1 #ifndef _MOVIT_GAMMA_EXPANSION_EFFECT_H
2 #define _MOVIT_GAMMA_EXPANSION_EFFECT_H 1
4 // An effect to convert the given gamma curve into linear light,
5 // typically inserted by the framework automatically at the beginning
6 // of the processing chain.
8 // Currently supports sRGB and Rec. 601/709.
13 #include "image_format.h"
15 #define EXPANSION_CURVE_SIZE 256
17 class GammaExpansionEffect : public Effect {
19 // Should not be instantiated by end users.
20 GammaExpansionEffect();
21 friend class EffectChain;
24 virtual std::string effect_type_id() const { return "GammaExpansionEffect"; }
25 std::string output_fragment_shader();
27 virtual bool needs_linear_light() const { return false; }
28 virtual bool needs_srgb_primaries() const { return false; }
30 // Actually processes its input in a nonlinear fashion,
31 // but does not touch alpha, and we are a special case anyway.
32 virtual AlphaHandling alpha_handling() const { return DONT_CARE_ALPHA_TYPE; }
35 GammaCurve source_curve;
36 float expansion_curve[EXPANSION_CURVE_SIZE];
39 #endif // !defined(_MOVIT_GAMMA_EXPANSION_EFFECT_H)