glossary alpha value the amount of transparency for color in pygamealpha values range from (completely transparentto (completely opaqueanti-aliasing technique for making shapes look smoother and less blocky by adding fuzzy colors to their edges anti-aliased drawings look smooth aliased drawings look blocky attributes variable that is part of an object for examplerect objects have members such as top and left which hold integer values for the rect object backwards compatibility writing code that is compatible with older versions of software python version has some backwards-incompatible features with python version but it is possible to write python programs that are backwards-compatible with python base case in recursionthe base case is the condition that stops further recursive function calls base case is necessary to prevent stack overflow errors blitting word that means copying the image on one surface object to another in programming in generalit means to copy one image to another image bounding rectangle the smallest rectangle that can be drawn around another shape camera view of particular part of the game world cameras are used when the game world is too large to fit on the player' screen caption in programmingthe caption is the text on the title bar of the window in pygamethe caption can be set with the pygame display set_caption(function cli seecommand line interface command line interface program that the user can use by seeing text on the screen and typing text through the keyboard old computers used to be able to only run cli programsbut new computers have graphical user interfaces constructor function the function that creates new object in pythonthese functions have the same name as the kind of objects they produce for examplepygame rect(creates rect objects display surface the surface object returned by the call to pygame display set_mode(this surface object is special because anything drawn on it email questions to the authoral@inventwithpython com