#include <assert.h>
#include <stdio.h>
+#include <unistd.h>
+
+#include "util.h"
#include <algorithm>
#include <memory>
constexpr unsigned patch_size_pixels = 12;
// Some global OpenGL objects.
-GLuint nearest_sampler, linear_sampler, mipmap_sampler;
+GLuint nearest_sampler, linear_sampler, smoothness_sampler;
GLuint vertex_vbo;
string read_file(const string &filename)
GLuint link_program(GLuint vs_obj, GLuint fs_obj)
{
- GLuint program = glCreateProgram();
- glAttachShader(program, vs_obj);
- glAttachShader(program, fs_obj);
- glLinkProgram(program);
+ GLuint program = glCreateProgram();
+ glAttachShader(program, vs_obj);
+ glAttachShader(program, fs_obj);
+ glLinkProgram(program);
GLint success;
glGetProgramiv(program, GL_LINK_STATUS, &success);
if (success == GL_FALSE) {
return vbo;
}
-void bind_sampler(GLuint program, const char *uniform_name, GLuint texture_unit, GLuint tex, GLuint sampler)
+void bind_sampler(GLuint program, GLint location, GLuint texture_unit, GLuint tex, GLuint sampler)
{
- GLint location = glGetUniformLocation(program, uniform_name);
if (location == -1) {
return;
}
GLuint sobel_fs_obj;
GLuint sobel_program;
GLuint sobel_vao;
+
+ GLuint uniform_tex, uniform_image_size;
};
Sobel::Sobel()
sobel_program = link_program(sobel_vs_obj, sobel_fs_obj);
// Set up the VAO containing all the required position/texcoord data.
- glCreateVertexArrays(1, &sobel_vao);
- glBindVertexArray(sobel_vao);
+ glCreateVertexArrays(1, &sobel_vao);
+ glBindVertexArray(sobel_vao);
GLint position_attrib = glGetAttribLocation(sobel_program, "position");
glEnableVertexArrayAttrib(sobel_vao, position_attrib);
glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
- GLint texcoord_attrib = glGetAttribLocation(sobel_program, "texcoord");
- glEnableVertexArrayAttrib(sobel_vao, texcoord_attrib);
- glVertexAttribPointer(texcoord_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+ uniform_tex = glGetUniformLocation(sobel_program, "tex");
}
void Sobel::exec(GLint tex0_view, GLint grad0_tex, int level_width, int level_height)
glUseProgram(sobel_program);
glBindTextureUnit(0, tex0_view);
glBindSampler(0, nearest_sampler);
- glProgramUniform1i(sobel_program, glGetUniformLocation(sobel_program, "tex"), 0);
- glProgramUniform1f(sobel_program, glGetUniformLocation(sobel_program, "inv_width"), 1.0f / level_width);
- glProgramUniform1f(sobel_program, glGetUniformLocation(sobel_program, "inv_height"), 1.0f / level_height);
+ glProgramUniform1i(sobel_program, uniform_tex, 0);
GLuint grad0_fbo; // TODO: cleanup
glCreateFramebuffers(1, &grad0_fbo);
glViewport(0, 0, level_width, level_height);
glBindFramebuffer(GL_FRAMEBUFFER, grad0_fbo);
- glBindVertexArray(sobel_vao);
+ glBindVertexArray(sobel_vao);
glUseProgram(sobel_program);
glDisable(GL_BLEND);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
GLuint motion_fs_obj;
GLuint motion_search_program;
GLuint motion_search_vao;
+
+ GLuint uniform_image_size, uniform_inv_image_size;
+ GLuint uniform_image0_tex, uniform_image1_tex, uniform_grad0_tex, uniform_flow_tex;
};
MotionSearch::MotionSearch()
motion_search_program = link_program(motion_vs_obj, motion_fs_obj);
// Set up the VAO containing all the required position/texcoord data.
- glCreateVertexArrays(1, &motion_search_vao);
- glBindVertexArray(motion_search_vao);
+ glCreateVertexArrays(1, &motion_search_vao);
+ glBindVertexArray(motion_search_vao);
glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
GLint position_attrib = glGetAttribLocation(motion_search_program, "position");
glEnableVertexArrayAttrib(motion_search_vao, position_attrib);
glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
- GLint texcoord_attrib = glGetAttribLocation(motion_search_program, "texcoord");
- glEnableVertexArrayAttrib(motion_search_vao, texcoord_attrib);
- glVertexAttribPointer(texcoord_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+ uniform_image_size = glGetUniformLocation(motion_search_program, "image_size");
+ uniform_inv_image_size = glGetUniformLocation(motion_search_program, "inv_image_size");
+ uniform_image0_tex = glGetUniformLocation(motion_search_program, "image0_tex");
+ uniform_image1_tex = glGetUniformLocation(motion_search_program, "image1_tex");
+ uniform_grad0_tex = glGetUniformLocation(motion_search_program, "grad0_tex");
+ uniform_flow_tex = glGetUniformLocation(motion_search_program, "flow_tex");
}
void MotionSearch::exec(GLuint tex0_view, GLuint tex1_view, GLuint grad0_tex, GLuint flow_tex, GLuint flow_out_tex, int level_width, int level_height, int width_patches, int height_patches)
{
glUseProgram(motion_search_program);
- bind_sampler(motion_search_program, "image0_tex", 0, tex0_view, nearest_sampler);
- bind_sampler(motion_search_program, "image1_tex", 1, tex1_view, linear_sampler);
- bind_sampler(motion_search_program, "grad0_tex", 2, grad0_tex, nearest_sampler);
- bind_sampler(motion_search_program, "flow_tex", 3, flow_tex, linear_sampler);
+ bind_sampler(motion_search_program, uniform_image0_tex, 0, tex0_view, nearest_sampler);
+ bind_sampler(motion_search_program, uniform_image1_tex, 1, tex1_view, linear_sampler);
+ bind_sampler(motion_search_program, uniform_grad0_tex, 2, grad0_tex, nearest_sampler);
+ bind_sampler(motion_search_program, uniform_flow_tex, 3, flow_tex, linear_sampler);
- glProgramUniform1f(motion_search_program, glGetUniformLocation(motion_search_program, "image_width"), level_width);
- glProgramUniform1f(motion_search_program, glGetUniformLocation(motion_search_program, "image_height"), level_height);
- glProgramUniform1f(motion_search_program, glGetUniformLocation(motion_search_program, "inv_image_width"), 1.0f / level_width);
- glProgramUniform1f(motion_search_program, glGetUniformLocation(motion_search_program, "inv_image_height"), 1.0f / level_height);
+ glProgramUniform2f(motion_search_program, uniform_image_size, level_width, level_height);
+ glProgramUniform2f(motion_search_program, uniform_inv_image_size, 1.0f / level_width, 1.0f / level_height);
GLuint flow_fbo; // TODO: cleanup
glCreateFramebuffers(1, &flow_fbo);
glViewport(0, 0, width_patches, height_patches);
glBindFramebuffer(GL_FRAMEBUFFER, flow_fbo);
- glBindVertexArray(motion_search_vao);
+ glBindVertexArray(motion_search_vao);
glUseProgram(motion_search_program);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
GLuint densify_fs_obj;
GLuint densify_program;
GLuint densify_vao;
+
+ GLuint uniform_width_patches, uniform_patch_size, uniform_patch_spacing;
+ GLuint uniform_image0_tex, uniform_image1_tex, uniform_flow_tex;
};
Densify::Densify()
densify_program = link_program(densify_vs_obj, densify_fs_obj);
// Set up the VAO containing all the required position/texcoord data.
- glCreateVertexArrays(1, &densify_vao);
- glBindVertexArray(densify_vao);
+ glCreateVertexArrays(1, &densify_vao);
+ glBindVertexArray(densify_vao);
glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
GLint position_attrib = glGetAttribLocation(densify_program, "position");
glEnableVertexArrayAttrib(densify_vao, position_attrib);
glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+
+ uniform_width_patches = glGetUniformLocation(densify_program, "width_patches");
+ uniform_patch_size = glGetUniformLocation(densify_program, "patch_size");
+ uniform_patch_spacing = glGetUniformLocation(densify_program, "patch_spacing");
+ uniform_image0_tex = glGetUniformLocation(densify_program, "image0_tex");
+ uniform_image1_tex = glGetUniformLocation(densify_program, "image1_tex");
+ uniform_flow_tex = glGetUniformLocation(densify_program, "flow_tex");
}
void Densify::exec(GLuint tex0_view, GLuint tex1_view, GLuint flow_tex, GLuint dense_flow_tex, int level_width, int level_height, int width_patches, int height_patches)
{
glUseProgram(densify_program);
- bind_sampler(densify_program, "image0_tex", 0, tex0_view, nearest_sampler);
- bind_sampler(densify_program, "image1_tex", 1, tex1_view, linear_sampler);
- bind_sampler(densify_program, "flow_tex", 2, flow_tex, nearest_sampler);
+ bind_sampler(densify_program, uniform_image0_tex, 0, tex0_view, nearest_sampler);
+ bind_sampler(densify_program, uniform_image1_tex, 1, tex1_view, linear_sampler);
+ bind_sampler(densify_program, uniform_flow_tex, 2, flow_tex, nearest_sampler);
- glProgramUniform1i(densify_program, glGetUniformLocation(densify_program, "width_patches"), width_patches);
- glProgramUniform2f(densify_program, glGetUniformLocation(densify_program, "patch_size"),
+ glProgramUniform1i(densify_program, uniform_width_patches, width_patches);
+ glProgramUniform2f(densify_program, uniform_patch_size,
float(patch_size_pixels) / level_width,
float(patch_size_pixels) / level_height);
float patch_spacing_x = float(level_width - patch_size_pixels) / (width_patches - 1);
float patch_spacing_y = float(level_height - patch_size_pixels) / (height_patches - 1);
- glProgramUniform2f(densify_program, glGetUniformLocation(densify_program, "patch_spacing"),
+ if (width_patches == 1) patch_spacing_x = 0.0f; // Avoid infinities.
+ if (height_patches == 1) patch_spacing_y = 0.0f;
+ glProgramUniform2f(densify_program, uniform_patch_spacing,
patch_spacing_x / level_width,
patch_spacing_y / level_height);
glViewport(0, 0, level_width, level_height);
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_ONE);
- glBindVertexArray(densify_vao);
+ glBindVertexArray(densify_vao);
glBindFramebuffer(GL_FRAMEBUFFER, dense_flow_fbo);
glDrawArraysInstanced(GL_TRIANGLE_STRIP, 0, 4, width_patches * height_patches);
}
+// Warp I_1 to I_w, and then compute the mean (I) and difference (I_t) of
+// I_0 and I_w. The prewarping is what enables us to solve the variational
+// flow for du,dv instead of u,v.
+//
+// See variational_refinement.txt for more information.
+class Prewarp {
+public:
+ Prewarp();
+ void exec(GLuint tex0_view, GLuint tex1_view, GLuint flow_tex, GLuint I_tex, GLuint I_t_tex, int level_width, int level_height);
+
+private:
+ GLuint prewarp_vs_obj;
+ GLuint prewarp_fs_obj;
+ GLuint prewarp_program;
+ GLuint prewarp_vao;
+
+ GLuint uniform_image0_tex, uniform_image1_tex, uniform_flow_tex;
+};
+
+Prewarp::Prewarp()
+{
+ prewarp_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ prewarp_fs_obj = compile_shader(read_file("prewarp.frag"), GL_FRAGMENT_SHADER);
+ prewarp_program = link_program(prewarp_vs_obj, prewarp_fs_obj);
+
+ // Set up the VAO containing all the required position/texcoord data.
+ glCreateVertexArrays(1, &prewarp_vao);
+ glBindVertexArray(prewarp_vao);
+ glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
+
+ GLint position_attrib = glGetAttribLocation(prewarp_program, "position");
+ glEnableVertexArrayAttrib(prewarp_vao, position_attrib);
+ glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+
+ uniform_image0_tex = glGetUniformLocation(prewarp_program, "image0_tex");
+ uniform_image1_tex = glGetUniformLocation(prewarp_program, "image1_tex");
+ uniform_flow_tex = glGetUniformLocation(prewarp_program, "flow_tex");
+}
+
+void Prewarp::exec(GLuint tex0_view, GLuint tex1_view, GLuint flow_tex, GLuint I_tex, GLuint I_t_tex, int level_width, int level_height)
+{
+ glUseProgram(prewarp_program);
+
+ bind_sampler(prewarp_program, uniform_image0_tex, 0, tex0_view, nearest_sampler);
+ bind_sampler(prewarp_program, uniform_image1_tex, 1, tex1_view, linear_sampler);
+ bind_sampler(prewarp_program, uniform_flow_tex, 2, flow_tex, nearest_sampler);
+
+ GLuint prewarp_fbo; // TODO: cleanup
+ glCreateFramebuffers(1, &prewarp_fbo);
+ GLenum bufs[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
+ glNamedFramebufferDrawBuffers(prewarp_fbo, 2, bufs);
+ glNamedFramebufferTexture(prewarp_fbo, GL_COLOR_ATTACHMENT0, I_tex, 0);
+ glNamedFramebufferTexture(prewarp_fbo, GL_COLOR_ATTACHMENT1, I_t_tex, 0);
+
+ glViewport(0, 0, level_width, level_height);
+ glDisable(GL_BLEND);
+ glBindVertexArray(prewarp_vao);
+ glBindFramebuffer(GL_FRAMEBUFFER, prewarp_fbo);
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+}
+
+// From I, calculate the partial derivatives I_x and I_y. We use a four-tap
+// central difference filter, since apparently, that's tradition (I haven't
+// measured quality versus a more normal 0.5 (I[x+1] - I[x-1]).)
+// The coefficients come from
+//
+// https://en.wikipedia.org/wiki/Finite_difference_coefficient
+//
+// Also computes β_0, since it depends only on I_x and I_y.
+class Derivatives {
+public:
+ Derivatives();
+ void exec(GLuint input_tex, GLuint I_x_y_tex, GLuint beta_0_tex, int level_width, int level_height);
+
+private:
+ GLuint derivatives_vs_obj;
+ GLuint derivatives_fs_obj;
+ GLuint derivatives_program;
+ GLuint derivatives_vao;
+
+ GLuint uniform_tex;
+};
+
+Derivatives::Derivatives()
+{
+ derivatives_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ derivatives_fs_obj = compile_shader(read_file("derivatives.frag"), GL_FRAGMENT_SHADER);
+ derivatives_program = link_program(derivatives_vs_obj, derivatives_fs_obj);
+
+ // Set up the VAO containing all the required position/texcoord data.
+ glCreateVertexArrays(1, &derivatives_vao);
+ glBindVertexArray(derivatives_vao);
+ glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
+
+ GLint position_attrib = glGetAttribLocation(derivatives_program, "position");
+ glEnableVertexArrayAttrib(derivatives_vao, position_attrib);
+ glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+
+ uniform_tex = glGetUniformLocation(derivatives_program, "tex");
+}
+
+void Derivatives::exec(GLuint input_tex, GLuint I_x_y_tex, GLuint beta_0_tex, int level_width, int level_height)
+{
+ glUseProgram(derivatives_program);
+
+ bind_sampler(derivatives_program, uniform_tex, 0, input_tex, nearest_sampler);
+
+ GLuint derivatives_fbo; // TODO: cleanup
+ glCreateFramebuffers(1, &derivatives_fbo);
+ GLenum bufs[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
+ glNamedFramebufferDrawBuffers(derivatives_fbo, 2, bufs);
+ glNamedFramebufferTexture(derivatives_fbo, GL_COLOR_ATTACHMENT0, I_x_y_tex, 0);
+ glNamedFramebufferTexture(derivatives_fbo, GL_COLOR_ATTACHMENT1, beta_0_tex, 0);
+
+ glViewport(0, 0, level_width, level_height);
+ glDisable(GL_BLEND);
+ glBindVertexArray(derivatives_vao);
+ glBindFramebuffer(GL_FRAMEBUFFER, derivatives_fbo);
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+}
+
+// Calculate the smoothness constraints between neighboring pixels;
+// s_x(x,y) stores smoothness between pixel (x,y) and (x+1,y),
+// and s_y(x,y) stores between (x,y) and (x,y+1). We'll sample with
+// border color (0,0) later, so that there's zero diffusion out of
+// the border.
+//
+// See variational_refinement.txt for more information.
+class ComputeSmoothness {
+public:
+ ComputeSmoothness();
+ void exec(GLuint flow_tex, GLuint diff_flow_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, int level_width, int level_height);
+
+private:
+ GLuint smoothness_vs_obj;
+ GLuint smoothness_fs_obj;
+ GLuint smoothness_program;
+ GLuint smoothness_vao;
+
+ GLuint uniform_flow_tex, uniform_diff_flow_tex;
+};
+
+ComputeSmoothness::ComputeSmoothness()
+{
+ smoothness_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ smoothness_fs_obj = compile_shader(read_file("smoothness.frag"), GL_FRAGMENT_SHADER);
+ smoothness_program = link_program(smoothness_vs_obj, smoothness_fs_obj);
+
+ // Set up the VAO containing all the required position/texcoord data.
+ glCreateVertexArrays(1, &smoothness_vao);
+ glBindVertexArray(smoothness_vao);
+ glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
+
+ GLint position_attrib = glGetAttribLocation(smoothness_program, "position");
+ glEnableVertexArrayAttrib(smoothness_vao, position_attrib);
+ glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+
+ uniform_flow_tex = glGetUniformLocation(smoothness_program, "flow_tex");
+ uniform_diff_flow_tex = glGetUniformLocation(smoothness_program, "diff_flow_tex");
+}
+
+void ComputeSmoothness::exec(GLuint flow_tex, GLuint diff_flow_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, int level_width, int level_height)
+{
+ glUseProgram(smoothness_program);
+
+ bind_sampler(smoothness_program, uniform_flow_tex, 0, flow_tex, nearest_sampler);
+ bind_sampler(smoothness_program, uniform_diff_flow_tex, 1, diff_flow_tex, nearest_sampler);
+
+ GLuint smoothness_fbo; // TODO: cleanup
+ glCreateFramebuffers(1, &smoothness_fbo);
+ GLenum bufs[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
+ glNamedFramebufferDrawBuffers(smoothness_fbo, 2, bufs);
+ glNamedFramebufferTexture(smoothness_fbo, GL_COLOR_ATTACHMENT0, smoothness_x_tex, 0);
+ glNamedFramebufferTexture(smoothness_fbo, GL_COLOR_ATTACHMENT1, smoothness_y_tex, 0);
+
+ glViewport(0, 0, level_width, level_height);
+
+ // Make sure the smoothness on the right and upper borders is zero.
+ // We could have done this by making a (W-1)x(H-1) texture instead
+ // (we're sampling smoothness with all-zero border color), but we'd
+ // have to adjust the sampling coordinates, which is annoying.
+ glScissor(0, 0, level_width - 1, level_height - 1);
+ glEnable(GL_SCISSOR_TEST);
+
+ glDisable(GL_BLEND);
+ glBindVertexArray(smoothness_vao);
+ glBindFramebuffer(GL_FRAMEBUFFER, smoothness_fbo);
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+ glDisable(GL_SCISSOR_TEST);
+}
+
+// Set up the equations set (two equations in two unknowns, per pixel).
+// We store five floats; the three non-redundant elements of the 2x2 matrix (A)
+// as 32-bit floats, and the two elements on the right-hand side (b) as 16-bit
+// floats. (Actually, we store the inverse of the diagonal elements, because
+// we only ever need to divide by them.) This fits into four u32 values;
+// R, G, B for the matrix (the last element is symmetric) and A for the two b values.
+// All the values of the energy term (E_I, E_G, E_S), except the smoothness
+// terms that depend on other pixels, are calculated in one pass.
+//
+// See variational_refinement.txt for more information.
+class SetupEquations {
+public:
+ SetupEquations();
+ void exec(GLuint I_x_y_tex, GLuint I_t_tex, GLuint diff_flow_tex, GLuint flow_tex, GLuint beta_0_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, GLuint equation_tex, int level_width, int level_height);
+
+private:
+ GLuint equations_vs_obj;
+ GLuint equations_fs_obj;
+ GLuint equations_program;
+ GLuint equations_vao;
+
+ GLuint uniform_I_x_y_tex, uniform_I_t_tex;
+ GLuint uniform_diff_flow_tex, uniform_flow_tex;
+ GLuint uniform_beta_0_tex;
+ GLuint uniform_smoothness_x_tex, uniform_smoothness_y_tex;
+
+};
+
+SetupEquations::SetupEquations()
+{
+ equations_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ equations_fs_obj = compile_shader(read_file("equations.frag"), GL_FRAGMENT_SHADER);
+ equations_program = link_program(equations_vs_obj, equations_fs_obj);
+
+ // Set up the VAO containing all the required position/texcoord data.
+ glCreateVertexArrays(1, &equations_vao);
+ glBindVertexArray(equations_vao);
+ glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
+
+ GLint position_attrib = glGetAttribLocation(equations_program, "position");
+ glEnableVertexArrayAttrib(equations_vao, position_attrib);
+ glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+
+ uniform_I_x_y_tex = glGetUniformLocation(equations_program, "I_x_y_tex");
+ uniform_I_t_tex = glGetUniformLocation(equations_program, "I_t_tex");
+ uniform_diff_flow_tex = glGetUniformLocation(equations_program, "diff_flow_tex");
+ uniform_flow_tex = glGetUniformLocation(equations_program, "flow_tex");
+ uniform_beta_0_tex = glGetUniformLocation(equations_program, "beta_0_tex");
+ uniform_smoothness_x_tex = glGetUniformLocation(equations_program, "smoothness_x_tex");
+ uniform_smoothness_y_tex = glGetUniformLocation(equations_program, "smoothness_y_tex");
+}
+
+void SetupEquations::exec(GLuint I_x_y_tex, GLuint I_t_tex, GLuint diff_flow_tex, GLuint flow_tex, GLuint beta_0_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, GLuint equation_tex, int level_width, int level_height)
+{
+ glUseProgram(equations_program);
+
+ bind_sampler(equations_program, uniform_I_x_y_tex, 0, I_x_y_tex, nearest_sampler);
+ bind_sampler(equations_program, uniform_I_t_tex, 1, I_t_tex, nearest_sampler);
+ bind_sampler(equations_program, uniform_diff_flow_tex, 2, diff_flow_tex, nearest_sampler);
+ bind_sampler(equations_program, uniform_flow_tex, 3, flow_tex, nearest_sampler);
+ bind_sampler(equations_program, uniform_beta_0_tex, 4, beta_0_tex, nearest_sampler);
+ bind_sampler(equations_program, uniform_smoothness_x_tex, 5, smoothness_x_tex, smoothness_sampler);
+ bind_sampler(equations_program, uniform_smoothness_y_tex, 6, smoothness_y_tex, smoothness_sampler);
+
+ GLuint equations_fbo; // TODO: cleanup
+ glCreateFramebuffers(1, &equations_fbo);
+ glNamedFramebufferTexture(equations_fbo, GL_COLOR_ATTACHMENT0, equation_tex, 0);
+
+ glViewport(0, 0, level_width, level_height);
+ glDisable(GL_BLEND);
+ glBindVertexArray(equations_vao);
+ glBindFramebuffer(GL_FRAMEBUFFER, equations_fbo);
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+}
+
+// Calculate the smoothness constraints between neighboring pixels;
+// s_x(x,y) stores smoothness between pixel (x,y) and (x+1,y),
+// and s_y(x,y) stores between (x,y) and (x,y+1). We'll sample with
+// border color (0,0) later, so that there's zero diffusion out of
+// the border.
+//
+// See variational_refinement.txt for more information.
+class SOR {
+public:
+ SOR();
+ void exec(GLuint diff_flow_tex, GLuint equation_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, int level_width, int level_height, int num_iterations);
+
+private:
+ GLuint sor_vs_obj;
+ GLuint sor_fs_obj;
+ GLuint sor_program;
+ GLuint sor_vao;
+
+ GLuint uniform_diff_flow_tex;
+ GLuint uniform_equation_tex;
+ GLuint uniform_smoothness_x_tex, uniform_smoothness_y_tex;
+};
+
+SOR::SOR()
+{
+ sor_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ sor_fs_obj = compile_shader(read_file("sor.frag"), GL_FRAGMENT_SHADER);
+ sor_program = link_program(sor_vs_obj, sor_fs_obj);
+
+ // Set up the VAO containing all the required position/texcoord data.
+ glCreateVertexArrays(1, &sor_vao);
+ glBindVertexArray(sor_vao);
+ glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
+
+ GLint position_attrib = glGetAttribLocation(sor_program, "position");
+ glEnableVertexArrayAttrib(sor_vao, position_attrib);
+ glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+
+ uniform_diff_flow_tex = glGetUniformLocation(sor_program, "diff_flow_tex");
+ uniform_equation_tex = glGetUniformLocation(sor_program, "equation_tex");
+ uniform_smoothness_x_tex = glGetUniformLocation(sor_program, "smoothness_x_tex");
+ uniform_smoothness_y_tex = glGetUniformLocation(sor_program, "smoothness_y_tex");
+}
+
+void SOR::exec(GLuint diff_flow_tex, GLuint equation_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, int level_width, int level_height, int num_iterations)
+{
+ glUseProgram(sor_program);
+
+ bind_sampler(sor_program, uniform_diff_flow_tex, 0, diff_flow_tex, nearest_sampler);
+ bind_sampler(sor_program, uniform_smoothness_x_tex, 1, smoothness_x_tex, smoothness_sampler);
+ bind_sampler(sor_program, uniform_smoothness_y_tex, 2, smoothness_y_tex, smoothness_sampler);
+ bind_sampler(sor_program, uniform_equation_tex, 3, equation_tex, nearest_sampler);
+
+ GLuint sor_fbo; // TODO: cleanup
+ glCreateFramebuffers(1, &sor_fbo);
+ glNamedFramebufferTexture(sor_fbo, GL_COLOR_ATTACHMENT0, diff_flow_tex, 0); // NOTE: Bind to same as we render from!
+
+ glViewport(0, 0, level_width, level_height);
+ glDisable(GL_BLEND);
+ glBindVertexArray(sor_vao);
+ glBindFramebuffer(GL_FRAMEBUFFER, sor_fbo);
+
+ for (int i = 0; i < num_iterations; ++i) {
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+ if (i != num_iterations - 1) {
+ glTextureBarrier();
+ }
+ }
+}
+
+// Simply add the differential flow found by the variational refinement to the base flow.
+// The output is in diff_flow_tex; we don't need to make a new texture.
+class AddBaseFlow {
+public:
+ AddBaseFlow();
+ void exec(GLuint base_flow_tex, GLuint diff_flow_tex, int level_width, int level_height);
+
+private:
+ GLuint add_flow_vs_obj;
+ GLuint add_flow_fs_obj;
+ GLuint add_flow_program;
+ GLuint add_flow_vao;
+
+ GLuint uniform_base_flow_tex;
+};
+
+AddBaseFlow::AddBaseFlow()
+{
+ add_flow_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ add_flow_fs_obj = compile_shader(read_file("add_base_flow.frag"), GL_FRAGMENT_SHADER);
+ add_flow_program = link_program(add_flow_vs_obj, add_flow_fs_obj);
+
+ // Set up the VAO containing all the required position/texcoord data.
+ glCreateVertexArrays(1, &add_flow_vao);
+ glBindVertexArray(add_flow_vao);
+ glBindBuffer(GL_ARRAY_BUFFER, vertex_vbo);
+
+ GLint position_attrib = glGetAttribLocation(add_flow_program, "position");
+ glEnableVertexArrayAttrib(add_flow_vao, position_attrib);
+ glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
+
+ uniform_base_flow_tex = glGetUniformLocation(add_flow_program, "base_flow_tex");
+}
+
+void AddBaseFlow::exec(GLuint base_flow_tex, GLuint diff_flow_tex, int level_width, int level_height)
+{
+ glUseProgram(add_flow_program);
+
+ bind_sampler(add_flow_program, uniform_base_flow_tex, 0, base_flow_tex, nearest_sampler);
+
+ GLuint add_flow_fbo; // TODO: cleanup
+ glCreateFramebuffers(1, &add_flow_fbo);
+ glNamedFramebufferTexture(add_flow_fbo, GL_COLOR_ATTACHMENT0, diff_flow_tex, 0);
+
+ glViewport(0, 0, level_width, level_height);
+ glEnable(GL_BLEND);
+ glBlendFunc(GL_ONE, GL_ONE);
+ glBindVertexArray(add_flow_vao);
+ glBindFramebuffer(GL_FRAMEBUFFER, add_flow_fbo);
+
+ glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+}
+
int main(void)
{
if (SDL_Init(SDL_INIT_EVERYTHING) == -1) {
glSamplerParameteri(linear_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glSamplerParameteri(linear_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
- glCreateSamplers(1, &mipmap_sampler);
- glSamplerParameteri(mipmap_sampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
- glSamplerParameteri(mipmap_sampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
- glSamplerParameteri(mipmap_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
- glSamplerParameteri(mipmap_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+ // The smoothness is sampled so that once we get to a smoothness involving
+ // a value outside the border, the diffusivity between the two becomes zero.
+ glCreateSamplers(1, &smoothness_sampler);
+ glSamplerParameteri(smoothness_sampler, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+ glSamplerParameteri(smoothness_sampler, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glSamplerParameteri(smoothness_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+ glSamplerParameteri(smoothness_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+ float zero[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+ glSamplerParameterfv(smoothness_sampler, GL_TEXTURE_BORDER_COLOR, zero);
float vertices[] = {
0.0f, 1.0f,
// Initial flow is zero, 1x1.
GLuint initial_flow_tex;
glCreateTextures(GL_TEXTURE_2D, 1, &initial_flow_tex);
- glTextureStorage2D(initial_flow_tex, 1, GL_RGB32F, 1, 1);
+ glTextureStorage2D(initial_flow_tex, 1, GL_RG16F, 1, 1);
GLuint prev_level_flow_tex = initial_flow_tex;
Sobel sobel;
MotionSearch motion_search;
Densify densify;
+ Prewarp prewarp;
+ Derivatives derivatives;
+ ComputeSmoothness compute_smoothness;
+ SetupEquations setup_equations;
+ SOR sor;
+ AddBaseFlow add_base_flow;
+
+ GLuint query;
+ glGenQueries(1, &query);
+ glBeginQuery(GL_TIME_ELAPSED, query);
for (int level = coarsest_level; level >= int(finest_level); --level) {
int level_width = WIDTH >> level;
// Create an output flow texture.
GLuint flow_out_tex;
glCreateTextures(GL_TEXTURE_2D, 1, &flow_out_tex);
- glTextureStorage2D(flow_out_tex, 1, GL_RG16F, width_patches, height_patches);
+ glTextureStorage2D(flow_out_tex, 1, GL_RGB16F, width_patches, height_patches);
// And draw.
motion_search.exec(tex0_view, tex1_view, grad0_tex, prev_level_flow_tex, flow_out_tex, level_width, level_height, width_patches, height_patches);
// Densification.
- // Set up an output texture.
+ // Set up an output texture (initially zero).
GLuint dense_flow_tex;
glCreateTextures(GL_TEXTURE_2D, 1, &dense_flow_tex);
- //glTextureStorage2D(dense_flow_tex, 1, GL_RGB16F, level_width, level_height);
- glTextureStorage2D(dense_flow_tex, 1, GL_RGBA32F, level_width, level_height);
+ glTextureStorage2D(dense_flow_tex, 1, GL_RGB16F, level_width, level_height);
// And draw.
densify.exec(tex0_view, tex1_view, flow_out_tex, dense_flow_tex, level_width, level_height, width_patches, height_patches);
- // TODO: Variational refinement.
+ // Everything below here in the loop belongs to variational refinement.
+ // It is not done yet.
+
+ // Prewarping; create I and I_t.
+ GLuint I_tex, I_t_tex;
+ glCreateTextures(GL_TEXTURE_2D, 1, &I_tex);
+ glCreateTextures(GL_TEXTURE_2D, 1, &I_t_tex);
+ glTextureStorage2D(I_tex, 1, GL_R16F, level_width, level_height);
+ glTextureStorage2D(I_t_tex, 1, GL_R16F, level_width, level_height);
+ prewarp.exec(tex0_view, tex1_view, dense_flow_tex, I_tex, I_t_tex, level_width, level_height);
+
+ // Calculate I_x and I_y. We're only calculating first derivatives;
+ // the others will be taken on-the-fly in order to sample from fewer
+ // textures overall, since sampling from the L1 cache is cheap.
+ // (TODO: Verify that this is indeed faster than making separate
+ // double-derivative textures.)
+ GLuint I_x_y_tex, beta_0_tex;
+ glCreateTextures(GL_TEXTURE_2D, 1, &I_x_y_tex);
+ glCreateTextures(GL_TEXTURE_2D, 1, &beta_0_tex);
+ glTextureStorage2D(I_x_y_tex, 1, GL_RG16F, level_width, level_height);
+ glTextureStorage2D(beta_0_tex, 1, GL_R16F, level_width, level_height);
+ derivatives.exec(I_tex, I_x_y_tex, beta_0_tex, level_width, level_height);
+
+ // We need somewhere to store du and dv (the flow increment, relative
+ // to the non-refined base flow u0 and v0). It starts at zero.
+ GLuint du_dv_tex;
+ glCreateTextures(GL_TEXTURE_2D, 1, &du_dv_tex);
+ glTextureStorage2D(du_dv_tex, 1, GL_RG16F, level_width, level_height);
+
+ // And for smoothness.
+ GLuint smoothness_x_tex, smoothness_y_tex;
+ glCreateTextures(GL_TEXTURE_2D, 1, &smoothness_x_tex);
+ glCreateTextures(GL_TEXTURE_2D, 1, &smoothness_y_tex);
+ glTextureStorage2D(smoothness_x_tex, 1, GL_R16F, level_width, level_height);
+ glTextureStorage2D(smoothness_y_tex, 1, GL_R16F, level_width, level_height);
+
+ // And finally for the equation set. See SetupEquations for
+ // the storage format.
+ GLuint equation_tex;
+ glCreateTextures(GL_TEXTURE_2D, 1, &equation_tex);
+ glTextureStorage2D(equation_tex, 1, GL_RGBA32UI, level_width, level_height);
+
+ for (int outer_idx = 0; outer_idx < level + 1; ++outer_idx) {
+ // Calculate the smoothness terms between the neighboring pixels,
+ // both in x and y direction.
+ compute_smoothness.exec(dense_flow_tex, du_dv_tex, smoothness_x_tex, smoothness_y_tex, level_width, level_height);
+
+ // Set up the 2x2 equation system for each pixel.
+ setup_equations.exec(I_x_y_tex, I_t_tex, du_dv_tex, dense_flow_tex, beta_0_tex, smoothness_x_tex, smoothness_y_tex, equation_tex, level_width, level_height);
+
+ // Run a few SOR (or quasi-SOR, since we're not really Jacobi) iterations.
+ // Note that these are to/from the same texture.
+ sor.exec(du_dv_tex, equation_tex, smoothness_x_tex, smoothness_y_tex, level_width, level_height, 5);
+ }
+
+ // Add the differential flow found by the variational refinement to the base flow,
+ // giving the final flow estimate for this level.
+ // The output is in diff_flow_tex; we don't need to make a new texture.
+ add_base_flow.exec(dense_flow_tex, du_dv_tex, level_width, level_height);
- prev_level_flow_tex = dense_flow_tex;
+ prev_level_flow_tex = du_dv_tex;
}
+ glEndQuery(GL_TIME_ELAPSED);
+
+ GLint available;
+ do {
+ glGetQueryObjectiv(query, GL_QUERY_RESULT_AVAILABLE, &available);
+ usleep(1000);
+ } while (!available);
+ GLuint64 time_elapsed;
+ glGetQueryObjectui64v(query, GL_QUERY_RESULT, &time_elapsed);
+ fprintf(stderr, "GPU time used = %.1f ms\n", time_elapsed / 1e6);
int level_width = WIDTH >> finest_level;
int level_height = HEIGHT >> finest_level;
glGetTextureImage(prev_level_flow_tex, 0, GL_RGB, GL_FLOAT, level_width * level_height * 3 * sizeof(float), dense_flow.get());
FILE *fp = fopen("flow.ppm", "wb");
+ FILE *flowfp = fopen("flow.flo", "wb");
fprintf(fp, "P6\n%d %d\n255\n", level_width, level_height);
+ fprintf(flowfp, "FEIH");
+ fwrite(&level_width, 4, 1, flowfp);
+ fwrite(&level_height, 4, 1, flowfp);
for (unsigned y = 0; y < unsigned(level_height); ++y) {
int yy = level_height - y - 1;
for (unsigned x = 0; x < unsigned(level_width); ++x) {
float dv = dense_flow[(yy * level_width + x) * 3 + 1];
float w = dense_flow[(yy * level_width + x) * 3 + 2];
- du /= w;
- dv /= w;
-
- float angle = atan2(dv * level_width, du * level_height);
- float magnitude = min(hypot(du * level_width, dv * level_height) / 20.0, 1.0);
-
- // HSV to RGB (from Wikipedia). Saturation is 1.
- float c = magnitude;
- float h = (angle + M_PI) * 6.0 / (2.0 * M_PI);
- float X = c * (1.0 - fabs(fmod(h, 2.0) - 1.0));
- float r = 0.0f, g = 0.0f, b = 0.0f;
- if (h < 1.0f) {
- r = c; g = X;
- } else if (h < 2.0f) {
- r = X; g = c;
- } else if (h < 3.0f) {
- g = c; b = X;
- } else if (h < 4.0f) {
- g = X; b = c;
- } else if (h < 5.0f) {
- r = X; b = c;
- } else if (h < 6.0f) {
- r = c; b = X;
- } else {
- // h is NaN, so black is fine.
- }
- float m = magnitude - c;
- r += m; g += m; b += m;
- r = max(min(r, 1.0f), 0.0f);
- g = max(min(g, 1.0f), 0.0f);
- b = max(min(b, 1.0f), 0.0f);
- putc(lrintf(r * 255.0f), fp);
- putc(lrintf(g * 255.0f), fp);
- putc(lrintf(b * 255.0f), fp);
+ du = (du / w) * level_width;
+ dv = (-dv / w) * level_height;
+
+ fwrite(&du, 4, 1, flowfp);
+ fwrite(&dv, 4, 1, flowfp);
+
+ uint8_t r, g, b;
+ flow2rgb(du, dv, &r, &g, &b);
+ putc(r, fp);
+ putc(g, fp);
+ putc(b, fp);
}
}
fclose(fp);
+ fclose(flowfp);
fprintf(stderr, "err = %d\n", glGetError());
}
projects / nageru / blobdiff