Midterm Review Computer Graphics Hardware Point and Line Drawing Polygon Filling C++ Fall 2004 CS-321 Dr. Mark L. Hornick

Computer Graphics Hardware Describe the fundamental difference in operation between a vector and raster device Discuss some relative advantages & disadvantages of both Compute the amount of video memory required for an N-color raster display of resolution n x m pixels Compute the video bus data transfer rate required for such a display with a specific refresh rate Fall 2004 CS-321 Dr. Mark L. Hornick

Point and Line Drawing Compare/contrast the various line generation algorithms Simple (y=mx+b) DDA Bresenham Compute the formulas for Bresenham’s algorithm Explain the purpose of anti-aliasing algorithms Describe how various anti-aliasing algorithms work Supersampling a thin line Supersampling a “thick line” using Uniform weighting Center weighting Fall 2004 CS-321 Dr. Mark L. Hornick

Polygon Filling Given an arbitrary shape, determine inside-outside using Odd-even rule Non-zero winding rule Compute line segment (x,y) intersections by solving parametric equations Explain how scan-line fill uses inside-outside testing and edge intersection information to determine when to fill Determine the progression of a recursive fill algorithm when filling a simple shape Using 4-connected recursion Using 8-connected recursion Explain boundary fill vs. flood fill Fall 2004 CS-321 Dr. Mark L. Hornick

C++ Language Concepts Explain which constructors are automatically generated by the compiler Explain the function of the default implementation of these automatically generated constructors. (i.e. what do they do?) Explain the specific circumstances under which the compiler no longer provides a default ctor and/or copy ctor Write example statements that cause The copy ctor to be invoked The operator= to be invoked State the order of construction in inheritance situations Explain which base class constructor is automatically invoked when derived objects are created (using derived class ctors) Explain the purpose of using an initializer to invoke a specific base class ctor Explain the function of the default implementation of operator=() Explain the function of the default implementation of the destructor Explain the order of destruction in inheritance situations Fall 2004 CS-321 Dr. Mark L. Hornick

C++ Inheritance & Polymorphism Describe the “virtual” method declarator specifier and its effect Explain the concept of an abstract base class Explain which methods can contain implementation and which cannot Explain the concept of a pure virtual method Explain when you must override a virtual method in a derived class When using a pointer to a base class to reference a derived class object, describe What happens when the base class method [is/is not] declared virtual What happens the base class (non-pure) virtual method is not overridden Fall 2004 CS-321 Dr. Mark L. Hornick

UML Class & Sequence Diagrams Given a class diagram, write the corresponding C++ class declaration(s) Given C++ class declaration(s), draw the corresponding class diagram and the relationship between classes Using appropriate connectors Given a sequence diagram illustrating method invocations, write the corresponding C++ code Given C++ code, create a sequence diagram Fall 2004 CS-321 Dr. Mark L. Hornick