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Re: [E-devel] [RFC] ELM GLView
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From: Carsten H. (T. R. <ra...@ra...> - 2011-06-03 07:10:02
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On Thu, 19 May 2011 16:37:11 +0900 "Sung W. Park" <su...@gm...> said:
just put it in svn now. yay! :) thanks! :)
> Thanks for your comments.
>
> Ok, I've added a focus_hook so it now handles events properly. Now
> the elmglviewgears
> handles key events and mouse events. You can rotate it using
> "Left,Right,Up,Down Arrows"
> or use the mouse and drag it. It doesn't actually have a real
> trackball feature
> implemented so you will notice it not rotating it properly if you
> rotate it too much.
>
> I've dropped the elm_glview_z_get function. I didn't think it was
> necessary for now.
> maybe we can add it later.
>
> Also, the gl_func_call api was for internal testing purpose and it was
> commented out
> in the patch but i've removed them completely in this patch.
>
> Also, I've made some changes with the API. It has been brought to my
> attention that there is a performance issue with the way the current APIs are
> implemented. Currently, the render function was registered using the
>
> "evas_object_image_pixels_get_callback_set"
>
> This is so that it doesn't trigger GL rendering when the image object
> isn't visible.
> Unfortunately, it causes and extra make_current to be called during
> the rendering
> life cycle of evas.
>
> Evas Render... -> (context switch) -> EvasGL Renders -> (context_switch) ->
> Evas Finishes rendering
>
> The context switch is quite expensive in the hw driver that i'm using
> so it actually
> lowers the performance quite a bit.
>
> SO, after discussing it with a few people, we've decided to give an
> option to the user
> to choose the rendering policy. If you choose to have render function
> render all the time,
> it avoids one extra context switch.
>
> EvasGL Renders -> (context_switch) -> Evas Renders
>
> Hence the render policy of RENDER_POLICY_ON_DEMAND vs. RENDER_POLICY_ALWAYS.
>
> I've also changed the name "elm_glview_display_func" to
> "elm_glview_render_func"
>
> Here's the latest set of elm_glview APIs...
> ______________________________________
>
> typedef enum _Elm_GLView_Resize_Policy
> {
> ELM_GLVIEW_RESIZE_POLICY_RECREATE = 1,
> ELM_GLVIEW_RESIZE_POLICY_SCALE = 2
> } Elm_GLView_Resize_Policy;
>
> typedef enum _Elm_GLView_Render_Policy
> {
> ELM_GLVIEW_RENDER_POLICY_ON_DEMAND = 1,
> ELM_GLVIEW_RENDER_POLICY_ALWAYS = 2
> } Elm_GLView_Render_Policy;
>
>
> Evas_Object *elm_glview_add(Evas_Object *parent);
> void elm_glview_size_set(Evas_Object *obj, Evas_Coord
> width, Evas_Coord height);
> void elm_glview_size_get(Evas_Object *obj, Evas_Coord
> *width, Evas_Coord *height);
> Evas_GL_API *elm_glview_gl_api_get(Evas_Object *obj);
> Eina_Bool elm_glview_mode_set(Evas_Object *obj, Elm_GLView_Mode mode);
> Eina_Bool elm_glview_scale_policy_set(Evas_Object *obj,
> Elm_GLView_Resize_Policy policy);
> Eina_Bool elm_glview_render_policy_set(Evas_Object *obj,
> Elm_GLView_Render_Policy policy);
> void elm_glview_render_func(Evas_Object *obj, Elm_GLView_Func
> func); void elm_glview_changed_set(Evas_Object *obj);
> ______________________________________
>
> I'm including the updated elm_glview patch/files and the updated
> elmglviewgears.
>
> Let me know if you have questions/comments.
>
> cheers,
> Sung
>
>
> On Wed, May 18, 2011 at 7:10 PM, Carsten Haitzler <ra...@ra...>
> wrote:
> >
> > On Fri, 13 May 2011 00:00:50 +0900 "Sung W. Park" <su...@gm...> said:
> >
> > ok. missing the focus hook thing u'd need if u want key events to work...
> > display_func -> render_func_set() probably better. z_get probably can be
> > skipped if really too much of a pita.
> >
> > whats the gl_func_call api for.. why pass the func - u already set it? could
> > set it then call a manual render.. if that's needed. is it really needed?
> > curious. :)
> >
> > > Hi all,
> > >
> > > As you all know, I've been working on adding GL rendering features to
> > > Evas and we now have an early working version of Evas_GL in the svn.
> > >
> > > Since then, there's been a request from people around me for an
> > > elementary widget that
> > > allows simple GL rendering. Since Evas_GL can be seen as a low level API
> > > it made sense to have a user friendly layer that allows GL rendering. I
> > > thought it
> > > went well with the EFL philosophy. Take away some control but make it
> > > easy to use for the users as you go up the layers from Evas->Ecore->ELM->
> > > etc.
> > >
> > > So, I've decided to take a crack at elm_glview. By the way, this is
> > > my first time writing
> > > an elementary widget so I KNOW I've missed a lot that i need to handle.
> > > Also, I'm aware of the fact thatI need to handle input events. I'll need
> > > to figure that out
> > > but I open to comments and suggestions. However, before I get all the
> > > nitty gritty
> > > detail right, I wanted to start a discussion with the community on the
> > > APIs and ask for suggestions.
> > >
> > > So far, after discussing this with a few people, we've come up with
> > > the following.
> > >
> > > typedef enum _Elm_GLView_Scale_Policy
> > > {
> > > ELM_GLVIEW_POLICY_RESIZE, /**< Resize the internal surface
> > > along with the image */
> > > ELM_GLVIEW_POLICY_SCALE /**< Only reize the internal image
> > > and not the surface */
> > > } Elm_GLView_Scale_Policy;
> > >
> > > Evas_Object *elm_glview_add(Evas_Object *parent);
> > > void elm_glview_size_set(Evas_Object *obj, Evas_Coord
> > > width, Evas_Coord height);
> > > void elm_glview_size_get(Evas_Object *obj, Evas_Coord
> > > *width, Evas_Coord *height);
> > > Evas_GL_API *elm_glview_gl_api_get(Evas_Object *obj);
> > > Eina_Bool elm_glview_mode_set(Evas_Object *obj, Elm_GLView_Mode
> > > mode); Eina_Bool elm_glview_scale_policy_set(Evas_Object *obj,
> > > Elm_GLView_Scale_Policy policy);
> > > void elm_glview_display_func(Evas_Object *obj,
> > > Elm_GLView_Func func);
> > > void elm_glview_changed_set(Evas_Object *obj);
> > > Eina_Bool elm_glview_z_get(Evas_Object *obj, Evas_Coord x,
> > > Evas_Coord y, Evas_Coord *z);
> > >
> > >
> > > Internally, elm_glview handles creating an image object, evas_gl
> > > object, evas_gl context,
> > > surface, doing make current for display function. You just need to set
> > > the display_function
> > > callback and put your GL calls in there. The scale policy concerns how the
> > > glview would resize. setting it to SCALE would keep the current
> > > glview but simply scale
> > > the underlying image. otherwise, it would recreate the surface. The
> > > API is pretty straight forward
> > > in my opinion. It's very much GLUT-like adapted for EFL.
> > >
> > > In order to use the elm_glview, you would do something like
> > >
> > > main()
> > > {
> > > ...
> > > // Add a GLView
> > > glview = elm_glview_add(win);
> > > glapi = elm_glview_gl_api_get(glview);
> > > elm_glview_mode_set(glview, ELM_GLVIEW_ALPHA | ELM_GLVIEW_DEPTH);
> > > elm_glview_scale_policy_set(glview, ELM_GLVIEW_POLICY_SCALE);
> > > elm_glview_display_func(glview, (Elm_GLView_Func)draw);
> > > evas_object_resize(glview, 256, 256);
> > > evas_object_show(glview);
> > > ecore_animator_add(on_animate, glview);
> > > ...
> > > }
> > >
> > > on_animate()
> > > {
> > > elm_glview_changed_set((Evas_Object*)data);
> > > return EINA_TRUE;
> > > }
> > >
> > > // GL calls
> > > draw()
> > > {
> > > elm_glview_size_get(..., &w, &h);
> > > glapi->glViewport(..., w, h);
> > > ...
> > > }
> > >
> > > I guess it's easier to see the sample files and run the code to see
> > > how they actually work.
> > > I'm including a patch that shows the above example. I'm including the
> > > following files.
> > >
> > > 1. elm_glview.path
> > > -. apply using: patch -p0 elm_glview.patch
> > > 2. elm_glview.c
> > > -. copy the file to src/lib
> > > -. make/ install elmentary
> > > 3. elmglviewsample1.c, elmglviewgears.c, Makefile
> > > -. do a make on the samples using the given makefile.
> > >
> > > Ok, that's all for now. I'd love to hear comments and suggestions on
> > > it as I continue to
> > > work on it.
> > >
> > > thanks!
> > >
> > > cheers,
> > > Sung
> >
> >
> > --
> > ------------- Codito, ergo sum - "I code, therefore I am" --------------
> > The Rasterman (Carsten Haitzler) ra...@ra...
> >
--
------------- Codito, ergo sum - "I code, therefore I am" --------------
The Rasterman (Carsten Haitzler) ra...@ra...
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