CODEWITHSUNDEEP
c#performancedrawing
Raevyn117
Raevyn117

Reputation: 21

Slow drawing when using many controls in C#

I've been trying to create a roll-playing game for a little over a year now, and I thought a good way to test it and flesh it out a bit would be to turn it into a Dungeons and Dragons variant. However, the inherent problem with using a DnD setup is that there's a lot to keep track of, to the point where it becomes impossible for a single person to do by themselves. As such, I thought of writing a C# program to help.

I ran into this problem when I tried using a series of PictureBox objects to represent the spaces on the map where characters can move. I wanted to use PictureBoxes because that would allow me to use images to represent terrain and characters occupying the given space. However, the map I am using is roughly 46 x 75 1-inch squares, totaling 3450 PictureBoxes. This, understandably, slows the application down so much that it actually freezes for minutes at a time while it redraws the map every so often.

I tried two solutions. First, I tried using a Panel object for its free scrolling capabilities in the hopes that the application wouldn't have to redraw the whole map, but rather only the subset of PictureBoxes visible at that time. This helped only a little, and not enough to make the application usable. Second, I looked online, including this forum, and found people having similar problems. However, the problems they were having were entirely unrelated to mine (aside from the whole slow redraw thing) and thus the solutions didn't really apply to me. I did see a few recurring lines that I tried:

this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
this.SetStyle(ControlStyles.ResizeRedraw, true);

I'm not really sure what they do, but they did help a bit. I am still seeing way too much lag, though.

I'm out of ideas at the moment. Is there a better control I could use or a different way of drawing? Thanks in advance for your help!

Upvotes: 1

Views: 1256

Answers (1)

TGH
TGH

Reputation: 39268

I would try to develop a solution that only renders the images that are visible on the screen at any given time. Images should only be rendered when you scroll them into focus. This is a common technique since rendering UI is usually the slowest operation by far. I would bind a view model object to the visible objects, which means you only have to render a subset of the images instead of the entire screen.

Grids with endless scroll sometimes use this approach.

Upvotes: 2

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