#include "effect_util.h"
#include "util.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)
{
// 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 = max(mipmap_width / 2, 1u);
mipmap_height = max(mipmap_height / 2, 1u);
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);
}
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("height", &height);
register_int("virtual_width", &virtual_width);
register_int("virtual_height", &virtual_height);
+ register_int("num_taps", &num_taps);
}
string SingleBlurPassEffect::output_fragment_shader()
{
char buf[256];
- sprintf(buf, "#define DIRECTION_VERTICAL %d\n", (direction == VERTICAL));
+ sprintf(buf, "#define DIRECTION_VERTICAL %d\n#define NUM_TAPS %d\n",
+ (direction == VERTICAL), num_taps);
return buf + read_file("blur_effect.frag");
}
// 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) {
+ 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
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[2 * (NUM_TAPS / 2 + 1)];
+ float* samples = new float[2 * (num_taps / 2 + 1)];
// Center sample.
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];
samples[2 * i + 1] = total_weight;
}
- set_uniform_vec2_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()
// DIRECTION_VERTICAL will be #defined to 1 if we are doing a vertical blur,
// 0 otherwise.
-#define NUM_TAPS 16
-
uniform vec2 PREFIX(samples)[NUM_TAPS / 2 + 1];
vec4 FUNCNAME(vec2 tc) {
// 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>
virtual void rewrite_graph(EffectChain *graph, Node *self);
virtual bool set_float(const std::string &key, float value);
+ virtual bool set_int(const std::string &key, int value);
private:
void update_radius();
-
+
+ int num_taps;
float radius;
SingleBlurPassEffect *hpass, *vpass;
unsigned input_width, input_height;
private:
BlurEffect *parent;
+ int num_taps;
float radius;
Direction direction;
int width, height, virtual_width, virtual_height;
};
float out_data[size * size];
- EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
- Effect *blur_effect = tester.get_chain()->add_effect(new BlurEffect());
- ASSERT_TRUE(blur_effect->set_float("radius", 0.0f));
- tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
-
- expect_equal(data, out_data, size, size);
+ for (int num_taps = 2; num_taps < 20; num_taps += 2) {
+ EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+ Effect *blur_effect = tester.get_chain()->add_effect(new BlurEffect());
+ ASSERT_TRUE(blur_effect->set_float("radius", 0.0f));
+ ASSERT_TRUE(blur_effect->set_int("num_taps", num_taps));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ expect_equal(data, out_data, size, size);
+ }
}
namespace {
expect_equal(expected_data, out_data, size, size, 0.1f, 1e-3);
}
+TEST(BlurEffectTest, BlurTwoDotsSmallRadiusFewerTaps) {
+ const float sigma = 3.0f;
+ const int size = 32;
+ const int x1 = 8;
+ const int y1 = 8;
+ const int x2 = 20;
+ const int y2 = 10;
+
+ float data[size * size], out_data[size * size], expected_data[size * size];
+ memset(data, 0, sizeof(data));
+ memset(expected_data, 0, sizeof(expected_data));
+
+ data[y1 * size + x1] = 1.0f;
+ data[y2 * size + x2] = 1.0f;
+
+ add_blurred_point(expected_data, size, x1, y1, 1.0f, sigma);
+ add_blurred_point(expected_data, size, x2, y2, 1.0f, sigma);
+
+ EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+ Effect *blur_effect = tester.get_chain()->add_effect(new BlurEffect());
+ ASSERT_TRUE(blur_effect->set_float("radius", sigma));
+ ASSERT_TRUE(blur_effect->set_int("num_taps", 10));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ // Set the limits a bit tighter than usual, since there is so little energy in here.
+ expect_equal(expected_data, out_data, size, size, 1e-3, 1e-5);
+}
+
} // namespace movit