Improve the color curve postprocessor

[libs/gl.git] / source / colorcurve.cpp

diff --git a/source/colorcurve.cpp b/source/colorcurve.cpp
index 81b5a43e7a6ef4d6724a39e2ea182e7ecd63586a..f1c090308458b4edbf9360d5018a80d817389471 100644 (file)
--- a/source/colorcurve.cpp
+++ b/source/colorcurve.cpp
@@ -23,23 +23,31 @@ ColorCurve::ColorCurve():
        curve.set_wrap(CLAMP_TO_EDGE);
        texturing.attach(1, curve);
 
-       set_peak(0.2);
-       set_brightness(1.5);
+       set_exposure_adjust(0.0f);
+       set_brightness_response(0.4f);
        set_linear();
 }
 
-void ColorCurve::set_peak(float p)
+void ColorCurve::set_exposure_adjust(float e)
+{
+       shdata.uniform("exposure", pow(2.0f, e));
+}
+
+void ColorCurve::set_brightness_response(float b)
+{
+       if(b<=0 || b>1)
+               throw invalid_argument("ColorCurve::set_brightness_response");
+       float t = (b<1 ? pow(b, 1/(1-b)) : 0.0f);
+       shdata.uniform("brightness_response", b, t, pow(t, b));
+}
+
+void ColorCurve::set_peak(float)
 {
-       if(p<0 || p>1)
-               throw invalid_argument("ColorCurve::set_peak");
-       shdata.uniform("peak", p);
 }
 
 void ColorCurve::set_brightness(float b)
 {
-       if(b<1)
-               throw invalid_argument("ColorCurve::set_brightness");
-       shdata.uniform("brightness", b);
+       set_brightness_response(1/b);
 }
 
 void ColorCurve::set_gamma(float g)