Update README.md

tests/oversample/README.md

@@ -61,3 +61,28 @@ texture bandwidth for text rendering since we end up minifying the texture
 without using mipmapping, but you probably are not going to be fill-bound
 by your text rendering.)
 
+## What about gamma?
+
+Gamma-correction for fonts just doesn't work. This doesn't seem to make
+much sense -- it's physically correct, it simulates what we'd see if you
+shrunk a font down really far, right?
+
+But you can play with it in the oversample.exe app. If you turn it on,
+white-on-black fonts become too thick (i.e. they become too bright), and
+black-on-white fonts become too thin (i.e. they are too dark). There is
+no way to adjust the font's inherent thickness (i.e. by switching to
+bold) to fix this for both; making the font thicker will make white
+text worse, and making the font thinner will make black text worse.
+
+Multiple people who have experimented with this independently (me,
+Fabian Giesen,and Maxim Shemanarev of Anti-Grain Geometry) have all
+oncluded that font rendering just generally looks better without
+gamma correction (or probably with some arbitrary power stuck in
+there, but it's not really correcting for gamma at that point). Maybe
+this is in part a product of how we're used to fonts being on screens
+which has changed how we expect them to look (e.g. perhaps hinting
+oversharpens them and prevents the real-world thinning you'd see in
+a black-on-white text).
+
+Nevertheless, even if you turn on gamma-correction, you will find that
+oversampling still helps in many cases for small fonts.