02-18-2021, 07:42 AM
Harry - I assume you are on version 3.0.8, correct? Please try something for me - go to Settings->Display Settings->Image Quality, and set it to Low and see if that impacts the performance at all for you. I already drop the image quality down when zoomed in more than 200%, so this will probably not have a large impact on the issue you are encountering. As far as what is going on, I believe there are a couple of issues:
1) The Surface Book 3 has a 3000x2000 resolution screen, and MobileSheets will try to scale up the images to fit the screen. If you zoom in 2.5x, for example, MobileSheets is increase the size of the page by 2.5x, so suddenly it is dealing with a container that is 7500x5000, and the image that is rendered is 7500x5000 pixels as well.
2) With each movement while annotating, the page is being rendered as part of the normal drawing, but this means a 7500x5000 pixel image may be rendered over and over, which is requiring a significant amount of processing power
My hope with Win2D is that it would automatically only render the part of the image that is actually visible on the screen, but it doesn't work that way unfortunately, so if I want it to only render a chunk of the page, I would have to implement that code myself. So there are a few things I will probably need to do to improve the rendering speed while annotating:
1) If "Draw Highlights behind Content" is disabled, I don't have to worry about blending the rendered image with the highlight annotations, so I can just render the annotations separately, meaning the page won't have to be re-rendered each time. This alone would probably eliminate all the performance problems you are experiencing.
2) If "Draw Highlights behind Content" is enabled, then I still have to do a considerable amount of image processing in order to blend the annotations that are visible on the screen with the rendered image of the page. Having said that, if I can find some way to properly cache the blended pixels, then it might be possible to prevent the redrawing of the page each time, and only render the non-highlight annotations on top of the page.
On Android, I'm able to draw the annotations separately from the image on the page, but I can still blend the pixels properly without having to redraw the image every time due to some of the advanced drawing techniques that are available. Unfortunately, I don't have anything like that in Win2D.
I'll work on implementing these changes for the next update. Thanks for your patience.
Mike
1) The Surface Book 3 has a 3000x2000 resolution screen, and MobileSheets will try to scale up the images to fit the screen. If you zoom in 2.5x, for example, MobileSheets is increase the size of the page by 2.5x, so suddenly it is dealing with a container that is 7500x5000, and the image that is rendered is 7500x5000 pixels as well.
2) With each movement while annotating, the page is being rendered as part of the normal drawing, but this means a 7500x5000 pixel image may be rendered over and over, which is requiring a significant amount of processing power
My hope with Win2D is that it would automatically only render the part of the image that is actually visible on the screen, but it doesn't work that way unfortunately, so if I want it to only render a chunk of the page, I would have to implement that code myself. So there are a few things I will probably need to do to improve the rendering speed while annotating:
1) If "Draw Highlights behind Content" is disabled, I don't have to worry about blending the rendered image with the highlight annotations, so I can just render the annotations separately, meaning the page won't have to be re-rendered each time. This alone would probably eliminate all the performance problems you are experiencing.
2) If "Draw Highlights behind Content" is enabled, then I still have to do a considerable amount of image processing in order to blend the annotations that are visible on the screen with the rendered image of the page. Having said that, if I can find some way to properly cache the blended pixels, then it might be possible to prevent the redrawing of the page each time, and only render the non-highlight annotations on top of the page.
On Android, I'm able to draw the annotations separately from the image on the page, but I can still blend the pixels properly without having to redraw the image every time due to some of the advanced drawing techniques that are available. Unfortunately, I don't have anything like that in Win2D.
I'll work on implementing these changes for the next update. Thanks for your patience.
Mike