Re: OpenGL Zoom / Pan

[Douglas Vechinski <douglas vechinski dynetics com>]

Try taking a look at the shapes.c example that comes with the gtkglext
package.  There are different ways do to them and it sort of depends
upon how you plan on setting up the scene/object to view how how you
plan to view it.

For example, if you are viewing an object and want to simulate a zoom in
or out, one easy way is to simply have an overall scale factor that you
increase or decrease and use a glScalef with the scale factor.  Or
another way, is to keep the scale unchanged but adjust the projection
mapping as in glOrtho().  To zoom in, you decrease the size of the x and
y bounds of the viewing volume according to your scale factor.

On Wed, 2006-02-22 at 19:28 +0100, Philippe CHAUVAT wrote:
> A little bit out of the list themas... but I wrote some program with 
> gtkglext and would like to do some Zoom, Pan, Rotate things with mouse 
> and/or keyboard.
>
> Does anyone know where to find some sample or tutorial about this ?
>
> Thanks in advance.
> Philippe
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