X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=lift_gamma_gain_effect.frag;h=9047d64bbc2230c263e6fb5a6025642435cf8cd0;hp=43766a6265218621888cbf7a11ffe862ddb0fbba;hb=18fdebc534adc6b7a4c36b290b01d598bcb671bc;hpb=e8650c7b7814c5beef59059b8acac3e5e7b8ddc6

diff --git a/lift_gamma_gain_effect.frag b/lift_gamma_gain_effect.frag
index 43766a6..9047d64 100644
--- a/lift_gamma_gain_effect.frag
+++ b/lift_gamma_gain_effect.frag
@@ -3,12 +3,18 @@ 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 = LAST_INPUT(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));
 	x.rgb *= PREFIX(gain_pow_inv_gamma);
+	x.rgb *= x.aaa;
 
 	return x;
 }