Implemented a function to invert images

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017 Roman Kisil
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Source/Common/Utilities/Utilities.h

@@ -29,5 +29,5 @@
 +(BOOL)appLaunchedBefore;
 + (BOOL)launchOnLogin;
 + (void)setLaunchOnLogin:(BOOL)launchOnLogin;
-
++(NSImage *)invertedImageFromImage:(NSImage*)image;
 @end

Source/Common/Utilities/Utilities.m

@@ -242,6 +242,75 @@
                                           timeStyle:NSDateFormatterFullStyle];
 }
 
++(NSImage *)invertedImageFromImage:(NSImage*)image{
+    // get width and height as integers, since we'll be using them as
+    // array subscripts, etc, and this'll save a whole lot of casting
+    CGSize size = image.size;
+    int width = size.width;
+    int height = size.height;
+    
+    // Create a suitable RGB+alpha bitmap context in BGRA colour space
+    CGColorSpaceRef colourSpace = CGColorSpaceCreateDeviceRGB();
+    unsigned char *memoryPool = (unsigned char *)calloc(width*height*4, 1);
+    CGContextRef context = CGBitmapContextCreate(memoryPool, width, height, 8, width * 4, colourSpace, kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast);
+    CGColorSpaceRelease(colourSpace);
+    
+    // draw the current image to the newly created context
+    NSRect imageRect = NSMakeRect(0, 0, image.size.width, image.size.height);
+    CGContextDrawImage(context, CGRectMake(0, 0, width, height), [image CGImageForProposedRect:&imageRect context:NULL hints:nil]);
+    
+    // run through every pixel, a scan line at a time...
+    for(int y = 0; y < height; y++)
+    {
+        // get a pointer to the start of this scan line
+        unsigned char *linePointer = &memoryPool[y * width * 4];
+        
+        // step through the pixels one by one...
+        for(int x = 0; x < width; x++)
+        {
+            // get RGB values. We're dealing with premultiplied alpha
+            // here, so we need to divide by the alpha channel (if it
+            // isn't zero, of course) to get uninflected RGB. We
+            // multiply by 255 to keep precision while still using
+            // integers
+            int r, g, b;
+            if(linePointer[3])
+            {
+                r = linePointer[0] * 255 / linePointer[3];
+                g = linePointer[1] * 255 / linePointer[3];
+                b = linePointer[2] * 255 / linePointer[3];
+            }
+            else
+                r = g = b = 0;
+            
+            // perform the colour inversion
+            r = 255 - r;
+            g = 255 - g;
+            b = 255 - b;
+            
+            // multiply by alpha again, divide by 255 to undo the
+            // scaling before, store the new values and advance
+            // the pointer we're reading pixel data from
+            linePointer[0] = r * linePointer[3] / 255;
+            linePointer[1] = g * linePointer[3] / 255;
+            linePointer[2] = b * linePointer[3] / 255;
+            linePointer += 4;
+        }
+    }
+    
+    // get a CG image from the context, wrap that into a
+    // NSImage
+    CGImageRef cgImage = CGBitmapContextCreateImage(context);
+    NSImage *returnImage = [[NSImage alloc] initWithCGImage:cgImage size:size];
+    
+    // clean up
+    CGImageRelease(cgImage);
+    CGContextRelease(context);
+    free(memoryPool);
+    
+    // and return
+    return returnImage;
+}
 
 @end
 

eqMac2.xcworkspace/xcuserdata/romanskisils.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Bucket
+   type = "0"
+   version = "2.0">
+   <Breakpoints>
+      <BreakpointProxy
+         BreakpointExtensionID = "Xcode.Breakpoint.FileBreakpoint">
+         <BreakpointContent
+            shouldBeEnabled = "Yes"
+            ignoreCount = "0"
+            continueAfterRunningActions = "No"
+            filePath = "Source/Common/Utilities/Utilities.m"
+            timestampString = "522534657.146549"
+            startingColumnNumber = "9223372036854775807"
+            endingColumnNumber = "9223372036854775807"
+            startingLineNumber = "295"
+            endingLineNumber = "295"
+            landmarkName = "+invertedImageFromImage:"
+            landmarkType = "7">
+         </BreakpointContent>
+      </BreakpointProxy>
+   </Breakpoints>
+</Bucket>