Debugging Animation for General Programs by Keyframe Interpolation

[[abstract]]Generally speaking, a programmer usually needs to use or maintain the code which is written by someone else. Before he/she is capable of modifying the code, he/she must understand the program. Several entities can help understanding a program. For example, a design document, if available, can greatly help the understanding of a program. However, a design document might be out of date or inconsistent to the code. Tracing the source code is often used as a last resort. It is common to trace a program by debugger. The programmers set break points inside the program and then execute the program in debug mode to observe the change of variable values in order to understand how does the program work. Most debuggers nowadays are textual and numerical based. It is inadequate when a program comprises of complicated data structures. In these years, several software visualization researches have been proposed to visualize software by the graphics, which are called visualize metaphors (VM). However, these research tools are typically limited to specific application domains, without generality. Tools that provide animation capability include ANIMAL[1], PlanAni[2], JEDAS[3], Jeliot3[4], POLKA[5], TANGO[6], and XTANGO[7]. These prototype software tools typically limit their visualization power to fixed problem domains such as education. Some requires writing extra code for the animation. In this thesis, we proposed an animation subsystem in xDIVA[8]. It can display the program dynamic behavior between the break points by animation so that a program can be understood in a more efficient manner. In our method, users do not need to write the extra code for animation. After a layout automatically arranges the VMs in a new break point, our approach computes the differences in VM’s positions and properties so that an interpolation between the two key frames at two break points can be constructed. An animation is then made from such an interpolation.