CVReturn as Swift.Error

CVError.swift

//
//  CVError.swift
//
//  Created by Jun Tanaka on 2016/12/13.
//  Copyright © 2016 Jun Tanaka. All rights reserved.
//

import CoreVideo

public enum CVError: Int32, Error {
	// Common
	case error = -6660
	case invalidArgument = -6661
	case allocationFailed = -6662
	case unsupported = -6663

	// CVDisplayLink
	case invalidDisplay = -6670
	case displayLinkAlreadyRunning = -6671
	case displayLinkNotRunning = -6672
	case displayLinkCallbacksNotSet = -6673

	// CVPixelBuffer
	case invalidPixelFormat = -6680
	case invalidSize = -6681
	case invalidPixelBufferAttributes = -6682
	case pixelBufferNotOpenGLCompatible = -6683
	case pixelBufferNotMetalCompatible = -6684

	// CVPixelBufferPool
	case wouldExceedAllocationThreshold = -6689
	case poolAllocationFailed = -6690
	case invalidPoolAttributes = -6691
	case retry = -6692
}

extension CVError {
	public init(code: CVReturn) {
		if let error = CVError(rawValue: code) {
			self = error
		} else if code == kCVReturnSuccess {
			fatalError("Passed kCVReturnSuccess to CVError(code:).")
		} else {
			fatalError("Passed unknown CVReturn value to CVError(code:).")
		}
	}

	public var code: CVReturn {
		return rawValue
	}
}

extension CVError: CustomStringConvertible {
	public var description: String {
		switch self {
		case .error:
			return "An otherwise undefined error occurred."
		case .invalidArgument:
			return "Invalid function parameter. For example, out of range or the wrong type."
		case .allocationFailed:
			return "Memory allocation for a buffer or buffer pool failed."
		case .unsupported:
			return "Unsupported."

		case .invalidDisplay:
			return "The display specified when creating a display link is invalid."
		case .displayLinkAlreadyRunning:
			return "The specified display link is already running."
		case .displayLinkNotRunning:
			return "The specified display link is not running."
		case .displayLinkCallbacksNotSet:
			return "No callback registered for the specified display link. You must set either the output callback or both the render and display callbacks."

		case .invalidPixelFormat:
			return "The buffer does not support the specified pixel format."
		case .invalidSize:
			return "The buffer cannot support the requested buffer size (usually too big)."
		case .invalidPixelBufferAttributes:
			return "A buffer cannot be created with the specified attributes."
		case .pixelBufferNotOpenGLCompatible:
			return "The pixel buffer is not compatible with OpenGL due to an unsupported buffer size, pixel format, or attribute."
		case .pixelBufferNotMetalCompatible:
			return "The pixel buffer is not compatible with Metal due to an unsupported buffer size, pixel format, or attribute."

		case .wouldExceedAllocationThreshold:
			return "Allocation for a pixel buffer failed because the threshold value set for the `kCVPixelBufferPoolAllocationThresholdKey` key in the `CVPixelBufferPoolCreatePixelBufferWithAuxAttributes` function would be surpassed."
		case .poolAllocationFailed:
			return "Allocation for a buffer pool failed, most likely due to a lack of resources. Check to make sure your parameters are in range."
		case .invalidPoolAttributes:
			return "A buffer pool cannot be created with the specified attributes."
		case .retry:
			return "A scan hasn't completely traversed the CVBufferPool due to a concurrent operation."
		}
	}
}

extension CVError: CustomDebugStringConvertible {
	public var debugDescription: String {
		return "CVError(code: \(code), description: \"\(description)\")"
	}
}