Re: [Dri-devel] mergedfb, cliprects, and DRI

[Richard F Weber]

Michel Dänzer wrote: On Mon, 2003-07-14 at 02:59, Alex Deucher wrote: --- Michel Dnzer <[EMAIL PROTECTED]> wrote: <snip> It's not clear to me what exactly you have tried, please describe in more detail. I created a virtual framebuffer of size 2080x480. I then started an instance of glxgears and resized the window to about 3/4 of the size of the frambuffer. I then started a second instance of glxgears and placed it next to the first instance, then resized it. it resized fine until I hit the 2048 boundry, then the window (the one I was resizing), went black; the first window was still showed gears. resizing smaller, the gears came back when I crossed the 2048 boundry again. Weird, I don't understand what would cause the window to go blank. What happens when you enlarge a single window beyond 2048, does it go blank as well, or is the rendering cropped to 2048? In the latter case I suspect this is a different problem. Sorry for jumping in, but I found the bug and initially posted comments to it on dri-users. I'll go over the basics quickly.   I've got a dual-head running 1280x1024 (virtual 2560x1024) on both heads using the mergedfb code to create a single desktop.  If I create an opengl application it works fine placing the window anywhere, up until 1 side of it hits the 2048 mark.  Once it hits 2048, the entire window goes blank.  Doesn't matter how large or small the window is, once it crosses 2048, it's done.  If I move the window back away from the border, the window shows it's contents again.  Judging from the framerates, the calculation is actually occurring in the background, but it's just not rendering to the screen.  Framerates jump from ~650 to ~1300 when the window doesn't draw to the screen. Now a couple of weirdness things.  1) If I maximize the window, the entire window goes blank except for about for the left ~600 pixels.  That far left is still drawing that portion of the window.  Sort of like: ------------------------------------------------- ---------------------- --------------------- |xxxxxxxx | | | |xxxxxxxx | | | |xxxxxxxx | | | ---------------------- --------------------- <--1280--> <--1280--> x = Drawn area -------------------------------------------------- 2) Just noticed this one.  If the window is maximized, and you have another dialog on top of it, Everything to the left of that dialog is drawn correctly.  Up until the window hits the 2048 mark on one side. ------------------------------------------------- ---------------------- --------------------- |xxxxxxxx | | | |xxxxxxxxxxxxxxxxxxxx| |xxxWW | |xxxxxxxx | | | ---------------------- --------------------- <--1280--> <--1280--> x = Drawn area W = Dialog on top of OpenGL Window -------------------------------------------------- 3) OpenGL Screensavers crash, burn, do nasty things.  Sometimes they'll show #1 above, usually they'll just hang the system. Now the weird thing is I booted up in Win2k, and you can run an acclerated OpenGL application full-screen, or move the window anywhere and it seems to work fine.  So it looks like it is _possible_ to run OpenGL on a wide desktop, just don't know how ATI does it.  Posted these comments to the board, and it was suggested that maybe they are using a cliprect hack to get things working.  Cross posted a response to both dri-users & dri-devel, where it was picked up. I'm running a Radeon 7500 VE dual-head, and if you need me to run any tests, or sample code, let me know and I'll do the best I can.  Hope this helps some. --Rich