X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=blur_effect.h;h=b543ebc5a52f627625b5579766edd91684fcffec;hp=ee890c25543fa41599e67d3e9284bfd68d8ee196;hb=81f33379cabb7cf8b47f2d2bd3892f853afc89ab;hpb=b618b34070d23b6da35c77f004678d8a9e55575b

diff --git a/blur_effect.h b/blur_effect.h
index ee890c2..b543ebc 100644
--- a/blur_effect.h
+++ b/blur_effect.h
@@ -1,45 +1,107 @@
-#ifndef _BLUR_EFFECT_H
-#define _BLUR_EFFECT_H 1
+#ifndef _MOVIT_BLUR_EFFECT_H
+#define _MOVIT_BLUR_EFFECT_H 1
+
+// A separable 2D blur implemented by a combination of mipmap filtering
+// and convolution (essentially giving a convolution with a piecewise linear
+// approximation to the true impulse response).
+//
+// Works in two passes; first horizontal, then vertical (BlurEffect,
+// which is what the user is intended to use, instantiates two copies of
+// SingleBlurPassEffect behind the scenes).
+//
+// The recommended number of taps is the default (16). Fewer will be faster
+// but uglier; a tradeoff that might be worth it as part of more complicated
+// effects. This can be set only before finalization, and must be an
+// even number.
+
+#include <epoxy/gl.h>
+#include <assert.h>
+#include <stddef.h>
+#include <string>
 
 #include "effect.h"
 
+namespace movit {
+
+class EffectChain;
+class Node;
 class SingleBlurPassEffect;
 
 class BlurEffect : public Effect {
 public:
 	BlurEffect();
 
-	virtual std::string output_fragment_shader() {
+	std::string effect_type_id() const override { return "BlurEffect"; }
+
+	void inform_input_size(unsigned input_num, unsigned width, unsigned height) override;
+
+	std::string output_fragment_shader() override {
 		assert(false);
 	}
-	virtual 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) override {
 		assert(false);
 	}
 
-	virtual bool needs_many_samples() const { return true; }
-	virtual bool needs_mipmaps() const { return true; }
-	virtual void add_self_to_effect_chain(std::vector<Effect *> *chain);
-	virtual bool set_float(const std::string &key, float value);
+	void rewrite_graph(EffectChain *graph, Node *self) override;
+	bool set_float(const std::string &key, float value) override;
+	bool set_int(const std::string &key, int value) override;
 	
 private:
+	void update_radius();
+
+	int num_taps;
+	float radius;
 	SingleBlurPassEffect *hpass, *vpass;
+	unsigned input_width, input_height;
 };
 
 class SingleBlurPassEffect : public Effect {
 public:
-	SingleBlurPassEffect();
-	std::string output_fragment_shader();
+	// If parent is non-nullptr, calls to inform_input_size will be forwarded
+	// so that it can make reasonable decisions for both blur passes.
+	SingleBlurPassEffect(BlurEffect *parent);
+	virtual ~SingleBlurPassEffect();
+	std::string effect_type_id() const override { return "SingleBlurPassEffect"; }
 
-	virtual bool needs_many_samples() const { return true; }
-	virtual bool needs_mipmaps() const { return true; }
+	std::string output_fragment_shader() override;
 
-	void set_uniforms(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num);
+	// We want this for the same reason as ResizeEffect; we could end up scaling
+	// down quite a lot.
+	bool needs_texture_bounce() const override { return true; }
+	MipmapRequirements needs_mipmaps() const override { return NEEDS_MIPMAPS; }
+	bool needs_srgb_primaries() const override { return false; }
+	AlphaHandling alpha_handling() const override { return INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK; }
+
+	void inform_input_size(unsigned input_num, unsigned width, unsigned height) override {
+		if (parent != nullptr) {
+			parent->inform_input_size(input_num, width, height);
+		}
+	}
+	bool changes_output_size() const override { return true; }
+	bool sets_virtual_output_size() const override { return true; }
+	bool one_to_one_sampling() const override { return false; }  // Can sample outside the border.
+
+	void get_output_size(unsigned *width, unsigned *height, unsigned *virtual_width, unsigned *virtual_height) const override {
+		*width = this->width;
+		*height = this->height;
+		*virtual_width = this->virtual_width;
+		*virtual_height = this->virtual_height;
+	}
+
+	void set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num) override;
+	void clear_gl_state() override;
 	
 	enum Direction { HORIZONTAL = 0, VERTICAL = 1 };
 
 private:
+	BlurEffect *parent;
+	int num_taps;
 	float radius;
 	Direction direction;
+	int width, height, virtual_width, virtual_height;
+	float *uniform_samples;
 };
 
-#endif // !defined(_BLUR_EFFECT_H)
+}  // namespace movit
+
+#endif // !defined(_MOVIT_BLUR_EFFECT_H)