-#define GL_GLEXT_PROTOTYPES 1
-
-#include <math.h>
-#include <GL/gl.h>
-#include <GL/glext.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 "init.h"
#include "util.h"
-// Must match blur_effect.frag.
-#define NUM_TAPS 16
+using namespace std;
+
+namespace movit {
+
+BlurEffect::BlurEffect()
+ : 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);
+ CHECK(hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL));
+ vpass = new SingleBlurPassEffect(NULL);
+ CHECK(vpass->set_int("direction", SingleBlurPassEffect::VERTICAL));
+
+ update_radius();
+}
+
+void BlurEffect::rewrite_graph(EffectChain *graph, Node *self)
+{
+ Node *hpass_node = graph->add_node(hpass);
+ Node *vpass_node = graph->add_node(vpass);
+ graph->connect_nodes(hpass_node, vpass_node);
+ 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.
+ 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) {
+ // 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);
+ }
-BlurEffect::BlurEffect() {
- hpass = new SingleBlurPassEffect();
- hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL);
- vpass = new SingleBlurPassEffect();
- vpass->set_int("direction", SingleBlurPassEffect::VERTICAL);
+ 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);
}
-void BlurEffect::add_self_to_effect_chain(std::vector<Effect *> *chain) {
- hpass->add_self_to_effect_chain(chain);
- vpass->add_self_to_effect_chain(chain);
+bool BlurEffect::set_float(const string &key, float value) {
+ if (key == "radius") {
+ radius = value;
+ update_radius();
+ return true;
+ }
+ return false;
}
-bool BlurEffect::set_float(const std::string &key, float value) {
- if (!hpass->set_float(key, value)) {
- 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 vpass->set_float(key, value);
+ return false;
}
-SingleBlurPassEffect::SingleBlurPassEffect()
- : radius(3.0f),
- direction(HORIZONTAL)
+SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent)
+ : parent(parent),
+ num_taps(16),
+ radius(3.0f),
+ direction(HORIZONTAL),
+ width(1280),
+ height(720),
+ uniform_samples(NULL)
{
- register_float("radius", (float *)&radius);
+ register_float("radius", &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);
+ register_int("num_taps", &num_taps);
}
-std::string SingleBlurPassEffect::output_fragment_shader()
+SingleBlurPassEffect::~SingleBlurPassEffect()
{
- return read_file("blur_effect.frag");
+ delete[] uniform_samples;
}
-void SingleBlurPassEffect::set_uniforms(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+string SingleBlurPassEffect::output_fragment_shader()
{
- Effect::set_uniforms(glsl_program_num, prefix, sampler_num);
-
- int base_texture_size, texture_size;
- if (direction == HORIZONTAL) {
- base_texture_size = texture_size = 1280; // FIXME
- } else if (direction == VERTICAL) {
- base_texture_size = texture_size = 720; // FIXME
- } else {
- assert(false);
- }
-
- // 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.
- //
- // FIXME: we really need to pick the same mipmap level for both horizontal and vertical!
- unsigned base_mipmap_level = 0;
- float adjusted_radius = radius;
- while (texture_size > 1 && adjusted_radius * 2.5f > NUM_TAPS / 2) {
- ++base_mipmap_level;
- texture_size /= 2; // Rounding down.
- adjusted_radius = radius * float(texture_size) / float(base_texture_size);
- }
-
- // In the second pass, we do the same, but don't sample from a mipmap;
- // that would re-blur the other direction in an ugly fashion, and we already
- // have the vertical box blur we need from that pass.
- //
- // TODO: We really need to present horizontal+vertical as a unit;
- // currently, there's really no guarantee vertical blur is the second pass.
- if (direction == VERTICAL) {
- base_mipmap_level = 0;
- }
+ char buf[256];
+ sprintf(buf, "#define DIRECTION_VERTICAL %d\n#define NUM_TAPS %d\n",
+ (direction == VERTICAL), num_taps);
+ uniform_samples = new float[2 * (num_taps / 2 + 1)];
+ register_uniform_vec2_array("samples", uniform_samples, num_taps / 2 + 1);
+ return buf + read_file("blur_effect.frag");
+}
- glActiveTexture(GL_TEXTURE0);
- check_error();
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, base_mipmap_level);
- check_error();
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, base_mipmap_level);
- check_error();
+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 / adjusted_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;
}
}
-#if 0
- // NOTE: This is currently broken.
-
// Since the GPU gives us bilinear sampling for free, we can get two
// samples for the price of one (for every but the center sample,
// in which case this trick doesn't buy us anything). Simply sample
//
// 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)];
// 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;
+ uniform_samples[2 * 0 + 0] = 0.0f;
+ uniform_samples[2 * 0 + 1] = weight[0];
+
+ int size;
+ if (direction == HORIZONTAL) {
+ size = width;
+ } else if (direction == VERTICAL) {
+ size = height;
+ } else {
+ assert(false);
+ }
+ float num_subtexels = size / movit_texel_subpixel_precision;
+ float inv_num_subtexels = movit_texel_subpixel_precision / size;
// 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;
- }
-#if 0
- // hack for easier visualization
- offset = 0.5f;
- total_weight = 8.0f;
-#endif
- float x = 0.0f, y = 0.0f;
-
- if (direction == HORIZONTAL) {
- x = (base_pos + offset) / (float)texture_size;
- } else if (direction == VERTICAL) {
- y = (base_pos + offset) / (float)texture_size;
- } else {
- assert(false);
- }
+ float pos1 = base_pos / (float)size;
+ float pos2 = (base_pos + 1) / (float)size;
+ float pos, total_weight;
+ combine_two_samples(w1, w2, pos1, pos2, num_subtexels, inv_num_subtexels, &pos, &total_weight, NULL);
- samples[4 * i + 0] = x;
- samples[4 * i + 1] = y;
- samples[4 * i + 2] = total_weight;
- samples[4 * i + 3] = 0.0f;
+ uniform_samples[2 * i + 0] = pos;
+ uniform_samples[2 * i + 1] = total_weight;
}
- set_uniform_vec4_array(glsl_program_num, prefix, "samples", samples, NUM_TAPS / 2 + 1);
-#else
- // Boring, at-whole-pixels sampling.
- float samples[4 * NUM_TAPS];
-
- // All other samples.
- for (unsigned i = 0; i < NUM_TAPS + 1; ++i) {
- float x = 0.0f, y = 0.0f;
-
- if (direction == HORIZONTAL) {
- x = i / (float)texture_size;
- } else if (direction == VERTICAL) {
- y = i / (float)texture_size;
- } else {
- assert(false);
- }
-
- samples[4 * i + 0] = x;
- samples[4 * i + 1] = y;
- samples[4 * i + 2] = weight[i];
- samples[4 * i + 3] = 0.0f;
- }
+ delete[] weight;
+}
- set_uniform_vec4_array(glsl_program_num, prefix, "samples", samples, NUM_TAPS + 1);
-#endif
+void SingleBlurPassEffect::clear_gl_state()
+{
}
+
+} // namespace movit
projects / movit / blobdiff