/// Adds a drawing request for part of a surface.
void draw_surface_part(const Surface* surface, const Vector& source,
const Vector& size, const Vector& dest, int layer);
/// Draws a text.
void draw_text(const Font* font, const std::string& text,
const Vector& position, FontAlignment alignment, int layer);
/// Adds a drawing request for part of a surface.
void draw_surface_part(const Surface* surface, const Vector& source,
const Vector& size, const Vector& dest, int layer);
/// Draws a text.
void draw_text(const Font* font, const std::string& text,
const Vector& position, FontAlignment alignment, int layer);