# Very slow blitting, trying to optimize **URL:** \ **Category:** wxRuby\ **Created:** [October 29, 2010, 4:30pm UTC](https://www.ruby-forum.com/t/very-slow-blitting-trying-to-optimize/198310 "2010-10-29T16:30:32Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![okkezSS](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/o/85f322/32.png) [@okkezSS](https://www.ruby-forum.com/u/okkezSS)\ **Post date:** [October 29, 2010, 4:30pm UTC](https://www.ruby-forum.com/t/very-slow-blitting-trying-to-optimize/198310/1 "2010-10-29T16:30:32Z")
Hello, I’m coding a 2D map editor for a small game engine on MSW and I’m running into blitting problems. The bigger my map is, the longer it takes to blit a tile on it. sometimes, when I try to draw a tile to fast, it even fails completely at blitting and I have to close and reopen the program for it to work again. I have attached the main drawing methods to this post. How it works: 1. I have a custom cache class that creates and retrieves bitmaps on demand to speed up things a bit. Used especially when using tiles, layers or the whole tilemap bitmap. All get\_X\_bitmap methods you see are used to retrieve bitmaps from cache. 2. The draw\_layer and draw\_tilemap methods have a rect argument. When not nil, only the region specified by this rect is redrawn. Again, this is to speed up the whole process. I did some basic speed test using the Time class to see how log it takes to blit a tile depending on the map size, using 32x32 tiles. On a 20x20 map, the whole process takes around 0.032 to 0.041 seconds On a 100x100 map, it can take up to 0.5 seconds The most weird part is when I try to draw tiles to fast on a big map. It starts to blit the first few tiles (with a log of lag) and then it completly fails. Blitting now takes 0.0 seconds and nothing is drawn on screen. Any idea on how I can fix this? And pease tell me if there is not enough imformation or source code, i can provide more.🙂 Thank you very much! - Sasha