/*

 Copyright (C) 2017 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Demonstrates using Quartz for drawing patterns.

 */

import UIKit

class QuartzPatternView: QuartzView {

    var coloredPatternColor: CGColor = {

        // Colored Pattern setup.  CGPatterns have callbacks to do the drawing.

        var coloredPatternCallbacks =

            CGPatternCallbacks(version: 0,

                               drawPattern: { (info: UnsafeMutableRawPointer?, context: CGContext) -> Swift.Void in

                                // Dark Blue

                                context.setFillColor(red: 29.0 / 255.0, green: 156.0 / 255.0, blue: 215.0 / 255.0, alpha: 1.00)

                                context.fill(CGRect(x: 0.0, y: 0.0, width: 8.0, height: 8.0))

                                context.fill(CGRect(x: 8.0, y: 8.0, width: 8.0, height: 8.0))

                                // Light Blue

                                context.setFillColor(red: 204.0 / 255.0, green: 224.0 / 255.0, blue: 244.0 / 255.0, alpha: 1.00)

                                context.fill(CGRect(x: 8.0, y: 0.0, width: 8.0, height: 8.0))

                                context.fill(CGRect(x: 0.0, y: 8.0, width: 8.0, height: 8.0)) },

                               releaseInfo: nil)

        // First we need to create a CGPatternRef that specifies the qualities of our pattern.

        let coloredPattern = CGPattern(info: nil,

                                       bounds: CGRect(x: 0.0, y: 0.0, width: 16.0, height: 16.0),

                                       matrix: CGAffineTransform.identity,

                                       xStep: 16.0,

                                       yStep: 16.0,

                                       tiling: .noDistortion,

                                       isColored: true,

                                       callbacks: &coloredPatternCallbacks)!

        // To draw a pattern, you need a pattern colorspace.

        // Since this is an colored pattern, the parent colorspace is NULL, indicating that it only has an alpha value.

        var coloredPatternColorSpace = CGColorSpace(patternBaseSpace: nil)!

        var alpha: CGFloat = 1.0

        // Since this pattern is colored, we'll create a CGColorRef for it to make drawing it easier and more efficient.

        // From here on, the colored pattern is referenced entirely via the associated CGColorRef rather than the

        // originally created CGPatternRef.

        return CGColor(patternSpace: coloredPatternColorSpace, pattern: coloredPattern, components: &alpha)!

    }()

    var uncoloredPattern: CGPattern = {

        var uncoloredPatternCallbacks =

            CGPatternCallbacks(version: 0,

                               drawPattern: {(info: UnsafeMutableRawPointer?, context: CGContext) -> Swift.Void in

                                // Dark Blue

                                context.fill(CGRect(x: 0.0, y: 0.0, width: 8.0, height: 8.0))

                                context.fill(CGRect(x: 8.0, y: 8.0, width: 8.0, height: 8.0)) },

                               releaseInfo: nil)

        // As above, we create a CGPatternRef that specifies the qualities of our pattern

        return CGPattern(info: nil,

                         bounds: CGRect(x: 0.0, y: 0.0, width: 16.0, height: 16.0),

                         matrix: CGAffineTransform.identity,

                         xStep: 16.0, yStep: 16.0,

                         tiling: .noDistortion,

                         isColored: false,

                         callbacks: &uncoloredPatternCallbacks)!

    }()

    var uncoloredPatternColorSpace: CGColorSpace = {

        var deviceRGB: CGColorSpace = CGColorSpaceCreateDeviceRGB()

        return CGColorSpace(patternBaseSpace: deviceRGB)!

    }()

    override func drawInContext(_ context: CGContext) {

        centerDrawing(inContext: context,  drawingExtent: CGRect(x:0.0, y:0.0, width:220.0, height:330.0))

        // Draw the colored pattern. Since we have a CGColorRef for this pattern, we just set

        // that color current and draw.

        context.setFillColor(coloredPatternColor)

        context.fill(CGRect(x: 10.0, y: 10.0, width: 90.0, height: 90.0))

        // You can also stroke with a pattern.

        context.setStrokeColor(coloredPatternColor)

        context.stroke(CGRect(x: 120.0, y: 10.0, width: 90.0, height: 90.0), width: 8)

        // Since we aren't encapsulating our pattern in a CGColorRef for the uncolored pattern case, setup requires two steps.

        // First you have to set the context's current colorspace (fill or stroke) to a pattern colorspace,

        // indicating to Quartz that you want to draw a pattern.

        context.setFillColorSpace(uncoloredPatternColorSpace)

        // Next you set the pattern and the color that you want the pattern to draw with.

        let color1: [CGFloat] = [1.0, 0.0, 0.0, 1.0]

        context.setFillPattern(uncoloredPattern, colorComponents: color1)

        // And finally you draw!

        context.fill(CGRect(x: 10.0, y: 120.0, width: 90.0, height: 90.0))

        // As long as the current colorspace is a pattern colorspace, you are free to change the pattern or pattern color

        let color2: [CGFloat] = [0.0, 1.0, 0.0, 1.0]

        context.setFillPattern(uncoloredPattern, colorComponents: color2)

        context.fill(CGRect(x: 10.0, y: 230.0, width: 90.0, height: 90.0))

        // And of course, just like the colored case, you can stroke with a pattern as well.

        context.setStrokeColorSpace(uncoloredPatternColorSpace)

        context.setStrokePattern(uncoloredPattern, colorComponents: color1)

        context.stroke(CGRect(x: 120.0, y: 120.0, width: 90.0, height: 90.0), width: 8)

    }

}