Performance issues on Shiny

[ghost]

I am having some performance problems with the show_pixels() function in shiny-server.

At first, the application starts out great. The longer the mouse is held down, even after less than a second, there is a significant decrease in frame updates.

Upon inspecting the resulting matrix, I can see that the values are continually added to the matrix in the pixels object. For example, though 1 is the highest value I have within a brush input matrix, the resulting pixel matrix may have values as high as 10 or 20 depending how long the area was pressed down. Is there a way to limit a cell update operation on a cell if it has already hit its maximum value?

Otherwise, is there something else I may do to alleviate performance problems?

Many thanks!