glViewport(0, 0, width, height);
fbos.render_to(gray_tex);
glBindVertexArray(gray_vao);
- glUseProgram(gray_program);
glDisable(GL_BLEND);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
glViewport(0, 0, level_width, level_height);
fbos.render_to(grad0_tex);
- glUseProgram(sobel_program);
glDisable(GL_BLEND);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
GLuint motion_search_program;
GLuint uniform_inv_image_size, uniform_inv_prev_level_size;
- GLuint uniform_image0_tex, uniform_image1_tex, uniform_grad0_tex, uniform_flow_tex;
+ GLuint uniform_image1_tex, uniform_grad0_tex, uniform_flow_tex;
};
MotionSearch::MotionSearch()
uniform_inv_image_size = glGetUniformLocation(motion_search_program, "inv_image_size");
uniform_inv_prev_level_size = glGetUniformLocation(motion_search_program, "inv_prev_level_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");
{
glUseProgram(motion_search_program);
- 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, zero_border_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);
glProgramUniform2f(motion_search_program, uniform_inv_image_size, 1.0f / level_width, 1.0f / level_height);
glViewport(0, 0, width_patches, height_patches);
fbos.render_to(flow_out_tex);
- glUseProgram(motion_search_program);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
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.
+// Calculate the diffusivity for each pixels, g(x,y). Smoothness (s) will
+// be calculated in the shaders on-the-fly by sampling in-between two
+// neighboring g(x,y) pixels, plus a border tweak to make sure we get
+// zero smoothness at the border.
//
// See variational_refinement.txt for more information.
-class ComputeSmoothness {
+class ComputeDiffusivity {
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, bool zero_diff_flow);
+ ComputeDiffusivity();
+ void exec(GLuint flow_tex, GLuint diff_flow_tex, GLuint diffusivity_tex, int level_width, int level_height, bool zero_diff_flow);
private:
- PersistentFBOSet<2> fbos;
+ PersistentFBOSet<1> fbos;
- GLuint smoothness_vs_obj;
- GLuint smoothness_fs_obj;
- GLuint smoothness_program;
+ GLuint diffusivity_vs_obj;
+ GLuint diffusivity_fs_obj;
+ GLuint diffusivity_program;
GLuint uniform_flow_tex, uniform_diff_flow_tex;
GLuint uniform_alpha, uniform_zero_diff_flow;
};
-ComputeSmoothness::ComputeSmoothness()
+ComputeDiffusivity::ComputeDiffusivity()
{
- 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);
-
- uniform_flow_tex = glGetUniformLocation(smoothness_program, "flow_tex");
- uniform_diff_flow_tex = glGetUniformLocation(smoothness_program, "diff_flow_tex");
- uniform_alpha = glGetUniformLocation(smoothness_program, "alpha");
- uniform_zero_diff_flow = glGetUniformLocation(smoothness_program, "zero_diff_flow");
+ diffusivity_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ diffusivity_fs_obj = compile_shader(read_file("diffusivity.frag"), GL_FRAGMENT_SHADER);
+ diffusivity_program = link_program(diffusivity_vs_obj, diffusivity_fs_obj);
+
+ uniform_flow_tex = glGetUniformLocation(diffusivity_program, "flow_tex");
+ uniform_diff_flow_tex = glGetUniformLocation(diffusivity_program, "diff_flow_tex");
+ uniform_alpha = glGetUniformLocation(diffusivity_program, "alpha");
+ uniform_zero_diff_flow = glGetUniformLocation(diffusivity_program, "zero_diff_flow");
}
-void ComputeSmoothness::exec(GLuint flow_tex, GLuint diff_flow_tex, GLuint smoothness_x_tex, GLuint smoothness_y_tex, int level_width, int level_height, bool zero_diff_flow)
+void ComputeDiffusivity::exec(GLuint flow_tex, GLuint diff_flow_tex, GLuint diffusivity_tex, int level_width, int level_height, bool zero_diff_flow)
{
- glUseProgram(smoothness_program);
+ glUseProgram(diffusivity_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);
- glProgramUniform1f(smoothness_program, uniform_alpha, vr_alpha);
- glProgramUniform1i(smoothness_program, uniform_zero_diff_flow, zero_diff_flow);
+ bind_sampler(diffusivity_program, uniform_flow_tex, 0, flow_tex, nearest_sampler);
+ bind_sampler(diffusivity_program, uniform_diff_flow_tex, 1, diff_flow_tex, nearest_sampler);
+ glProgramUniform1f(diffusivity_program, uniform_alpha, vr_alpha);
+ glProgramUniform1i(diffusivity_program, uniform_zero_diff_flow, zero_diff_flow);
glViewport(0, 0, level_width, level_height);
glDisable(GL_BLEND);
- fbos.render_to(smoothness_x_tex, smoothness_y_tex);
+ fbos.render_to(diffusivity_tex);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
-
- // Make sure the smoothness on the right and upper borders is zero.
- // We could have done this by making (W-1)xH and Wx(H-1) textures instead
- // (we're sampling smoothness with all-zero border color), but we'd
- // have to adjust the sampling coordinates, which is annoying.
- glClearTexSubImage(smoothness_x_tex, 0, level_width - 1, 0, 0, 1, level_height, 1, GL_RED, GL_FLOAT, nullptr);
- glClearTexSubImage(smoothness_y_tex, 0, 0, level_height - 1, 0, level_width, 1, 1, GL_RED, GL_FLOAT, nullptr);
}
// Set up the equations set (two equations in two unknowns, per pixel).
// 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.
+// The equation set is split in two; one contains only the pixels needed for
+// the red pass, and one only for the black pass (see sor.frag). This reduces
+// the amount of data the SOR shader has to pull in, at the cost of some
+// complexity when the equation texture ends up with half the size and we need
+// to adjust texture coordinates. The contraction is done along the horizontal
+// axis, so that on even rows (0, 2, 4, ...), the “red” texture will contain
+// pixels 0, 2, 4, 6, etc., and on odd rows 1, 3, 5, etc..
+//
+// See variational_refinement.txt for more information about the actual
+// equations in use.
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, bool zero_diff_flow);
+ void exec(GLuint I_x_y_tex, GLuint I_t_tex, GLuint diff_flow_tex, GLuint 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);
private:
- PersistentFBOSet<1> fbos;
+ PersistentFBOSet<2> fbos;
GLuint equations_vs_obj;
GLuint equations_fs_obj;
GLuint uniform_I_x_y_tex, uniform_I_t_tex;
GLuint uniform_diff_flow_tex, uniform_base_flow_tex;
GLuint uniform_beta_0_tex;
- GLuint uniform_smoothness_x_tex, uniform_smoothness_y_tex;
+ GLuint uniform_diffusivity_tex;
GLuint uniform_gamma, uniform_delta, uniform_zero_diff_flow;
};
SetupEquations::SetupEquations()
{
- equations_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+ equations_vs_obj = compile_shader(read_file("equations.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);
uniform_diff_flow_tex = glGetUniformLocation(equations_program, "diff_flow_tex");
uniform_base_flow_tex = glGetUniformLocation(equations_program, "base_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");
+ uniform_diffusivity_tex = glGetUniformLocation(equations_program, "diffusivity_tex");
uniform_gamma = glGetUniformLocation(equations_program, "gamma");
uniform_delta = glGetUniformLocation(equations_program, "delta");
uniform_zero_diff_flow = glGetUniformLocation(equations_program, "zero_diff_flow");
}
-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 smoothness_x_tex, GLuint smoothness_y_tex, GLuint equation_tex, int level_width, int level_height, bool zero_diff_flow)
+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)
{
glUseProgram(equations_program);
bind_sampler(equations_program, uniform_diff_flow_tex, 2, diff_flow_tex, nearest_sampler);
bind_sampler(equations_program, uniform_base_flow_tex, 3, base_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, zero_border_sampler);
- bind_sampler(equations_program, uniform_smoothness_y_tex, 6, smoothness_y_tex, zero_border_sampler);
+ bind_sampler(equations_program, uniform_diffusivity_tex, 5, diffusivity_tex, zero_border_sampler);
glProgramUniform1f(equations_program, uniform_delta, vr_delta);
glProgramUniform1f(equations_program, uniform_gamma, vr_gamma);
glProgramUniform1i(equations_program, uniform_zero_diff_flow, zero_diff_flow);
- glViewport(0, 0, level_width, level_height);
+ glViewport(0, 0, (level_width + 1) / 2, level_height);
glDisable(GL_BLEND);
- fbos.render_to(equation_tex);
+ fbos.render_to({equation_red_tex, equation_black_tex});
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
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, bool zero_diff_flow, ScopedTimer *sor_timer);
+ void 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, ScopedTimer *sor_timer);
private:
PersistentFBOSet<1> fbos;
GLuint sor_program;
GLuint uniform_diff_flow_tex;
- GLuint uniform_equation_tex;
- GLuint uniform_smoothness_x_tex, uniform_smoothness_y_tex;
+ GLuint uniform_equation_red_tex, uniform_equation_black_tex;
+ GLuint uniform_diffusivity_tex;
GLuint uniform_phase, uniform_zero_diff_flow;
};
sor_program = link_program(sor_vs_obj, sor_fs_obj);
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");
+ uniform_equation_red_tex = glGetUniformLocation(sor_program, "equation_red_tex");
+ uniform_equation_black_tex = glGetUniformLocation(sor_program, "equation_black_tex");
+ uniform_diffusivity_tex = glGetUniformLocation(sor_program, "diffusivity_tex");
uniform_phase = glGetUniformLocation(sor_program, "phase");
uniform_zero_diff_flow = glGetUniformLocation(sor_program, "zero_diff_flow");
}
-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, bool zero_diff_flow, ScopedTimer *sor_timer)
+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, ScopedTimer *sor_timer)
{
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, zero_border_sampler);
- bind_sampler(sor_program, uniform_smoothness_y_tex, 2, smoothness_y_tex, zero_border_sampler);
- bind_sampler(sor_program, uniform_equation_tex, 3, equation_tex, nearest_sampler);
+ bind_sampler(sor_program, uniform_diffusivity_tex, 1, diffusivity_tex, zero_border_sampler);
+ bind_sampler(sor_program, uniform_equation_red_tex, 2, equation_red_tex, nearest_sampler);
+ bind_sampler(sor_program, uniform_equation_black_tex, 3, equation_black_tex, nearest_sampler);
glProgramUniform1i(sor_program, uniform_zero_diff_flow, zero_diff_flow);
Densify densify;
Prewarp prewarp;
Derivatives derivatives;
- ComputeSmoothness compute_smoothness;
+ ComputeDiffusivity compute_diffusivity;
SetupEquations setup_equations;
SOR sor;
AddBaseFlow add_base_flow;
// Similarly, gradients are zero outside the border, since the edge is taken
// to be constant.
glCreateSamplers(1, &zero_border_sampler);
- glSamplerParameteri(zero_border_sampler, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
- glSamplerParameteri(zero_border_sampler, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glSamplerParameteri(zero_border_sampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ glSamplerParameteri(zero_border_sampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glSamplerParameteri(zero_border_sampler, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
glSamplerParameteri(zero_border_sampler, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
- float zero[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+ 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.
glSamplerParameterfv(zero_border_sampler, GL_TEXTURE_BORDER_COLOR, zero);
// Initial flow is zero, 1x1.
// Create a new texture; we could be fancy and render use a multi-level
// texture, but meh.
- GLuint grad0_tex = pool.get_texture(GL_RG16F, level_width, level_height);
+ GLuint grad0_tex = pool.get_texture(GL_R32UI, level_width, level_height);
// Find the derivative.
{
// but not read until we've written something sane to it.
GLuint du_dv_tex = pool.get_texture(GL_RG16F, level_width, level_height);
- // And for smoothness.
- GLuint smoothness_x_tex = pool.get_texture(GL_R16F, level_width, level_height);
- GLuint smoothness_y_tex = pool.get_texture(GL_R16F, level_width, level_height);
+ // And for diffusivity.
+ GLuint diffusivity_tex = pool.get_texture(GL_R16F, level_width, level_height);
// And finally for the equation set. See SetupEquations for
// the storage format.
- GLuint equation_tex = pool.get_texture(GL_RGBA32UI, level_width, level_height);
+ GLuint equation_red_tex = pool.get_texture(GL_RGBA32UI, (level_width + 1) / 2, level_height);
+ GLuint equation_black_tex = pool.get_texture(GL_RGBA32UI, (level_width + 1) / 2, 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.
+ // Calculate the diffusivity term for each pixel.
{
- ScopedTimer timer("Compute smoothness", &varref_timer);
- compute_smoothness.exec(base_flow_tex, du_dv_tex, smoothness_x_tex, smoothness_y_tex, level_width, level_height, outer_idx == 0);
+ ScopedTimer timer("Compute diffusivity", &varref_timer);
+ compute_diffusivity.exec(base_flow_tex, du_dv_tex, diffusivity_tex, level_width, level_height, outer_idx == 0);
}
// Set up the 2x2 equation system for each pixel.
{
ScopedTimer timer("Set up equations", &varref_timer);
- setup_equations.exec(I_x_y_tex, I_t_tex, du_dv_tex, base_flow_tex, beta_0_tex, smoothness_x_tex, smoothness_y_tex, equation_tex, level_width, level_height, outer_idx == 0);
+ setup_equations.exec(I_x_y_tex, I_t_tex, du_dv_tex, base_flow_tex, beta_0_tex, diffusivity_tex, equation_red_tex, equation_black_tex, level_width, level_height, outer_idx == 0);
}
- // Run a few SOR (or quasi-SOR, since we're not really Jacobi) iterations.
- // Note that these are to/from the same texture.
+ // Run a few SOR iterations. Note that these are to/from the same texture.
{
ScopedTimer timer("SOR", &varref_timer);
- sor.exec(du_dv_tex, equation_tex, smoothness_x_tex, smoothness_y_tex, level_width, level_height, 5, outer_idx == 0, &timer);
+ sor.exec(du_dv_tex, equation_red_tex, equation_black_tex, diffusivity_tex, level_width, level_height, 5, outer_idx == 0, &timer);
}
}
pool.release_texture(I_t_tex);
pool.release_texture(I_x_y_tex);
pool.release_texture(beta_0_tex);
- pool.release_texture(smoothness_x_tex);
- pool.release_texture(smoothness_y_tex);
- pool.release_texture(equation_tex);
+ pool.release_texture(diffusivity_tex);
+ pool.release_texture(equation_red_tex);
+ pool.release_texture(equation_black_tex);
// Add the differential flow found by the variational refinement to the base flow,
// giving the final flow estimate for this level.
bind_sampler(blend_program, uniform_image1_tex, 1, tex1, linear_sampler);
bind_sampler(blend_program, uniform_flow_tex, 2, flow_tex, linear_sampler); // May be upsampled.
glProgramUniform1f(blend_program, uniform_alpha, alpha);
- //glProgramUniform1f(blend_program, uniform_flow_consistency_tolerance, 1.0f /
glViewport(0, 0, level_width, level_height);
fbos.render_to(output_tex);
- glUseProgram(blend_program);
glDisable(GL_BLEND); // A bit ironic, perhaps.
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
ScopedTimer timer("Blend", &total_timer);
blend.exec(tex0, tex1, flow_tex, output_tex, width, height, alpha);
}
+ pool.release_texture(flow_tex);
total_timer.end();
timers.print();