Friday, January 1, 2016

Internet Explorer WebGL bug

I was doing some experiments with a 2d scatter plot with more than 5k points (see http://yetanothermathprogrammingconsultant.blogspot.com/2015/12/visualization-of-large-multi-criteria_18.html for more information). The Bokeh visualization tool allows to speed things up by using WebGL in the browser. This will allow some graphics related operations to be executed on the GPU (Graphics Processing Unit). For some operations this makes quite some difference in speed. However, this showed a bug in MS Internet Explorer (or MS Edge which I am using). The correct plot after selecting some points is on the left. MS IE draws all points however with a size of one pixel if WebGL is used. Chrome does the right thing (whether WebGL is used or not). MS IE also works correctly if the plot is created without WebGL support.

Correct Plot
MS IE version
The Bokeh docs seem to confirm this: "Making a selections of markers on Internet Explorer will reduce the size of the markers to 1 pixel (looks like a bug in IE)."