Method on_draw

samples/engine-performance/engine-performance.cpp:169–298

}

void sample_engine_performance::on_draw()
{
    glfwMakeContextCurrent(window);

    int width, height;
    glfwGetWindowSize(window, &width, &height);

    imgui->begin_frame();

    const uint32_t viewIndex = 0;
    const float4x4 projectionMatrix = cam.get_projection_matrix(float(width) / float(height));
    const float4x4 viewMatrix = cam.get_view_matrix();
    const float4x4 viewProjectionMatrix = projectionMatrix * viewMatrix;
    const frustum camera_frustum(viewProjectionMatrix);

    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    payload.views.clear();
    payload.views.emplace_back(view_data(viewIndex, cam.pose, projectionMatrix));

    payload.render_components.clear();

    {
        simple_cpu_timer t;
        t.start();
        const std::vector<entity> visible_entity_list = scene.get_collision_system()->get_visible_entities(camera_frustum);
        t.stop();

        ImGui::Text("Frustum Cull Took %f ms", (float)t.elapsed_ms());
        ImGui::Text("Visible Entities %i", visible_entity_list.size());

        auto assemble_render_component = [](base_object & t)
        {
            render_component r;
            r.material          = t.get_component<material_component>();
            r.mesh              = t.get_component<mesh_component>();
            r.world_matrix      = t.get_component<transform_component>()->get_world_transform().matrix();
            r.render_sort_order = 0;
            return r;
        };

        // Render everything
        for (auto & t : scene.get_graph().graph_objects)
        { 
            render_component r = assemble_render_component(t.second);
            payload.render_components.emplace_back(r);
        };

        for (size_t i = 0; i < visible_entity_list.size(); ++i)
        {
            const entity e = visible_entity_list[i];
            base_object & obj = scene.get_graph().get_object(e);
            render_component r = assemble_render_component(obj);
            payload.render_components.emplace_back(r);
        }

    }