// rest of the curve relatively little. Thus, we actually convert to gamma 2.2
// before lift, and then back again afterwards. (Gain and gamma are,
// up to constants, commutative with the de-gamma operation.)
+//
+// Also, gamma is a case where we would not want premultiplied alpha.
+// Thus, we have to divide away alpha first, and then re-multiply it back later.
#include "effect.h"
class LiftGammaGainEffect : public Effect {
public:
LiftGammaGainEffect();
+ virtual std::string effect_type_id() const { return "LiftGammaGainEffect"; }
std::string output_fragment_shader();
- void set_uniforms(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num);
+ void set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num);
private:
RGBTriplet lift, gamma, gain;