// 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 diffusivity_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;
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 diffusivity_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);
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 diffusivity_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_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_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 diffusivity_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_diffusivity_tex, 1, diffusivity_tex, zero_border_sampler);
- bind_sampler(sor_program, uniform_equation_tex, 2, equation_tex, nearest_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);
// 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 diffusivity term for each pixel.
// 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, diffusivity_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, diffusivity_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_x_y_tex);
pool.release_texture(beta_0_tex);
pool.release_texture(diffusivity_tex);
- pool.release_texture(equation_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.
projects / nageru / blobdiff