3 ms·
"The pixels on the edge are supposed to be halfway between white and black to indicate being half-covered by the circle, but if you pile them up on top of each
by whatshisface 5y ago
"The pixels on the edge are supposed to be halfway between white and black to indicate being half-covered by the circle, but if you pile them up on top of each other anything with a little black adds up with its duplicates to complete black."
- heartbeats 5y agoBut if you zoom in, it looks the same.
- nocturnial 5y agoThat's because people, including me when I started programming, confuse alpha with coverage. Most people use the alpha value for coverage. Most of the time it doesn't really matter visually but there some edge cases where it does matter. The best docs I could find in a short amount of time, are those from anti-grain[1] where the author describes it as a "second alpha channel. [1] http://agg.sourceforge.net/antigrain.com/doc/basic_renderers/basic_renderers.agdoc.html http://agg.sourceforge.net/antigrain.com/doc/basic_renderers...