Squash linear gamma back into the sRGB curve at the end.

[movit] / effect_chain.cpp

diff --git a/effect_chain.cpp b/effect_chain.cpp
index a8381505109affe8ade2becd09009c58b15b1233..56d470fb572e7764e0c78d02bf8d8a0e0a08f506 100644 (file)
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@ -10,6 +10,7 @@
 #include "util.h"
 #include "effect_chain.h"
 #include "gamma_expansion_effect.h"
+#include "gamma_compression_effect.h"
 #include "lift_gamma_gain_effect.h"
 #include "colorspace_conversion_effect.h"
 #include "texture_enum.h"
@@ -42,24 +43,34 @@ Effect *instantiate_effect(EffectId effect)
        assert(false);
 }
 
+void EffectChain::normalize_to_linear_gamma()
+{
+       GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
+       gamma_conversion->set_int("source_curve", current_gamma_curve);
+       effects.push_back(gamma_conversion);
+       current_gamma_curve = GAMMA_LINEAR;
+}
+
+void EffectChain::normalize_to_srgb()
+{
+       assert(current_gamma_curve == GAMMA_LINEAR);
+       ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
+       colorspace_conversion->set_int("source_space", current_color_space);
+       colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
+       effects.push_back(colorspace_conversion);
+       current_color_space = COLORSPACE_sRGB;
+}
+
 Effect *EffectChain::add_effect(EffectId effect_id)
 {
        Effect *effect = instantiate_effect(effect_id);
 
        if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
-               GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
-               gamma_conversion->set_int("source_curve", current_gamma_curve);
-               effects.push_back(gamma_conversion);
-               current_gamma_curve = GAMMA_LINEAR;
+               normalize_to_linear_gamma();
        }
 
        if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
-               assert(current_gamma_curve == GAMMA_LINEAR);
-               ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
-               colorspace_conversion->set_int("source_space", current_color_space);
-               colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
-               effects.push_back(colorspace_conversion);
-               current_color_space = COLORSPACE_sRGB;
+               normalize_to_srgb();
        }
 
        // not handled yet
@@ -113,6 +124,19 @@ std::string replace_prefix(const std::string &text, const std::string &prefix)
 
 void EffectChain::finalize()
 {
+       // TODO: If we want a non-sRGB output color space, convert.
+
+       if (current_gamma_curve != output_format.gamma_curve) {
+               if (current_gamma_curve != GAMMA_LINEAR) {
+                       normalize_to_linear_gamma();
+               }
+               assert(current_gamma_curve == GAMMA_LINEAR);
+               GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
+               gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
+               effects.push_back(gamma_conversion);
+               current_gamma_curve = output_format.gamma_curve;
+       }
+
        std::string frag_shader = read_file("header.glsl");
 
        for (unsigned i = 0; i < effects.size(); ++i) {