Fix a bug where DeconvolutionSharpenEffect would forget one line of the kernel.

[movit] / dither_effect.h

diff --git a/dither_effect.h b/dither_effect.h
index 943220aed55ad3dc524e4404b06ef2838f917831..f9f371c0c5f5f2025761164bc386ec42665e7fdf 100644 (file)
--- a/dither_effect.h
+++ b/dither_effect.h
@@ -1,5 +1,5 @@
-#ifndef _DITHER_EFFECT_H
-#define _DITHER_EFFECT_H 1
+#ifndef _MOVIT_DITHER_EFFECT_H
+#define _MOVIT_DITHER_EFFECT_H 1
 
 // Implements simple rectangular-PDF dither.
 //
@@ -43,15 +43,28 @@
 // like many LCD monitors do, but it starts to get very hairy, again, for limited gains.)
 // The dither is also deterministic across runs.
 
+#include <GL/glew.h>
+#include <string>
+
 #include "effect.h"
 
 class DitherEffect : public Effect {
-public:
+private:
+       // Should not be instantiated by end users;
+       // call EffectChain::set_dither_bits() instead.
        DitherEffect();
+       friend class EffectChain;
+
+public:
        ~DitherEffect();
        virtual std::string effect_type_id() const { return "DitherEffect"; }
        std::string output_fragment_shader();
 
+       // Note that if we did error diffusion, we'd actually want to diffuse the
+       // premultiplied error. However, we need to do dithering in the same
+       // space as quantization, whether that be pre- or postmultiply.
+       virtual AlphaHandling alpha_handling() const { return DONT_CARE_ALPHA_TYPE; }
+
        void set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num);
 
 private:
@@ -65,4 +78,4 @@ private:
        bool need_texture_update;
 };
 
-#endif // !defined(_DITHER_EFFECT_H)
+#endif // !defined(_MOVIT_DITHER_EFFECT_H)