Results 1 to 6 of 6

Thread: direct access to vram

  1. #1
    Junior Member Newbie
    Join Date
    Aug 2003
    Location
    germany
    Posts
    3

    direct access to vram

    hello

    i want to combine typical opengl (triangles) with my voxel-engine. at the moment i render the voxels as a bitmap and bind it to a texture and draw it as a quader to the background.
    is there a faster way in opengl? can i get the adress of the backscreenbuffer, so i can directly draw to it.

    greetings,
    KC1

    [This message has been edited by KC1 (edited 08-12-2003).]

  2. #2
    Junior Member Newbie
    Join Date
    Aug 2003
    Location
    germany
    Posts
    3

    Re: direct access to vram

    i thing i found something: glCopyPixels()


    KC1

  3. #3
    Senior Member Regular Contributor
    Join Date
    Sep 2002
    Location
    Poland
    Posts
    196

    Re: direct access to vram

    Texture is already stored in VRAM so to speed this up can use texture compression. You can directly get into VRAM if you want to store e.g. some vertex data. There is a function from nVidia which allocates memory similar to malloc (with three more parameters) called wglAllocateMemoryNV. I don't know ATI function like that but, you should check search their website if you want.

    [This message has been edited by glYaro (edited 08-12-2003).]

  4. #4
    Senior Member OpenGL Pro
    Join Date
    Jul 2001
    Location
    France
    Posts
    1,662

    Re: direct access to vram

    You're not advise to use vram directly (that's why only Nvidia does so).

    Textures are normally stored in vram, but to ensure that (at least to tell Opengl you want to do so), use textures priorities.

  5. #5
    Junior Member Newbie
    Join Date
    Aug 2003
    Location
    Waterloo, Ontario, Canada
    Posts
    10

    Re: direct access to vram

    OpenGL doesn't provide any mechanism for direct frame buffer access like DirectX does with surfaces. I run into this a lot porting DirectX games to MacOS.

    Your best bet is probably to render directly to the texture after it is bound. See this example on NeHe: http://nehe.gamedev.net/data/lessons....asp?lesson=29
    Rob Targosz
    McAfee Canada, Inc.

  6. #6
    Junior Member Newbie
    Join Date
    Aug 2003
    Location
    germany
    Posts
    3

    Re: direct access to vram

    thanks to all for answers

    @rtargosz
    yes, you are right, yesterday i found an example looking like this from nehe and it works good

Similar Threads

  1. Access exactly in the same order in the RAM and VRAM, height data!
    By Darkpower in forum OpenGL: Basic Coding
    Replies: 1
    Last Post: 12-11-2013, 11:49 AM
  2. Can OpenGL access all the memory on a single 4GB VRAM GPU?
    By SirLordConny in forum OpenGL: Windows
    Replies: 1
    Last Post: 10-26-2012, 11:53 AM
  3. Direct State Access
    By ViolentHamster in forum OpenGL: General
    Replies: 43
    Last Post: 05-08-2012, 06:53 AM
  4. Direct Texture access
    By inwu00 in forum OpenGL: Advanced Coding
    Replies: 6
    Last Post: 07-12-2010, 10:40 PM
  5. Direct VRAM acces
    By ibachar in forum OpenGL: General
    Replies: 5
    Last Post: 05-16-2006, 04:32 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Proudly hosted by Digital Ocean