X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=dither_effect.h;h=cad6488921b67c5f60a3a1ac17fb97dec440b474;hp=d0f2423c26831c1705475f49052db0eeb7d496d0;hb=fc55857d9ccf1edcc141fa0853a8bf2d6b40b4dc;hpb=ff9e68a3f5abb179bd7bf9fb84df48327f148583

diff --git a/dither_effect.h b/dither_effect.h
index d0f2423..cad6488 100644
--- a/dither_effect.h
+++ b/dither_effect.h
@@ -46,12 +46,22 @@
 #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:
@@ -59,6 +69,7 @@ private:
 
 	int width, height, num_bits;
 	int last_width, last_height, last_num_bits;
+	int texture_width, texture_height;
 
 	GLuint texnum;
 	bool need_texture_update;