Re: [Boost-users] gil and OpenGL

Subject: Re: [Boost-users] gil and OpenGL
From: mailinglist_at_[hidden]
Date: 2010-01-10 14:06:26

Thank you for your reply but I still do not understand how to cast the
channel to the byte pointer.

I will provide the snippet which is causing the performance issues.

data = (unsigned char*)malloc(src_view.width()*src_view.height()*4);
int i=0;
for (int y=0; y < src_view.height(); y++) {
    for (int x=0; x < src_view.width(); x++) {
        data[i++] = get_color(src_view(x,y), boost::gil::red_t());
        data[i++] = get_color(src_view(x,y), boost::gil::green_t());
        data[i++] = get_color(src_view(x,y), boost::gil::blue_t());
        data[i++] = get_color(src_view(x,y), boost::gil::alpha_t());
    }
}

Later on "data" is passed to the OpenGL function which renders the textures.

Unfortunately I find the gil doxygen documentation more confusing then
helping.

I hope it is clearer what I am trying to do with that image.
In the case you have more questions shoot ahead, I am very frustrated
because I am trying for days to solve that problem and most people seem to
have very little knowledge of gil.

Regards,
Viktor

-----Ursprüngliche Nachricht-----
Von: boost-users-bounces_at_[hidden]
[mailto:boost-users-bounces_at_[hidden]] Im Auftrag von Christian
Henning
Gesendet: Sonntag, 10. Januar 2010 19:36
An: boost-users_at_[hidden]
Betreff: Re: [Boost-users] gil and OpenGL

Hi there, depending on the memory layout of you could just cast the
first channel of your first pixel into a byte pointer. BTW, what do
you mean by color information?

Regards,
Christian

On Sat, Jan 9, 2010 at 9:15 PM,  <mailinglist_at_[hidden]> wrote:
> This is my first post in any mailinglist ever so i hope i am doing this
> right.
>
>
>
> I successfully integrated the boost::gil module into my code to load some
> images and process their content so that I can display it as a texture in
> OpenGL.
>
>
>
> My problem right now is the massive performance issue in retrieving the
> color information from the loaded image.
>
> I am looping through every row and column and retrieve the red, green,
blue
> and alpha color with the get_color method and push those values to a char
> array.
>
>
>
> So I was wondering what the best approach would be to get the color
> information from the gil image into OpenGL or at least a char array.
>
>
>
> Thanks in advance.
>
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>
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