6 #include <SDL2/SDL_error.h>
7 #include <SDL2/SDL_events.h>
8 #include <SDL2/SDL_image.h>
9 #include <SDL2/SDL_keyboard.h>
10 #include <SDL2/SDL_mouse.h>
11 #include <SDL2/SDL_video.h>
19 #include "gpu_timers.h"
29 #define BUFFER_OFFSET(i) ((char *)nullptr + (i))
35 // Weighting constants for the different parts of the variational refinement.
36 // These don't correspond 1:1 to the values given in the DIS paper,
37 // since we have different normalizations and ranges in some cases.
38 // These are found through a simple grid search on some MPI-Sintel data,
39 // although the error (EPE) seems to be fairly insensitive to the precise values.
40 // Only the relative values matter, so we fix alpha (the smoothness constant)
41 // at unity and tweak the others.
42 static float vr_alpha = 1.0f, vr_delta = 0.25f, vr_gamma = 0.25f;
44 bool enable_timing = true;
45 bool detailed_timing = false;
46 bool enable_warmup = false;
47 bool in_warmup = false;
48 bool enable_variational_refinement = true; // Just for debugging.
49 bool enable_interpolation = false;
51 // Some global OpenGL objects.
52 // TODO: These should really be part of DISComputeFlow.
53 GLuint nearest_sampler, linear_sampler, zero_border_sampler;
56 // Structures for asynchronous readback. We assume everything is the same size (and GL_RG16F).
57 struct ReadInProgress {
59 string filename0, filename1;
60 string flow_filename, ppm_filename; // Either may be empty for no write.
62 stack<GLuint> spare_pbos;
63 deque<ReadInProgress> reads_in_progress;
65 int find_num_levels(int width, int height)
68 for (int w = width, h = height; w > 1 || h > 1; ) {
76 string read_file(const string &filename)
78 FILE *fp = fopen(filename.c_str(), "r");
80 perror(filename.c_str());
84 int ret = fseek(fp, 0, SEEK_END);
86 perror("fseek(SEEK_END)");
92 ret = fseek(fp, 0, SEEK_SET);
94 perror("fseek(SEEK_SET)");
100 ret = fread(&str[0], size, 1, fp);
106 fprintf(stderr, "Short read when trying to read %d bytes from %s\n",
107 size, filename.c_str());
116 GLuint compile_shader(const string &shader_src, GLenum type)
118 GLuint obj = glCreateShader(type);
119 const GLchar* source[] = { shader_src.data() };
120 const GLint length[] = { (GLint)shader_src.size() };
121 glShaderSource(obj, 1, source, length);
122 glCompileShader(obj);
124 GLchar info_log[4096];
125 GLsizei log_length = sizeof(info_log) - 1;
126 glGetShaderInfoLog(obj, log_length, &log_length, info_log);
127 info_log[log_length] = 0;
128 if (strlen(info_log) > 0) {
129 fprintf(stderr, "Shader compile log: %s\n", info_log);
133 glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
134 if (status == GL_FALSE) {
135 // Add some line numbers to easier identify compile errors.
136 string src_with_lines = "/* 1 */ ";
138 for (char ch : shader_src) {
139 src_with_lines.push_back(ch);
142 snprintf(buf, sizeof(buf), "/* %3zu */ ", ++lineno);
143 src_with_lines += buf;
147 fprintf(stderr, "Failed to compile shader:\n%s\n", src_with_lines.c_str());
159 GLuint load_texture(const char *filename, unsigned *width_ret, unsigned *height_ret, MipmapPolicy mipmaps)
161 SDL_Surface *surf = IMG_Load(filename);
162 if (surf == nullptr) {
163 fprintf(stderr, "IMG_Load(%s): %s\n", filename, IMG_GetError());
167 // For whatever reason, SDL doesn't support converting to YUV surfaces
168 // nor grayscale, so we'll do it ourselves.
169 SDL_Surface *rgb_surf = SDL_ConvertSurfaceFormat(surf, SDL_PIXELFORMAT_RGBA32, /*flags=*/0);
170 if (rgb_surf == nullptr) {
171 fprintf(stderr, "SDL_ConvertSurfaceFormat(%s): %s\n", filename, SDL_GetError());
175 SDL_FreeSurface(surf);
177 unsigned width = rgb_surf->w, height = rgb_surf->h;
178 const uint8_t *sptr = (uint8_t *)rgb_surf->pixels;
179 unique_ptr<uint8_t[]> pix(new uint8_t[width * height * 4]);
181 // Extract the Y component, and convert to bottom-left origin.
182 for (unsigned y = 0; y < height; ++y) {
183 unsigned y2 = height - 1 - y;
184 memcpy(pix.get() + y * width * 4, sptr + y2 * rgb_surf->pitch, width * 4);
186 SDL_FreeSurface(rgb_surf);
188 int num_levels = (mipmaps == WITH_MIPMAPS) ? find_num_levels(width, height) : 1;
191 glCreateTextures(GL_TEXTURE_2D, 1, &tex);
192 glTextureStorage2D(tex, num_levels, GL_RGBA8, width, height);
193 glTextureSubImage2D(tex, 0, 0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, pix.get());
195 if (mipmaps == WITH_MIPMAPS) {
196 glGenerateTextureMipmap(tex);
200 *height_ret = height;
205 GLuint link_program(GLuint vs_obj, GLuint fs_obj)
207 GLuint program = glCreateProgram();
208 glAttachShader(program, vs_obj);
209 glAttachShader(program, fs_obj);
210 glLinkProgram(program);
212 glGetProgramiv(program, GL_LINK_STATUS, &success);
213 if (success == GL_FALSE) {
214 GLchar error_log[1024] = {0};
215 glGetProgramInfoLog(program, 1024, nullptr, error_log);
216 fprintf(stderr, "Error linking program: %s\n", error_log);
222 void bind_sampler(GLuint program, GLint location, GLuint texture_unit, GLuint tex, GLuint sampler)
224 if (location == -1) {
228 glBindTextureUnit(texture_unit, tex);
229 glBindSampler(texture_unit, sampler);
230 glProgramUniform1i(program, location, texture_unit);
233 template<size_t num_elements>
234 void PersistentFBOSet<num_elements>::render_to(const array<GLuint, num_elements> &textures)
236 auto it = fbos.find(textures);
237 if (it != fbos.end()) {
238 glBindFramebuffer(GL_FRAMEBUFFER, it->second);
243 glCreateFramebuffers(1, &fbo);
244 GLenum bufs[num_elements];
245 for (size_t i = 0; i < num_elements; ++i) {
246 glNamedFramebufferTexture(fbo, GL_COLOR_ATTACHMENT0 + i, textures[i], 0);
247 bufs[i] = GL_COLOR_ATTACHMENT0 + i;
249 glNamedFramebufferDrawBuffers(fbo, num_elements, bufs);
251 fbos[textures] = fbo;
252 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
255 template<size_t num_elements>
256 void PersistentFBOSetWithDepth<num_elements>::render_to(GLuint depth_rb, const array<GLuint, num_elements> &textures)
258 auto key = make_pair(depth_rb, textures);
260 auto it = fbos.find(key);
261 if (it != fbos.end()) {
262 glBindFramebuffer(GL_FRAMEBUFFER, it->second);
267 glCreateFramebuffers(1, &fbo);
268 GLenum bufs[num_elements];
269 glNamedFramebufferRenderbuffer(fbo, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth_rb);
270 for (size_t i = 0; i < num_elements; ++i) {
271 glNamedFramebufferTexture(fbo, GL_COLOR_ATTACHMENT0 + i, textures[i], 0);
272 bufs[i] = GL_COLOR_ATTACHMENT0 + i;
274 glNamedFramebufferDrawBuffers(fbo, num_elements, bufs);
277 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
280 GrayscaleConversion::GrayscaleConversion()
282 gray_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
283 gray_fs_obj = compile_shader(read_file("gray.frag"), GL_FRAGMENT_SHADER);
284 gray_program = link_program(gray_vs_obj, gray_fs_obj);
286 // Set up the VAO containing all the required position/texcoord data.
287 glCreateVertexArrays(1, &gray_vao);
288 glBindVertexArray(gray_vao);
290 GLint position_attrib = glGetAttribLocation(gray_program, "position");
291 glEnableVertexArrayAttrib(gray_vao, position_attrib);
292 glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
294 uniform_tex = glGetUniformLocation(gray_program, "tex");
297 void GrayscaleConversion::exec(GLint tex, GLint gray_tex, int width, int height, int num_layers)
299 glUseProgram(gray_program);
300 bind_sampler(gray_program, uniform_tex, 0, tex, nearest_sampler);
302 glViewport(0, 0, width, height);
303 fbos.render_to(gray_tex);
304 glBindVertexArray(gray_vao);
306 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
311 sobel_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
312 sobel_fs_obj = compile_shader(read_file("sobel.frag"), GL_FRAGMENT_SHADER);
313 sobel_program = link_program(sobel_vs_obj, sobel_fs_obj);
315 uniform_tex = glGetUniformLocation(sobel_program, "tex");
318 void Sobel::exec(GLint tex_view, GLint grad_tex, int level_width, int level_height, int num_layers)
320 glUseProgram(sobel_program);
321 bind_sampler(sobel_program, uniform_tex, 0, tex_view, nearest_sampler);
323 glViewport(0, 0, level_width, level_height);
324 fbos.render_to(grad_tex);
326 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
329 MotionSearch::MotionSearch()
331 motion_vs_obj = compile_shader(read_file("motion_search.vert"), GL_VERTEX_SHADER);
332 motion_fs_obj = compile_shader(read_file("motion_search.frag"), GL_FRAGMENT_SHADER);
333 motion_search_program = link_program(motion_vs_obj, motion_fs_obj);
335 uniform_inv_image_size = glGetUniformLocation(motion_search_program, "inv_image_size");
336 uniform_inv_prev_level_size = glGetUniformLocation(motion_search_program, "inv_prev_level_size");
337 uniform_out_flow_size = glGetUniformLocation(motion_search_program, "out_flow_size");
338 uniform_image_tex = glGetUniformLocation(motion_search_program, "image_tex");
339 uniform_grad_tex = glGetUniformLocation(motion_search_program, "grad_tex");
340 uniform_flow_tex = glGetUniformLocation(motion_search_program, "flow_tex");
343 void MotionSearch::exec(GLuint tex_view, GLuint grad_tex, GLuint flow_tex, GLuint flow_out_tex, int level_width, int level_height, int prev_level_width, int prev_level_height, int width_patches, int height_patches, int num_layers)
345 glUseProgram(motion_search_program);
347 bind_sampler(motion_search_program, uniform_image_tex, 0, tex_view, linear_sampler);
348 bind_sampler(motion_search_program, uniform_grad_tex, 1, grad_tex, nearest_sampler);
349 bind_sampler(motion_search_program, uniform_flow_tex, 2, flow_tex, linear_sampler);
351 glProgramUniform2f(motion_search_program, uniform_inv_image_size, 1.0f / level_width, 1.0f / level_height);
352 glProgramUniform2f(motion_search_program, uniform_inv_prev_level_size, 1.0f / prev_level_width, 1.0f / prev_level_height);
353 glProgramUniform2f(motion_search_program, uniform_out_flow_size, width_patches, height_patches);
355 glViewport(0, 0, width_patches, height_patches);
356 fbos.render_to(flow_out_tex);
357 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
360 Densify::Densify(const OperatingPoint &op)
363 densify_vs_obj = compile_shader(read_file("densify.vert"), GL_VERTEX_SHADER);
364 densify_fs_obj = compile_shader(read_file("densify.frag"), GL_FRAGMENT_SHADER);
365 densify_program = link_program(densify_vs_obj, densify_fs_obj);
367 uniform_patch_size = glGetUniformLocation(densify_program, "patch_size");
368 uniform_image_tex = glGetUniformLocation(densify_program, "image_tex");
369 uniform_flow_tex = glGetUniformLocation(densify_program, "flow_tex");
372 void Densify::exec(GLuint tex_view, GLuint flow_tex, GLuint dense_flow_tex, int level_width, int level_height, int width_patches, int height_patches, int num_layers)
374 glUseProgram(densify_program);
376 bind_sampler(densify_program, uniform_image_tex, 0, tex_view, linear_sampler);
377 bind_sampler(densify_program, uniform_flow_tex, 1, flow_tex, nearest_sampler);
379 glProgramUniform2f(densify_program, uniform_patch_size,
380 float(op.patch_size_pixels) / level_width,
381 float(op.patch_size_pixels) / level_height);
383 glViewport(0, 0, level_width, level_height);
385 glBlendFunc(GL_ONE, GL_ONE);
386 fbos.render_to(dense_flow_tex);
387 glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
388 glClear(GL_COLOR_BUFFER_BIT);
389 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, width_patches * height_patches * num_layers);
394 prewarp_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
395 prewarp_fs_obj = compile_shader(read_file("prewarp.frag"), GL_FRAGMENT_SHADER);
396 prewarp_program = link_program(prewarp_vs_obj, prewarp_fs_obj);
398 uniform_image_tex = glGetUniformLocation(prewarp_program, "image_tex");
399 uniform_flow_tex = glGetUniformLocation(prewarp_program, "flow_tex");
402 void Prewarp::exec(GLuint tex_view, GLuint flow_tex, GLuint I_tex, GLuint I_t_tex, GLuint normalized_flow_tex, int level_width, int level_height, int num_layers)
404 glUseProgram(prewarp_program);
406 bind_sampler(prewarp_program, uniform_image_tex, 0, tex_view, linear_sampler);
407 bind_sampler(prewarp_program, uniform_flow_tex, 1, flow_tex, nearest_sampler);
409 glViewport(0, 0, level_width, level_height);
411 fbos.render_to(I_tex, I_t_tex, normalized_flow_tex);
412 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
415 Derivatives::Derivatives()
417 derivatives_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
418 derivatives_fs_obj = compile_shader(read_file("derivatives.frag"), GL_FRAGMENT_SHADER);
419 derivatives_program = link_program(derivatives_vs_obj, derivatives_fs_obj);
421 uniform_tex = glGetUniformLocation(derivatives_program, "tex");
424 void Derivatives::exec(GLuint input_tex, GLuint I_x_y_tex, GLuint beta_0_tex, int level_width, int level_height, int num_layers)
426 glUseProgram(derivatives_program);
428 bind_sampler(derivatives_program, uniform_tex, 0, input_tex, nearest_sampler);
430 glViewport(0, 0, level_width, level_height);
432 fbos.render_to(I_x_y_tex, beta_0_tex);
433 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
436 ComputeDiffusivity::ComputeDiffusivity()
438 diffusivity_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
439 diffusivity_fs_obj = compile_shader(read_file("diffusivity.frag"), GL_FRAGMENT_SHADER);
440 diffusivity_program = link_program(diffusivity_vs_obj, diffusivity_fs_obj);
442 uniform_flow_tex = glGetUniformLocation(diffusivity_program, "flow_tex");
443 uniform_diff_flow_tex = glGetUniformLocation(diffusivity_program, "diff_flow_tex");
444 uniform_alpha = glGetUniformLocation(diffusivity_program, "alpha");
445 uniform_zero_diff_flow = glGetUniformLocation(diffusivity_program, "zero_diff_flow");
448 void ComputeDiffusivity::exec(GLuint flow_tex, GLuint diff_flow_tex, GLuint diffusivity_tex, int level_width, int level_height, bool zero_diff_flow, int num_layers)
450 glUseProgram(diffusivity_program);
452 bind_sampler(diffusivity_program, uniform_flow_tex, 0, flow_tex, nearest_sampler);
453 bind_sampler(diffusivity_program, uniform_diff_flow_tex, 1, diff_flow_tex, nearest_sampler);
454 glProgramUniform1f(diffusivity_program, uniform_alpha, vr_alpha);
455 glProgramUniform1i(diffusivity_program, uniform_zero_diff_flow, zero_diff_flow);
457 glViewport(0, 0, level_width, level_height);
460 fbos.render_to(diffusivity_tex);
461 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
464 SetupEquations::SetupEquations()
466 equations_vs_obj = compile_shader(read_file("equations.vert"), GL_VERTEX_SHADER);
467 equations_fs_obj = compile_shader(read_file("equations.frag"), GL_FRAGMENT_SHADER);
468 equations_program = link_program(equations_vs_obj, equations_fs_obj);
470 uniform_I_x_y_tex = glGetUniformLocation(equations_program, "I_x_y_tex");
471 uniform_I_t_tex = glGetUniformLocation(equations_program, "I_t_tex");
472 uniform_diff_flow_tex = glGetUniformLocation(equations_program, "diff_flow_tex");
473 uniform_base_flow_tex = glGetUniformLocation(equations_program, "base_flow_tex");
474 uniform_beta_0_tex = glGetUniformLocation(equations_program, "beta_0_tex");
475 uniform_diffusivity_tex = glGetUniformLocation(equations_program, "diffusivity_tex");
476 uniform_gamma = glGetUniformLocation(equations_program, "gamma");
477 uniform_delta = glGetUniformLocation(equations_program, "delta");
478 uniform_zero_diff_flow = glGetUniformLocation(equations_program, "zero_diff_flow");
481 void SetupEquations::exec(GLuint I_x_y_tex, GLuint I_t_tex, GLuint diff_flow_tex, GLuint base_flow_tex, GLuint beta_0_tex, GLuint diffusivity_tex, GLuint equation_red_tex, GLuint equation_black_tex, int level_width, int level_height, bool zero_diff_flow, int num_layers)
483 glUseProgram(equations_program);
485 bind_sampler(equations_program, uniform_I_x_y_tex, 0, I_x_y_tex, nearest_sampler);
486 bind_sampler(equations_program, uniform_I_t_tex, 1, I_t_tex, nearest_sampler);
487 bind_sampler(equations_program, uniform_diff_flow_tex, 2, diff_flow_tex, nearest_sampler);
488 bind_sampler(equations_program, uniform_base_flow_tex, 3, base_flow_tex, nearest_sampler);
489 bind_sampler(equations_program, uniform_beta_0_tex, 4, beta_0_tex, nearest_sampler);
490 bind_sampler(equations_program, uniform_diffusivity_tex, 5, diffusivity_tex, zero_border_sampler);
491 glProgramUniform1f(equations_program, uniform_delta, vr_delta);
492 glProgramUniform1f(equations_program, uniform_gamma, vr_gamma);
493 glProgramUniform1i(equations_program, uniform_zero_diff_flow, zero_diff_flow);
495 glViewport(0, 0, (level_width + 1) / 2, level_height);
497 fbos.render_to(equation_red_tex, equation_black_tex);
498 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
503 sor_vs_obj = compile_shader(read_file("sor.vert"), GL_VERTEX_SHADER);
504 sor_fs_obj = compile_shader(read_file("sor.frag"), GL_FRAGMENT_SHADER);
505 sor_program = link_program(sor_vs_obj, sor_fs_obj);
507 uniform_diff_flow_tex = glGetUniformLocation(sor_program, "diff_flow_tex");
508 uniform_equation_red_tex = glGetUniformLocation(sor_program, "equation_red_tex");
509 uniform_equation_black_tex = glGetUniformLocation(sor_program, "equation_black_tex");
510 uniform_diffusivity_tex = glGetUniformLocation(sor_program, "diffusivity_tex");
511 uniform_phase = glGetUniformLocation(sor_program, "phase");
512 uniform_num_nonzero_phases = glGetUniformLocation(sor_program, "num_nonzero_phases");
515 void SOR::exec(GLuint diff_flow_tex, GLuint equation_red_tex, GLuint equation_black_tex, GLuint diffusivity_tex, int level_width, int level_height, int num_iterations, bool zero_diff_flow, int num_layers, ScopedTimer *sor_timer)
517 glUseProgram(sor_program);
519 bind_sampler(sor_program, uniform_diff_flow_tex, 0, diff_flow_tex, nearest_sampler);
520 bind_sampler(sor_program, uniform_diffusivity_tex, 1, diffusivity_tex, zero_border_sampler);
521 bind_sampler(sor_program, uniform_equation_red_tex, 2, equation_red_tex, nearest_sampler);
522 bind_sampler(sor_program, uniform_equation_black_tex, 3, equation_black_tex, nearest_sampler);
524 if (!zero_diff_flow) {
525 glProgramUniform1i(sor_program, uniform_num_nonzero_phases, 2);
528 // NOTE: We bind to the texture we are rendering from, but we never write any value
529 // that we read in the same shader pass (we call discard for red values when we compute
530 // black, and vice versa), and we have barriers between the passes, so we're fine
532 glViewport(0, 0, level_width, level_height);
534 fbos.render_to(diff_flow_tex);
536 for (int i = 0; i < num_iterations; ++i) {
538 ScopedTimer timer("Red pass", sor_timer);
539 if (zero_diff_flow && i == 0) {
540 glProgramUniform1i(sor_program, uniform_num_nonzero_phases, 0);
542 glProgramUniform1i(sor_program, uniform_phase, 0);
543 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
547 ScopedTimer timer("Black pass", sor_timer);
548 if (zero_diff_flow && i == 0) {
549 glProgramUniform1i(sor_program, uniform_num_nonzero_phases, 1);
551 glProgramUniform1i(sor_program, uniform_phase, 1);
552 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
553 if (zero_diff_flow && i == 0) {
554 glProgramUniform1i(sor_program, uniform_num_nonzero_phases, 2);
556 if (i != num_iterations - 1) {
563 AddBaseFlow::AddBaseFlow()
565 add_flow_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
566 add_flow_fs_obj = compile_shader(read_file("add_base_flow.frag"), GL_FRAGMENT_SHADER);
567 add_flow_program = link_program(add_flow_vs_obj, add_flow_fs_obj);
569 uniform_diff_flow_tex = glGetUniformLocation(add_flow_program, "diff_flow_tex");
572 void AddBaseFlow::exec(GLuint base_flow_tex, GLuint diff_flow_tex, int level_width, int level_height, int num_layers)
574 glUseProgram(add_flow_program);
576 bind_sampler(add_flow_program, uniform_diff_flow_tex, 0, diff_flow_tex, nearest_sampler);
578 glViewport(0, 0, level_width, level_height);
580 glBlendFunc(GL_ONE, GL_ONE);
581 fbos.render_to(base_flow_tex);
583 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
586 ResizeFlow::ResizeFlow()
588 resize_flow_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
589 resize_flow_fs_obj = compile_shader(read_file("resize_flow.frag"), GL_FRAGMENT_SHADER);
590 resize_flow_program = link_program(resize_flow_vs_obj, resize_flow_fs_obj);
592 uniform_flow_tex = glGetUniformLocation(resize_flow_program, "flow_tex");
593 uniform_scale_factor = glGetUniformLocation(resize_flow_program, "scale_factor");
596 void ResizeFlow::exec(GLuint flow_tex, GLuint out_tex, int input_width, int input_height, int output_width, int output_height, int num_layers)
598 glUseProgram(resize_flow_program);
600 bind_sampler(resize_flow_program, uniform_flow_tex, 0, flow_tex, nearest_sampler);
602 glProgramUniform2f(resize_flow_program, uniform_scale_factor, float(output_width) / input_width, float(output_height) / input_height);
604 glViewport(0, 0, output_width, output_height);
606 fbos.render_to(out_tex);
608 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, num_layers);
611 DISComputeFlow::DISComputeFlow(int width, int height, const OperatingPoint &op)
612 : width(width), height(height), op(op), densify(op)
614 // Make some samplers.
615 glCreateSamplers(1, &nearest_sampler);
616 glSamplerParameteri(nearest_sampler, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
617 glSamplerParameteri(nearest_sampler, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
618 glSamplerParameteri(nearest_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
619 glSamplerParameteri(nearest_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
621 glCreateSamplers(1, &linear_sampler);
622 glSamplerParameteri(linear_sampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
623 glSamplerParameteri(linear_sampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
624 glSamplerParameteri(linear_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
625 glSamplerParameteri(linear_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
627 // The smoothness is sampled so that once we get to a smoothness involving
628 // a value outside the border, the diffusivity between the two becomes zero.
629 // Similarly, gradients are zero outside the border, since the edge is taken
631 glCreateSamplers(1, &zero_border_sampler);
632 glSamplerParameteri(zero_border_sampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
633 glSamplerParameteri(zero_border_sampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
634 glSamplerParameteri(zero_border_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
635 glSamplerParameteri(zero_border_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
636 float zero[] = { 0.0f, 0.0f, 0.0f, 0.0f }; // Note that zero alpha means we can also see whether we sampled outside the border or not.
637 glSamplerParameterfv(zero_border_sampler, GL_TEXTURE_BORDER_COLOR, zero);
639 // Initial flow is zero, 1x1.
640 glCreateTextures(GL_TEXTURE_2D_ARRAY, 1, &initial_flow_tex);
641 glTextureStorage3D(initial_flow_tex, 1, GL_RG16F, 1, 1, 1);
642 glClearTexImage(initial_flow_tex, 0, GL_RG, GL_FLOAT, nullptr);
644 // Set up the vertex data that will be shared between all passes.
651 glCreateBuffers(1, &vertex_vbo);
652 glNamedBufferData(vertex_vbo, sizeof(vertices), vertices, GL_STATIC_DRAW);
654 glCreateVertexArrays(1, &vao);
655 glBindVertexArray(vao);
656 glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
658 GLint position_attrib = 0; // Hard-coded in every vertex shader.
659 glEnableVertexArrayAttrib(vao, position_attrib);
660 glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
663 GLuint DISComputeFlow::exec(GLuint tex, FlowDirection flow_direction, ResizeStrategy resize_strategy)
665 int num_layers = (flow_direction == FORWARD_AND_BACKWARD) ? 2 : 1;
666 int prev_level_width = 1, prev_level_height = 1;
667 GLuint prev_level_flow_tex = initial_flow_tex;
671 glBindVertexArray(vao);
673 ScopedTimer total_timer("Compute flow", &timers);
674 for (int level = op.coarsest_level; level >= int(op.finest_level); --level) {
675 char timer_name[256];
676 snprintf(timer_name, sizeof(timer_name), "Level %d (%d x %d)", level, width >> level, height >> level);
677 ScopedTimer level_timer(timer_name, &total_timer);
679 int level_width = width >> level;
680 int level_height = height >> level;
681 float patch_spacing_pixels = op.patch_size_pixels * (1.0f - op.patch_overlap_ratio);
683 // Make sure we have patches at least every Nth pixel, e.g. for width=9
684 // and patch_spacing=3 (the default), we put out patch centers in
685 // x=0, x=3, x=6, x=9, which is four patches. The fragment shader will
686 // lock all the centers to integer coordinates if needed.
687 int width_patches = 1 + ceil(level_width / patch_spacing_pixels);
688 int height_patches = 1 + ceil(level_height / patch_spacing_pixels);
690 // Make sure we always read from the correct level; the chosen
691 // mipmapping could otherwise be rather unpredictable, especially
692 // during motion search.
694 glGenTextures(1, &tex_view);
695 glTextureView(tex_view, GL_TEXTURE_2D_ARRAY, tex, GL_R8, level, 1, 0, 2);
697 // Create a new texture to hold the gradients.
698 GLuint grad_tex = pool.get_texture(GL_R32UI, level_width, level_height, num_layers);
700 // Find the derivative.
702 ScopedTimer timer("Sobel", &level_timer);
703 sobel.exec(tex_view, grad_tex, level_width, level_height, num_layers);
706 // Motion search to find the initial flow. We use the flow from the previous
707 // level (sampled bilinearly; no fancy tricks) as a guide, then search from there.
709 // Create an output flow texture.
710 GLuint flow_out_tex = pool.get_texture(GL_RGB16F, width_patches, height_patches, num_layers);
714 ScopedTimer timer("Motion search", &level_timer);
715 motion_search.exec(tex_view, grad_tex, prev_level_flow_tex, flow_out_tex, level_width, level_height, prev_level_width, prev_level_height, width_patches, height_patches, num_layers);
717 pool.release_texture(grad_tex);
721 // Set up an output texture (cleared in Densify).
722 GLuint dense_flow_tex = pool.get_texture(GL_RGB16F, level_width, level_height, num_layers);
726 ScopedTimer timer("Densification", &level_timer);
727 densify.exec(tex_view, flow_out_tex, dense_flow_tex, level_width, level_height, width_patches, height_patches, num_layers);
729 pool.release_texture(flow_out_tex);
731 // Everything below here in the loop belongs to variational refinement.
732 ScopedTimer varref_timer("Variational refinement", &level_timer);
734 // Prewarping; create I and I_t, and a normalized base flow (so we don't
735 // have to normalize it over and over again, and also save some bandwidth).
737 // During the entire rest of the variational refinement, flow will be measured
738 // in pixels, not 0..1 normalized OpenGL texture coordinates.
739 // This is because variational refinement depends so heavily on derivatives,
740 // which are measured in intensity levels per pixel.
741 GLuint I_tex = pool.get_texture(GL_R16F, level_width, level_height, num_layers);
742 GLuint I_t_tex = pool.get_texture(GL_R16F, level_width, level_height, num_layers);
743 GLuint base_flow_tex = pool.get_texture(GL_RG16F, level_width, level_height, num_layers);
745 ScopedTimer timer("Prewarping", &varref_timer);
746 prewarp.exec(tex_view, dense_flow_tex, I_tex, I_t_tex, base_flow_tex, level_width, level_height, num_layers);
748 pool.release_texture(dense_flow_tex);
749 glDeleteTextures(1, &tex_view);
751 // Calculate I_x and I_y. We're only calculating first derivatives;
752 // the others will be taken on-the-fly in order to sample from fewer
753 // textures overall, since sampling from the L1 cache is cheap.
754 // (TODO: Verify that this is indeed faster than making separate
755 // double-derivative textures.)
756 GLuint I_x_y_tex = pool.get_texture(GL_RG16F, level_width, level_height, num_layers);
757 GLuint beta_0_tex = pool.get_texture(GL_R16F, level_width, level_height, num_layers);
759 ScopedTimer timer("First derivatives", &varref_timer);
760 derivatives.exec(I_tex, I_x_y_tex, beta_0_tex, level_width, level_height, num_layers);
762 pool.release_texture(I_tex);
764 // We need somewhere to store du and dv (the flow increment, relative
765 // to the non-refined base flow u0 and v0). It's initially garbage,
766 // but not read until we've written something sane to it.
767 GLuint diff_flow_tex = pool.get_texture(GL_RG16F, level_width, level_height, num_layers);
769 // And for diffusivity.
770 GLuint diffusivity_tex = pool.get_texture(GL_R16F, level_width, level_height, num_layers);
772 // And finally for the equation set. See SetupEquations for
773 // the storage format.
774 GLuint equation_red_tex = pool.get_texture(GL_RGBA32UI, (level_width + 1) / 2, level_height, num_layers);
775 GLuint equation_black_tex = pool.get_texture(GL_RGBA32UI, (level_width + 1) / 2, level_height, num_layers);
777 for (int outer_idx = 0; outer_idx < level + 1; ++outer_idx) {
778 // Calculate the diffusivity term for each pixel.
780 ScopedTimer timer("Compute diffusivity", &varref_timer);
781 compute_diffusivity.exec(base_flow_tex, diff_flow_tex, diffusivity_tex, level_width, level_height, outer_idx == 0, num_layers);
784 // Set up the 2x2 equation system for each pixel.
786 ScopedTimer timer("Set up equations", &varref_timer);
787 setup_equations.exec(I_x_y_tex, I_t_tex, diff_flow_tex, base_flow_tex, beta_0_tex, diffusivity_tex, equation_red_tex, equation_black_tex, level_width, level_height, outer_idx == 0, num_layers);
790 // Run a few SOR iterations. Note that these are to/from the same texture.
792 ScopedTimer timer("SOR", &varref_timer);
793 sor.exec(diff_flow_tex, equation_red_tex, equation_black_tex, diffusivity_tex, level_width, level_height, 5, outer_idx == 0, num_layers, &timer);
797 pool.release_texture(I_t_tex);
798 pool.release_texture(I_x_y_tex);
799 pool.release_texture(beta_0_tex);
800 pool.release_texture(diffusivity_tex);
801 pool.release_texture(equation_red_tex);
802 pool.release_texture(equation_black_tex);
804 // Add the differential flow found by the variational refinement to the base flow,
805 // giving the final flow estimate for this level.
806 // The output is in diff_flow_tex; we don't need to make a new texture.
808 // Disabling this doesn't save any time (although we could easily make it so that
809 // it is more efficient), but it helps debug the motion search.
810 if (op.variational_refinement) {
811 ScopedTimer timer("Add differential flow", &varref_timer);
812 add_base_flow.exec(base_flow_tex, diff_flow_tex, level_width, level_height, num_layers);
814 pool.release_texture(diff_flow_tex);
816 if (prev_level_flow_tex != initial_flow_tex) {
817 pool.release_texture(prev_level_flow_tex);
819 prev_level_flow_tex = base_flow_tex;
820 prev_level_width = level_width;
821 prev_level_height = level_height;
829 // Scale up the flow to the final size (if needed).
830 if (op.finest_level == 0 || resize_strategy == DO_NOT_RESIZE_FLOW) {
831 return prev_level_flow_tex;
833 GLuint final_tex = pool.get_texture(GL_RG16F, width, height, num_layers);
834 resize_flow.exec(prev_level_flow_tex, final_tex, prev_level_width, prev_level_height, width, height, num_layers);
835 pool.release_texture(prev_level_flow_tex);
840 Splat::Splat(const OperatingPoint &op)
843 splat_vs_obj = compile_shader(read_file("splat.vert"), GL_VERTEX_SHADER);
844 splat_fs_obj = compile_shader(read_file("splat.frag"), GL_FRAGMENT_SHADER);
845 splat_program = link_program(splat_vs_obj, splat_fs_obj);
847 uniform_splat_size = glGetUniformLocation(splat_program, "splat_size");
848 uniform_alpha = glGetUniformLocation(splat_program, "alpha");
849 uniform_image_tex = glGetUniformLocation(splat_program, "image_tex");
850 uniform_flow_tex = glGetUniformLocation(splat_program, "flow_tex");
851 uniform_inv_flow_size = glGetUniformLocation(splat_program, "inv_flow_size");
854 void Splat::exec(GLuint image_tex, GLuint bidirectional_flow_tex, GLuint flow_tex, GLuint depth_rb, int width, int height, float alpha)
856 glUseProgram(splat_program);
858 bind_sampler(splat_program, uniform_image_tex, 0, image_tex, linear_sampler);
859 bind_sampler(splat_program, uniform_flow_tex, 1, bidirectional_flow_tex, nearest_sampler);
861 glProgramUniform2f(splat_program, uniform_splat_size, op.splat_size / width, op.splat_size / height);
862 glProgramUniform1f(splat_program, uniform_alpha, alpha);
863 glProgramUniform2f(splat_program, uniform_inv_flow_size, 1.0f / width, 1.0f / height);
865 glViewport(0, 0, width, height);
867 glEnable(GL_DEPTH_TEST);
868 glDepthFunc(GL_LESS); // We store the difference between I_0 and I_1, where less difference is good. (Default 1.0 is effectively +inf, which always loses.)
870 fbos.render_to(depth_rb, flow_tex);
872 // Evidently NVIDIA doesn't use fast clears for glClearTexImage, so clear now that
873 // we've got it bound.
874 glClearColor(1000.0f, 1000.0f, 0.0f, 1.0f); // Invalid flow.
875 glClearDepth(1.0f); // Effectively infinity.
876 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
878 glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, width * height * 2);
880 glDisable(GL_DEPTH_TEST);
885 fill_vs_obj = compile_shader(read_file("hole_fill.vert"), GL_VERTEX_SHADER);
886 fill_fs_obj = compile_shader(read_file("hole_fill.frag"), GL_FRAGMENT_SHADER);
887 fill_program = link_program(fill_vs_obj, fill_fs_obj);
889 uniform_tex = glGetUniformLocation(fill_program, "tex");
890 uniform_z = glGetUniformLocation(fill_program, "z");
891 uniform_sample_offset = glGetUniformLocation(fill_program, "sample_offset");
894 void HoleFill::exec(GLuint flow_tex, GLuint depth_rb, GLuint temp_tex[3], int width, int height)
896 glUseProgram(fill_program);
898 bind_sampler(fill_program, uniform_tex, 0, flow_tex, nearest_sampler);
900 glProgramUniform1f(fill_program, uniform_z, 1.0f - 1.0f / 1024.0f);
902 glViewport(0, 0, width, height);
904 glEnable(GL_DEPTH_TEST);
905 glDepthFunc(GL_LESS); // Only update the values > 0.999f (ie., only invalid pixels).
907 fbos.render_to(depth_rb, flow_tex); // NOTE: Reading and writing to the same texture.
909 // Fill holes from the left, by shifting 1, 2, 4, 8, etc. pixels to the right.
910 for (int offs = 1; offs < width; offs *= 2) {
911 glProgramUniform2f(fill_program, uniform_sample_offset, -offs / float(width), 0.0f);
912 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
915 glCopyImageSubData(flow_tex, GL_TEXTURE_2D, 0, 0, 0, 0, temp_tex[0], GL_TEXTURE_2D, 0, 0, 0, 0, width, height, 1);
917 // Similar to the right; adjust Z a bit down, so that we re-fill the pixels that
918 // were overwritten in the last algorithm.
919 glProgramUniform1f(fill_program, uniform_z, 1.0f - 2.0f / 1024.0f);
920 for (int offs = 1; offs < width; offs *= 2) {
921 glProgramUniform2f(fill_program, uniform_sample_offset, offs / float(width), 0.0f);
922 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
925 glCopyImageSubData(flow_tex, GL_TEXTURE_2D, 0, 0, 0, 0, temp_tex[1], GL_TEXTURE_2D, 0, 0, 0, 0, width, height, 1);
928 glProgramUniform1f(fill_program, uniform_z, 1.0f - 3.0f / 1024.0f);
929 for (int offs = 1; offs < height; offs *= 2) {
930 glProgramUniform2f(fill_program, uniform_sample_offset, 0.0f, -offs / float(height));
931 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
934 glCopyImageSubData(flow_tex, GL_TEXTURE_2D, 0, 0, 0, 0, temp_tex[2], GL_TEXTURE_2D, 0, 0, 0, 0, width, height, 1);
937 glProgramUniform1f(fill_program, uniform_z, 1.0f - 4.0f / 1024.0f);
938 for (int offs = 1; offs < height; offs *= 2) {
939 glProgramUniform2f(fill_program, uniform_sample_offset, 0.0f, offs / float(height));
940 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
944 glDisable(GL_DEPTH_TEST);
947 HoleBlend::HoleBlend()
949 blend_vs_obj = compile_shader(read_file("hole_fill.vert"), GL_VERTEX_SHADER); // Reuse the vertex shader from the fill.
950 blend_fs_obj = compile_shader(read_file("hole_blend.frag"), GL_FRAGMENT_SHADER);
951 blend_program = link_program(blend_vs_obj, blend_fs_obj);
953 uniform_left_tex = glGetUniformLocation(blend_program, "left_tex");
954 uniform_right_tex = glGetUniformLocation(blend_program, "right_tex");
955 uniform_up_tex = glGetUniformLocation(blend_program, "up_tex");
956 uniform_down_tex = glGetUniformLocation(blend_program, "down_tex");
957 uniform_z = glGetUniformLocation(blend_program, "z");
958 uniform_sample_offset = glGetUniformLocation(blend_program, "sample_offset");
961 void HoleBlend::exec(GLuint flow_tex, GLuint depth_rb, GLuint temp_tex[3], int width, int height)
963 glUseProgram(blend_program);
965 bind_sampler(blend_program, uniform_left_tex, 0, temp_tex[0], nearest_sampler);
966 bind_sampler(blend_program, uniform_right_tex, 1, temp_tex[1], nearest_sampler);
967 bind_sampler(blend_program, uniform_up_tex, 2, temp_tex[2], nearest_sampler);
968 bind_sampler(blend_program, uniform_down_tex, 3, flow_tex, nearest_sampler);
970 glProgramUniform1f(blend_program, uniform_z, 1.0f - 4.0f / 1024.0f);
971 glProgramUniform2f(blend_program, uniform_sample_offset, 0.0f, 0.0f);
973 glViewport(0, 0, width, height);
975 glEnable(GL_DEPTH_TEST);
976 glDepthFunc(GL_LEQUAL); // Skip over all of the pixels that were never holes to begin with.
978 fbos.render_to(depth_rb, flow_tex); // NOTE: Reading and writing to the same texture.
980 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
982 glDisable(GL_DEPTH_TEST);
987 blend_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
988 blend_fs_obj = compile_shader(read_file("blend.frag"), GL_FRAGMENT_SHADER);
989 blend_program = link_program(blend_vs_obj, blend_fs_obj);
991 uniform_image_tex = glGetUniformLocation(blend_program, "image_tex");
992 uniform_flow_tex = glGetUniformLocation(blend_program, "flow_tex");
993 uniform_alpha = glGetUniformLocation(blend_program, "alpha");
994 uniform_flow_consistency_tolerance = glGetUniformLocation(blend_program, "flow_consistency_tolerance");
997 void Blend::exec(GLuint image_tex, GLuint flow_tex, GLuint output_tex, int level_width, int level_height, float alpha)
999 glUseProgram(blend_program);
1000 bind_sampler(blend_program, uniform_image_tex, 0, image_tex, linear_sampler);
1001 bind_sampler(blend_program, uniform_flow_tex, 1, flow_tex, linear_sampler); // May be upsampled.
1002 glProgramUniform1f(blend_program, uniform_alpha, alpha);
1004 glViewport(0, 0, level_width, level_height);
1005 fbos.render_to(output_tex);
1006 glDisable(GL_BLEND); // A bit ironic, perhaps.
1007 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
1010 Interpolate::Interpolate(int width, int height, const OperatingPoint &op)
1011 : width(width), height(height), flow_level(op.finest_level), op(op), splat(op) {
1012 // Set up the vertex data that will be shared between all passes.
1013 float vertices[] = {
1019 glCreateBuffers(1, &vertex_vbo);
1020 glNamedBufferData(vertex_vbo, sizeof(vertices), vertices, GL_STATIC_DRAW);
1022 glCreateVertexArrays(1, &vao);
1023 glBindVertexArray(vao);
1024 glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
1026 GLint position_attrib = 0; // Hard-coded in every vertex shader.
1027 glEnableVertexArrayAttrib(vao, position_attrib);
1028 glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
1031 GLuint Interpolate::exec(GLuint image_tex, GLuint bidirectional_flow_tex, GLuint width, GLuint height, float alpha)
1035 ScopedTimer total_timer("Interpolate", &timers);
1037 glBindVertexArray(vao);
1039 // Pick out the right level to test splatting results on.
1041 glGenTextures(1, &tex_view);
1042 glTextureView(tex_view, GL_TEXTURE_2D_ARRAY, image_tex, GL_RGBA8, flow_level, 1, 0, 2);
1044 int flow_width = width >> flow_level;
1045 int flow_height = height >> flow_level;
1047 GLuint flow_tex = pool.get_texture(GL_RG16F, flow_width, flow_height);
1048 GLuint depth_rb = pool.get_renderbuffer(GL_DEPTH_COMPONENT16, flow_width, flow_height); // Used for ranking flows.
1051 ScopedTimer timer("Splat", &total_timer);
1052 splat.exec(tex_view, bidirectional_flow_tex, flow_tex, depth_rb, flow_width, flow_height, alpha);
1054 glDeleteTextures(1, &tex_view);
1057 temp_tex[0] = pool.get_texture(GL_RG16F, flow_width, flow_height);
1058 temp_tex[1] = pool.get_texture(GL_RG16F, flow_width, flow_height);
1059 temp_tex[2] = pool.get_texture(GL_RG16F, flow_width, flow_height);
1062 ScopedTimer timer("Fill holes", &total_timer);
1063 hole_fill.exec(flow_tex, depth_rb, temp_tex, flow_width, flow_height);
1064 hole_blend.exec(flow_tex, depth_rb, temp_tex, flow_width, flow_height);
1067 pool.release_texture(temp_tex[0]);
1068 pool.release_texture(temp_tex[1]);
1069 pool.release_texture(temp_tex[2]);
1070 pool.release_renderbuffer(depth_rb);
1072 GLuint output_tex = pool.get_texture(GL_RGBA8, width, height);
1074 ScopedTimer timer("Blend", &total_timer);
1075 blend.exec(image_tex, flow_tex, output_tex, width, height, alpha);
1077 pool.release_texture(flow_tex);
1086 GLuint TexturePool::get_texture(GLenum format, GLuint width, GLuint height, GLuint num_layers)
1088 for (Texture &tex : textures) {
1089 if (!tex.in_use && !tex.is_renderbuffer && tex.format == format &&
1090 tex.width == width && tex.height == height && tex.num_layers == num_layers) {
1097 if (num_layers == 0) {
1098 glCreateTextures(GL_TEXTURE_2D, 1, &tex.tex_num);
1099 glTextureStorage2D(tex.tex_num, 1, format, width, height);
1101 glCreateTextures(GL_TEXTURE_2D_ARRAY, 1, &tex.tex_num);
1102 glTextureStorage3D(tex.tex_num, 1, format, width, height, num_layers);
1104 tex.format = format;
1106 tex.height = height;
1107 tex.num_layers = num_layers;
1109 tex.is_renderbuffer = false;
1110 textures.push_back(tex);
1114 GLuint TexturePool::get_renderbuffer(GLenum format, GLuint width, GLuint height)
1116 for (Texture &tex : textures) {
1117 if (!tex.in_use && tex.is_renderbuffer && tex.format == format &&
1118 tex.width == width && tex.height == height) {
1125 glCreateRenderbuffers(1, &tex.tex_num);
1126 glNamedRenderbufferStorage(tex.tex_num, format, width, height);
1128 tex.format = format;
1130 tex.height = height;
1132 tex.is_renderbuffer = true;
1133 textures.push_back(tex);
1137 void TexturePool::release_texture(GLuint tex_num)
1139 for (Texture &tex : textures) {
1140 if (!tex.is_renderbuffer && tex.tex_num == tex_num) {
1149 void TexturePool::release_renderbuffer(GLuint tex_num)
1151 for (Texture &tex : textures) {
1152 if (tex.is_renderbuffer && tex.tex_num == tex_num) {
1161 // OpenGL uses a bottom-left coordinate system, .flo files use a top-left coordinate system.
1162 void flip_coordinate_system(float *dense_flow, unsigned width, unsigned height)
1164 for (unsigned i = 0; i < width * height; ++i) {
1165 dense_flow[i * 2 + 1] = -dense_flow[i * 2 + 1];
1169 // Not relevant for RGB.
1170 void flip_coordinate_system(uint8_t *dense_flow, unsigned width, unsigned height)
1174 void write_flow(const char *filename, const float *dense_flow, unsigned width, unsigned height)
1176 FILE *flowfp = fopen(filename, "wb");
1177 fprintf(flowfp, "FEIH");
1178 fwrite(&width, 4, 1, flowfp);
1179 fwrite(&height, 4, 1, flowfp);
1180 for (unsigned y = 0; y < height; ++y) {
1181 int yy = height - y - 1;
1182 fwrite(&dense_flow[yy * width * 2], width * 2 * sizeof(float), 1, flowfp);
1187 // Not relevant for RGB.
1188 void write_flow(const char *filename, const uint8_t *dense_flow, unsigned width, unsigned height)
1193 void write_ppm(const char *filename, const float *dense_flow, unsigned width, unsigned height)
1195 FILE *fp = fopen(filename, "wb");
1196 fprintf(fp, "P6\n%d %d\n255\n", width, height);
1197 for (unsigned y = 0; y < unsigned(height); ++y) {
1198 int yy = height - y - 1;
1199 for (unsigned x = 0; x < unsigned(width); ++x) {
1200 float du = dense_flow[(yy * width + x) * 2 + 0];
1201 float dv = dense_flow[(yy * width + x) * 2 + 1];
1204 flow2rgb(du, dv, &r, &g, &b);
1213 void write_ppm(const char *filename, const uint8_t *rgba, unsigned width, unsigned height)
1215 unique_ptr<uint8_t[]> rgb_line(new uint8_t[width * 3 + 1]);
1217 FILE *fp = fopen(filename, "wb");
1218 fprintf(fp, "P6\n%d %d\n255\n", width, height);
1219 for (unsigned y = 0; y < height; ++y) {
1220 unsigned y2 = height - 1 - y;
1221 for (size_t x = 0; x < width; ++x) {
1222 memcpy(&rgb_line[x * 3], &rgba[(y2 * width + x) * 4], 4);
1224 fwrite(rgb_line.get(), width * 3, 1, fp);
1231 static constexpr GLenum gl_format = GL_RG;
1232 static constexpr GLenum gl_type = GL_FLOAT;
1233 static constexpr int num_channels = 2;
1237 using type = uint8_t;
1238 static constexpr GLenum gl_format = GL_RGBA;
1239 static constexpr GLenum gl_type = GL_UNSIGNED_BYTE;
1240 static constexpr int num_channels = 4;
1243 template <class Type>
1244 void finish_one_read(GLuint width, GLuint height)
1246 using T = typename Type::type;
1247 constexpr int bytes_per_pixel = Type::num_channels * sizeof(T);
1249 assert(!reads_in_progress.empty());
1250 ReadInProgress read = reads_in_progress.front();
1251 reads_in_progress.pop_front();
1253 unique_ptr<T[]> flow(new typename Type::type[width * height * Type::num_channels]);
1254 void *buf = glMapNamedBufferRange(read.pbo, 0, width * height * bytes_per_pixel, GL_MAP_READ_BIT); // Blocks if the read isn't done yet.
1255 memcpy(flow.get(), buf, width * height * bytes_per_pixel); // TODO: Unneeded for RGBType, since flip_coordinate_system() does nothing.:
1256 glUnmapNamedBuffer(read.pbo);
1257 spare_pbos.push(read.pbo);
1259 flip_coordinate_system(flow.get(), width, height);
1260 if (!read.flow_filename.empty()) {
1261 write_flow(read.flow_filename.c_str(), flow.get(), width, height);
1262 fprintf(stderr, "%s %s -> %s\n", read.filename0.c_str(), read.filename1.c_str(), read.flow_filename.c_str());
1264 if (!read.ppm_filename.empty()) {
1265 write_ppm(read.ppm_filename.c_str(), flow.get(), width, height);
1269 template <class Type>
1270 void schedule_read(GLuint tex, GLuint width, GLuint height, const char *filename0, const char *filename1, const char *flow_filename, const char *ppm_filename)
1272 using T = typename Type::type;
1273 constexpr int bytes_per_pixel = Type::num_channels * sizeof(T);
1275 if (spare_pbos.empty()) {
1276 finish_one_read<Type>(width, height);
1278 assert(!spare_pbos.empty());
1279 reads_in_progress.emplace_back(ReadInProgress{ spare_pbos.top(), filename0, filename1, flow_filename, ppm_filename });
1280 glBindBuffer(GL_PIXEL_PACK_BUFFER, spare_pbos.top());
1282 glGetTextureImage(tex, 0, Type::gl_format, Type::gl_type, width * height * bytes_per_pixel, nullptr);
1283 glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
1286 void compute_flow_only(int argc, char **argv, int optind)
1288 const char *filename0 = argc >= (optind + 1) ? argv[optind] : "test1499.png";
1289 const char *filename1 = argc >= (optind + 2) ? argv[optind + 1] : "test1500.png";
1290 const char *flow_filename = argc >= (optind + 3) ? argv[optind + 2] : "flow.flo";
1293 unsigned width1, height1, width2, height2;
1294 GLuint tex0 = load_texture(filename0, &width1, &height1, WITHOUT_MIPMAPS);
1295 GLuint tex1 = load_texture(filename1, &width2, &height2, WITHOUT_MIPMAPS);
1297 if (width1 != width2 || height1 != height2) {
1298 fprintf(stderr, "Image dimensions don't match (%dx%d versus %dx%d)\n",
1299 width1, height1, width2, height2);
1303 // Move them into an array texture, since that's how the rest of the code
1306 glCreateTextures(GL_TEXTURE_2D_ARRAY, 1, &image_tex);
1307 glTextureStorage3D(image_tex, 1, GL_RGBA8, width1, height1, 2);
1308 glCopyImageSubData(tex0, GL_TEXTURE_2D, 0, 0, 0, 0, image_tex, GL_TEXTURE_2D_ARRAY, 0, 0, 0, 0, width1, height1, 1);
1309 glCopyImageSubData(tex1, GL_TEXTURE_2D, 0, 0, 0, 0, image_tex, GL_TEXTURE_2D_ARRAY, 0, 0, 0, 1, width1, height1, 1);
1310 glDeleteTextures(1, &tex0);
1311 glDeleteTextures(1, &tex1);
1313 // Set up some PBOs to do asynchronous readback.
1315 glCreateBuffers(5, pbos);
1316 for (int i = 0; i < 5; ++i) {
1317 glNamedBufferData(pbos[i], width1 * height1 * 2 * 2 * sizeof(float), nullptr, GL_STREAM_READ);
1318 spare_pbos.push(pbos[i]);
1321 int levels = find_num_levels(width1, height1);
1324 glCreateTextures(GL_TEXTURE_2D_ARRAY, 1, &tex_gray);
1325 glTextureStorage3D(tex_gray, levels, GL_R8, width1, height1, 2);
1327 GrayscaleConversion gray;
1328 gray.exec(image_tex, tex_gray, width1, height1, /*num_layers=*/2);
1329 glGenerateTextureMipmap(tex_gray);
1331 OperatingPoint op = operating_point3;
1332 if (!enable_variational_refinement) {
1333 op.variational_refinement = false;
1335 DISComputeFlow compute_flow(width1, height1, op);
1337 if (enable_warmup) {
1339 for (int i = 0; i < 10; ++i) {
1340 GLuint final_tex = compute_flow.exec(tex_gray, DISComputeFlow::FORWARD, DISComputeFlow::RESIZE_FLOW_TO_FULL_SIZE);
1341 compute_flow.release_texture(final_tex);
1346 GLuint final_tex = compute_flow.exec(tex_gray, DISComputeFlow::FORWARD, DISComputeFlow::RESIZE_FLOW_TO_FULL_SIZE);
1347 //GLuint final_tex = compute_flow.exec(tex_gray, DISComputeFlow::FORWARD_AND_BACKWARD, DISComputeFlow::RESIZE_FLOW_TO_FULL_SIZE);
1349 schedule_read<FlowType>(final_tex, width1, height1, filename0, filename1, flow_filename, "flow.ppm");
1350 compute_flow.release_texture(final_tex);
1352 // See if there are more flows on the command line (ie., more than three arguments),
1353 // and if so, process them.
1354 int num_flows = (argc - optind) / 3;
1355 for (int i = 1; i < num_flows; ++i) {
1356 const char *filename0 = argv[optind + i * 3 + 0];
1357 const char *filename1 = argv[optind + i * 3 + 1];
1358 const char *flow_filename = argv[optind + i * 3 + 2];
1359 GLuint width, height;
1360 GLuint tex0 = load_texture(filename0, &width, &height, WITHOUT_MIPMAPS);
1361 if (width != width1 || height != height1) {
1362 fprintf(stderr, "%s: Image dimensions don't match (%dx%d versus %dx%d)\n",
1363 filename0, width, height, width1, height1);
1366 glCopyImageSubData(tex0, GL_TEXTURE_2D, 0, 0, 0, 0, image_tex, GL_TEXTURE_2D_ARRAY, 0, 0, 0, 0, width1, height1, 1);
1367 glDeleteTextures(1, &tex0);
1369 GLuint tex1 = load_texture(filename1, &width, &height, WITHOUT_MIPMAPS);
1370 if (width != width1 || height != height1) {
1371 fprintf(stderr, "%s: Image dimensions don't match (%dx%d versus %dx%d)\n",
1372 filename1, width, height, width1, height1);
1375 glCopyImageSubData(tex1, GL_TEXTURE_2D, 0, 0, 0, 0, image_tex, GL_TEXTURE_2D_ARRAY, 0, 0, 0, 1, width1, height1, 1);
1376 glDeleteTextures(1, &tex1);
1378 gray.exec(image_tex, tex_gray, width1, height1, /*num_layers=*/2);
1379 glGenerateTextureMipmap(tex_gray);
1381 GLuint final_tex = compute_flow.exec(tex_gray, DISComputeFlow::FORWARD, DISComputeFlow::RESIZE_FLOW_TO_FULL_SIZE);
1383 schedule_read<FlowType>(final_tex, width1, height1, filename0, filename1, flow_filename, "");
1384 compute_flow.release_texture(final_tex);
1386 glDeleteTextures(1, &tex_gray);
1388 while (!reads_in_progress.empty()) {
1389 finish_one_read<FlowType>(width1, height1);
1393 // Interpolate images based on
1395 // Herbst, Seitz, Baker: “Occlusion Reasoning for Temporal Interpolation
1396 // Using Optical Flow”
1398 // or at least a reasonable subset thereof. Unfinished.
1399 void interpolate_image(int argc, char **argv, int optind)
1401 const char *filename0 = argc >= (optind + 1) ? argv[optind] : "test1499.png";
1402 const char *filename1 = argc >= (optind + 2) ? argv[optind + 1] : "test1500.png";
1403 //const char *out_filename = argc >= (optind + 3) ? argv[optind + 2] : "interpolated.png";
1406 unsigned width1, height1, width2, height2;
1407 GLuint tex0 = load_texture(filename0, &width1, &height1, WITH_MIPMAPS);
1408 GLuint tex1 = load_texture(filename1, &width2, &height2, WITH_MIPMAPS);
1410 if (width1 != width2 || height1 != height2) {
1411 fprintf(stderr, "Image dimensions don't match (%dx%d versus %dx%d)\n",
1412 width1, height1, width2, height2);
1416 // Move them into an array texture, since that's how the rest of the code
1418 int levels = find_num_levels(width1, height1);
1420 glCreateTextures(GL_TEXTURE_2D_ARRAY, 1, &image_tex);
1421 glTextureStorage3D(image_tex, levels, GL_RGBA8, width1, height1, 2);
1422 glCopyImageSubData(tex0, GL_TEXTURE_2D, 0, 0, 0, 0, image_tex, GL_TEXTURE_2D_ARRAY, 0, 0, 0, 0, width1, height1, 1);
1423 glCopyImageSubData(tex1, GL_TEXTURE_2D, 0, 0, 0, 0, image_tex, GL_TEXTURE_2D_ARRAY, 0, 0, 0, 1, width1, height1, 1);
1424 glDeleteTextures(1, &tex0);
1425 glDeleteTextures(1, &tex1);
1426 glGenerateTextureMipmap(image_tex);
1428 // Set up some PBOs to do asynchronous readback.
1430 glCreateBuffers(5, pbos);
1431 for (int i = 0; i < 5; ++i) {
1432 glNamedBufferData(pbos[i], width1 * height1 * 4 * sizeof(uint8_t), nullptr, GL_STREAM_READ);
1433 spare_pbos.push(pbos[i]);
1436 OperatingPoint op = operating_point3;
1437 if (!enable_variational_refinement) {
1438 op.variational_refinement = false;
1440 DISComputeFlow compute_flow(width1, height1, op);
1441 GrayscaleConversion gray;
1442 Interpolate interpolate(width1, height1, op);
1445 glCreateTextures(GL_TEXTURE_2D_ARRAY, 1, &tex_gray);
1446 glTextureStorage3D(tex_gray, levels, GL_R8, width1, height1, 2);
1447 gray.exec(image_tex, tex_gray, width1, height1, /*num_layers=*/2);
1448 glGenerateTextureMipmap(tex_gray);
1450 if (enable_warmup) {
1452 for (int i = 0; i < 10; ++i) {
1453 GLuint bidirectional_flow_tex = compute_flow.exec(tex_gray, DISComputeFlow::FORWARD_AND_BACKWARD, DISComputeFlow::DO_NOT_RESIZE_FLOW);
1454 GLuint interpolated_tex = interpolate.exec(image_tex, bidirectional_flow_tex, width1, height1, 0.5f);
1455 compute_flow.release_texture(bidirectional_flow_tex);
1456 interpolate.release_texture(interpolated_tex);
1461 GLuint bidirectional_flow_tex = compute_flow.exec(tex_gray, DISComputeFlow::FORWARD_AND_BACKWARD, DISComputeFlow::DO_NOT_RESIZE_FLOW);
1463 for (int frameno = 1; frameno < 60; ++frameno) {
1464 char ppm_filename[256];
1465 snprintf(ppm_filename, sizeof(ppm_filename), "interp%04d.ppm", frameno);
1467 float alpha = frameno / 60.0f;
1468 GLuint interpolated_tex = interpolate.exec(image_tex, bidirectional_flow_tex, width1, height1, alpha);
1470 schedule_read<RGBAType>(interpolated_tex, width1, height1, filename0, filename1, "", ppm_filename);
1471 interpolate.release_texture(interpolated_tex);
1474 while (!reads_in_progress.empty()) {
1475 finish_one_read<RGBAType>(width1, height1);
1479 int main(int argc, char **argv)
1481 static const option long_options[] = {
1482 { "smoothness-relative-weight", required_argument, 0, 's' }, // alpha.
1483 { "intensity-relative-weight", required_argument, 0, 'i' }, // delta.
1484 { "gradient-relative-weight", required_argument, 0, 'g' }, // gamma.
1485 { "disable-timing", no_argument, 0, 1000 },
1486 { "detailed-timing", no_argument, 0, 1003 },
1487 { "ignore-variational-refinement", no_argument, 0, 1001 }, // Still calculates it, just doesn't apply it.
1488 { "interpolate", no_argument, 0, 1002 },
1489 { "warmup", no_argument, 0, 1004 }
1493 int option_index = 0;
1494 int c = getopt_long(argc, argv, "s:i:g:", long_options, &option_index);
1501 vr_alpha = atof(optarg);
1504 vr_delta = atof(optarg);
1507 vr_gamma = atof(optarg);
1510 enable_timing = false;
1513 enable_variational_refinement = false;
1516 enable_interpolation = true;
1519 detailed_timing = true;
1522 enable_warmup = true;
1525 fprintf(stderr, "Unknown option '%s'\n", argv[option_index]);
1530 if (SDL_Init(SDL_INIT_EVERYTHING) == -1) {
1531 fprintf(stderr, "SDL_Init failed: %s\n", SDL_GetError());
1534 SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
1535 SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 0);
1536 SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 0);
1537 SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
1539 SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
1540 SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
1541 SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 5);
1542 // SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
1543 window = SDL_CreateWindow("OpenGL window",
1544 SDL_WINDOWPOS_UNDEFINED,
1545 SDL_WINDOWPOS_UNDEFINED,
1547 SDL_WINDOW_OPENGL | SDL_WINDOW_HIDDEN);
1548 SDL_GLContext context = SDL_GL_CreateContext(window);
1549 assert(context != nullptr);
1551 glDisable(GL_DITHER);
1553 // FIXME: Should be part of DISComputeFlow (but needs to be initialized
1554 // before all the render passes).
1555 float vertices[] = {
1561 glCreateBuffers(1, &vertex_vbo);
1562 glNamedBufferData(vertex_vbo, sizeof(vertices), vertices, GL_STATIC_DRAW);
1563 glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
1565 if (enable_interpolation) {
1566 interpolate_image(argc, argv, optind);
1568 compute_flow_only(argc, argv, optind);