-#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();
- std::string output_fragment_shader();
- virtual bool needs_many_samples() const { return true; }
- virtual bool needs_mipmaps() const { return true; }
+ std::string effect_type_id() const override { return "BlurEffect"; }
+
+ void inform_input_size(unsigned input_num, unsigned width, unsigned height) override;
- void set_uniforms(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num);
+ std::string output_fragment_shader() override {
+ assert(false);
+ }
+ void set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num) override {
+ assert(false);
+ }
+ 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:
+ // 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"; }
+
+ std::string output_fragment_shader() override;
+
+ // 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)