Indicates whether the alpha channel values for
color are forced to
1, which is the largest representable value.
- iOS 8.0+
- macOS 10.11+
- tvOS 9.0+
The default value is
If enabled, alpha channel fragment values are only forced for
color. Other attachments are unaffected.
You may use
alpha when you want to write an alpha value that represents partial coverage of the pixel, but also want to disable blending (by forcing alpha to one).