glUseProgram(frag_shader);
glUniform1i(glGetUniformLocation(frag_shader, "tex"), 0);
glUniform1i(glGetUniformLocation(frag_shader, "do_r"), config.r);
glUseProgram(frag_shader);
glUniform1i(glGetUniformLocation(frag_shader, "tex"), 0);
glUniform1i(glGetUniformLocation(frag_shader, "do_r"), config.r);