These routines are meant to provide a high level mechanism to create and manipulate world canvases (canvases which have a co-ordinate system based on real-world co-ordinates). ... Parameters: . ... The world canvas will be automatically destroyed if the pixel canvas is destroyed. void canvas_destroy (KWorldCanvas canvas) . ... void canvas_convert_ellipse_coords (KWorldCanvas canvas, flag to_world, flag linear, double *centre_x, double *centre_y, double *radius_x, double *radius_y, double *rotation) . ...