From da3f639ef2cb28731a3bc24e8f3db6d3572142fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jesu=CC=81s=20A=2E=20A=CC=81lvarez?= <zydeco@namedfork.net>
Date: Fri, 1 Mar 2024 23:31:06 +0100
Subject: [PATCH] prefer pixel-perfect scaling when filter is set to nearest

---
 Mini vMac/ScreenView.m | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/Mini vMac/ScreenView.m b/Mini vMac/ScreenView.m
index 97eee3c..926f265 100644
--- a/Mini vMac/ScreenView.m	
+++ b/Mini vMac/ScreenView.m	
@@ -29,7 +29,7 @@ static ScreenView *sharedScreenView = nil;
     [self updateVideoLayer];
     [self.layer addSublayer:videoLayer];
     [[AppDelegate sharedInstance] addObserver:self forKeyPath:@"sharedEmulator" options:NSKeyValueObservingOptionNew context:NULL];
-    [[NSUserDefaults standardUserDefaults] addObserver:self forKeyPath:@"screenFilter" options:NSKeyValueObservingOptionNew context:NULL];
+    [[NSUserDefaults standardUserDefaults] addObserver:self forKeyPath:@"screenFilter" options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld context:NULL];
 }
 
 + (instancetype)sharedScreenView {
@@ -57,17 +57,25 @@ static ScreenView *sharedScreenView = nil;
 - (void)layoutSubviews {
     [super layoutSubviews];
     CGRect viewBounds = self.bounds;
-    CGFloat screenScale = MAX(screenSize.width / viewBounds.size.width, screenSize.height / viewBounds.size.height);
-    if (screenScale > 0.9 && screenScale <= 1.0) {
+    CGFloat screenScale = MIN(viewBounds.size.width / screenSize.width, viewBounds.size.height / screenSize.height);
+    NSString *screenFilter = [[NSUserDefaults standardUserDefaults] stringForKey:@"screenFilter"];
+    if ([screenFilter isEqualToString:kCAFilterNearest] && screenScale > 1.0) {
+        screenScale = floor(screenScale);
+    } else if (screenScale > 1.0 && screenScale <= 1.1) {
         screenScale = 1.0;
     }
-    screenBounds = CGRectMake(0, 0, screenSize.width / screenScale, screenSize.height / screenScale);
+    screenBounds = CGRectMake(0, 0, screenSize.width * screenScale, screenSize.height * screenScale);
     screenBounds.origin.x = (viewBounds.size.width - screenBounds.size.width)/2;
     screenBounds = CGRectIntegral(screenBounds);
+
+    if ([UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPad && (viewBounds.size.height - screenBounds.size.height) >= 30.0) {
+        // move under multitasking indicator on iPad
+        screenBounds.origin.y += 30;
+    }
     videoLayer.frame = screenBounds;
-    screenBounds.origin.y = self.frame.origin.y;
+    screenBounds.origin.y += self.frame.origin.y;
     BOOL scaleIsIntegral = (floor(screenScale) == screenScale);
-    NSString *screenFilter = scaleIsIntegral ? kCAFilterNearest : [[NSUserDefaults standardUserDefaults] stringForKey:@"screenFilter"];
+    if (scaleIsIntegral) screenFilter = kCAFilterNearest;
     videoLayer.magnificationFilter = screenFilter;
     videoLayer.minificationFilter = screenFilter;
 }
@@ -75,13 +83,19 @@ static ScreenView *sharedScreenView = nil;
 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context {
     if ([object isEqual:[NSUserDefaults standardUserDefaults]]) {
         if ([keyPath isEqualToString:@"screenFilter"]) {
+            NSString *oldValue = change[NSKeyValueChangeOldKey];
             NSString *value = change[NSKeyValueChangeNewKey];
             videoLayer.magnificationFilter = value;
             videoLayer.minificationFilter = value;
+            if ([value isEqualToString:kCAFilterNearest] || [oldValue isEqualToString:kCAFilterNearest]) {
+                [self setNeedsLayout];
+                [self layoutIfNeeded];
+            }
         }
     } else if (object == [AppDelegate sharedInstance] && [keyPath isEqualToString:@"sharedEmulator"]) {
         [self updateVideoLayer];
-        [self layoutSubviews];
+        [self setNeedsLayout];
+        [self layoutIfNeeded];
     }
 }