-#include <math.h>
+#include <epoxy/gl.h>
#include <assert.h>
+#include <math.h>
+#include <algorithm>
#include "blur_effect.h"
#include "effect_chain.h"
+#include "effect_util.h"
#include "util.h"
-#include "opengl.h"
// Must match blur_effect.frag.
#define NUM_TAPS 16
+
+using namespace std;
+
+namespace movit {
BlurEffect::BlurEffect()
- : radius(3.0f)
+ : radius(3.0f),
+ input_width(1280),
+ input_height(720)
{
- hpass = new SingleBlurPassEffect();
- hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL);
- vpass = new SingleBlurPassEffect();
- vpass->set_int("direction", SingleBlurPassEffect::VERTICAL);
+ // The first blur pass will forward resolution information to us.
+ hpass = new SingleBlurPassEffect(this);
+ CHECK(hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL));
+ vpass = new SingleBlurPassEffect(NULL);
+ CHECK(vpass->set_int("direction", SingleBlurPassEffect::VERTICAL));
update_radius();
}
graph->replace_receiver(self, hpass_node);
graph->replace_sender(self, vpass_node);
self->disabled = true;
+}
+
+// We get this information forwarded from the first blur pass,
+// since we are not part of the chain ourselves.
+void BlurEffect::inform_input_size(unsigned input_num, unsigned width, unsigned height)
+{
+ assert(input_num == 0);
+ assert(width != 0);
+ assert(height != 0);
+ input_width = width;
+ input_height = height;
+ update_radius();
}
void BlurEffect::update_radius()
// We only have 16 taps to work with on each side, and we want that to
// reach out to about 2.5*sigma. Bump up the mipmap levels (giving us
// box blurs) until we have what we need.
- //
- // TODO: Consider the actual width and height (they influence mipmap
- // sizes subtly).
- unsigned base_mipmap_level = 0;
+ unsigned mipmap_width = input_width, mipmap_height = input_height;
float adjusted_radius = radius;
- while (adjusted_radius * 1.5f > NUM_TAPS / 2) {
- ++base_mipmap_level;
- adjusted_radius /= 2.0f;
+ while ((mipmap_width > 1 || mipmap_height > 1) && adjusted_radius * 1.5f > NUM_TAPS / 2) {
+ // Find the next mipmap size (round down, minimum 1 pixel).
+ mipmap_width = max(mipmap_width / 2, 1u);
+ mipmap_height = max(mipmap_height / 2, 1u);
+
+ // Approximate when mipmap sizes are odd, but good enough.
+ adjusted_radius = radius * float(mipmap_width) / float(input_width);
}
bool ok = hpass->set_float("radius", adjusted_radius);
- ok |= hpass->set_int("width", 1280 / (1 << base_mipmap_level)); // FIXME
- ok |= hpass->set_int("height", 720 / (1 << base_mipmap_level)); // FIXME
+ ok |= hpass->set_int("width", mipmap_width);
+ ok |= hpass->set_int("height", mipmap_height);
+ ok |= hpass->set_int("virtual_width", mipmap_width);
+ ok |= hpass->set_int("virtual_height", mipmap_height);
ok |= vpass->set_float("radius", adjusted_radius);
- ok |= vpass->set_int("width", 1280 / (1 << base_mipmap_level)); // FIXME
- ok |= vpass->set_int("height", 720 / (1 << base_mipmap_level)); // FIXME
+ ok |= vpass->set_int("width", mipmap_width);
+ ok |= vpass->set_int("height", mipmap_height);
+ ok |= vpass->set_int("virtual_width", input_width);
+ ok |= vpass->set_int("virtual_height", input_height);
assert(ok);
}
-bool BlurEffect::set_float(const std::string &key, float value) {
+bool BlurEffect::set_float(const string &key, float value) {
if (key == "radius") {
radius = value;
update_radius();
return false;
}
-SingleBlurPassEffect::SingleBlurPassEffect()
- : radius(3.0f),
+SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent)
+ : parent(parent),
+ radius(3.0f),
direction(HORIZONTAL),
width(1280),
height(720)
register_int("direction", (int *)&direction);
register_int("width", &width);
register_int("height", &height);
+ register_int("virtual_width", &virtual_width);
+ register_int("virtual_height", &virtual_height);
}
-std::string SingleBlurPassEffect::output_fragment_shader()
+string SingleBlurPassEffect::output_fragment_shader()
{
- return read_file("blur_effect.frag");
+ char buf[256];
+ sprintf(buf, "#define DIRECTION_VERTICAL %d\n", (direction == VERTICAL));
+ return buf + read_file("blur_effect.frag");
}
-void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
{
Effect::set_gl_state(glsl_program_num, prefix, sampler_num);
} else {
float sum = 0.0f;
for (unsigned i = 0; i < NUM_TAPS + 1; ++i) {
- float z = i / radius;
-
// Gaussian blur is a common, but maybe not the prettiest choice;
// it can feel a bit too blurry in the fine detail and too little
// long-tail. This is a simple logistic distribution, which has
// a narrower peak but longer tails.
+ //
+ // We interpret the radius as sigma, similar to Gaussian blur.
+ // Wikipedia says that sigma² = pi² s² / 3, which yields:
+ const float s = (sqrt(3.0) / M_PI) * radius;
+ float z = i / (2.0 * s);
+
weight[i] = 1.0f / (cosh(z) * cosh(z));
if (i == 0) {
//
// We pack the parameters into a float4: The relative sample coordinates
// in (x,y), and the weight in z. w is unused.
- float samples[4 * (NUM_TAPS / 2 + 1)];
+ float samples[2 * (NUM_TAPS / 2 + 1)];
// Center sample.
- samples[4 * 0 + 0] = 0.0f;
- samples[4 * 0 + 1] = 0.0f;
- samples[4 * 0 + 2] = weight[0];
- samples[4 * 0 + 3] = 0.0f;
+ samples[2 * 0 + 0] = 0.0f;
+ samples[2 * 0 + 1] = weight[0];
// All other samples.
for (unsigned i = 1; i < NUM_TAPS / 2 + 1; ++i) {
float w2 = weight[base_pos + 1];
float offset, total_weight;
- if (w1 + w2 < 1e-6) {
- offset = 0.5f;
- total_weight = 0.0f;
- } else {
- offset = w2 / (w1 + w2);
- total_weight = w1 + w2;
- }
- float x = 0.0f, y = 0.0f;
+ combine_two_samples(w1, w2, &offset, &total_weight, NULL);
if (direction == HORIZONTAL) {
- x = (base_pos + offset) / (float)width;
+ samples[2 * i + 0] = (base_pos + offset) / (float)width;
} else if (direction == VERTICAL) {
- y = (base_pos + offset) / (float)height;
+ samples[2 * i + 0] = (base_pos + offset) / (float)height;
} else {
assert(false);
}
- samples[4 * i + 0] = x;
- samples[4 * i + 1] = y;
- samples[4 * i + 2] = total_weight;
- samples[4 * i + 3] = 0.0f;
+ samples[2 * i + 1] = total_weight;
}
- set_uniform_vec4_array(glsl_program_num, prefix, "samples", samples, NUM_TAPS / 2 + 1);
+ set_uniform_vec2_array(glsl_program_num, prefix, "samples", samples, NUM_TAPS / 2 + 1);
}
void SingleBlurPassEffect::clear_gl_state()
{
}
+
+} // namespace movit