X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=lift_gamma_gain_effect.frag;h=7342d7505eb53da6e66167b4921138ef2f5a68dc;hp=775941ebc641e35049b7b333422eed4b9e237dcc;hb=3a918307fb46478ea8080222a58406cfe04a7cbe;hpb=b10c546f579c7ccb5939161e61a71cd18a3f9bbd

diff --git a/lift_gamma_gain_effect.frag b/lift_gamma_gain_effect.frag
index 775941e..7342d75 100644
--- a/lift_gamma_gain_effect.frag
+++ b/lift_gamma_gain_effect.frag
@@ -1,11 +1,17 @@
+// Implicit uniforms:
+//
 // These are calculated in the host code to save some arithmetic.
-uniform vec3 PREFIX(gain_pow_inv_gamma);  // gain^(1/gamma).
-uniform vec3 PREFIX(inv_gamma_22);  // 2.2 / gamma.
+// uniform vec3 PREFIX(gain_pow_inv_gamma);  // gain^(1/gamma).
+// uniform vec3 PREFIX(inv_gamma_22);  // 2.2 / gamma.
 
 vec4 FUNCNAME(vec2 tc) {
 	vec4 x = INPUT(tc);
 
 	x.rgb /= x.aaa;
+
+	// pow() of negative numbers is undefined, so clip out-of-gamut values.
+	x.rgb = max(x.rgb, 0.0);
+
 	x.rgb = pow(x.rgb, vec3(1.0/2.2));
 	x.rgb += PREFIX(lift) * (vec3(1) - x.rgb);
 	x.rgb = pow(x.rgb, PREFIX(inv_gamma_22));