From 9ce297bf9a2f38379ad1aaa64d37af377c2f1ed3 Mon Sep 17 00:00:00 2001
From: Joshua Goins <josh@redstrate.com>
Date: Thu, 16 Sep 2021 18:28:56 -0400
Subject: [PATCH] Properly clear mask image, and load regular layer when a mask
 is present

---
 SilicaViewer/Document.swift | 71 ++++++++++++++++++++-----------------
 1 file changed, 38 insertions(+), 33 deletions(-)

diff --git a/SilicaViewer/Document.swift b/SilicaViewer/Document.swift
index b4be7f9..165074e 100644
--- a/SilicaViewer/Document.swift
+++ b/SilicaViewer/Document.swift
@@ -339,7 +339,10 @@ class Document: NSDocument {
             let maskBitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue).union(.byteOrder16Big)
             
             let maskContext = CGContext(data: nil, width: info.width, height: info.height, bitsPerComponent: 16, bytesPerRow: 0, space: grayColorSpace, bitmapInfo: maskBitmapInfo.rawValue)
-                
+            
+            maskContext?.setFillColor(.white)
+            maskContext?.fill(CGRect(origin: .zero, size: CGSize(width: info.width, height: info.height)))
+
             if layer.mask != nil {
                 for chunk in layer.mask!.chunks {
                     let x = chunk.x
@@ -357,44 +360,46 @@ class Document: NSDocument {
                         maskContext?.draw(chunk.image.cgImage(forProposedRect: nil, context: NSGraphicsContext.current, hints: nil)!, in: rect)
                     }
                 }
-            } else {
-                for chunk in layer.data.chunks {
-                    let x = chunk.x
-                    var y = chunk.y
-                    
-                    let (width, height) = getTileSize(x: x, y: y)
-                    
-                    if y == rows {
-                        y = 0
-                    }
+            }
+            
+            for chunk in layer.data.chunks {
+                let x = chunk.x
+                var y = chunk.y
                 
-                    let rect = NSRect(x: info.tileSize * x, y: info.height - (info.tileSize * y), width: width, height: height)
-                    
-                    var op = CGBlendMode.copy
-                    if layer.data.blendMode == 12 {
-                        op = .hardLight
-                    }
-                    
-                    layerContext?.setAlpha(CGFloat(layer.data.opacity))
-                    layerContext?.setBlendMode(op)
-                    
-                    if !layer.data.hidden {
-                        layerContext?.draw(chunk.image.cgImage(forProposedRect: nil, context: NSGraphicsContext.current, hints: nil)!, in: rect)
-                    }
+                let (width, height) = getTileSize(x: x, y: y)
+                
+                if y == rows {
+                    y = 0
+                }
+            
+                let rect = NSRect(x: info.tileSize * x, y: info.height - (info.tileSize * y), width: width, height: height)
+                
+                var op = CGBlendMode.copy
+                if layer.data.blendMode == 12 {
+                    op = .hardLight
+                }
+                
+                layerContext?.setAlpha(CGFloat(layer.data.opacity))
+                layerContext?.setBlendMode(op)
+                
+                if !layer.data.hidden {
+                    layerContext?.draw(chunk.image.cgImage(forProposedRect: nil, context: NSGraphicsContext.current, hints: nil)!, in: rect)
                 }
             }
-            
-            var layerImage = (layerContext?.makeImage())!
-            if layer.mask != nil {
-                let maskImage = (maskContext?.makeImage())!
-                                
-                layerImage = layerImage.masking(maskImage)!
-            }
-            
+    
+            let layerImage = (layerContext?.makeImage())!
+ 
             ccgContext?.setAlpha(1.0)
             ccgContext?.setBlendMode(.sourceAtop)
             
-            ccgContext?.draw(layerImage, in: CGRect(x: 0, y: 0, width: info.width, height: info.height))
+            if layer.mask != nil {
+                let maskImage = (maskContext?.makeImage())!
+                let newImage = layerImage.masking(maskImage)!
+                                
+                ccgContext?.draw(newImage, in: CGRect(x: 0, y: 0, width: info.width, height: info.height))
+            } else {
+                ccgContext?.draw(layerImage, in: CGRect(x: 0, y: 0, width: info.width, height: info.height))
+            }
         }
         
         var image = NSImage(cgImage: (ccgContext?.makeImage())!, size: NSSize(width: info.width, height: info.height))