From ram to vram
BlitzMax Forums/BlitzMax Programming/From ram to vram
| ||
| Large animations! I am looking for a way to handle large animations without overflowing the vram. The animations are a series of png’s in a folder (not a strip). My current thinking is to first load and store all the images in the system-ram and then real-time load it from ram to vram on a need to show basis. Is this a good approach? And how can be implemented (ram -> vram)? |
| ||
| BMAX does this for you anyway. The first load goes to sram and, when you drawimage, it is sent to vram. That's why there is a slight delay when drawing an image the first time. The DX driver uses the DX memory cache manager replacing least used surfaces. What I have done is created a resource manager where each resource has a 'keep cached' priority attached. At set points I draw the resource to ensure it has a good chance of being in VRAM (i.e. before a section which will use it). Hope it helps. |
| ||
| Thanks, very helpful! So is it something like this.. Or am i doing too much. I want to insure that only the currImg is in the Vram
Local images:TImage[]
images:+[LoadImage("img00.png") ]
images:+[LoadImage("img01.png") ]
images:+[LoadImage("img02.png") ]
Local frame:Int = 0
SetGraphicsDriver D3D7Max2DDriver()
Graphics 512,512
While Not KeyDown(KEY_ESCAPE)
Cls
SetColor 255,255,255
SetBlend AlphaBlend
frame = (frame + 1) Mod Len(images)
Local currImg:TImage = New TImage
currImg = images[frame]
DrawImage currImg,0,0
currImg = Null
Flip 1
Wend
End
|
| ||
| Don't know how OGL manages VRAM but it *will* load every drawn image from RAM to VRAM and, afaik, you cannot remove it. I have only checked the source for DX which will remove or replace unused surfaces when a threshold is reached on the 'last-used/least-used' basis. <EDIT> What I am trying to say is that you can decide when to move them from RAM to VRAM (by drawing them) but cannot decide when to get them out of VRAM. |
| ||
| Actually i meant to do it DX the OGL is just a mistake. Ok i see. It is a problem if I can't remove stuff from the vram. My app crash when it draws to many images. Can i manually set the vram limit in DX ? |
| ||
| You app shouldn't crash. It might affect performance if you're drawing lots of images as it deletes old surfaces and moves new ones in but it should n't crash. Using OGL I *THINK* you get white rectangles when you have filled VRAM but even then it doesn't crash. |
| ||
| Ok thanks alot, i will run a test again, and hope that it i something else that made it crash. BTW; I know it sounds a little strange with so extensive animations, but i am trying to port some childrens flash games. And they like thier animations!! ; ) |
| ||
| They do,. Consider the max size of the textures your graphics cards can handle as well. Lots of large textures takes its toll on memory. |
| ||
| Here's one for the VRAM gurus.... What happens in this scenario? (Using pseudo syntax) global Myimage.TImage For x=1 to 1000 cls MyImage.Load "filename"+x+".jpg" MYImage.Draw Flip next x Has 1000 textures been created by the GPU or is only one being used and reused each frame update? |
| ||
| A new surface is created each time because the base image changes. The other,redundant, surfaces will remain in VRAM until the caching algo decides they haven't been used recently enough. |
| ||
| Anyway to adapt the above code so only 1 surface is used/reused? |
| ||
| And while we're at it, how would we "flush" or destroy all current GPU created surfaces? |
| ||
| Cant you just do loadpixmap and drawpixmap? If you don't need to keep the image in video ram then the transfer TO video ram can be combined with the draw to the backbuffer, rather than transferring it to an image (which takes the same time as transferring it from a pixmap). Might possibly be faster. You could load all of your pixmaps for all images into main memory and then just drawpixmap one frame at a time. |
| ||
| Actually, I'm just trying to apply this to my normal game engine. In DX mode, this is not a problem because of the managed handling, but in OpenGL you don't have texture management so once you fill up vram you apparently get white squares? So I was just wondering if the above loop (cycling through 1000 images) would eventually start displaying white squares? |
| ||
| Like I said use pixmaps, you don't even need to keep a copy of each frame in video ram, unless you want to pre-load a whole bunch of frames and have them play back at maximum framerate. |
| ||
| but in OpenGL you don't have texture management so once you fill up vram you apparently get white squares Surely this is not true? Guess you can test it with your code. |
| ||
| I started a thread in the beginners section about the texture management issue. |
| ||
| "but in OpenGL you don't have texture management so once you fill up vram you apparently get white squares" I don't think that's true, but maybe the driver on some machines handled it that way. I've seen images still work as normal when video ram is full, due to stuff getting spooled off to main memory. |
   |