FlySketch Graphic Compositing Modes
If you are running FlySketch 1.5 on Mac OS X 10.4 or later, you will notice an extra palette with various “Compositing modes”. What the heck are those?
Definitions direct from Apple:
- Clear: Transparent.
- Copy: Source image.
- Destination Atop: Destination image wherever both images are opaque, source image wherever source image is opaque but destination image is transparent, and transparent elsewhere.
- Destination In: Destination image wherever both images are opaque, and transparent elsewhere.
- Destination Out: Destination image wherever destination image is opaque but source image is transparent, and transparent elsewhere.
- Destination Over: Destination image wherever destination image is opaque, and source image elsewhere.
- Plus Darker: Sum of source and destination images, with color values approaching 0 as a limit.
- Plus Lighter: Sum of source and destination images, with color values approaching 1 as a limit.
- Source Atop: Source image wherever both images are opaque, destination image wherever destination image is opaque but source image is transparent, and transparent elsewhere.
- Source In: Source image wherever both images are opaque, and transparent elsewhere.
- Source Out: Source image wherever source image is opaque but destination image is transparent, and transparent elsewhere.
- Source Over: Source image wherever source image is opaque, and destination image elsewhere.
- XOR: Exclusive OR of source and destination images. Works only with black and white images and is not recommended for color contexts.
Information Credit: http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/ApplicationKit/Classes/NSImage_Class/Reference/Reference.html
