X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=blur_effect.cpp;h=027d25b1113ef83e37f472e5dc561b95251a5484;hp=285169851705309c0867b50bac0408c6284ca1a2;hb=95edbfccb0843da3cc105dadc5bc6d8e102f6071;hpb=5058b68995b5d39042df42df06d55559ee535d38 diff --git a/blur_effect.cpp b/blur_effect.cpp index 2851698..027d25b 100644 --- a/blur_effect.cpp +++ b/blur_effect.cpp @@ -1,112 +1,158 @@ -#define GL_GLEXT_PROTOTYPES 1 - -#include -#include -#include +#include #include +#include +#include #include "blur_effect.h" +#include "effect_chain.h" +#include "effect_util.h" #include "util.h" -// Must match blur_effect.frag. -#define NUM_TAPS 16 +using namespace std; + +namespace movit { -BlurEffect::BlurEffect() { - hpass = new SingleBlurPassEffect(); - hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL); - vpass = new SingleBlurPassEffect(); - vpass->set_int("direction", SingleBlurPassEffect::VERTICAL); +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::add_self_to_effect_chain(EffectChain *chain, const std::vector &inputs) { - assert(inputs.size() == 1); - hpass->add_self_to_effect_chain(chain, inputs); +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); - std::vector vpass_inputs; - vpass_inputs.push_back(hpass); - vpass->add_self_to_effect_chain(chain, vpass_inputs); + // 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 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) { - 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() +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_uniforms(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_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; - } - - 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(); + 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) { @@ -115,14 +161,11 @@ void SingleBlurPassEffect::set_uniforms(GLuint glsl_program_num, const std::stri 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 @@ -133,72 +176,40 @@ void SingleBlurPassEffect::set_uniforms(GLuint glsl_program_num, const std::stri // // 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; - } -#if 0 - // hack for easier visualization - offset = 0.5f; - total_weight = 8.0f; -#endif - float x = 0.0f, y = 0.0f; + combine_two_samples(w1, w2, &offset, &total_weight, NULL); if (direction == HORIZONTAL) { - x = (base_pos + offset) / (float)texture_size; + samples[2 * i + 0] = (base_pos + offset) / (float)width; } else if (direction == VERTICAL) { - y = (base_pos + offset) / (float)texture_size; + 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); -#else - // Boring, at-whole-pixels sampling. - float samples[4 * NUM_TAPS]; + set_uniform_vec2_array(glsl_program_num, prefix, "samples", samples, num_taps / 2 + 1); - // 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; + delete[] samples; +} - set_uniform_vec4_array(glsl_program_num, prefix, "samples", samples, NUM_TAPS + 1); -#endif +void SingleBlurPassEffect::clear_gl_state() +{ } + +} // namespace movit