Results 1 to 2 of 2

Thread: Color matrix

  1. #1
    Senior Member OpenGL Guru
    Join Date
    Dec 2000
    Reutlingen, Germany

    Color matrix


    i would like to use the color matrix to adjust brightness and contrast. I read in a book how to do this, but it seems not to work:

    glMatrixMode (GL_COLOR);
    glTranslatef (0.5,0.5,0.5);

    (I call those functions after glClear, but before everything is drawn.)

    This should darken everything i think, but it just happens nothing.

    I checked for error codes, but there are none. I checked the required extension (ARB_imaging), but itīs there (Geforce 2).
    So, where could be the error?

    Hope someone knows how to do it properly.

    GLIM - Immediate Mode Emulation for GL3

  2. #2
    Junior Member Newbie
    Join Date
    Oct 2002
    Los Angeles, Ca, USA

    Re: Color matrix

    Appears you are using it correctly.
    What are you drawing?
    Color Matrix should work with
    glDrawPixels as well as glTexSubImage2D
    but I dont believe it works with
    primatives like lines or polys.

    Also, wont work with the new ati radeon
    drivers at all. Nvidia is generally supported
    but slow slow slow.

Similar Threads

  1. color matrix and tangent space
    By gumby in forum OpenGL: Advanced Coding
    Replies: 1
    Last Post: 02-22-2003, 08:51 AM
  2. Color Matrix ...
    By imported_Christoph in forum OpenGL: Basic Coding
    Replies: 0
    Last Post: 10-11-2002, 05:07 AM
  3. color matrix from arb_imaging
    By mmm in forum OpenGL: Advanced Coding
    Replies: 5
    Last Post: 08-04-2002, 04:25 AM
  4. Color matrix and color channel
    By ada in forum OpenGL: Advanced Coding
    Replies: 0
    Last Post: 07-02-2002, 06:36 AM
  5. The color matrix and glDrawPixels()
    By in forum OpenGL: Basic Coding
    Replies: 5
    Last Post: 02-24-2002, 10:59 AM

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