From c2b39ba358d2ee2a420ea21e649c7b14587f832f Mon Sep 17 00:00:00 2001
From: dscyrescotti <dscyrescotti@gmail.com>
Date: Wed, 22 May 2024 21:37:55 +0700
Subject: [PATCH] bug: fix stroke glitching

---
 Memola/App/MemolaApp.swift                    |  5 ++
 Memola/Canvas/Contexts/GraphicContext.swift   |  6 ++-
 .../SolidPointStrokeGenerator.swift           | 24 +++++++++-
 Memola/Canvas/Geometries/Stroke/Stroke.swift  | 46 +++++++++++++------
 Memola/Features/Memo/Toolbar/Toolbar.swift    | 14 ++++--
 5 files changed, 75 insertions(+), 20 deletions(-)

diff --git a/Memola/App/MemolaApp.swift b/Memola/App/MemolaApp.swift
index 68edd1f..4804ebc 100644
--- a/Memola/App/MemolaApp.swift
+++ b/Memola/App/MemolaApp.swift
@@ -13,6 +13,11 @@ struct MemolaApp: App {
         WindowGroup {
             MemosView()
                 .persistence(\.viewContext)
+                .onReceive(NotificationCenter.default.publisher(for: UIApplication.willTerminateNotification)) { _ in
+                    withPersistenceSync(\.backgroundContext) { context in
+                        try context.saveIfNeeded()
+                    }
+                }
         }
     }
 }
diff --git a/Memola/Canvas/Contexts/GraphicContext.swift b/Memola/Canvas/Contexts/GraphicContext.swift
index 19b0a5f..576d44c 100644
--- a/Memola/Canvas/Contexts/GraphicContext.swift
+++ b/Memola/Canvas/Contexts/GraphicContext.swift
@@ -153,8 +153,10 @@ extension GraphicContext {
     func endStroke(at point: CGPoint) {
         guard currentPoint != nil, let currentStroke else { return }
         currentStroke.finish(at: point)
-        withPersistence(\.backgroundContext) { [currentStroke] context in
-            currentStroke.object?.bounds = currentStroke.bounds
+        let batchIndex = currentStroke.batchIndex
+        let quads = Array(currentStroke.quads[batchIndex..<currentStroke.quads.count])
+        currentStroke.saveQuads(for: quads)
+        withPersistence(\.backgroundContext) { context in
             try context.saveIfNeeded()
             if let stroke = currentStroke.object {
                 context.refresh(stroke, mergeChanges: false)
diff --git a/Memola/Canvas/Geometries/Stroke/Generators/SolidPointStrokeGenerator.swift b/Memola/Canvas/Geometries/Stroke/Generators/SolidPointStrokeGenerator.swift
index d00c498..0e31d2d 100644
--- a/Memola/Canvas/Geometries/Stroke/Generators/SolidPointStrokeGenerator.swift
+++ b/Memola/Canvas/Geometries/Stroke/Generators/SolidPointStrokeGenerator.swift
@@ -29,6 +29,7 @@ struct SolidPointStrokeGenerator: StrokeGenerator {
             let control = CGPoint.middle(p1: start, p2: end)
             addCurve(from: start, to: end, by: control, on: stroke)
         case 3:
+            stroke.removeQuads(from: stroke.quadIndex + 1)
             let index = stroke.keyPoints.endIndex - 1
             var start = stroke.keyPoints[index - 2]
             var end = CGPoint.middle(p1: stroke.keyPoints[index - 2], p2: stroke.keyPoints[index - 1])
@@ -39,7 +40,7 @@ struct SolidPointStrokeGenerator: StrokeGenerator {
             end = CGPoint.middle(p1: stroke.keyPoints[index - 1], p2: stroke.keyPoints[index])
             addCurve(from: start, to: end, by: control, on: stroke)
         default:
-            adjustKeyPoint(on: stroke)
+            smoothOutPath(on: stroke)
             let index = stroke.keyPoints.endIndex - 1
             let start = CGPoint.middle(p1: stroke.keyPoints[index - 2], p2: stroke.keyPoints[index - 1])
             let control = stroke.keyPoints[index - 1]
@@ -57,6 +58,27 @@ struct SolidPointStrokeGenerator: StrokeGenerator {
         }
     }
 
+    private func smoothOutPath(on stroke: Stroke) {
+        stroke.removeQuads(from: stroke.quadIndex + 1)
+        adjustKeyPoint(on: stroke)
+        switch stroke.keyPoints.endIndex {
+        case 4:
+            let index = stroke.keyPoints.endIndex - 2
+            let start = stroke.keyPoints[index - 2]
+            let end = CGPoint.middle(p1: stroke.keyPoints[index - 2], p2: stroke.keyPoints[index - 1])
+            let control = CGPoint.middle(p1: start, p2: end)
+            addCurve(from: start, to: end, by: control, on: stroke)
+            fallthrough
+        default:
+            let index = stroke.keyPoints.endIndex - 2
+            let start = CGPoint.middle(p1: stroke.keyPoints[index - 2], p2: stroke.keyPoints[index - 1])
+            let control = stroke.keyPoints[index - 1]
+            let end = CGPoint.middle(p1: stroke.keyPoints[index - 1], p2: stroke.keyPoints[index])
+            addCurve(from: start, to: end, by: control, on: stroke)
+        }
+        stroke.quadIndex = stroke.quads.endIndex - 1
+    }
+
     private func adjustKeyPoint(on stroke: Stroke) {
         let index = stroke.keyPoints.endIndex - 1
         let prev = stroke.keyPoints[index - 1]
diff --git a/Memola/Canvas/Geometries/Stroke/Stroke.swift b/Memola/Canvas/Geometries/Stroke/Stroke.swift
index f5bbcbd..32081b2 100644
--- a/Memola/Canvas/Geometries/Stroke/Stroke.swift
+++ b/Memola/Canvas/Geometries/Stroke/Stroke.swift
@@ -116,20 +116,38 @@ extension Stroke {
             color: color
         )
         quads.append(quad)
-        withPersistence(\.backgroundContext) { [weak self, _quad = quad, object, bounds] context in
-            let quad = QuadObject(\.backgroundContext)
-            quad.originX = _quad.originX.cgFloat
-            quad.originY = _quad.originY.cgFloat
-            quad.size = _quad.size.cgFloat
-            quad.rotation = _quad.rotation.cgFloat
-            quad.shape = _quad.shape
-            quad.color = _quad.getColor()
-            quad.stroke = object
-            object?.quads.add(quad)
-            self?.bounds[0] = min(_quad.originX.cgFloat, bounds[0])
-            self?.bounds[1] = min(_quad.originY.cgFloat, bounds[1])
-            self?.bounds[2] = max(_quad.originX.cgFloat, bounds[2])
-            self?.bounds[3] = max(_quad.originY.cgFloat, bounds[3])
+    }
+
+    func removeQuads(from index: Int) {
+        let dropCount = quads.endIndex - max(1, index)
+        quads.removeLast(dropCount)
+        let quads = Array(quads[batchIndex..<index])
+        batchIndex = index
+        saveQuads(for: quads)
+    }
+
+    func saveQuads(for quads: [Quad]) {
+        var topLeft: CGPoint = CGPoint(x: bounds[0], y: bounds[1])
+        var bottomRight: CGPoint = CGPoint(x: bounds[2], y: bounds[3])
+        withPersistence(\.backgroundContext) { [weak self, object] context in
+            guard let self else { return }
+            for _quad in quads {
+                let quad = QuadObject(\.backgroundContext)
+                quad.originX = _quad.originX.cgFloat
+                quad.originY = _quad.originY.cgFloat
+                quad.size = _quad.size.cgFloat
+                quad.rotation = _quad.rotation.cgFloat
+                quad.shape = _quad.shape
+                quad.color = _quad.getColor()
+                quad.stroke = object
+                object?.quads.add(quad)
+                topLeft.x = min(quad.originX, topLeft.x)
+                topLeft.y = min(quad.originY, topLeft.y)
+                bottomRight.x = max(quad.originX, bottomRight.x)
+                bottomRight.y = max(quad.originY, bottomRight.y)
+            }
+            bounds = [topLeft.x, topLeft.y, bottomRight.x, bottomRight.y]
+            object?.bounds = bounds
         }
     }
 }
diff --git a/Memola/Features/Memo/Toolbar/Toolbar.swift b/Memola/Features/Memo/Toolbar/Toolbar.swift
index f7ac714..32b13a8 100644
--- a/Memola/Features/Memo/Toolbar/Toolbar.swift
+++ b/Memola/Features/Memo/Toolbar/Toolbar.swift
@@ -128,9 +128,17 @@ struct Toolbar: View {
     }
 
     func closeMemo() {
-        withPersistenceSync(\.viewContext) { context in
-            try context.saveIfNeeded()
+        DispatchQueue.global(qos: .userInitiated).async {
+            DispatchQueue.main.async {
+                canvas.state = .closing
+            }
+            withPersistenceSync(\.viewContext) { context in
+                try context.saveIfNeeded()
+            }
+            DispatchQueue.main.async {
+                canvas.state = .closed
+                dismiss()
+            }
         }
-        dismiss()
     }
 }