Improved Contour plot drawing speed for large dataset, especially when some level's fill colors are set to be none.  

E.g. for 130,000 row of XYZ data, if you plot contour and turn the speed mode off. It may take a few minutes. In Origin 2020, it will be a few seconds. 

Improved scatter drawing speed when turning off speed mode to show all data, specially for square shaped scatter plot and colormapped scatter plot, it's almost 5-10 times faster.

Also, support a new plot type, Color Dots. It can be almost 8 times faster than normal colormapped scatter plot.

For scatter plot with solid rectangle and circle shapes, improve the drawing speed when turn on transparency. It can be 1.5 times faster than before.