Add ability to query PictureEvents whether they change the buffer stack
Add ability to query PictureEvents whether they change the buffer stack

Oletus/glbrush.js,garg/glbrush.js,garg/glbrush.js,Oletus/glbrush.js,garg/glbrush.js,Bercon/glbrush.js,garg/examplepressure,garg/examplepressure,Oletus/glbrush.js,garg/examplepressure,Bercon/glbrush.js,garg/examplepressure,Bercon/glbrush.js,Bercon/glbrush.js,garg/glbrush.js