-#include <math.h>
+#include <GL/glew.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),
{
// The first blur pass will forward resolution information to us.
hpass = new SingleBlurPassEffect(this);
- hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL);
+ CHECK(hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL));
vpass = new SingleBlurPassEffect(NULL);
- vpass->set_int("direction", SingleBlurPassEffect::VERTICAL);
+ CHECK(vpass->set_int("direction", SingleBlurPassEffect::VERTICAL));
update_radius();
}
float adjusted_radius = radius;
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 = std::max(mipmap_width / 2, 1u);
- mipmap_height = std::max(mipmap_height / 2, 1u);
+ 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", 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", 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();
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");
}
-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) {
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;
- }
+ combine_two_samples(w1, w2, &offset, &total_weight, NULL);
+
float x = 0.0f, y = 0.0f;
if (direction == HORIZONTAL) {
void SingleBlurPassEffect::clear_gl_state()
{
}
+
+} // namespace movit