+// Compress to Rec. 601/Rec. 709 gamma curve.
+
+#if 0
+
+// if we have the lut
+uniform sampler1D PREFIX(rec709_inverse_tex);
+
+vec4 FUNCNAME(vec2 tc) {
+ vec4 x = LAST_INPUT(tc);
+
+ x.r = texture1D(PREFIX(rec709_inverse_tex), x.r).x;
+ x.g = texture1D(PREFIX(rec709_inverse_tex), x.g).x;
+ x.b = texture1D(PREFIX(rec709_inverse_tex), x.b).x;
+
+ return x;
+}
+
+#else
+
+// use arithmetic (slow)
+vec4 FUNCNAME(vec2 tc) {
+ vec4 x = LAST_INPUT(tc);
+
+ vec3 a = vec3(4.5) * x.rgb;
+ vec3 b = vec3(1.099) * pow(x.rgb, vec3(0.45)) - vec3(0.099);
+ vec3 f = vec3(greaterThan(x.rgb, vec3(0.018)));
+
+ return vec4(mix(a, b, f), x.a);
+}
+
+#endif