Finally get SOR working.

[nageru] / flow.cpp

diff --git a/flow.cpp b/flow.cpp
index b7f6d9c4c347b59cd7e893c08617a041c98ba6ba..8b09c8840999148ee3c0d3a0375e0af6c833da08 100644 (file)
--- a/flow.cpp
+++ b/flow.cpp
@@ -783,11 +783,12 @@ private:
        GLuint uniform_diff_flow_tex;
        GLuint uniform_equation_tex;
        GLuint uniform_smoothness_x_tex, uniform_smoothness_y_tex;
+       GLuint uniform_image_size, uniform_phase;
 };
 
 SOR::SOR()
 {
-       sor_vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
+       sor_vs_obj = compile_shader(read_file("sor.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);
 
@@ -804,6 +805,8 @@ SOR::SOR()
        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_image_size = glGetUniformLocation(sor_program, "image_size");
+       uniform_phase = glGetUniformLocation(sor_program, "phase");
 }
 
 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)
@@ -815,12 +818,22 @@ void SOR::exec(GLuint diff_flow_tex, GLuint equation_tex, GLuint smoothness_x_te
        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);
 
+       glProgramUniform2f(sor_program, uniform_image_size, level_width, level_height);
+
+       // NOTE: We bind to the texture we are rendering from, but we never write any value
+       // that we read in the same shader pass (we call discard for red values when we compute
+       // black, and vice versa), and we have barriers between the passes, so we're fine
+       // as per the spec.
        glViewport(0, 0, level_width, level_height);
        glDisable(GL_BLEND);
        glBindVertexArray(sor_vao);
-       fbos.render_to(diff_flow_tex);  // NOTE: Bind to same as we render from!
+       fbos.render_to(diff_flow_tex);
 
        for (int i = 0; i < num_iterations; ++i) {
+               glProgramUniform1i(sor_program, uniform_phase, 0);
+               glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+               glTextureBarrier();
+               glProgramUniform1i(sor_program, uniform_phase, 1);
                glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
                if (i != num_iterations - 1) {
                        glTextureBarrier();