X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=blur_effect.cpp;h=80aef747c8a6bba0da40f20b0a06e91b810e2937;hp=c8cf539e0542a3184d9f6d1f1d7d23acc77752d6;hb=2b6a8585772bf9ae742a2ee36144a0cdd5ba0524;hpb=3d1f6c11c53cd9d3d5c1fb60f4accf050b7f135e diff --git a/blur_effect.cpp b/blur_effect.cpp index c8cf539..80aef74 100644 --- a/blur_effect.cpp +++ b/blur_effect.cpp @@ -1,32 +1,52 @@ -#include +#include #include +#include +#include #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; BlurEffect::BlurEffect() - : radius(3.0f) + : radius(3.0f), + input_width(1280), + input_height(720) { - hpass = new SingleBlurPassEffect(); - hpass->set_int("direction", SingleBlurPassEffect::HORIZONTAL); - vpass = new SingleBlurPassEffect(); - vpass->set_int("direction", SingleBlurPassEffect::VERTICAL); + // 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) +void BlurEffect::rewrite_graph(EffectChain *graph, Node *self) { - assert(inputs.size() == 1); - hpass->add_self_to_effect_chain(chain, inputs); - - std::vector vpass_inputs; - vpass_inputs.push_back(hpass); - vpass->add_self_to_effect_chain(chain, vpass_inputs); + 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() @@ -34,28 +54,33 @@ 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. - // - // TODO: Consider the actual width and height (they influence mipmap - // sizes subtly). - unsigned base_mipmap_level = 0; + unsigned mipmap_width = input_width, mipmap_height = input_height; float adjusted_radius = radius; - while (adjusted_radius * 1.5f > NUM_TAPS / 2) { - ++base_mipmap_level; - adjusted_radius /= 2.0f; + 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); } bool ok = hpass->set_float("radius", adjusted_radius); - ok |= hpass->set_int("width", 1280 / (1 << base_mipmap_level)); // FIXME - ok |= hpass->set_int("height", 720 / (1 << base_mipmap_level)); // FIXME + 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", 1280 / (1 << base_mipmap_level)); // FIXME - ok |= vpass->set_int("height", 720 / (1 << base_mipmap_level)); // FIXME + 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(); @@ -64,8 +89,9 @@ bool BlurEffect::set_float(const std::string &key, float value) { return false; } -SingleBlurPassEffect::SingleBlurPassEffect() - : radius(3.0f), +SingleBlurPassEffect::SingleBlurPassEffect(BlurEffect *parent) + : parent(parent), + radius(3.0f), direction(HORIZONTAL), width(1280), height(720) @@ -74,14 +100,16 @@ SingleBlurPassEffect::SingleBlurPassEffect() 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); @@ -96,12 +124,16 @@ void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const std::stri } 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) { @@ -140,13 +172,8 @@ void SingleBlurPassEffect::set_gl_state(GLuint glsl_program_num, const std::stri 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) {