1 files changed, 57 insertions, 0 deletions
diff --git a/Invert.m b/Invert.m
index a41eb46..b5675eb 100644
--- a/Invert.m
+++ b/Invert.m
@@ -1,10 +1,67 @@
 #import "Invert.h"
 
+#define MAX_DISPLAYS 8
+
 @implementation Invert
 
+- (id)init
+{
+    self = [super init];
+    if (self) {
+        _inverted = NO;
+    }
+    return self;
+}
+
 - (void)toggleInvertColors:(NSEvent *)event
 {
     NSLog(@"Toggling");
+
+    if (!_inverted) {
+        [self invertColors];
+
+        _inverted = YES;
+    }
+    else {
+        [self restoreColors];
+
+        _inverted = NO;
+    }
+}
+
+- (void)invertColors
+{
+    const CGGammaValue inverted_gamma[2] = {1, 0};
+
+    CGDirectDisplayID active_displays[MAX_DISPLAYS];
+    uint32_t display_count;
+
+    CGError error = CGGetActiveDisplayList(
+        MAX_DISPLAYS,
+        &active_displays[0],
+        &display_count
+    );
+    if (error != kCGErrorSuccess) {
+        // return 69;
+    }
+
+    for (int i = 0; i < display_count; i++) {
+        error = CGSetDisplayTransferByTable(
+            active_displays[i],
+            2,
+            inverted_gamma,
+            inverted_gamma,
+            inverted_gamma
+        );
+        if (error != kCGErrorSuccess) {
+            // TODO: error handling
+        }
+    }
+}
+
+- (void)restoreColors
+{
+    CGDisplayRestoreColorSyncSettings();
 }
 
 @end