1.　　首先把兩張圖讀進來，求出高與寬和設定time的最大值

2.　　利用atan()這個數學函式算出角度，以圖的中心為基準width/2和height/2

把x,y帶入atan(-(y-height/2)/(x-width/2))*180/PI

-　　當求出的角度<隨著時間比例變的角度，則將新的圖覆蓋到舊的圖

-　　反之，用舊的圖覆蓋舊的圖



3.　　但是，這會產生一個問題，因為斜率一樣，且atan()求出的角度範圍只有-90~90度，所以一三象限或者二四象限會發生同時wipe的情況。為了解決這個情況，我將atan()求出的角度轉成0~360度，這樣各自的象限就有自己的工作，則不會產生同時wipe的情況

4.　　以上簡述就可完成clock wipe的功能-1. two maps read come, find the height and width and set the time of maximum



2. Use atan () math functions calculate the angle to the center of the benchmark the width/height/2

X, y into the atan (- (y-height/2)/(x-width/2))* 180/PI

- Obtained when the angle <With time the proportion of change of angle, then the new map to cover the old map

- On the contrary, cover with the old map old map



3. this will create a problem because of the slope, and atan () Find the angle range of-90 to 90 degrees, so the thirteen quadrant or twenty-four-quadrant will occur at the same time wipe. In order to address this situation, I will atan () Find the angle of turn into a 0 to 360 degrees, so that the respective quadrant has its own work, is not at the same time wipe

4. briefly summarized above, can be completed clock wipe one s function