X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=blur_effect.h;h=0c7dccc826b9ae9ccb4be6b352aa1e288fb787e9;hp=ee890c25543fa41599e67d3e9284bfd68d8ee196;hb=8fe95ce120431f3c593828d0f26185580943c7db;hpb=b618b34070d23b6da35c77f004678d8a9e55575b

diff --git a/blur_effect.h b/blur_effect.h
index ee890c2..0c7dccc 100644
--- a/blur_effect.h
+++ b/blur_effect.h
@@ -1,6 +1,14 @@
 #ifndef _BLUR_EFFECT_H
 #define _BLUR_EFFECT_H 1
 
+// A separable 2D blur implemented by a combination of mipmap filtering
+// and convolution (essentially giving a convolution with a piecewise linear
+// approximation to the true impulse response).
+//
+// Works in two passes; first horizontal, then vertical (BlurEffect,
+// which is what the user is intended to use, instantiates two copies of
+// SingleBlurPassEffect behind the scenes).
+
 #include "effect.h"
 
 class SingleBlurPassEffect;