Parse Radial Gradients

Author: swhitty

Samples/gradient.svg renamed to Samples/linearGradient.svg

@@ -1,5 +1,5 @@
 //
-//  DOM.Gradient.swift
+//  DOM.LinearGradient.swift
 //  SwiftDraw
 //
 //  Created by Simon Whitty on 31/12/16.

Samples/radialGradient.svg

@@ -0,0 +1,77 @@
+//
+//  DOM.RadialGradient.swift
+//  SwiftDraw
+//
+//  Created by Simon Whitty on 13/8/22.
+//  Copyright 2022 Simon Whitty
+//
+//  Distributed under the permissive zlib license
+//  Get the latest version from here:
+//
+//  https://github.com/swhitty/SwiftDraw
+//
+//  This software is provided 'as-is', without any express or implied
+//  warranty.  In no event will the authors be held liable for any damages
+//  arising from the use of this software.
+//
+//  Permission is granted to anyone to use this software for any purpose,
+//  including commercial applications, and to alter it and redistribute it
+//  freely, subject to the following restrictions:
+//
+//  1. The origin of this software must not be misrepresented; you must not
+//  claim that you wrote the original software. If you use this software
+//  in a product, an acknowledgment in the product documentation would be
+//  appreciated but is not required.
+//
+//  2. Altered source versions must be plainly marked as such, and must not be
+//  misrepresented as being the original software.
+//
+//  3. This notice may not be removed or altered from any source distribution.
+//
+
+extension DOM {
+
+    final class RadialGradient: Element {
+
+        var id: String
+
+        var stops: [Stop]
+        var gradientUnits: Units?
+
+        //references another RadialGradient element id within defs
+        var href: URL?
+
+        init(id: String) {
+            self.id = id
+            self.stops = []
+        }
+
+        struct Stop: Equatable {
+            var offset: Float
+            var color: Color
+            var opacity: Float
+
+            init(offset: Float, color: Color, opacity: Opacity = 1.0) {
+                self.offset = offset
+                self.color = color
+                self.opacity = opacity
+            }
+        }
+    }
+}
+
+extension DOM.RadialGradient: Equatable {
+    static func ==(lhs: DOM.RadialGradient, rhs: DOM.RadialGradient) -> Bool {
+        return
+        lhs.id == rhs.id &&
+        lhs.stops == rhs.stops
+    }
+}
+
+extension DOM.RadialGradient {
+
+    enum Units: String {
+        case userSpaceOnUse
+        case objectBoundingBox
+    }
+}

SwiftDraw/DOM.Gradient.swift renamed to SwiftDraw/DOM.LinearGradient.swift

@@ -54,6 +54,7 @@ extension DOM {
     struct Defs {
       var clipPaths = [ClipPath]()
       var linearGradients = [LinearGradient]()
+      var radialGradients = [RadialGradient]()
       var masks = [Mask]()
       var patterns = [Pattern]()
 

SwiftDraw/DOM.RadialGradient.swift

@@ -0,0 +1,76 @@
+//
+//  Parser.XML.LinearGradient.swift
+//  SwiftDraw
+//
+//  Created by Simon Whitty on 31/12/16.
+//  Copyright 2020 Simon Whitty
+//
+//  Distributed under the permissive zlib license
+//  Get the latest version from here:
+//
+//  https://github.com/swhitty/SwiftDraw
+//
+//  This software is provided 'as-is', without any express or implied
+//  warranty.  In no event will the authors be held liable for any damages
+//  arising from the use of this software.
+//
+//  Permission is granted to anyone to use this software for any purpose,
+//  including commercial applications, and to alter it and redistribute it
+//  freely, subject to the following restrictions:
+//
+//  1. The origin of this software must not be misrepresented; you must not
+//  claim that you wrote the original software. If you use this software
+//  in a product, an acknowledgment in the product documentation would be
+//  appreciated but is not required.
+//
+//  2. Altered source versions must be plainly marked as such, and must not be
+//  misrepresented as being the original software.
+//
+//  3. This notice may not be removed or altered from any source distribution.
+//
+
+extension XMLParser {
+
+    func parseLinearGradients(_ e: XML.Element) throws -> [DOM.LinearGradient] {
+        var gradients = [DOM.LinearGradient]()
+
+        for n in e.children {
+            if n.name == "linearGradient" {
+                gradients.append(try parseLinearGradient(n))
+            } else {
+                gradients.append(contentsOf: try parseLinearGradients(n))
+            }
+        }
+        return gradients
+    }
+
+    func parseLinearGradient(_ e: XML.Element) throws -> DOM.LinearGradient {
+        guard e.name == "linearGradient" else {
+            throw Error.invalid
+        }
+
+        let nodeAtt: AttributeParser = try parseAttributes(e)
+        let node = DOM.LinearGradient(id: try nodeAtt.parseString("id"))
+        node.x1 = try nodeAtt.parseCoordinate("x1")
+        node.y1 = try nodeAtt.parseCoordinate("y1")
+        node.x2 = try nodeAtt.parseCoordinate("x2")
+        node.y2 = try nodeAtt.parseCoordinate("y2")
+
+        for n in e.children where n.name == "stop" {
+            let att: AttributeParser = try parseAttributes(n)
+            node.stops.append(try parseLinearGradientStop(att))
+        }
+
+        node.gradientUnits = try nodeAtt.parseRaw("gradientUnits")
+        node.href  = try? nodeAtt.parseUrl("xlink:href")
+
+        return node
+    }
+
+    func parseLinearGradientStop(_ att: AttributeParser) throws -> DOM.LinearGradient.Stop {
+        let offset: DOM.Float? = try? att.parsePercentage("offset")
+        let color: DOM.Color = try att.parseFill("stop-color").getColor()
+        let opacity: DOM.Float? = try att.parsePercentage("stop-opacity")
+        return DOM.LinearGradient.Stop(offset: offset ?? 0, color: color, opacity: opacity ?? 1.0)
+    }
+}

SwiftDraw/DOM.SVG.swift

@@ -0,0 +1,72 @@
+//
+//  Parser.XML.RadialGradient.swift
+//  SwiftDraw
+//
+//  Created by Simon Whitty on 13/8/22.
+//  Copyright 2022 Simon Whitty
+//
+//  Distributed under the permissive zlib license
+//  Get the latest version from here:
+//
+//  https://github.com/swhitty/SwiftDraw
+//
+//  This software is provided 'as-is', without any express or implied
+//  warranty.  In no event will the authors be held liable for any damages
+//  arising from the use of this software.
+//
+//  Permission is granted to anyone to use this software for any purpose,
+//  including commercial applications, and to alter it and redistribute it
+//  freely, subject to the following restrictions:
+//
+//  1. The origin of this software must not be misrepresented; you must not
+//  claim that you wrote the original software. If you use this software
+//  in a product, an acknowledgment in the product documentation would be
+//  appreciated but is not required.
+//
+//  2. Altered source versions must be plainly marked as such, and must not be
+//  misrepresented as being the original software.
+//
+//  3. This notice may not be removed or altered from any source distribution.
+//
+
+extension XMLParser {
+
+    func parseRadialGradients(_ e: XML.Element) throws -> [DOM.RadialGradient] {
+        var gradients = [DOM.RadialGradient]()
+
+        for n in e.children {
+            if n.name == "radialGradient" {
+                gradients.append(try parseRadialGradient(n))
+            } else {
+                gradients.append(contentsOf: try parseRadialGradients(n))
+            }
+        }
+        return gradients
+    }
+
+    func parseRadialGradient(_ e: XML.Element) throws -> DOM.RadialGradient {
+        guard e.name == "radialGradient" else {
+            throw Error.invalid
+        }
+
+        let nodeAtt: AttributeParser = try parseAttributes(e)
+        let node = DOM.RadialGradient(id: try nodeAtt.parseString("id"))
+
+        for n in e.children where n.name == "stop" {
+            let att: AttributeParser = try parseAttributes(n)
+            node.stops.append(try parseRadialGradientStop(att))
+        }
+
+        node.gradientUnits = try nodeAtt.parseRaw("gradientUnits")
+        node.href  = try? nodeAtt.parseUrl("xlink:href")
+
+        return node
+    }
+
+    func parseRadialGradientStop(_ att: AttributeParser) throws -> DOM.RadialGradient.Stop {
+        let offset: DOM.Float? = try? att.parsePercentage("offset")
+        let color: DOM.Color = try att.parseFill("stop-color").getColor()
+        let opacity: DOM.Float? = try att.parsePercentage("stop-opacity")
+        return DOM.RadialGradient.Stop(offset: offset ?? 0, color: color, opacity: opacity ?? 1.0)
+    }
+}

SwiftDraw/Parser.XML.Gradient.swift

@@ -90,6 +90,7 @@ extension XMLParser {
     var defs = DOM.SVG.Defs()
     defs.clipPaths = try parseClipPaths(e)
     defs.linearGradients = try parseLinearGradients(e)
+    defs.radialGradients = try parseRadialGradients(e)
     defs.masks = try parseMasks(e)
     defs.patterns = try parsePatterns(e)