-#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),
+ : num_taps(16),
+ radius(3.0f),
input_width(1280),
input_height(720)
{
// 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();
}
// box blurs) until we have what we need.
unsigned mipmap_width = input_width, mipmap_height = input_height;
float adjusted_radius = radius;
- while ((mipmap_width > 1 || mipmap_height > 1) && adjusted_radius * 1.5f > NUM_TAPS / 2) {
+ 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 |= hpass->set_int("num_taps", num_taps);
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);
+ ok |= vpass->set_int("num_taps", num_taps);
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;
}
+bool BlurEffect::set_int(const string &key, int value) {
+ if (key == "num_taps") {
+ if (value < 2 || value % 2 != 0) {
+ return false;
+ }
+ num_taps = value;
+ update_radius();
+ return true;
+ }
+ return false;
+}
+
SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent)
: parent(parent),
+ num_taps(16),
radius(3.0f),
direction(HORIZONTAL),
width(1280),
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);
+ register_int("num_taps", &num_taps);
}
-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#define NUM_TAPS %d\n",
+ (direction == VERTICAL), num_taps);
+ 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);
// Compute the weights; they will be symmetrical, so we only compute
// the right side.
- float weight[NUM_TAPS + 1];
+ float* weight = new float[num_taps + 1];
if (radius < 1e-3) {
weight[0] = 1.0f;
- for (unsigned i = 1; i < NUM_TAPS + 1; ++i) {
+ for (int i = 1; i < num_taps + 1; ++i) {
weight[i] = 0.0f;
}
} else {
float sum = 0.0f;
- for (unsigned i = 0; i < NUM_TAPS + 1; ++i) {
- float z = i / radius;
-
+ for (int i = 0; i < num_taps + 1; ++i) {
// 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) {
sum += 2.0f * weight[i];
}
}
- for (unsigned i = 0; i < NUM_TAPS + 1; ++i) {
+ for (int i = 0; i < num_taps + 1; ++i) {
weight[i] /= sum;
}
}
//
// 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 = new float[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) {
+ for (int i = 1; i < num_taps / 2 + 1; ++i) {
unsigned base_pos = i * 2 - 1;
float w1 = weight[base_pos];
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;
-
+ int size;
if (direction == HORIZONTAL) {
- x = (base_pos + offset) / (float)width;
+ size = width;
} else if (direction == VERTICAL) {
- y = (base_pos + offset) / (float)height;
+ size = 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;
+ float pos1 = base_pos / (float)size;
+ float pos2 = (base_pos + 1) / (float)size;
+ float pos, total_weight;
+ combine_two_samples(w1, w2, pos1, pos2, size, &pos, &total_weight, NULL);
+
+ samples[2 * i + 0] = pos;
+ 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);
+
+ delete[] weight;
+ delete[] samples;
}
void SingleBlurPassEffect::clear_gl_state()
{
}
+
+} // namespace movit