Part of the Khronos Group
OpenGL.org

The Industry's Foundation for High Performance Graphics

from games to virtual reality, mobile phones to supercomputers

Results 1 to 3 of 3

Thread: ...glTexSubImage bug?

  1. #1
    Member Regular Contributor
    Join Date
    Feb 2000
    Location
    milano, italy
    Posts
    282

    ...glTexSubImage bug?

    to have a procedural skydome texture above my head, i use perlin noise and glTexSubImage2D() function.

    when i update the whole texture, everything works good, but is a bit slow.

    to make it faster, i use the texture as a wrappable buffer, and i update only a single line of the texture while i modify the texture matrix accordingly to make the texture scroll.

    well, if i use the generic MS implementation, it works.

    if i use the nvidia ICD driver (tested on a tnt and nv10) it don't work: it seems to don't accept lines != 0 into the offset param.

    have i found another nvidia ICD bug?
    what are your experiences?

    Dolo/\/\ightY
    Dolo/\/\ightY

  2. #2
    Junior Member Regular Contributor
    Join Date
    Apr 2000
    Posts
    101

    Re: ...glTexSubImage bug?

    glTexSubImage2D seems to be really slow??
    is this the only way to modify | replace a texture???

    I am searching for a best direct way to access to my texture buffers....

    thanks

  3. #3
    Member Regular Contributor
    Join Date
    Feb 2000
    Location
    milano, italy
    Posts
    282

    Re: ...glTexSubImage bug?

    texture update can be done with a bunch of functions, but from tests i've made, subimage updates are the fastest.

    glTexSubImage() is not that slow: it depends on what is the size of the texture.
    for a RGB 2D fire procedural texture of 64x64 pixels is fast enough

    for my skydome the texture is 512x512 alpha, and is working very fast, (bug apart)
    since i update a bunch of texture lines every once.

    unfortunately, opengl doesn't support direct memory access

    Dolo/\/\ightY


    [This message has been edited by dmy (edited 05-03-2000).]
    Dolo/\/\ightY

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •