Meshing Guidelines

MeshingKit

MeshingKit is a Swift package for creating mesh gradients in SwiftUI. It provides 68 predefined gradient templates, animated gradients, Metal shader noise effects, and platform-specific export functionality.

Build Commands

# Swift Package Manager build
swift build

# Build for a specific target
swift build --target MeshingKit

# Xcode build for iOS Simulator
xcodebuild build -project Sources/Meshin/Meshin.xcodeproj -scheme Meshin -destination "generic/platform=iOS Simulator"

Test Commands

# Run tests with verbose output
swift test --verbose

# Run tests with code coverage
swift test --enable-code-coverage

Lint

# Run SwiftLint with strict mode
swiftlint --strict

# Pre-commit hook runs on staged files
# Setup: scripts/setup-hooks.sh

Architecture

Main API

MeshingKit.swift exposes static methods for creating gradients:

// Create a static mesh gradient
MeshingKit.gradient(template: myTemplate)

// Create an animated mesh gradient view
MeshingKit.animatedGradient(template: myTemplate)

// Create with custom animation pattern
MeshingKit.animatedGradient(template: template, animationPattern: .fluid)

Template System

GradientTemplate Protocol:

public protocol GradientTemplate: Sendable {
    var size: Int { get }
    var points: [SIMD2<Float>] { get }
    var colors: [Color] { get }
    var background: Color { get }
}

Custom Template Example:

struct MyGradient: GradientTemplate {
    var size: Int { 3 }

    var points: [SIMD2<Float>] {
        [
            SIMD2(0, 0), SIMD2(0.5, 0), SIMD2(1, 0),
            SIMD2(0, 0.5), SIMD2(0.5, 0.5), SIMD2(1, 0.5),
            SIMD2(0, 1), SIMD2(0.5, 1), SIMD2(1, 1)
        ]
    }

    var colors: [Color] {
        [.red, .green, .blue, .yellow, .purple, .orange, .pink, .cyan, .mint]
    }

    var background: Color { .black }
}

PredefinedTemplate Enum:

// All 68 templates
let allTemplates = PredefinedTemplate.allCases

// Search by name (uses NaturalLanguage)
let sunsetTemplates = PredefinedTemplate.find(by: "sunset")

// Access base template
let base = PredefinedTemplate.aurora.baseTemplate

Templates are organized by grid size:

• GradientTemplateSize2 - 2x2 grids (4 points)
• GradientTemplateSize3 - 3x3 grids (9 points)
• GradientTemplateSize4 - 4x4 grids (16 points)

Key Views

AnimatedMeshGradientView: SwiftUI view for animated gradients with configurable speed.

ParameterizedNoiseView: Metal shader-based noise effect for textures and visual effects.

Search

PredefinedTemplate.find(by: token) uses:

• NaturalLanguage framework for lemmatization
• CamelCase splitting for method-style queries
• Semantic matching for gradient names

Export APIs

ExportFormat Enum

public enum ExportFormat: String, CaseIterable, Identifiable, Sendable {
    case png, jpg, mp4
    public var id: Self { self }
    public var fileExtension: String { rawValue }
}

VideoExportError Enum

public enum VideoExportError: Error, Sendable {
    case frameRenderingFailed
    case failedToStartWriting
    case pixelBufferPoolCreationFailed
    case pixelBufferCreationFailed
    case failedToAppendPixelBuffer
    case failedToAddInput
    case failedToCreateOutputURL
    case fileNotAccessible
    case unsupportedFormat
    case photosPermissionDenied
}

iOS - Photo Library

saveGradientToPhotoAlbum:

@MainActor
static func saveGradientToPhotoAlbum(
    template: any GradientTemplate,
    size: CGSize,
    scale: CGFloat = 1.0,
    blurRadius: CGFloat = 0,
    showDots: Bool = false,
    smoothsColors: Bool = true,
    completion: @escaping (Result<Void, Error>) -> Void
)

exportVideoToPhotoLibrary:

static func exportVideoToPhotoLibrary(
    template: any GradientTemplate,
    size: CGSize,
    duration: TimeInterval = 5.0,
    frameRate: Int32 = 30,
    blurRadius: CGFloat = 0,
    showDots: Bool = false,
    animate: Bool = true,
    smoothsColors: Bool = true,
    completion: @escaping (Result<URL, Error>) -> Void
)

PhotoLibraryError:

public enum PhotoLibraryError: Error, Sendable {
    case permissionDenied
    case saveFailed(Error)
}

macOS - Disk Save

saveToDisk:

@MainActor
static func saveToDisk(
    image: NSImage,
    fileName: String = "gradient",
    format: ExportFormat = .png,
    completion: @escaping (Result<URL, Error>) -> Void
)

saveGradientToDisk:

@MainActor
static func saveGradientToDisk(
    template: any GradientTemplate,
    size: CGSize,
    scale: CGFloat = 1.0,
    blurRadius: CGFloat = 0,
    showDots: Bool = false,
    smoothsColors: Bool = true,
    fileName: String = "gradient",
    format: ExportFormat = .png,
    completion: @escaping (Result<URL, Error>) -> Void
)

exportVideo (macOS):

@MainActor
static func exportVideo(
    template: any GradientTemplate,
    size: CGSize,
    duration: TimeInterval = 5.0,
    frameRate: Int32 = 30,
    blurRadius: CGFloat = 0,
    showDots: Bool = false,
    animate: Bool = true,
    smoothsColors: Bool = true
) async throws -> URL

SaveToDiskError:

public enum SaveToDiskError: Error, Sendable {
    case userCancelled
    case cgImageCreationFailed
    case imageEncodingFailed(Error)
}

Export Examples

iOS - Save to Photo Library:

MeshingKit.saveGradientToPhotoAlbum(
    template: .aurora,
    size: CGSize(width: 1080, height: 1920)
) { result in
    switch result {
    case .success:
        print("Saved to photo library!")
    case .failure(let error):
        print("Error: \(error)")
    }
}

iOS - Export Video to Photo Library:

MeshingKit.exportVideoToPhotoLibrary(
    template: .midnightDreams,
    size: CGSize(width: 1080, height: 1920),
    duration: 5.0,
    frameRate: 30
) { result in
    switch result {
    case .success(let url):
        print("Video saved: \(url)")
    case .failure(let error):
        print("Error: \(error)")
    }
}

macOS - Save to Disk:

MeshingKit.saveGradientToDisk(
    template: .sunsetWave,
    size: CGSize(width: 1920, height: 1080),
    blurRadius: 10,
    fileName: "my-gradient",
    format: .png
) { result in
    switch result {
    case .success(let url):
        print("Saved to: \(url)")
    case .failure(let error):
        print("Error: \(error)")
    }
}

macOS - Export Video:

let videoURL = try await MeshingKit.exportVideo(
    template: .aurora,
    size: CGSize(width: 1920, height: 1080),
    duration: 5.0,
    frameRate: 30,
    animate: true
)
print("Video exported to: \(videoURL)")

Animation

AnimatedMeshGradientView

struct AnimatedMeshGradientView: View {
    public let template: any GradientTemplate
    public let animationSpeed: Double

    public init(
        template: any GradientTemplate,
        animationSpeed: Double = 1.0
    )
}

AnimationPattern

public enum AnimationPattern: String, CaseIterable, Identifiable, Sendable {
    case fluid, waves, ripples, pulse, none
}

Animated Positions

The GradientAnimation.swift module provides animation functions for video export:

static func animatedPositions(
    for date: Double,
    positions: [SIMD2<Float>],
    animate: Bool
) -> [SIMD2<Float>]

Metal Shaders

ParameterizedNoiseView:

Uses Metal shaders to generate procedural noise textures:

struct ParameterizedNoiseView: View {
    @State private var noiseParameter: Float = 0.5

    public init(parameter: Float = 0.5)

    public var body: some View { ... }
}

Source Structure

Sources/MeshingKit/
├── MeshingKit.swift                       # Main API
├── GradientTemplate.swift                 # Protocol
├── PredefinedTemplate.swift               # 68 templates + search
├── GradientExport.swift                   # ExportFormat, VideoExportError
├── GradientExport+iOS.swift               # iOS photo library
├── GradientExport+macOS.swift             # macOS disk save
├── GradientAnimation.swift                # Animation functions
├── GradientVideoExport.swift              # Video export public API
├── GradientVideoExportHelper.swift        # Video export implementation
├── Color+Hex.swift                        # Color utilities
├── AnimatedMeshGradientView.swift         # Animated view
├── AnimationPattern.swift                 # Animation patterns
├── ParameterizedNoiseView.swift           # Metal shader noise
├── GradientTemplateSize2.swift            # 2x2 templates
├── GradientTemplateSize3.swift            # 3x3 templates
└── GradientTemplateSize4.swift            # 4x4 templates

Sources/Meshin/                            # Demo app (SwiftUI)
├── MeshinApp.swift                        # App entry point
├── MeshinViewModel.swift                  # Export state management
└── GradientSamplesView.swift              # Template list + export UI

Tests/MeshingKitTests/                     # Swift Testing suite
scripts/                                   # Git hooks
codemagic.yaml                             # CI configuration
.swiftlint.yml                             # SwiftLint config

Meshin Demo App

The Meshin app demonstrates how to use MeshingKit in a real SwiftUI application:

Running Meshin

# macOS
xcodebuild build -project Sources/Meshin/Meshin.xcodeproj -scheme Meshin -destination "generic/platform=macOS"

# iOS Simulator
xcodebuild build -project Sources/Meshin/Meshin.xcodeproj -scheme Meshin -destination "generic/platform=iOS Simulator"

Features

• Template Browser: Browse all 68 predefined gradients by size (2x2, 3x3, 4x4)
• Full-Screen Preview: Tap any template to view it full-screen
• Animation Toggle: Enable/disable gradient animation
• Export Options:
  • iOS: Save to Photo Library, Export Video to Photo Library
  • macOS: Save to Disk (PNG/JPG), Export Video to Disk

Key Files

• MeshinViewModel.swift - Demonstrates proper usage of MeshingKit export APIs
• GradientSamplesView.swift - Shows how to integrate gradients with UI

Example: Using MeshinViewModel

@MainActor
final class MyViewModel: ObservableObject {
    @Published var selectedTemplate: PredefinedTemplate?
    @Published var isExporting = false

    func saveToPhotoLibrary() {
        guard let template = selectedTemplate else { return }

        MeshingKit.saveGradientToPhotoAlbum(
            template: template,
            size: CGSize(width: 1080, height: 1920)
        ) { result in
            switch result {
            case .success: print("Saved!")
            case .failure(let error): print("Error: \(error)")
            }
        }
    }
}

Important Conventions

• All public types conform to Sendable for concurrency safety
• Tests use Swift Testing framework with #expect macro
• Template files are excluded from SwiftLint (see .swiftlint.yml) due to size
• CI runs on Codemagic (see codemagic.yaml)
• Video export uses streaming approach (memory-efficient)
• PredefinedTemplate uses NaturalLanguage for smart search

Common Patterns

Creating a Gradient View

let template = PredefinedTemplate.aurora
let gradientView = MeshingKit.gradient(template: template)

Creating an Animated Gradient

let animatedView = MeshingKit.animatedGradient(
    template: PredefinedTemplate.midnightDreams,
    animationSpeed: 1.5
)

Custom Animation Pattern

MeshingKit.animatedGradient(
    template: template,
    animationPattern: .waves
)

Export with Customization

// iOS with blur
MeshingKit.saveGradientToPhotoAlbum(
    template: template,
    size: CGSize(width: 1080, height: 1920),
    blurRadius: 15,
    smoothsColors: true
) { /* ... */ }

// macOS with corner radius
MeshingKit.saveGradientToDisk(
    template: template,
    size: size,
    showDots: false
) { /* ... */ }

Notes

• Grid sizes: 2x2 (4 points), 3x3 (9 points), 4x4 (16 points)
• Video export supports MP4 (H.264 codec)
• Image export supports PNG and JPG
• All async APIs properly handle MainActor isolation
• Error enums provide type-safe error handling

Source: rryam/MeshingKit — distributed by TomeVault.