[android-developers] Re: draw texture in OpenGL Android from 0,0 coordinates

"Use absolute screen coordinates in OpenGL"? That defeats the purpose of much of OpenGL. The reason it takes you from world coordinates to object coordinates to camera coordinates to clip coordinates to device coordinates is (among other things) so that you never DO need to know the device (absolute screen) coordinates.

Yes, all those coordinate transforms can be quite confusing, especially for a beginner, but please understand that they are there for good reasons instead of trying to bypass them all.

http://www.opengl.org/resources/faq/technical/transformations.htm#tran0001 is one of the better explanations on the web of all these transformations.

The post by "Dark Photon" at http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=233764 is also very good. You might want to start with it.

On Friday, March 2, 2012 12:44:03 AM UTC-8, Rikki wrote:

Thanks for the reply. I did the same thing but its getting difficult
to manage the coordinates in floating points. Is there a way out to
use the absolute screen coordinates in OpenGL? if so can you provide
with some example to do it.

On Feb 10, 6:44 pm, niko20 <nikolatesl...@yahoo.com> wrote:
> No, you shouldn't change the vertices if you don't have to.
>
> To "move" an image just perform a glTranslate. So what you do is like
> this:
>
> glTranslate(0,0);
> DrawYourImage();
> glTranslate(x,x);
> DrawYourImage();
> glTranslate(x,x);
> DrawYourImage();
>
> Etc.
>
> -niko
>
> On Feb 8, 12:58 am,Rikki<tteam...@gmail.com> wrote:
>
>
>
> > I'm new to opengGL and excuse if the questions are too naive. I'm
> > going through some tuturials for seeking help on learning this. I have
> > a small program written where i'm drawing a texture on a
> > GLSurfaceView.
>
> > I want to draw a number of textures(bitmap images) in a sequential
> > order starting from 0,0 coordinates. Also I need some gap in images on
> > the screen. Please help. Do I need to change the positioning of
> > vertices buffer. please suggest.
>
> > For more code details, checkout hte below link:
>
> >http://stackoverflow.com/questions/9188857/draw-texture-in-opengl-and...- Hide quoted text -
>
> - Show quoted text -

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