   complex gui performance
  hey all,i know that opengl guis have been discussed to death, and i have already read a majority of these posts here - but haven''t found any exactly relevant to my question here.specifically, i am (or we are) looking to create gui elements that handle relatively complex text processing. which is to say that users will be typing a fair amount in it, and will be viewing a decent amount of marked-up text. its not huge quantities, but it is significant. this is in conjunction to 3d models being rendered along side and/or behind the text. the 3d models, however, are not particularly complex and don''t require heavy processing at all.based on many criteria, it looks like opengl will probably be the g-lib of choice. i am not to sure on performance though. in my previous workings with opengl, i have used text textures, and blitted each character out, one at a time. while this worked wonderfully for labels, values and other basic information, is this really an efficient approach for large volumes?has anyone tried, for example, to render a full page of text in gl? was the performance acceptable?i would really appreciate any input or guidance on this.thanks,   ---craig(at)cod3rz(dot)net 
  I just ran a quick test and, using bitmap fonts, I can render screenfulls of text (1024 * 768 resolution, 76 lines of text) at 295 frames a second.  Admittedly this is on a GeForce Fx5900, but I shouldn''t think you''d have any problems on other cards.Enigma ;  Textured fonts should offer the best performance.Also, a big increase in performance can be gained if you can cache the characters/polygons needed to be rendered and form a triangle strip with it and render it in 1 go by using vertex arrays instead of rendering letter by letter. However, it is easier said then done and might require memory allocations and might not be easy to implement. Most people are unlikely to go to that extent.  ;  enigma - cool, those are good results. i think you have the best approach tho'' - just try it!considering that we do not need to rotate, scale or decal the text in any way, i think i would agree with using bitmap fonts.did you use glut, wgl or other?gamersg - i assume you mean something like with display lists? building the list based on a line of text and then rendering that? mmm....interesting idea, thanks, i will play with that.however, many of our client machines are in the +/- p500 w/ 64MB ram and no 3d acceleration. so i''m a little worried about textured fonts...thanks   ---craig(at)cod3rz(dot)net ;  Sorry, I meant textured fonts, not bitmap fonts.  I use windows API calls to generate a texture at run-time and then draw the text using textured quads (although it would probably be better to use triangle strips).  You can grab the code that does this from my NeHe LOTR-TTT entry if you want (warning the full zip is about 5.8Mb).  It''s the FontManager class.  Looking at your target spec though I''d say bitmap fonts might be the way to go - try it and see!Enigma 