Google isn't helping. :) 'Layer' means so many things in code that it's like Googling for music by the band called 'Download'...
I won't try to say what I think I want, I tried enough things to confuse the hell out of me and none worked so that is wasting your time. Instead I'll state exactly what I need, and hope for the best answer, as it won't be what I thought of this time. I'm drawing a GPS track on a chart (actually, an aerial image). So far so good, but the image is huge, it's slow to load and doesn't always render in W98. (More on this in a recent post here, I'm still hoping for some ideas to help with that because Paint Shop has no trouble with it on the same system). ------- What I want to do is load the image, then load one (or more) track data files. I want to see the track(s) drawn on top of the chart, but not ON it exactly, I want to be able to delete tracks, or even parts of tracks, or highlight selected subsets of tracks... Thus I need layers that are transparent, ideally done in a way that does not make a ful bitmap-sized form for each layer printed. A few things I learned: 1. Anything printed to a window is a single opaque image, any 'transparency' (perhaps not including alpha stuff specific to WXP or other systems I'm not using) is a thing arranged prior to rendering a single plane of graphic data. 2. A bitmap copied to another variable is still the same bitmap, at least until one of them is edited, then Copy On Write occurs. This could be very slow for a huge one... 3. Transparency in drawing tools appears to be equivalent to lifting the pen or brush. It does not cause an image plane to 'melt' showing me what was originally underneath. If it had, it might have helped me, but it won't. (I'd played around with two bitmaps on one panel...) Anyway, I found many ways to try, none useful. And I guess there is a CORRECT way. Looking at Scribble didn't help, as it doesn't do layers anyway. Actually I couldn't even see how Scribble defines its background as white, yet, though I'm about to go in and see if it just drew a filled rectangle with a default colour or something because I can't see any explicit setting of that white background anywhere... ------------------------------------------------------------------------------ Register Now & Save for Velocity, the Web Performance & Operations Conference from O'Reilly Media. Velocity features a full day of expert-led, hands-on workshops and two days of sessions from industry leaders in dedicated Performance & Operations tracks. Use code vel09scf and Save an extra 15% before 5/3. http://p.sf.net/sfu/velocityconf _______________________________________________ wxlua-users mailing list wxlua-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wxlua-users
