Hard-assert on something that has bitten me too many times now.

[movit] / lift_gamma_gain_effect.frag

diff --git a/lift_gamma_gain_effect.frag b/lift_gamma_gain_effect.frag
index acd9d5162ca34c219bfa555feb191c1ea5a2cbd8..7342d7505eb53da6e66167b4921138ef2f5a68dc 100644 (file)
--- a/lift_gamma_gain_effect.frag
+++ b/lift_gamma_gain_effect.frag
@@ -1,14 +1,22 @@
+// 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));
        x.rgb *= PREFIX(gain_pow_inv_gamma);
+       x.rgb *= x.aaa;
 
        return x;
 }