
• pix._slope() - > SlopePIX
• pixA._lookup(pix: pixB, axis: .x) -> LookupPIX
• pixA._lumaBlur(pix: pixB, radius: 0.5) -> LumaBlurPIX
• pixA._displace(pix: pixB, distance: 0.5) -> DisplacePIX
• pixA._remap(pix: pixB) -> RemapPIX

Keep in mind that these funcs will create new PIXs.
Be careful of overloading GPU memory if in a loop.

MIDI

Here's an example of live midi values in range 0.0 to 1.0.

let circle = CirclePIX(res: ._1024)
circle.radius = .midi("13")
circle.color = .midi("17")

You can find the addresses by enabeling logging like this:

MIDI.main.log = true

High Bit Mode

Some effects like DisplacePIX and SlopePIX can benefit from a higher bit depth.
The default is 8 bits. Change it like this: PixelKit.main.bits = ._16

Enable high bit mode before you create any PIXs.

Note resources do not support higher bits yet.
There is currently there is some gamma offset with resources.

MetalPIXs

let metalPix = MetalPIX(res: ._1080p, code:
    """
    pix = float4(u, v, 0.0, 1.0);
    """
)

let metalEffectPix = MetalEffectPIX(code:
    """
    float gamma = 0.25;
    pix = pow(inPix, 1.0 / gamma);
    """
)
metalEffectPix.inPix = CameraPIX()

let metalMergerEffectPix = MetalMergerEffectPIX(code:
    """
    pix = pow(inPixA, 1.0 / inPixB);
    """
)
metalMergerEffectPix.inPixA = CameraPIX()
metalMergerEffectPix.inPixB = ImagePIX("img_name")

let metalMultiEffectPix = MetalMultiEffectPIX(code:
    """
    float4 inPixA = inTexs.sample(s, uv, 0);
    float4 inPixB = inTexs.sample(s, uv, 1);
    float4 inPixC = inTexs.sample(s, uv, 2);
    pix = inPixA + inPixB + inPixC;
    """
)
metalMultiEffectPix.inPixs = [ImagePIX("img_a"), ImagePIX("img_b"), ImagePIX("img_c")]

Uniforms:

var lumUniform = MetalUniform(name: "lum")
let metalPix = MetalPIX(res: ._1080p, code:
    """
    pix = float4(in.lum, in.lum, in.lum, 1.0);
    """,
    uniforms: [lumUniform]
)
lumUniform.value = 0.5

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Apps

Pixel Nodes

a Live Graphics Node Editor for iPad
powered by PixelKit

Layer Cam

a camera app lets you live layer filters of your choice.
combine effects to create new cool styles.

VJLive

VJLive is a dual deck asset playback system with effects.
Assets can be loaded from Photos. Live camera support. AirPlay support.

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by Anton Heestand, Hexagons