Re: [Boost-users] gil and OpenGL

Viktor, here is a small snippet: rgba8_image_t img( 320, 240 ); rgba8_view_t v = view( img ); rgba8_pixel_t ppp = *v.begin(); unsigned char* data = &ppp[0]; Let me know if you have more questions. Regards, Christian On Sun, Jan 10, 2010 at 2:06 PM, wrote:

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@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] Im Auftrag von Christian Henning Gesendet: Sonntag, 10. Januar 2010 19:36 An: boost-users@lists.boost.org 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,   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.

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