When I create a custom NSCursor in Objective-C the alpha channel mask appears to XOR the screen below. I am expecting an alpha channel value of zero to be transparent, not XOR the graphics below. I am certain my mask data is correct ARGB where A=0 for transparent and A=255 for opaque. What am I doing wrong?
static void maincustomcursor(bigmap *thedata, point hotspot) { NSPoint thepoint; NSImage *newimage; NSCursor *thecursor; CGImageRef theimage; CGBitmapInfo theinfo; CGContextRef thecont; CGColorSpaceRef thecolor; int width, height, across; width = (*thedata).width; height = (*thedata).height; if (width != smalliconsize || height != smalliconsize) return; if (hotspot.h < 0) hotspot.h = 0; if (hotspot.h >= smalliconsize) hotspot.h = smalliconsize - 1; if (hotspot.v < 0) hotspot.v = 0; if (hotspot.v >= smalliconsize) hotspot.v = smalliconsize - 1; thepoint = NSMakePoint(hotspot.h, hotspot.v); across = (*thedata).rowbytes; thecolor = CGColorSpaceCreateDeviceRGB(); theinfo = (CGBitmapInfo)kCGImageAlphaPremultipliedFirst; thecont = CGBitmapContextCreate((*thedata).baseaddr, width, height, 8, across, thecolor, theinfo); theimage = CGBitmapContextCreateImage(thecont); newimage = [[NSImage alloc] initWithCGImage:theimage size:NSZeroSize]; thecursor = [[NSCursor alloc] initWithImage:newimage hotSpot:thepoint]; [thecursor set]; [thecursor release]; [newimage release]; CGImageRelease(theimage); CGContextRelease(thecont); CGColorSpaceRelease(thecolor); } 