Sometimes while debugging your project it's useful to quickly visualize things like vectors and points on-screen to aid problem solving.
In Simulant, every Stage has a debug property. The Debug object allows quickly adding points and lines with the following methods:
draw_line(const Vec3 &start, const Vec3 &end, const Colour &colour, double duration, bool depth_test)draw_ray(const Vec3 &start, const Vec3 &dir, const Colour &colour, double duration, bool depth_test)draw_point(const Vec3 &position, const Colour &colour, double duration, bool depth_test)Most of the arguments are self explanatory with the exception of duration. duration is the length of time to persist this line or point. By default this is 0 seconds (meaning you need to call draw_X() every frame), however if you want to persist a debug element across frames you can specify the length of time that the debug element should live.
stage->debug->draw_line(Vec3(0, 0, 0), Vec3(1, 1, 1), Colour::RED);
stage->debug->draw_ray(Vec3(0, 0, 0), Vec3(0, 1, 0)); // Defaults to WHITE
// Draws a blue point for 1 second that won't be depth tested
stage->debug->draw_point(Vec3(0, 0, 0), Colour::BLUE, 1.0f, false);